Miles

[ianrauk]

The trick is that you have to be totally aware that you will be slower than if you are riding a df bike. Once you accept that and ride accordingly. Its easy.

This. /\ It took me a long time to accept that fact after many years of a df commute.
However, I am one of the rare few that couldn't get on with a Brompton, so sold mine.

 

[biggs682]

Being in isolation mean that my biking is measured in time rather distance as the turbo trainer doesn't move

 

[nickyboy]

Small wheeled bikes are slower than big wheeled bikes. The reason is that the rolling resistance of the tyres is higher

The reason for this is the hysteresis (tyre deformation) when cycling is proportionately greater on a small tyre than a big one. If your wheels are going round twice as quickly, your tyre is forced to deform twice as often

 

[DRM]

Being in isolation mean that my biking is measured in time rather distance as the turbo trainer doesn't move

Yes but your legs move, which will make things a lot easier than starting over again when you're finally released into the great outdoors

 

[biggs682]

Yes but your legs move, which will make things a lot easier than starting over again when you're finally released into the great outdoors

That's what i am hoping

 

[DRM]

It does, I've been using Zwift over winter & when it's been impossible to get out, it does keep a basic level of fitness up. it's awful coming out of winter prior to getting a trainer.

 

[SkipdiverJohn]

Small wheeled bikes are slower than big wheeled bikes. The reason is that the rolling resistance of the tyres is higher

The reason for this is the hysteresis (tyre deformation) when cycling is proportionately greater on a small tyre than a big one. If your wheels are going round twice as quickly, your tyre is forced to deform twice as often

Absolutely right, even though the extra hysteresis effect might be quite small in the scheme of things. The game-changer that favours big wheels is when the surfaces get rougher, and the wheels drop further into depressions the smaller they are. That not only gives you the sickening jolting ride, that limits the appeal of small wheelers, but it absorbs a noticeable amount of energy. Traditional heavy roadsters didn't settle on 28" wheels because someone sucked their finger and stuck it in the air to see which way the wind was blowing. It was realised very early on, that with the poor quality roads of the day, a bigger wheel rolled better. 26" wheels were a development that gave a good compromise between ride quality, and more nimble handling than you get on 28's. Don't believe bigger is better? Try rollerskating on a rough unmade track and see how fast you are!

 

[Ian H]

All of which begs the question as to why Moulton AMs are perfectly fine and fast over distance.

 

[SkipdiverJohn]

Moulton suspension will clean up the perceived ride quality as felt by the rider. It will not however, magically prevent small wheels travelling more in the vertical plane over a rough surface compared to big wheels. If you were to do a back-to-back test under laboratory conditions, for the same aerodynamic frontal area and total weight, a big wheel rider would need to produce less watts to attain the same speed as a small wheeler.

 

[rogerzilla]

My Brompton is actually geared the same as my other 3-speed bikes, with a 60" middle gear. I just have to work harder.

 

[Smudge]

Small wheeled bikes dont have the momentum like larger wheeled bikes, so they will slow down quicker without you constantly putting the power in. But they will accelerate faster and get up to speed quicker, but then you have to put in more effort to keep that speed.
Obviously bigger wheels perform better on rough surfaces.

 

[Blue Hills]

Small wheeled bikes are slower than big wheeled bikes. The reason is that the rolling resistance of the tyres is higher

The reason for this is the hysteresis (tyre deformation) when cycling is proportionately greater on a small tyre than a big one. If your wheels are going round twice as quickly, your tyre is forced to deform twice as often

Interesting.
I have a 5speed brommie (as above) and a Dahon Speed Pro (20 inch wheels) - have ridden both up mountains and on long rides (70 plus for sure on brommie and about same on speed pro) without problems but I do kind of have the impression that I need to drive/pedal the things forward more - ie less "given" by the bike.

 

[SkipdiverJohn]

Small wheels have less inertia, so they gain and lose energy more quickly. For nippy acceleration, that's a benefit; for the maintenance of forward momentum once up to speed it's a disadvantage. Roadies often moan like hell about how much they hate bikes with heavy rims and especially M+ tyres - because what they don't like is having to fight against all that inertia to get the bike up to speed. The large mass located at a distance from the centre of rotation acts as a flywheel and stores energy.

 

[Fab Foodie]

The reason for this is the hysteresis (tyre deformation) when cycling is proportionately greater on a small tyre than a big one. If your wheels are going round twice as quickly, your tyre is forced to deform twice as often

You might want to rethink the logic of that....

 

[Ian H]

You might want to rethink the logic of that....

Made me smile as well.