pengyou
11-01-07, 12:30 PM
How does an average folding bike do at 25-30 mph? How durable are they?
Folding Bikes - FB and speed
Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.View Full Version : FB and speed
law4jba
11-01-07, 12:53 PM
I've had my fixed gear swift up to 30 mph. Besides a bit of bouncing in the saddle at the elevated cadence, the bike handled fine.
Bacciagalupe
11-01-07, 02:05 PM
The "average" sub-$700 folding bike is set up with hybrid geometry, somewhat upright position and medium-width tires. You'd have to work pretty hard to hit 25 on the flats. Durability and component quality is a little less than a non-folding bike IMO.
Once you hit $700, you're typically dealing with stiffer frames, flexible positions, drop bars, better gearing options, and so forth. It'd be pretty close to an entry-level road bike. Durability is pretty good.
If you go above $1500, there isn't much performance, durability or quality difference between a folder & a road bike; the folder will probably be a little less comfortable.
One caveat: 20" wheels have a lot of oversteer, so they are trickier on the descents. I feel far more comfortable bombing down a hill at 45mph with my 700c cross bike than I do at 35mph on my folding bike.
Once you hit $700, you're typically dealing with stiffer frames, flexible positions, drop bars, better gearing options, and so forth. It'd be pretty close to an entry-level road bike. Durability is pretty good.
If you go above $1500, there isn't much performance, durability or quality difference between a folder & a road bike; the folder will probably be a little less comfortable.
One caveat: 20" wheels have a lot of oversteer, so they are trickier on the descents. I feel far more comfortable bombing down a hill at 45mph with my 700c cross bike than I do at 35mph on my folding bike.
14R
11-01-07, 05:06 PM
I have a ard time keeping my 16" wheeled Brompton above 21mph for more than a few minutes. I cannot blame all on the bike though...
Pine Cone
11-01-07, 05:36 PM
How does an average folding bike do at 25-30 mph? How durable are they?
How does an average bike do at average speeds of 25-30 mph? How durable are they? I would hate to ride most of the average bikes sold in any country. I would guess that the average bike in the US costs under $250 and I wouldn't feel safe riding it at higher speeds or longer rides without major modifications.
The average folding bike is similar to the average non-folding bike. Neither is particularly great at higher speeds, and average components are pretty average. If you are just talking about average speeds of 10-15 mph and zipping down a hill at 25+ mph either will do just fine. My DT VIIIH is very stable and feels very safe at 30 or 35 mph. Now that I have a longer stem on my DT Mini it does fine at 25-30 but with the stock 2006/2007 stempost higher speeds were a bit scary.:eek:
Comparing $$ spent, you can get a better bike for the money with a non-folder. For the above $400 bikes, you would probably have to spend $100-$300 more for a good folder vs. a good similarly-equipted standard road bike.
For high performance bikes you have lots more choices in non-folders, but you can get pretty nice folders if you are willing to pay for it.
The target market for folders tends towards durability and affordibility. Personally I wouldn't want a carbon-framed folder since it wouldn't fare well getting knocked around in the back of my car on on a crowded bus or train compartment. If you are willing to spend more than about $300 there are plenty of durable folders that will do fine for short distances of 25+ mph. If you want to ride long, fast hard miles you would do better with a $1000 standard road bike or a $1200+ folder from Birdy or Bike-Friday or Dahon.
How does an average bike do at average speeds of 25-30 mph? How durable are they? I would hate to ride most of the average bikes sold in any country. I would guess that the average bike in the US costs under $250 and I wouldn't feel safe riding it at higher speeds or longer rides without major modifications.
The average folding bike is similar to the average non-folding bike. Neither is particularly great at higher speeds, and average components are pretty average. If you are just talking about average speeds of 10-15 mph and zipping down a hill at 25+ mph either will do just fine. My DT VIIIH is very stable and feels very safe at 30 or 35 mph. Now that I have a longer stem on my DT Mini it does fine at 25-30 but with the stock 2006/2007 stempost higher speeds were a bit scary.:eek:
Comparing $$ spent, you can get a better bike for the money with a non-folder. For the above $400 bikes, you would probably have to spend $100-$300 more for a good folder vs. a good similarly-equipted standard road bike.
For high performance bikes you have lots more choices in non-folders, but you can get pretty nice folders if you are willing to pay for it.
The target market for folders tends towards durability and affordibility. Personally I wouldn't want a carbon-framed folder since it wouldn't fare well getting knocked around in the back of my car on on a crowded bus or train compartment. If you are willing to spend more than about $300 there are plenty of durable folders that will do fine for short distances of 25+ mph. If you want to ride long, fast hard miles you would do better with a $1000 standard road bike or a $1200+ folder from Birdy or Bike-Friday or Dahon.
SesameCrunch
11-01-07, 05:36 PM
If you need to go 25-30 mph regularly, why do you need a folding bike? There's no substitute for a good road bike at those speeds IMHO.
pm124
11-01-07, 10:17 PM
If you need to go 25-30 mph regularly, why do you need a folding bike? There's no substitute for a good road bike at those speeds IMHO.
??
Pengyou shensheng--
Small wheeled bikes are fast. Contrary to conventional wisdom, they are possibly a bit faster with stiff suspension on board since it may decrease rolling resistance. Most speed records were set on small wheels. (And, yes, if you look them up, in a variety of conditions!)
I find my small wheeled suspension folder to be possibly faster (still not sure about this) and definitely more comfortable and thus less tiring than a road bike on long rides. But it depends on your needs.
If you are taking it on crowded public transport, you'll need something like a Birdy. This is a fast bike that eats up fully loaded long tours on harsh roads, but is not appropriate for fast group rides if you are a puller and sprinter. (I do them, but I'm a sitter and spinner.) Also in ths general size, the Dahon Mu SL and Jetstream XP are fast bikes. Incremental improvments may one day render Dahon king, but for now the frame hinge and weaker stem are major concerns. While you can put 40,000 hard miles on a Birdy without a worry, Dahons cannot yet take that kind of use. They are priced about in the same range as full size bikes, with a SRAM X9/American Classic equipped bike coming in at $900US.
If you are putting it in your closet, a Moulton (separable), Airnimal, or Reach might be more appropriate in the tight suspension category. A Swift is a very fast, cost-effective, and relatively light bike with a harsher ride, but not too different from a road bike with respect to harshness and should be custom ordered with drop bars, etc. (Only been on one once.) If you are a steel frame person, there is nothing like a custom, hand built Bike Friday Pocket Rocket Pro or Moulton. These bikes really ride well, but are not as easy to take into trains, planes, cafes, etc. The folded size is big and it takes a while to fold them.
Check out: http://birdy.yeahbike.com/ for the Birdy (2008 Speed model available in Europe is Tune equipped and a bit lighter. Japanese models are available with Ti frames.)
http://www.bikefriday.com/node/1591 for the Pocket Rocket
Of course, there are doubters out there, but I wouldn't ride a road bike.
The bikes I lust after are the new 8Kg Reach and the Bridgestone Moulton, though I haven't ridden either.
??
Pengyou shensheng--
Small wheeled bikes are fast. Contrary to conventional wisdom, they are possibly a bit faster with stiff suspension on board since it may decrease rolling resistance. Most speed records were set on small wheels. (And, yes, if you look them up, in a variety of conditions!)
I find my small wheeled suspension folder to be possibly faster (still not sure about this) and definitely more comfortable and thus less tiring than a road bike on long rides. But it depends on your needs.
If you are taking it on crowded public transport, you'll need something like a Birdy. This is a fast bike that eats up fully loaded long tours on harsh roads, but is not appropriate for fast group rides if you are a puller and sprinter. (I do them, but I'm a sitter and spinner.) Also in ths general size, the Dahon Mu SL and Jetstream XP are fast bikes. Incremental improvments may one day render Dahon king, but for now the frame hinge and weaker stem are major concerns. While you can put 40,000 hard miles on a Birdy without a worry, Dahons cannot yet take that kind of use. They are priced about in the same range as full size bikes, with a SRAM X9/American Classic equipped bike coming in at $900US.
If you are putting it in your closet, a Moulton (separable), Airnimal, or Reach might be more appropriate in the tight suspension category. A Swift is a very fast, cost-effective, and relatively light bike with a harsher ride, but not too different from a road bike with respect to harshness and should be custom ordered with drop bars, etc. (Only been on one once.) If you are a steel frame person, there is nothing like a custom, hand built Bike Friday Pocket Rocket Pro or Moulton. These bikes really ride well, but are not as easy to take into trains, planes, cafes, etc. The folded size is big and it takes a while to fold them.
Check out: http://birdy.yeahbike.com/ for the Birdy (2008 Speed model available in Europe is Tune equipped and a bit lighter. Japanese models are available with Ti frames.)
http://www.bikefriday.com/node/1591 for the Pocket Rocket
Of course, there are doubters out there, but I wouldn't ride a road bike.
The bikes I lust after are the new 8Kg Reach and the Bridgestone Moulton, though I haven't ridden either.
pm124
11-01-07, 10:24 PM
This is the fastest folder you can possibly get: http://tw.video.yahoo.com/video/play?vid=1292778
jnb-rare
11-01-07, 10:44 PM
Perhaps the OP is thinking about a folding, electric conversion? I notice some posts in the e-bike forum.
Either that or regular peloton riding. Or maybe Pike's Peak downhill?
Anyway, the kind of bike you might PEDAL to 25 or 30mph could be different than the kind of bike you'd SIT ON while going 25-30mph. Downhills with the Stelvios on my MU SL, 25-30mph (40-48kph) definitely feels more squirrely than my old mountain bike with wide slicks -- especially when the road surface isn't so good.
Either that or regular peloton riding. Or maybe Pike's Peak downhill?
Anyway, the kind of bike you might PEDAL to 25 or 30mph could be different than the kind of bike you'd SIT ON while going 25-30mph. Downhills with the Stelvios on my MU SL, 25-30mph (40-48kph) definitely feels more squirrely than my old mountain bike with wide slicks -- especially when the road surface isn't so good.
spambait11
11-01-07, 10:51 PM
Small wheeled bikes are fast. Contrary to conventional wisdom, they are possibly a bit faster with stiff suspension on board since it may decrease rolling resistance. Most speed records were set on small wheels. (And, yes, if you look them up, in a variety of conditions!)
What do you keep referring to when you say this? The Varna Diablo II?
What do you keep referring to when you say this? The Varna Diablo II?
Fear&Trembling
11-02-07, 08:06 AM
Most folders will handle 25 -30 mph fine - more appositely though, will your body?
At speeds above 40mph, I much prefer 700c wheels beneath me.
At speeds above 40mph, I much prefer 700c wheels beneath me.
SesameCrunch
11-02-07, 08:13 AM
Small wheeled bikes are fast. Contrary to conventional wisdom, they are possibly a bit faster with stiff suspension on board since it may decrease rolling resistance. Most speed records were set on small wheels. (And, yes, if you look them up, in a variety of conditions!)
The question is about folders, not small wheel size.
I find my small wheeled suspension folder to be possibly faster (still not sure about this) and definitely more comfortable and thus less tiring than a road bike on long rides. But it depends on your needs.
It's completely illogical to think that a folding bike with suspension is faster than a racing oriented road bike. The additional weight of the folding mechanisms and suspension adds at least 5 pounds to a bike. The rear suspension sucks up energy when pedaling. There's no folding bike in the world that could match up with a 16lb racing rig.
The question is about folders, not small wheel size.
I find my small wheeled suspension folder to be possibly faster (still not sure about this) and definitely more comfortable and thus less tiring than a road bike on long rides. But it depends on your needs.
It's completely illogical to think that a folding bike with suspension is faster than a racing oriented road bike. The additional weight of the folding mechanisms and suspension adds at least 5 pounds to a bike. The rear suspension sucks up energy when pedaling. There's no folding bike in the world that could match up with a 16lb racing rig.
Foldable Two
11-02-07, 01:47 PM
Hey, I did 26.3 MPH on my 2005 Dahon Boardwalk D7 on a long smooth downhill in the 2007 Portland Bridge pedal on Tioga Pool Comp 1.75" slicks.
That was the limit of 7th gear. The ride was very smooth.
I doubt the friends we sold the D7s to yesterday will get up to that speed. (My wife freaks-out at any down hill, whether on the old Dahons or her new Pocket Crusoe.)
That was the limit of 7th gear. The ride was very smooth.
I doubt the friends we sold the D7s to yesterday will get up to that speed. (My wife freaks-out at any down hill, whether on the old Dahons or her new Pocket Crusoe.)
awetmore
11-02-07, 02:59 PM
One caveat: 20" wheels have a lot of oversteer, so they are trickier on the descents. I feel far more comfortable bombing down a hill at 45mph with my 700c cross bike than I do at 35mph on my folding bike.
What do you mean by oversteer? In car terms this would mean that the front wheels are sliding forward instead of carrying you through the turn. Pushing a bike to that limit usually involves a lot of crashing.
I don't think that most folding bike designers understand bicycle handling very well. They tend to copy road or mountain bike head tube angles and fork offsets. Doing so results in bicycles with very low trail, so very little natural stability. Folding bikes should have reduced fork offset. I like low trail bicycles (and my full size bicycles have lower trail than almost all production bikes made today), but you can go too far.
alex
What do you mean by oversteer? In car terms this would mean that the front wheels are sliding forward instead of carrying you through the turn. Pushing a bike to that limit usually involves a lot of crashing.
I don't think that most folding bike designers understand bicycle handling very well. They tend to copy road or mountain bike head tube angles and fork offsets. Doing so results in bicycles with very low trail, so very little natural stability. Folding bikes should have reduced fork offset. I like low trail bicycles (and my full size bicycles have lower trail than almost all production bikes made today), but you can go too far.
alex
pm124
11-02-07, 03:05 PM
The question is about folders, not small wheel size.
It's completely illogical to think that a folding bike with suspension is faster than a racing oriented road bike. The additional weight of the folding mechanisms and suspension adds at least 5 pounds to a bike. The rear suspension sucks up energy when pedaling. There's no folding bike in the world that could match up with a 16lb racing rig.
Folders are definitely heavier, but that doesn't make any difference on a flat. It also doesn't have much to do with suspension, which can come in at a couple hundred grams in Pantour hubs or a simple elastomer set up. But, yes, on climbs you will pay lugging around that extra weight.
The idea is that suspension causes less tire sidewall deformation on uneven surfaces. Smaller tires hit the road at a more acute angle causing increased sidewall deformation. However, this is more than offset by a smaller volume of air in the tire. (Remember old PV = nRT?)
Another factor: When you hit a bit of uneven road, it pushes back, and will push back harder against a stiffer tire (e.g., one on a small wheel). Here, too, the suspension will potentially help you get over that deformity.
If you ride the bike properly (e.g., spin in a circular motion, lifting and pushing at the same time), then it will not soak anything up. Thus, another way that it makes you faster is to teach proper riding style!
How does a folder slow you down then? 1) It is heavier, 2) one cannot pull on the handlebars (unless it is a Moulton), 3) there is no diamond, thus it is less stiff. I do fine in a peleton until we hit the uphill. Probably more of a body fat problem than a bike problem, but I can't get out of the saddle to compensate.
It's completely illogical to think that a folding bike with suspension is faster than a racing oriented road bike. The additional weight of the folding mechanisms and suspension adds at least 5 pounds to a bike. The rear suspension sucks up energy when pedaling. There's no folding bike in the world that could match up with a 16lb racing rig.
Folders are definitely heavier, but that doesn't make any difference on a flat. It also doesn't have much to do with suspension, which can come in at a couple hundred grams in Pantour hubs or a simple elastomer set up. But, yes, on climbs you will pay lugging around that extra weight.
The idea is that suspension causes less tire sidewall deformation on uneven surfaces. Smaller tires hit the road at a more acute angle causing increased sidewall deformation. However, this is more than offset by a smaller volume of air in the tire. (Remember old PV = nRT?)
Another factor: When you hit a bit of uneven road, it pushes back, and will push back harder against a stiffer tire (e.g., one on a small wheel). Here, too, the suspension will potentially help you get over that deformity.
If you ride the bike properly (e.g., spin in a circular motion, lifting and pushing at the same time), then it will not soak anything up. Thus, another way that it makes you faster is to teach proper riding style!
How does a folder slow you down then? 1) It is heavier, 2) one cannot pull on the handlebars (unless it is a Moulton), 3) there is no diamond, thus it is less stiff. I do fine in a peleton until we hit the uphill. Probably more of a body fat problem than a bike problem, but I can't get out of the saddle to compensate.
pm124
11-02-07, 03:15 PM
What do you keep referring to when you say this? The Varna Diablo II?
Most of the historical HPV speed records, including the Moulton: http://www.ihpva.org/hpva/hpvarech.html
Look at this insane thing John Howard took to 152 MPH: http://www.canosoarus.com/08LSRbicycle/LSR%20Bike01.htm
Here is the Moulton: http://www.treehugger.com/files/2004/11/bike.php which is perhaps even stranger.
Most of the historical HPV speed records, including the Moulton: http://www.ihpva.org/hpva/hpvarech.html
Look at this insane thing John Howard took to 152 MPH: http://www.canosoarus.com/08LSRbicycle/LSR%20Bike01.htm
Here is the Moulton: http://www.treehugger.com/files/2004/11/bike.php which is perhaps even stranger.
pm124
11-02-07, 03:25 PM
Most folders will handle 25 -30 mph fine - more appositely though, will your body?
At speeds above 40mph, I much prefer 700c wheels beneath me.
At speeds above 40mph, I much prefer 12" wheels beneath me.
But on I bike, I'd have to go with nice fat 26" wheels.
At speeds above 40mph, I much prefer 700c wheels beneath me.
At speeds above 40mph, I much prefer 12" wheels beneath me.
But on I bike, I'd have to go with nice fat 26" wheels.
spambait11
11-02-07, 03:27 PM
Most of the historical HPV speed records, including the Moulton: http://www.ihpva.org/hpva/hpvarech.html
Look at this insane thing John Howard took to 152 MPH: http://www.canosoarus.com/08LSRbicycle/LSR%20Bike01.htm
Here is the Moulton: http://www.treehugger.com/files/2004/11/bike.php which is perhaps even stranger.
I see. So SC is right: you're differentiating between folding bikes vs. smaller wheels in general.
Look at this insane thing John Howard took to 152 MPH: http://www.canosoarus.com/08LSRbicycle/LSR%20Bike01.htm
Here is the Moulton: http://www.treehugger.com/files/2004/11/bike.php which is perhaps even stranger.
I see. So SC is right: you're differentiating between folding bikes vs. smaller wheels in general.
pm124
11-02-07, 03:29 PM
I see. So SC is right: you're differentiating between folding bikes vs. smaller wheels in general.
Yes. I'm still pre-verbal sometimes. Though there shouldn't be much of a difference if the folder were built properly (e.g., no frame hinge).
Yes. I'm still pre-verbal sometimes. Though there shouldn't be much of a difference if the folder were built properly (e.g., no frame hinge).
Fat Boy
11-02-07, 04:19 PM
What do you mean by oversteer? In car terms this would mean that the front wheels are sliding forward instead of carrying you through the turn. Pushing a bike to that limit usually involves a lot of crashing.
alex
Actually, in car terms it's the other way around. The rear sliding towards the outside of the corner and the front continuing on the path that they were pointed until the car spins. Regardless, I'm a bit confused by the term as well when attributed to a bicycle. Perhaps he just meant that the steering response was quicker.
alex
Actually, in car terms it's the other way around. The rear sliding towards the outside of the corner and the front continuing on the path that they were pointed until the car spins. Regardless, I'm a bit confused by the term as well when attributed to a bicycle. Perhaps he just meant that the steering response was quicker.
Fat Boy
11-02-07, 04:21 PM
It's completely illogical to think that a folding bike with suspension is faster than a racing oriented road bike. The additional weight of the folding mechanisms and suspension adds at least 5 pounds to a bike. The rear suspension sucks up energy when pedaling. There's no folding bike in the world that could match up with a 16lb racing rig.
Ya, but he likes his kool-aid and has been repeating this same basic message on every thread that's even remotely related. I think he's going to enter an A-bike in the TDF next year and clean up.
Ya, but he likes his kool-aid and has been repeating this same basic message on every thread that's even remotely related. I think he's going to enter an A-bike in the TDF next year and clean up.
Simple Simon
11-02-07, 05:02 PM
It's completely illogical to think that a folding bike with suspension is faster than a racing oriented road bike. The additional weight of the folding mechanisms and suspension adds at least 5 pounds to a bike. The rear suspension sucks up energy when pedaling. There's no folding bike in the world that could match up with a 16lb racing rig.
I'm with SesameCrunch & Fear&T on this. I know as this is a folding / small wheel forum so we tend to get enthusiastic about these, especially for multimodal work and travelling, which is what they are designed for, but for longer rides I'll take the 700c thankyou.
Back in the days, I once disabled the suspension on an early moulton - guess what - it was faster ! ... especially on climbs (without ol' Bob).
I'm with SesameCrunch & Fear&T on this. I know as this is a folding / small wheel forum so we tend to get enthusiastic about these, especially for multimodal work and travelling, which is what they are designed for, but for longer rides I'll take the 700c thankyou.
Back in the days, I once disabled the suspension on an early moulton - guess what - it was faster ! ... especially on climbs (without ol' Bob).
SesameCrunch
11-02-07, 08:06 PM
I'm with SesameCrunch & Fear&T on this. I know as this is a folding / small wheel forum so we tend to get enthusiastic about these, especially for multimodal work and travelling, which is what they are designed for, but for longer rides I'll take the 700c thankyou.
Back in the days, I once disabled the suspension on an early moulton - guess what - it was faster ! ... especially on climbs (without ol' Bob).
Having 5 folders in my current fleet, I understand being enthusiastic about folders - I've been guilty of that myself sometimes :o. Let's not even talk about the obscene amount of time I spend on this Forum :eek:!
Back in the days, I once disabled the suspension on an early moulton - guess what - it was faster ! ... especially on climbs (without ol' Bob).
Having 5 folders in my current fleet, I understand being enthusiastic about folders - I've been guilty of that myself sometimes :o. Let's not even talk about the obscene amount of time I spend on this Forum :eek:!
Simple Simon
11-03-07, 07:13 AM
Having 5 folders in my current fleet, I understand being enthusiastic about folders - I've been guilty of that myself sometimes :o. Let's not even talk about the obscene amount of time I spend on this Forum :eek:!
Its an illness .. 12 point plan anyone :D
Its an illness .. 12 point plan anyone :D
Bacciagalupe
11-03-07, 08:23 AM
What do you mean by oversteer?
"Excessively responsive handling." I don't own a car, so I have no idea how that term would apply there. :D
I don't think that most folding bike designers understand bicycle handling very well. They tend to copy road or mountain bike head tube angles and fork offsets....
That may be the case, but unless you're drastically modifying the geometry, small-wheeled bikes are less stable and turn more responsively than 700c bikes.
For example, my Swift has a wheelbase of 1010mm, which is slightly longer than my cross bike; it also has a straight fork. The Swift has excellent acceleration (with the right tires, that is ;) ) and is better at dodging obstacles; the cross is much more stable, descends better, handles loads better, and handles bumps better.
For general riding, it's not a big deal. For some uses, e.g. urban riding, it's a selling point. For touring, long rides, group rides, fast rides and technical descents, handling is definitely one factor among many to consider.
"Excessively responsive handling." I don't own a car, so I have no idea how that term would apply there. :D
I don't think that most folding bike designers understand bicycle handling very well. They tend to copy road or mountain bike head tube angles and fork offsets....
That may be the case, but unless you're drastically modifying the geometry, small-wheeled bikes are less stable and turn more responsively than 700c bikes.
For example, my Swift has a wheelbase of 1010mm, which is slightly longer than my cross bike; it also has a straight fork. The Swift has excellent acceleration (with the right tires, that is ;) ) and is better at dodging obstacles; the cross is much more stable, descends better, handles loads better, and handles bumps better.
For general riding, it's not a big deal. For some uses, e.g. urban riding, it's a selling point. For touring, long rides, group rides, fast rides and technical descents, handling is definitely one factor among many to consider.
awetmore
11-03-07, 08:54 AM
"Excessively responsive handling." I don't own a car, so I have no idea how that term would apply there. :D
How did you pick the term for bicycle handling? I've spent a lot of time studying bicycle handling, and oversteer is not a term that is used to describe it.
That may be the case, but unless you're drastically modifying the geometry, small-wheeled bikes are less stable and turn more responsively than 700c bikes.
For example, my Swift has a wheelbase of 1010mm, which is slightly longer than my cross bike; it also has a straight fork. The Swift has excellent acceleration (with the right tires, that is ;) ) and is better at dodging obstacles; the cross is much more stable, descends better, handles loads better, and handles bumps better.
For general riding, it's not a big deal. For some uses, e.g. urban riding, it's a selling point. For touring, long rides, group rides, fast rides and technical descents, handling is definitely one factor among many to consider.
Folding bicycles are a drastic change on geometry.
Your cross bike probably has a head tube angle of 72 degrees and 45mm of fork offset. This gives it 65mm of trail and 20mm of front wheel flop:
http://kogswell.com/geo.php?h1=690&i1=73&j1=45&d2.x=14&d2.y=11
Your Swift Folder has the same figures (72 degree HTA, 45mm of fork offset), but the wheels are only much smaller. This drops the trail to 45mm and the wheel flop to 9mm:
http://kogswell.com/geo.php?h1=470&i1=73&j1=45&d2.x=14&d2.y=11
If you wanted to make your cyclocross bike handle like your Swift Folder you'd need to need to grossly redesign the front end. 74 degree head tube angle and 60mm of fork offset is close:
http://kogswell.com/geo.php?h1=690&i1=74&j1=60&d2.x=14&d2.y=11
To change the Swift Folder to behave like the cyclocross frame you really should have much less fork offset. 15mm is getting you there:
http://kogswell.com/geo.php?h1=470&i1=73&j1=15&d2.x=14&d2.y=11
That is a drastic change, removing 30mm of fork offset. The curve in the fork blades would be almost immperceptable.
Personally I like road bikes that have around 40-45mm of fork offset like your Swift Folder. However they require wider tires to handle well. This is one of the reasons that I like the Avocet Fasgrip Freestyle on 406mm wheeled folding bikes. It is a wide tire (around 40-42mm) that has low rolling resistance and runs well at moderate pressures (I'd run it at around 50-60psi). It is probably as fast as the very narrow tires (like the Conti GP3000) that many people like to run, but greatly improves the handling of the bike.
The other thing that helps low trail bikes is to carry the load on the front instead of the rear. Folding bikes are good for this anywhere since there is typically a lot of space between the top of the front wheel and the handlebars.
The mistake is that folding bike manufacturers almost universally try to copy big bike head tube angles and fork offsets instead of modifying them for the small wheels. For some people (me) this works out well because we like lower trail bicycles. For the skinny/high pressure set with rear loads it is a big mistake.
I don't think that trail and wheel flop define everything about handling. The smaller wheels make other differences too. I'd still like to see greater experimentation and study of small bike handling than what appears to be out there.
alex
How did you pick the term for bicycle handling? I've spent a lot of time studying bicycle handling, and oversteer is not a term that is used to describe it.
That may be the case, but unless you're drastically modifying the geometry, small-wheeled bikes are less stable and turn more responsively than 700c bikes.
For example, my Swift has a wheelbase of 1010mm, which is slightly longer than my cross bike; it also has a straight fork. The Swift has excellent acceleration (with the right tires, that is ;) ) and is better at dodging obstacles; the cross is much more stable, descends better, handles loads better, and handles bumps better.
For general riding, it's not a big deal. For some uses, e.g. urban riding, it's a selling point. For touring, long rides, group rides, fast rides and technical descents, handling is definitely one factor among many to consider.
Folding bicycles are a drastic change on geometry.
Your cross bike probably has a head tube angle of 72 degrees and 45mm of fork offset. This gives it 65mm of trail and 20mm of front wheel flop:
http://kogswell.com/geo.php?h1=690&i1=73&j1=45&d2.x=14&d2.y=11
Your Swift Folder has the same figures (72 degree HTA, 45mm of fork offset), but the wheels are only much smaller. This drops the trail to 45mm and the wheel flop to 9mm:
http://kogswell.com/geo.php?h1=470&i1=73&j1=45&d2.x=14&d2.y=11
If you wanted to make your cyclocross bike handle like your Swift Folder you'd need to need to grossly redesign the front end. 74 degree head tube angle and 60mm of fork offset is close:
http://kogswell.com/geo.php?h1=690&i1=74&j1=60&d2.x=14&d2.y=11
To change the Swift Folder to behave like the cyclocross frame you really should have much less fork offset. 15mm is getting you there:
http://kogswell.com/geo.php?h1=470&i1=73&j1=15&d2.x=14&d2.y=11
That is a drastic change, removing 30mm of fork offset. The curve in the fork blades would be almost immperceptable.
Personally I like road bikes that have around 40-45mm of fork offset like your Swift Folder. However they require wider tires to handle well. This is one of the reasons that I like the Avocet Fasgrip Freestyle on 406mm wheeled folding bikes. It is a wide tire (around 40-42mm) that has low rolling resistance and runs well at moderate pressures (I'd run it at around 50-60psi). It is probably as fast as the very narrow tires (like the Conti GP3000) that many people like to run, but greatly improves the handling of the bike.
The other thing that helps low trail bikes is to carry the load on the front instead of the rear. Folding bikes are good for this anywhere since there is typically a lot of space between the top of the front wheel and the handlebars.
The mistake is that folding bike manufacturers almost universally try to copy big bike head tube angles and fork offsets instead of modifying them for the small wheels. For some people (me) this works out well because we like lower trail bicycles. For the skinny/high pressure set with rear loads it is a big mistake.
I don't think that trail and wheel flop define everything about handling. The smaller wheels make other differences too. I'd still like to see greater experimentation and study of small bike handling than what appears to be out there.
alex
pengyou
11-03-07, 09:00 AM
Thanks! Yes, one of my thoughts is about a folding ebike. I often have to take busses and trains to really out of the way places in rural china, then fend for myself with taxi drivers with vehicles that look old enough to have been used on the 10,000 mile march with Chairman Mao :( I was originally hoping to beef up a battery system on a fairly lightweight but rugged ebike to do the whole distance - without the train or bus - but after looking at the cost of batteries for such a conversion I have decided to look for plan 2, which is looking for a good folding bike that I can take with me on the train or bus. I have ridden a couple of folding bikes and was rather impressed with them but for one thing. The front ends seem way too light and squirrelly, like they are just begging to have a motor added or some other weight to give them more stability...(OK, OK I know, added a motor to a front end us a bit controversial). I have never considered anything but a 20" tire in this decision because, from my experience, the bigger the tire is the more stable the bike will be on uneven (rips, potholes, small tree branches, etc) surfaces. I am guessing that having a bike frame that is a bit on the long side might be an advantage because I will often have to travel as much as 50 miles. Longer bikes seem to be a bit more comfortable.
spambait11
11-03-07, 10:06 AM
You're bike will be extremely heavy with your batteries and cargo. You're probably better off getting a gas scooter.
Bacciagalupe
11-03-07, 06:03 PM
How did you pick the term for bicycle handling? I've spent a lot of time studying bicycle handling, and oversteer is not a term that is used to describe it.
Picked it up from someone else, no idea whom. Since the term also covers "more steering than vehicle handler intended / expected," it works for me.
Folding bicycles are a drastic change on geometry.
Ya think? :D
Trail is important, but handling is affected by multiple aspects of a bike's geometry: wheelbase, BB height and position, seat tube angle. Taller handleposts may be another factor as well. (Oddly enough I haven't noticed any major changes in 20" handling based on tire changes, only acceleration, max speed and comfort.)
In addition, change one specific aspect of bike geometry, and 2 other things change, yes? ;) What other effects will reducing fork offset have on the bike? Would it slow down handling and potentially deteriorate handling at slow speeds?
I expect there are mechanical reasons why folding bike manufacturers don't use forks with lower offsets. I assume if you sat down with a folding-bike frame maker who has spent time experimenting with different forks, they could tell you what their research turned up. Maybe some of the Wal-Mart folding bikes skipped on the R&D, but there's no doubt that Bike Friday and even Dahon has done some R&D on this. I have zero doubt that if Dahon could make a 20" bike that steered the same as a 26" or 700c bike, it'd be a part of their lineup.
At any rate, unless you're going to go out and pick up a custom fork, the vast majority of folding bikes will have [insert term of choice to indicate less stable handling] than a 700c bike designed/marketed for that exact same purpose.
Picked it up from someone else, no idea whom. Since the term also covers "more steering than vehicle handler intended / expected," it works for me.
Folding bicycles are a drastic change on geometry.
Ya think? :D
Trail is important, but handling is affected by multiple aspects of a bike's geometry: wheelbase, BB height and position, seat tube angle. Taller handleposts may be another factor as well. (Oddly enough I haven't noticed any major changes in 20" handling based on tire changes, only acceleration, max speed and comfort.)
In addition, change one specific aspect of bike geometry, and 2 other things change, yes? ;) What other effects will reducing fork offset have on the bike? Would it slow down handling and potentially deteriorate handling at slow speeds?
I expect there are mechanical reasons why folding bike manufacturers don't use forks with lower offsets. I assume if you sat down with a folding-bike frame maker who has spent time experimenting with different forks, they could tell you what their research turned up. Maybe some of the Wal-Mart folding bikes skipped on the R&D, but there's no doubt that Bike Friday and even Dahon has done some R&D on this. I have zero doubt that if Dahon could make a 20" bike that steered the same as a 26" or 700c bike, it'd be a part of their lineup.
At any rate, unless you're going to go out and pick up a custom fork, the vast majority of folding bikes will have [insert term of choice to indicate less stable handling] than a 700c bike designed/marketed for that exact same purpose.
pengyou
11-03-07, 07:31 PM
Yes, but I have never seen a folding gas scooter :( I think 2 sets of some kind of Lithium batts at about 12 pounds each with a 30 pound set up will get me where I need to go.
Fat Boy
11-03-07, 09:42 PM
Oversteer has a very specific meaning as defined by The Society of Automotive Engineers. Specifically, that the sum of the rear tire slip angles are greater than the sum of the front tire slip angles. The slip anlges that are experienced by a bicycle are pretty stinkin' small. The ultimate result of oversteer on a motorcycle can be a high-side crash while low-sides are more often understeer. Good motorcycle racers are not worried about oversteer, but intentionally understeering a bike is dicey business at best.
Probably a better term to use is for what you are describing is steering response...in this case, very quick steering response.
A lot of geometry work has been done on 20" tires, specifically on BMX bikes. What are the head angles / trail numbers of your average BMX'er? They're very stable, that's for sure. I'd guess a slack angle and a lot of trail.
Probably a better term to use is for what you are describing is steering response...in this case, very quick steering response.
A lot of geometry work has been done on 20" tires, specifically on BMX bikes. What are the head angles / trail numbers of your average BMX'er? They're very stable, that's for sure. I'd guess a slack angle and a lot of trail.
spambait11
11-03-07, 09:44 PM
Yes, but I have never seen a folding gas scooter :(
http://www.goped.com/Products/
:)
http://www.goped.com/Products/
:)
Bacciagalupe
11-04-07, 10:01 AM
American Heritage Dictionary: "To turn more sharply than the operator would expect. Used of vehicles, especially automobiles." ( http://www.bartleby.com/61/44/O0194450.html )
Merriam-Webster: "the tendency of an automobile to steer into a sharper turn than the driver intends sometimes with a thrusting of the rear to the outside; also : the action or an instance of oversteer" ( http://www.merriam-webster.com/dictionary/oversteer )
:D
Merriam-Webster: "the tendency of an automobile to steer into a sharper turn than the driver intends sometimes with a thrusting of the rear to the outside; also : the action or an instance of oversteer" ( http://www.merriam-webster.com/dictionary/oversteer )
:D
Fat Boy
11-04-07, 12:47 PM
I bet you look up sexual terms in the dictionary and giggle at them, too, huh? My point is that the term you were using wasn't particularly helpful in explain the phenomena that you were describing. As a person that uses understeer and oversteer on a daily basis (along with many other terms describing limit handling characterstics), I was trying to help you out.
pm124
11-07-07, 09:28 PM
Yes, but I have never seen a folding gas scooter :( I think 2 sets of some kind of Lithium batts at about 12 pounds each with a 30 pound set up will get me where I need to go.
I've seen some of the great masses of electric folding bikes in China. But I've never seen a high quality electric folding bike there. I know that some higher end folders are sold there, but I haven't seen any. If you are on rutted roads, you'll be better off with bigger wheels.
I've seen some of the great masses of electric folding bikes in China. But I've never seen a high quality electric folding bike there. I know that some higher end folders are sold there, but I haven't seen any. If you are on rutted roads, you'll be better off with bigger wheels.
pm124
11-08-07, 08:48 AM
Ya, but he likes his kool-aid and has been repeating this same basic message on every thread that's even remotely related. I think he's going to enter an A-bike in the TDF next year and clean up.
You are a real charmer. I'm sure you have lots of friends off line, too.
You are a real charmer. I'm sure you have lots of friends off line, too.
Sammyboy
11-08-07, 10:15 AM
Actually, in car terms it's the other way around. The rear sliding towards the outside of the corner and the front continuing on the path that they were pointed until the car spins. Regardless, I'm a bit confused by the term as well when attributed to a bicycle. Perhaps he just meant that the steering response was quicker.
This is exactly right. Oversteer means the back end steps out, meaning the car is pointed more round the corner than you intend, or has oversteered. At the extreme end, it means a spin. Understeer means the wheels can't turn the car enough and it ploughs on, rather than going where you point it, or understeers. At the extreme end, this means ploughing off the outside of the bend.
This is exactly right. Oversteer means the back end steps out, meaning the car is pointed more round the corner than you intend, or has oversteered. At the extreme end, it means a spin. Understeer means the wheels can't turn the car enough and it ploughs on, rather than going where you point it, or understeers. At the extreme end, this means ploughing off the outside of the bend.
EvilV
11-08-07, 10:21 AM
I bet you look up sexual terms in the dictionary and giggle at them, too, huh? My point is that the term you were using wasn't particularly helpful in explain the phenomena that you were describing. As a person that uses understeer and oversteer on a daily basis (along with many other terms describing limit handling characterstics), I was trying to help you out.
Why so aggressive and unpleasant?
This is a forum for civil people. You could just say, 'That's not the way I see it - here's my view,' and say what you want to add to the discussion. We actually don't usually get uncivil remarks here, and speaking for myself, I don't think we want them.
Why so aggressive and unpleasant?
This is a forum for civil people. You could just say, 'That's not the way I see it - here's my view,' and say what you want to add to the discussion. We actually don't usually get uncivil remarks here, and speaking for myself, I don't think we want them.
pm124
11-08-07, 06:33 PM
Why so aggressive and unpleasant?
This is a forum for civil people. You could just say, 'That's not the way I see it - here's my view,' and say what you want to add to the discussion. We actually don't usually get uncivil remarks here, and speaking for myself, I don't think we want them.
I'll second that.
Speaking of over-performing, perfectly steering small wheeled bikes, how is the Moulton?
This is a forum for civil people. You could just say, 'That's not the way I see it - here's my view,' and say what you want to add to the discussion. We actually don't usually get uncivil remarks here, and speaking for myself, I don't think we want them.
I'll second that.
Speaking of over-performing, perfectly steering small wheeled bikes, how is the Moulton?
EvilV
11-09-07, 05:57 AM
I'll second that.
Speaking of over-performing, perfectly steering small wheeled bikes, how is the Moulton?
I've got it layed up indoors now the weather has turned nasty. I take it out on sunny afternoons but I'm damned if I'll ride it on wet cold days or worse still if there's salt on the roads which there will be soon. Being a rather classy machine the cold dark garage is out of the question - you don't put up aristocracy in a stable do you.
Meanwhile the little Merc is still earning her keep. That little beauty is as good as ever. She sleeps in the hallway near a radiator. My family are patient with these eccentricities.
Noticing your 'car free' slogan - I had to pay £250 yesterday to get the cam belt on my diesel car changed. Given that at Top Dead Centre the space in the combustion chamber is about 2mm, I didn't fancy the cost of a new engine (£4,500) if the cam belt broke and the heavyweight diesel pistons walloped valves sticking down into the cylinders. They reckon its a total write off issue for the engine.
Speaking of over-performing, perfectly steering small wheeled bikes, how is the Moulton?
I've got it layed up indoors now the weather has turned nasty. I take it out on sunny afternoons but I'm damned if I'll ride it on wet cold days or worse still if there's salt on the roads which there will be soon. Being a rather classy machine the cold dark garage is out of the question - you don't put up aristocracy in a stable do you.
Meanwhile the little Merc is still earning her keep. That little beauty is as good as ever. She sleeps in the hallway near a radiator. My family are patient with these eccentricities.
Noticing your 'car free' slogan - I had to pay £250 yesterday to get the cam belt on my diesel car changed. Given that at Top Dead Centre the space in the combustion chamber is about 2mm, I didn't fancy the cost of a new engine (£4,500) if the cam belt broke and the heavyweight diesel pistons walloped valves sticking down into the cylinders. They reckon its a total write off issue for the engine.
pm124
11-09-07, 08:48 AM
I've got it layed up indoors now the weather has turned nasty. I take it out on sunny afternoons but I'm damned if I'll ride it on wet cold days or worse still if there's salt on the roads which there will be soon. Being a rather classy machine the cold dark garage is out of the question - you don't put up aristocracy in a stable do you.
Meanwhile the little Merc is still earning her keep. That little beauty is as good as ever. She sleeps in the hallway near a radiator. My family are patient with these eccentricities.
Noticing your 'car free' slogan - I had to pay £250 yesterday to get the cam belt on my diesel car changed. Given that at Top Dead Centre the space in the combustion chamber is about 2mm, I didn't fancy the cost of a new engine (£4,500) if the cam belt broke and the heavyweight diesel pistons walloped valves sticking down into the cylinders. They reckon its a total write off issue for the engine.
Sorry to hear that. I assume your family won't put up with being piled up on the Merc for routine outings.
Meanwhile the little Merc is still earning her keep. That little beauty is as good as ever. She sleeps in the hallway near a radiator. My family are patient with these eccentricities.
Noticing your 'car free' slogan - I had to pay £250 yesterday to get the cam belt on my diesel car changed. Given that at Top Dead Centre the space in the combustion chamber is about 2mm, I didn't fancy the cost of a new engine (£4,500) if the cam belt broke and the heavyweight diesel pistons walloped valves sticking down into the cylinders. They reckon its a total write off issue for the engine.
Sorry to hear that. I assume your family won't put up with being piled up on the Merc for routine outings.
makeinu
11-09-07, 10:10 AM
This is exactly right. Oversteer means the back end steps out, meaning the car is pointed more round the corner than you intend, or has oversteered. At the extreme end, it means a spin. Understeer means the wheels can't turn the car enough and it ploughs on, rather than going where you point it, or understeers. At the extreme end, this means ploughing off the outside of the bend.
Yeah, but it seems that (as the definitions provided by Bac imply) that the back end stepping out is caused by trying to turn too sharp. In other words, if the steering were less responsive then the same input at the steering control (wheel or handlebars) would result in a wider turn which would eliminate the phenomenon of the back wheel sliding out. On the other hand, for the same input, more responsive steering implies a sharper turn which would worsen the sliding.
So, all else being equal, they go hand in hand and are, thus, appropriately referred to by the same term.
Why so aggressive and unpleasant?
This is a forum for civil people. You could just say, 'That's not the way I see it - here's my view,' and say what you want to add to the discussion. We actually don't usually get uncivil remarks here, and speaking for myself, I don't think we want them.
Thanks EvilV. People like you are what makes "Folding Bikes" the most civil and pleasant subforum on BF. (seriously, the rest of BF is a jungle compared to this place)
Yeah, but it seems that (as the definitions provided by Bac imply) that the back end stepping out is caused by trying to turn too sharp. In other words, if the steering were less responsive then the same input at the steering control (wheel or handlebars) would result in a wider turn which would eliminate the phenomenon of the back wheel sliding out. On the other hand, for the same input, more responsive steering implies a sharper turn which would worsen the sliding.
So, all else being equal, they go hand in hand and are, thus, appropriately referred to by the same term.
Why so aggressive and unpleasant?
This is a forum for civil people. You could just say, 'That's not the way I see it - here's my view,' and say what you want to add to the discussion. We actually don't usually get uncivil remarks here, and speaking for myself, I don't think we want them.
Thanks EvilV. People like you are what makes "Folding Bikes" the most civil and pleasant subforum on BF. (seriously, the rest of BF is a jungle compared to this place)
EvilV
11-09-07, 11:22 AM
Well I just think we come here to help each other find out stuff and to encourage enthusiasm. I've seen the way it goes on some of the forums and it isn't terribly encouraging of the exchange of ideas. There are people here who must spend countless ideas sharing their skill and experience. I think the fact that people behave in a decent ordinary way here helps make that continue.