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-   -   Does 20" v.s. 16" wheels really matters on long distances? (http://www.bikeforums.net/folding-bikes/98559-does-20-v-s-16-wheels-really-matters-long-distances.html)

josr 04-10-05 01:35 AM

Does 20" v.s. 16" wheels really matters on long distances?
 
Hello,

I read everywhere that 20" folders are better for longer distances than 16" (i am going to buy the first folder, so I have no experience).

Can someone explain me why larger wheels drive better? Is this only because 1 rotation of your feet result in less distance, so a 20" is faster? Are 16" using a lager cogwheel/cranck (=cost more energy to rotate) to compensate the small wheels?

If you can drive 20-25 kmh (12-16 mph) on a normal bike, does it cost much more energy to reach the same speed on a 16"" or 20" folder?

Thanks!

Jos

cyclistbrian 04-10-05 04:19 AM

I would say the benefits of 20" wheels would be:
1) Somewhat more comfortable ride.
2) Easier to find high quality tires (20" are commonly found on recumbents)
3) Easier to find emergency replacement tire at department store.
4) If you hit a pothole the 16" tire will drop that much furthur in increasing the probablility of damage.
5) Small wheels carry less inertia than larger wheels. It's hard enough with 20" wheels (I know, I used to ride a dual 20" recumbent) to keep up on the road. It will be that much harder with 16's.
6) The smaller the wheel the harder it will be to come up with a usefull gear range. Again, it's hard enough with 20" wheels.

There are good 16" tires available as a result of the recumbent trike market but in my experience they are generally mail order only and expensive. I suppose a folder with 16" wheels would fold more compactly. If you are seeking ultimate compactness in order to stowe a bike on a small aircraft or boat that might trump all of the benefits of a larger wheel. But overall I think the ride of a 20" wheel bike would be superior.

Willing to hear different from 16" advocates.

Brian Daniels
East Nassau NY

ruchai 04-10-05 04:20 AM

It's not gearing that make 20" bikes better than 16" bikes. It's the resistance of smaller wheels need to climb ripples on the road. If the road is as smooth as glass then there will be no differences. The advantage of 16" wheels seems to be for neater folding. Today 20" wheel folders like Dahon and Giant Halfway can fold very well. To me 16" wheels for folders is finished.

Anthony King 04-10-05 04:08 PM

I don't know anybody that tours on 16" wheels. But plenty of people tour on 20" wheels, Bike Fridays, Dahons, etc. That should tell you alot.
I'll reiterate a couple of the above reasons--on long distance rides you may encounter less than ideal road conditions, and replacements for 20" can be found almost anywhere since BMX tires come in the size.
I think one reason not mentioned is the bike itself, 16" bikes often make compromises for compact folding that are not noticable over, say 10 miles, but would be over longer distances.

wpflem 04-10-05 04:26 PM

Quote:

Originally Posted by Anthony King
I don't anybody that tours on 16" wheels. But plenty of people tour on 20" wheels, Bike Fridays, Dahons, etc. That should tell you alot.
I'll reiterate a couple of the above reasons--on long distance rides you may encounter less than ideal road conditions, and replacements for 20" can be found almost anywhere since BMX tires come in the size.
I think one reason not mentioned is the bike itself, 16" bikes often make compromises for compact folding that are not noticable over, say 10 miles, but would be over longer distances.

Brompton Owners Tour: "...the riding performance of the Brompton should not be under-rated: many existing owners use a Brompton for long journeys and for painless touring: indeed a lot of Brompton devotees claim to prefer the ride of a Brompton to that of a conventional bike..."
reference: http://www.bromptonbicycle.co.uk/ind...any.philosophy

James H Haury 04-10-05 04:30 PM

I rode 20 or more miles( I do not have a bike computer) on my 20" one speed yeah Yesterday. I really would not wish to do that on my 16 " Dahon or yeah. 20" wheels give a better ride.While I am at it let me say my sprung leather saddle was quite comfy.Re bromptons i believe The wheel tire combo on a Brommie is actually 17 inches.

James H Haury 04-10-05 04:33 PM

Quote:

Originally Posted by cyclistbrian
I would say the benefits of 20" wheels would be:
1) Somewhat more comfortable ride.
2) Easier to find high quality tires (20" are commonly found on recumbents)
3) Easier to find emergency replacement tire at department store.
4) If you hit a pothole the 16" tire will drop that much furthur in increasing the probablility of damage.
5) Small wheels carry less inertia than larger wheels. It's hard enough with 20" wheels (I know, I used to ride a dual 20" recumbent) to keep up on the road. It will be that much harder with 16's.
6) The smaller the wheel the harder it will be to come up with a usefull gear range. Again, it's hard enough with 20" wheels.

There are good 16" tires available as a result of the recumbent trike market but in my experience they are generally mail order only and expensive. I suppose a folder with 16" wheels would fold more compactly. If you are seeking ultimate compactness in order to stowe a bike on a small aircraft or boat that might trump all of the benefits of a larger wheel. But overall I think the ride of a 20" wheel bike would be superior.

Willing to hear different from 16" advocates.

Brian Daniels
East Nassau NY

All very good points and well laid out.

wpflem 04-10-05 05:46 PM

Quote:

Originally Posted by James H Haury
I rode 20 or more miles( I do not have a bike computer) on my 20" one speed yeah Yesterday. I really would not wish to do that on my 16 " Dahon or yeah. 20" wheels give a better ride.While I am at it let me say my sprung leather saddle was quite comfy.Re bromptons i believe The wheel tire combo on a Brommie is actually 17 inches.

The Brompton wheel is billed as 16 inches, but it is a little bigger than the 16 inch found on the Dahons so it may be better classified as 17 inches. Also the rear suspension of the Brompton gives it a smoother ride.

spambait11 04-10-05 07:59 PM

Quote:

Originally Posted by josr
If you can drive 20-25 kmh (12-16 mph) on a normal bike, does it cost much more energy to reach the same speed on a 16"" or 20" folder?

I don't think so; Brompton's 16" tires (ETRTO 349) can really fly when inflated correctly (I also own a Bike Friday and a Birdy, but prefer the fit of the Brompton).

But it's not just the tires. When deciding, you might want to take the machine itself into consideration. If you don't fit well on a Brompton (the default assumption anytime anyone suggests a folding bike with 16" wheels), then you will probably not ride well either. I can also say I fly on 20" tires, but this is on a recumbent. ;)

Take everything you read with a grain of salt.

Dahon.Steve 04-10-05 09:46 PM

The 16' inch wheel when inflated to a high pressure gives a very rough ride. Unfortunately, you have to keep the pressure high on a 16' inch wheel or you'll lose performance. The 20' inch wheel does not need to be inflated this high and can be ridden at a lower pressure without too much loss in performance. Furthermore, the 16' inch wheel gives a "squarly" ride compared to a 20 inch wheel that feels more stable. This is particularly important when you're riding at night!

Anthony King 04-10-05 10:22 PM

Quote:

Originally Posted by josr
If you can drive 20-25 kmh (12-16 mph) on a normal bike, does it cost much more energy to reach the same speed on a 16"" or 20" folder?

No. A 70 inch gear is a 70 inch gear is a 70 inch gear, doesn't matter how big the wheel is, it's all taken into consideration when the gearing is calculated--one revolution of the pedals moves you 70 inches. In fact, accelation should be a little bit faster on a smaller wheel.

Quality of the ride is affected by several factors, and wheel size is just one. Bromptons, as mentioned, are famed for their rides, on their bikes the inherent shock absorbing inferiority of a small wheel is offset by the suspension and frame design.
Remember that all of these comparisons assume equal quality--all things being equal, a larger wheel gives a smoother ride, but top-notch 16" wheel bike will probably give a better ride than an entry level 700c bike.

Didn't mean to slag all 16" bikes in my first post--the Brompton is in a different category than other 16 inchers.

James H Haury 04-11-05 08:36 AM

I must concur a bike that does not fit you well will not be as comfortable as it could be .The totality of the bike must be considered.

ETRTO 520 04-14-05 04:05 PM

Small wheels are a big subject. In addition to the various practical considerations raised above, there are matters of physics. Not being qualified, I won't attempt to summarize them. "Bicycling Science" (3d Ed., ed. by David Gordon Wilson, MIT Press) devotes a few pages to the subject.

Anthony King 04-16-05 11:21 PM

I rode my Dahon Classic (16" wheels) about 20 miles today. I made it from downtown Dallas to downtown Irving in 38 mins (it's about 10 miles) aided by a 6mph SE wind.

I've never been on my 16 incher so much in one day. I have been riding it alot more lately because I ride on my new commute I ride a train without good spots for a full size bike. Here are some thoughts--
On a flat, smooth road it's as good as anything else, and fun. Bumps aren't too bid a deal because I have 1.75 inch tires on the bike. The problem I have is with hills, but I can't chalk it up to the wheels. The effective top tube length on my bike is short for me, though this may be a problem inherent to the emphasis on small folding size on 16 inchers. When I stand up to pump up a hill my knees come within a couple of inches of the handlebars. It doesn't feel comfortable at all and I don't feel like I can put alot of power into when I'm standing up because I'm cramped.

Perhaps there is someone out there who has a better fitting sixteen incher who can tell us about climbing and/or hard pedalling while standing on the bike.

I was thinking about selling this bike, but there is no way I'm going to now. In the next couple of months I'm going to put on a Nexus 7 speed hub and some handlebars that will allow me to stretch out more, even if it means somewhat compromising the folded size.

Moe£ 04-17-05 04:24 AM

Yesterday I was out riding with my brother. We rode about 50 miles on asphalt roads, pretty decent surface. Islands with a lot of smaller hills, not to steep.

He has a '03 Dahon Helios P8 with 20" wheels. I have a '04 Dahon Presto Lite with 16" wheels. His bike is pretty much in its original state, except bar ends. Mine has fatter tyres, larger chainwheel and spd pedals among other things.

Anyway, about actual rolling resistance, We noticed no real difference. I could stay in his backdraft downhill and he could stay in mine. We are about equally strong riders and took turns in front all day. He has 8 speeds, mine has 3 speeds in internal hub. Didn't make any practical difference for average speed, although I generally keep a higher cadence than he does.

So in my experience, the riding surface has to be worse than normal asphalt roads for the 20" wheels to be an advantage over 16". My 16" Schwalbe Big Apples are probably more comforfable than his skinnier original 20" wheels.

My 50 öre, £Moe, Sweden

wpflem 04-17-05 07:56 AM

Quote:

Originally Posted by Moe£
Yesterday I was out riding with my brother. We rode about 50 miles on asphalt roads, pretty decent surface. Islands with a lot of smaller hills, not to steep.

He has a '03 Dahon Helios P8 with 20" wheels. I have a '04 Dahon Presto Lite with 16" wheels. His bike is pretty much in its original state, except bar ends. Mine has fatter tyres, larger chainwheel and spd pedals among other things.

Anyway, about actual rolling resistance, We noticed no real difference. I could stay in his backdraft downhill and he could stay in mine. We are about equally strong riders and took turns in front all day. He has 8 speeds, mine has 3 speeds in internal hub. Didn't make any practical difference for average speed, although I generally keep a higher cadence than he does.

So in my experience, the riding surface has to be worse than normal asphalt roads for the 20" wheels to be an advantage over 16". My 16" Schwalbe Big Apples are probably more comforfable than his skinnier original 20" wheels.

My 50 öre, £Moe, Sweden


Sounds like a good way to compare. Your results reflect my subjective experience. I needed a brother with 20 inch wheels for my Piccolo Commute test--posted on a separate thread herein.

Dahon.Steve 04-18-05 07:55 PM

Quote:

Originally Posted by Anthony King
Quality of the ride is affected by several factors, and wheel size is just one. Bromptons, as mentioned, are famed for their rides, on their bikes the inherent shock absorbing inferiority of a small wheel is offset by the suspension and frame design.
Remember that all of these comparisons assume equal quality--all things being equal, a larger wheel gives a smoother ride, but top-notch 16" wheel bike will probably give a better ride than an entry level 700c bike.

Didn't mean to slag all 16" bikes in my first post--the Brompton is in a different category than other 16 inchers.

I put a suspension seat post on my Dahon Piccolo and can ride that bike 45 miles without too much saddle discomfort. I found that a folding bike like Dahon or Brompton NEEDS some kind of suspension because you are sitting straight up and your rear end hits all the ruts, bumps and potholes. The geometry of the folding bike just about requires a suspension or Brooks Champion Flyer.

In fact, when I put a Champion flyer on my Speed 8 and a suspension seat post on my Piccolo, I could travel the same distance with each bike. Although with my Speed 8, I could ride more carefree because the larger wheel is more stable on rough roads whereas with the 16' inch wheel, I had to be more conscious of the asphalt condition.

53-11_alltheway 04-19-05 12:03 AM

Who makes racing style tires in these smaller sizes?


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