PDA

View Full Version : BikeFriday says that smaller wheels are faster...


gosmsgo
11-07-07, 07:13 AM
Up to 33 mph

agree or disagree?

I want to believe that and I am considering ordering a bike friday tandem but if its true then why arent small wheel bikes more popular?

Is it really just the looks or the slightly bumpier ride?

Speedo
11-07-07, 07:24 AM
I suspect that this is one of those "all things being equal" kind of statements, and all things are rarely ever equal.

I have a Bike Friday NWT. I would never claim that my wheels are "faster" than the wheels on my other bikes. On the other hand, I don't have the feeling that I'm taking a significant performance hit either.

What bumpier ride?

Speedo

veganboyjosh
11-07-07, 08:24 AM
i think sheldon brown talks about this somewhere on his site...but it's been several years since i came across that section, and i can't remember where it was.

perhaps he'll post to this thread...

invisiblehand
11-07-07, 09:28 AM
Up to 33 mph

agree or disagree?

I want to believe that and I am considering ordering a bike friday tandem but if its true then why arent small wheel bikes more popular?

Is it really just the looks or the slightly bumpier ride?

Actually, they write that under 16 mph small wheels are faster; between 16 and 33 mph, the difference is very small; and that over 33 mph, big wheels are faster.

http://www.bikefriday.com/node/1660?question=1662&x=8&y=6

Regarding bicycle development and why big wheels are used, see this article ...

http://www.hadland.me.uk/page15.html

-G

gosmsgo
11-07-07, 09:36 AM
Actually, they write that under 16 mph small wheels are faster; between 16 and 33 mph, the difference is very small; and that over 33 mph, big wheels are faster.

http://www.bikefriday.com/node/1660?question=1662&x=8&y=6

Regarding bicycle development and why big wheels are used, see this article ...

http://www.hadland.me.uk/page15.html

-G

You are correct. Most of us I assume do not average above 33 mph so overall from 0-33 small wheels are faster.

If you do average over 33 mph then you are the best kept secret in the cycling world.

Bacciagalupe
11-07-07, 10:30 AM
Typically, small wheels are more or less a wash in terms of performance. Numerous other factors will be more important, such as rider position, geometry, tire size, tire width, wheel type etc.

As far as I can tell, small wheels are less popular due to:
• harsher ride
• twitchy steering
• market forces

I don't know much about tandems, but I'd expect the very long wheelbase, tire choice and saddle would compensate for the ride & steering. I'd contact BF and try to get them to explain the differences in ride feel for their tandems vs 26" or 700c.

FWIW I have a feeling their prices are going to be pretty good, compared to an S&S coupled tandem.

lecky
11-07-07, 10:38 AM
My sense on big wheeled bikes is that I get a lot of drag from cross-winds catching the wheels, whereas very little with small wheels, and in real world conditions this makes a big difference. Am I kidding myself?

makeinu
11-07-07, 11:30 AM
I agree with many of the other sentiments here. All other factors being equal, larger wheels are probably better, but in most cases other factors dominate to such a great extent that they never come close to being equal enough for wheel size to be a significant factor.

Small wheel bikes aren't popular because the change isn't significant enough to justify deviating from the standard. It's like deciding between a 20T chainring and a 15T rear cog or a 24T chainring and a 18T rear cog based on efficiency. No matter which is theoretically more efficient the difference will be so small that it would pale in comparison to seemingly trivial circumstances like what you can find in stock or whether or not you would prefer the chainring to take up less space.

Wheel size is far less important than you think. I'm not even sure if what people say about the bumpiness of the ride is true, as the tighter cornering afforded by smaller wheels means that you can more easily avoid those bumps.

Speedo
11-07-07, 01:22 PM
Wheel size is far less important than you think. I'm not even sure if what people say about the bumpiness of the ride is true, as the tighter cornering afforded by smaller wheels means that you can more easily avoid those bumps.

Oh! That just reminded me! The biggest difference between my small wheeled bikes and my big wheeled bikes is that the size of a "wheel eating pothole" is smaller for a small wheeled bike. So, effectively, there are more wheel eating potholes when you are on a small wheeled bike.

This only seems to make a difference around here in the early spring before town road crews have been out to patch the preceding winter's crop of potholes.

Speedo

edzo
11-07-07, 01:27 PM
it is the harsher ride of small wheels that make them sub par for long rides, and slower overall. if you are uncomfortable you will ride slower no matter if your wheels are faster

but yes I can spin my brommie up to speed very quickly due to less rotational weight

edzo
11-07-07, 01:29 PM
Wheel size is far less important than you think. I'm not even sure if what people say about the bumpiness of the ride is true, as the tighter cornering afforded by smaller wheels means that you can more easily avoid those bumps.

sorry, but if you are avoiding all the little bumps you'll be spending way too much time steering and less time enjoying the ride, or going sraight ahead... you will go a lot slower if you try to avoid numerous bumps to compensate and make the ride smoother.

Speedo
11-07-07, 01:40 PM
it is the harsher ride of small wheels that make them sub par for long rides

I'm just not buying that harsher ride. I have a Bike Friday NWT and the ride is as comfortable as any other bike I've ridden. I did back to back centuries on it this past summer. I did ride a Brompton for a week in the spring of 2006. A 35 mile day was a looooong day. There's more that goes into the ride than the wheel size.

Speedo

vik
11-07-07, 01:47 PM
I have bikes with 16",20", 26",650C & 700C wheels. If we are talking an upright tandem I'm confident I'd be faster on a 26"/700C wheeled tandem than a 20" wheeled tandem on any route. The rougher the ground the bigger the dufference.

As was noted in the post above there is more to speed than wheel size. I have a European lowracer recumbent with a 20" front wheel that is crazy fast, but that is due to the low aero drag. The same aero drag and dual 700C wheels would be even faster.

invisiblehand
11-07-07, 02:01 PM
My NWT is pretty comfortable and fast ... faster than my cyclocross bike with skinny tires for sure. Generally, smaller wheels have wider tires which more than compensate for many of the effects discussed here other than the giant pothole that Speedo mentioned.

makeinu
11-07-07, 02:21 PM
Oh! That just reminded me! The biggest difference between my small wheeled bikes and my big wheeled bikes is that the size of a "wheel eating pothole" is smaller for a small wheeled bike. So, effectively, there are more wheel eating potholes when you are on a small wheeled bike.

This only seems to make a difference around here in the early spring before town road crews have been out to patch the preceding winter's crop of potholes.

Speedo

Yeah, there are more wheel eating potholes, but they're also easier to dodge.

sorry, but if you are avoiding all the little bumps you'll be spending way too much time steering and less time enjoying the ride, or going sraight ahead... you will go a lot slower if you try to avoid numerous bumps to compensate and make the ride smoother.

Well, I don't know if I would necessarily agree that the ride is smoother with a larger wheel. In the case of a single bump, a larger wheel hits it sooner and stops rolling over it later. So the total time spent "making yourself light" is longer. With a smaller wheel the bump is a shorter (but stronger) jolt. As long as I can maintain stability I'd prefer the short strong jolt.

Over a series of bumps spaced over 20 inches apart the larger wheel makes it smoother because it doesn't get a chance to sink back down, but I wouldn't want to ride over that kind of terrain either way....I'd rather go around the whole patch.

In any case, I think a good suspension is a way way more effective bump killer than a few extra inches of wheel.

Amuro Lee
11-08-07, 11:55 AM
A good article written in Chinese.
However, I don't have the ability to translate it into English. I tried to use an online translator to translate it.
I hope you can still understand what does the author want to explain.
Author: zhangt71
Source: http://www.chinabike.net/newbbs/dispbbs.asp?boardID=181&ID=86544&page=2 (http://www.chinabike.net/newbbs/dispbbs.asp?boardID=181&ID=86544&page=2)

Article translated by google translate:
http://www.google.com/translate?u=http%3A%2F%2Fwww.6wlife.com%2Fdispbbs-4-1-239-0-1-0.html&langpair=zh%7Cen&hl=en&ie=UTF8

Dahon.Steve
11-08-07, 03:28 PM
Up to 33 mph

agree or disagree?

I want to believe that and I am considering ordering a bike friday tandem but if its true then why arent small wheel bikes more popular?

Is it really just the looks or the slightly bumpier ride?

Who knows?

I do know this. If you hit a small rock at that speed on a small wheel, you'll get the scare of your life! I would feel uncomfortable at that speed on a road bike. A mountain bike might be a different story.

-=£em in Pa=-
11-08-07, 04:15 PM
agree :beer:

sometimes less really is more ! :)