Folding Bikes - What is the fastest safe speed on a folder?

I am tootling around on my Dahon Speed and enjoying it more and more...but the other day I can down an overpass - well, I had to go up it first - and started to pick up speed...so I started to upshift to go faster and when I was in 7th gear I was starting to get a bit apprehensive about it all.

What are the limits with this bike? The brakes seem to be very good - am I dealing mostly with the psychological issue? If I adjust my seating position will it make any difference? Raise/lower the handle bars?

BTW, I like my bike...almost as much as I liked the dog I had when I was just a little pup..and more than I like most people :)

That depends on your ability

ive gone around 30 down the steep hill behind my house on a 1970s bickerton lol

edit: although i dont think this is a safe speed on a old 70s bickerton :)

Last time I was down hill in my Downtube 8FS, when I start doing 16mil/h about 25km/h I was little afraid, because the front suspension is soft, so, it is like you loose control at high speeds in a full suspension bike, I learned in NOT done for speeding :)

Regards

lol sounds funny, last time my cousin came up ( a long time ago ), she went down that hill on my mountain bike (sold now) and she fell off and shes still scared of the hill now :)

I've done 40+ on my 1970s Raleigh Twenty with a cheapo suspension fork so I'm sure that you'd be fine above and beyond that on a Dahon Speed. Always ride within what feels comfortable and safe, but try and push the envelope every now and again for maximum fun and exhilaration - that's my credo at any rate.

i agree, also my bickerton has no suspension so it made it even more painfull :)

Part of it is how close you are to traffic. If you are on a clear road with no cars I would go a lot faster than if traffic was wizzing by me.

Like littlepixel I have done +45mph on my modified twenty. Just stay within your individual abilities and you'll. A fine, juan162

Like littlepixel I have done +45mph on my modified twenty. Just stay within your individual abilities and you'll. A fine, juan162

:eek: very INCREDIBLE....

Tour de France average speed (on very high tech bikes) is 25mph and you do +45mph in a folder???

mmm... +45mph = 72km/h, you could go in the highway at that speed, without any problem

:roflmao:


Regards

:eek: very INCREDIBLE....

Tour de France average speed (on very high tech bikes) is 25mph and you do +45mph in a folder???

mmm... +45mph = 72km/h, you could go in the highway at that speed, without any problem

:roflmao:


Regards

I'm sure it was down hill or for a very short stretch, in which case it's something really easy to do. I have reached 30 mph on my Dahon Mariner folding bike for like a split second on flat ground. On a hill it would be no problem.

Doesn't seem unreasonable. Alan Scholz did 40MPH on his tikit, no sweat (http://www.youtube.com/watch?v=vGN69k82J7I&hl=en) (fast forward to 1:40). I think a well-set-up Dahon could do that too.

I detect some skepticism. I didn't say I sustained that speed for very long-it was a steep decent of less than a mile in the fingerlakes in NY state. However, i did do it and regularly do better than 30mph on the local descents. BTW, pros can do way faster than 45mph on decents. If i'm not mistaken, they can sometimes do 60+mph if they are really trying to bomb down a hill. That's how Biloki -I know that's gotta be spelled wrong- completely destroyed himself on a decent when Lance Armstrong had to go offeroad a few years back. I love how people assume that if someone claims to ride faster than what they think feasible, they must be lying.

My top speed on my Dahon Speed D7 was 28.5mph. It felt perfectly stable although I did not. It seemed insanely fast, car speed minus the car, seatbelt, airbags, etc. Life affirming if you don't die though. Weirdly enough I hit 20 or 21 most days on a nice flat smooth stetch by a scenic lake nearby and think nothing of it at all, I would readily go faster if I didn't have to turn off - on a longer stright I'd go for 25mph under my own steam on the flat and not care one jot. Funny how those few mph and shooting down a hill with street furniture and traffic changed everything.

:eek:

It really was 'brown trousers time' that day

Tour de France average speed (on very high tech bikes) is 25mph and you do +45mph in a folder???


I'm sure if the Tour de France were downhill all the way, their average speed would be much higher. ;)

Now that I got that out of my system, I thought I might add that I only average 15-17mph on most rides. I'm just fat so I have a very strong decending muscle!

Owlmaster, you must not know many serious roadies. My bro in law is only a cat 4 rider here in NJ but will routinely average 21-24mph over a 45 minute race. He averages 18-20mph on century rides, depending on weather and terain. You need to do your homework before trying to call somone out.

I didn't call you out? I was just trying to explain to Tovar that if I, a newbie, could get up to 30 mph on flat ground on a Mariner then getting 45 mph on a folding bike by someone more experienced on a downhill or a short sprint would be no problem by an average person. Tovar seemed amazed that "you were going faster then Tour de France Pros!!" I was just trying to explain to him that it really wasnt that insane. That's why I quoted him, not you.

I actually don't know any roadies, I'm just a bike to work commuter newbie, averaging not more than 15 mph for half an hour, with my cruise speed being 18-19mph in between stoplights.

I'm sorry if it seemed like I was callign you out, I didn't mean for it to sound that way.

What is the fastest safe speed on a folder?

I agree with owlmaster08, nobody is calling nothing, those are only opinions, that is it all.

I am not skeptic, was only a joke.

To answer this I will say that safe speed is variable it depends on:

bicycle and track conditions + driver's ability + weather + obstacles, etc. and you should be protected in case of a crash (damage vary with speed, there is not seatbelt in a bicycle)


Regards.

I've seen 34 mph on my IXFS. I'd have been quite happy going faster, but I spun out (it's only about 76 gear inches in top) and it wasn't a steep enough hill to go faster on inertia alone! I'm sure I can go faster on the Mini, but I don't have a speedo on that. Yet.

I don't know what is the obsession with "faster is better" but I like to add that its wiser to ride with a good dose of common sense, concentration and safety. I have ridden in many different countries with no incident, fast and slow speeds, but recently was humbled by a recent tumble at a local coastal bike path. At only 20km/h, I was not paying attention to golf-size fruit on the bike path! Helmet cracked. Nursing some bruises and as one gets older, it takes longer to heal :(

http://lovethefold.blogspot.com/2008/07/i-cant-believe-i-crashed.html

So the short answer to your question is - ride as fast as it is safe to do so. This could very well mean 60kmh+ on a clear, wide downhill or 15kmh on a crowded street. If necessary, get off your bike and push. Its ok.

Safety gear is compulsory - helmet, gloves, shoes.

http://i98.photobucket.com/albums/l260/oldiesonfoldies/zdamagehelmet2.jpg

i agree oldies but when you start going fast (I) just want to go faster and faster, and the adrenalin is great, also juan i dont think you could do that on a flat straight on a folder, my mate is a pro cycler and he can only do 30mph hammering it on a flat straight road.

The fastest I've put my Boardwalk D7 up to is about 42km/h, and it felt perfectly stable at that speed. :) I'm sure you could go much faster on hills with it - but there's no big hills here in Shanghai to try that theory out. :D

I noticed , when I hit a 'massive' er, 28 mph on my HH7, that the slightest mishap would land me in hospital. (again) See Oldisonfoldies post about hitting fruit with narrow Stelvio tires.

As a kid I went down a steep hill 'speed testing', put the front brake on when a wobble started, and the brake blocks flew out - they'd been fitted backwards. Hit a lamp-post and broke an arm and a collarbone. The bike looked like it had been run over by a train.

Have tried to avoid repeating the experience.

I think potholes and road debris are pretty dangerous, the faster you go, the more difficulty you'll have spotting them, as your vision is necessarily focused much further ahead.

I've had 74km/h on my Mini, and 82 on the Swift, and routinely got over 70 on the R20 (until I changed my commute route).

There is a very serious problem with speed on a bicycle; a sudden inadvertent steering movement may initiate speed wobbles, also called the death wobble. It is very difficult to recover from this and easy to crash. But as far as I know, this is the only danger with going fast (other than misjudging a corner or brakes fading or something obvious like that). Of course, there is also the danger of the tyre failing if it is in poor condition or a crappy quality.

Yeah, those wobbles stink. At slower speeds, sometimes I have an itch, or need to adjust my backpack etc. I then hit a stick, bump, etc. Steering goes out of control (one hand can't bring it back in control). I then go flying. This has hapened a couple times over the past year, but havent got hurt at all yet. I guess I am young still, so maybe it's because I know it's happening and am "flexible" enough to land on my feet and sacrifice the bike. Each time I am happy I am fine bit grimace at the thought of my Mariner beign broken. Surprisingly, it has survived each fall without any problems.

At faster speeds I always keep both hands on the handle bar and pay full attention to the road. As people have suggested here, the faster you go the more dangerous it is, but as long as you pay full attention and there aren't any hazards you will probably be ok (there are always risks riding).

If my bike is NOT done for going FAST, don't use it for high speeding.

Is not designed to go fast, I am already taking a risk.

If I want to go FAST, I need to be sure that it will stop properly when is time to do it. (A1 maintenance).

Regards

Yeah, those wobbles stink. At slower speeds, sometimes I have an itch, or need to adjust my backpack etc. I then hit a stick, bump, etc. Steering goes out of control (one hand can't bring it back in control).
When you ride one handed, do you move your hand towards the center of the handlebar closer to the stem? Doing so will give you more straight line control.

I thought the world record for a bicycle was 51.29 mph, that from a Moulton AM with a fairing on, thats what, about 82 kmh ?

I thought the world record for a bicycle was 51.29 mph, that from a Moulton AM with a fairing on, thats what, about 82 kmh ?

The fastest landspeed on a bicycle is apparently 152.2mph, yes, that is so incredible i'll say it again 152.2mph. Claimed by http://www.canosoarus.com/08LSRbicycle/LSR%20Bike01.htm
I personally think 'drafting' a rocket is cheating.

The World Unpaced Cycling record was in 1986 at the 3rd international HPV scientific symposium at Vancouver achieved by Jim Glover on a Moulton AM7 with a speed of 51.29 mph over 200m (fully faired conventional riding position). :speedy:

The World Unpaced Cycling record was in 1986 at the 3rd international HPV scientific symposium at Vancouver achieved by Jim Glover on a Moulton AM7 with a speed of 51.29 mph over 200m (fully faired conventional riding position). :speedy:


Pity he didn't use his R20 Stowaway, then he could really have shown them something !

Personally, the thought riding a bike at 50 mph on a public road, probably strewn with clag and minute debris, is seriously scary, but maybe I'm just a wuss.

Thanks! It seems I hit a nerve here :) I will play around with my seat position and handle bar height. I have noticed that I spend a lot of time looking at the ground when I go downhill...that could magnify the effects of the speed considerably.

juan i dont think you could do that on a straight on a folder, my mate is a pro cycler and he can only do 30mph hammering it on a flat straight road.

Come on. I can sprint up to 30 on the flat on a vintage roadie. I'm pretty sure I could do it on my IXFS if I had the gearing. Heck, even with the gearing I've got, I could probably spin it with a supreme effort. Give me better tyres and about 85 gear inches, and I'm certain I could.

The top speed for a folder is 88 mph. After that point, fire erupts from your tires and you start hearing Huey Lewis tunes.

http://www.brinkleys.org/users/tsl/Files/btf.jpg

Speed really has nothing to do with the size of your wheel. It's largely a matter of fitness and enough gear inches. With that said, I know I can sprint faster than 30 mph on a flat for a short distance. I couldn't maintain it for a long period of time, but that's why they call it a sprint.:) I will tell you one thing-my twenty easily weighs 29lbs so if iknow I'm going out on a fast group ride, I would sooner grab my 18lb road bike.

Speed really has nothing to do with the size of your wheel. It's largely a matter of fitness and enough gear inches.

People are muddling two issues here.

How fast you can ride on the flats in low windspeed conditions? That depends on your fitness, technique, aerodynamic positioning and bike design.

How fast you can safely ride on a steep downhill before the bike becomes too hard to control? That depends in large part on the stability of the bike at high speeds. This is what the OP wanted feedback on.

The fastest landspeed on a bicycle is apparently 152.2mph, yes, that is so incredible i'll say it again 152.2mph. Claimed by http://www.canosoarus.com/08LSRbicycle/LSR%20Bike01.htm
I personally think 'drafting' a rocket is cheating.

The World Unpaced Cycling record was in 1986 at the 3rd international HPV scientific symposium at Vancouver achieved by Jim Glover on a Moulton AM7 with a speed of 51.29 mph over 200m (fully faired conventional riding position). :speedy:

:eek::eek:Rocket pacing! That's insane! :eek::eek:

Sure would like to try it some time :o...

How fast you can safely ride on a steep downhill before the bike becomes too hard to control? That depends in large part on the stability of the bike at high speeds. This is what the OP wanted feedback on.
I think this relates to if you can ride the bike without hands. Am I wrong assuming that the bike is safer in high speeds if you can ride it without hands in low speed on a level road? I’m thinking of this scenario: you ride 50 km downhill – you must take your other hand from the handle bar – the front tyre hits a small pebble.

I think this relates to if you can ride the bike without hands. Am I wrong assuming that the bike is safer in high speeds if you can ride it without hands in low speed on a level road? I’m thinking of this scenario: you ride 50 km downhill – you must take your other hand from the handle bar – the front tyre hits a small pebble.

I don't think I'd let go of the bars cruising downhill at speed. But there's probably some truth to what you say. Bikes with less twitchy steering, ie, that have a large positive trail and thus are easy to ride 'no hands', are possibly safer at hgh speed than bikes with quick steering. However, high speed bike wobble is poorly understood and difficult to predict.

The maximum safe speed for a folder on British motorways would be 70mph and 30mph in residential areas. Same as cars really. Sammyboy is a threat when at full pelt in residential areas of Southampton or London. He would need a Dahon Speed Pro to be allowed on the motorways.

People have been seen breaking these speed limits after seeing Sammyboy riding naked behind them on his Downtube FS-FS (Full Suspension-Fully Starkers!) Unfortunately it did not trigger the speed cameras much to the anger of the local police in Hampshire.

I do know that an orange Downtube FS exceeded 70mph yesterday quite safely. It was in the back of Snafu21's not so green 4x4 returning after a Hyde Park Folding Society meeting :D

i went almost 60km/h when going down a steep and long slope on my mod dahon vitesse..still stable but not advisable..i don't think any of the brakes on a stock foldy is able to stop the bike in time..especially with 20' wheels..

Gentlemen, we need to settle this ONCE and for all.....I propose we all meet at the top of some insanely steep mountain road, somewhere in Bolivia or Columbia and see who can reach the fastest speed while negotiating impossibly crazy hairpin bends...that don't have guard rails. The winner is the rider who doesn't plunge to their death. :bike2:

You mean like Bolivia's highway of death?

http://bp2.blogger.com/_BqWviijUrNw/R02wamQVdLI/AAAAAAAAAgo/rCckV0e3rH0/s400/bolivia-highway-8-1.jpg

http://bp2.blogger.com/_BqWviijUrNw/R02vMmQVdEI/AAAAAAAAAfw/AYoTXcm5Kc8/s400/bolivia-highway-6-1.jpg

only time ive had a wobble was on a scooter on a sandy beach, it wobbled becuase of big ripples in the sand and i ended up flying off face planted myself in the sand and whacked my shin on the scooter. and i did this when i was 10 LOL, ive never experienced a wobble on a bike but i think i would be able to controll it. If you just keep your bike in a straight line then you should have no wobbles, and before coming to a turning or w/e then slowly put pressure on the breaks instead of whacking them on when you meet the corner or you might end up faceplanting yourself (yes i have done this aswell :)) so i have learned from my experiences :D

No problem doing that downhill on my Brompton lol!

sammy, also i think you could not do 30mph on a flat straight on a folder, once i get a new folder ill buy a speedo go down the big hill i was talking about and see how fast i go, ill also peddle in top gear downhill all the way.

I hit about 45 on a very steep (although not that long) hill on my Friday. That's about as fast as I have any need or inclination to go. As far as the wobble goes, the WORST thing you can do is hold the bars tight. That just makes it worse. The trick is to carry most of your weight on the pedals and hold the bars loosely. I've had a wobble at about 30mph in a crit where there was a big crash right next to me. I clamped down on the bars and got a big wobble. I just had to force myself to let go, and the wobble went away. Nothing like a speed wobble during a sprint finish to get your heart rate up!

As far as the wobble goes, the WORST thing you can do is hold the bars tight. That just makes it worse. The trick is to carry most of your weight on the pedals and hold the bars loosely.

+1, great advice. Use your abs to hold your body up so you don't put too much weight on the bars.

With any wheeled vehicle, I use the following formula to figure out what is a safe speed...

Density Of Surroundings (include people, traffic etc.) + Road Conditions (how well kept up) + Bike Conditions (brake condition, regular tune-up, whether or not I own the bike) = Right Speed To Ride.

Since I figured out this formula, I have had no major or overly scary problems-even suprises-cropping up.

Speed Kills!

;)

I don't like going fast on my Strida at all... talk about wobbly... it's almost impossible at speed. I think this is why the excellent disc brakes were put on it!

5 mph on Stelvio tyres at 100 psi, on gravel. At 6mph, it threw me off.