Compromise?

[Lanterne Rouge]

oldpotatoe got me thinking after a comment he made in the Bike Friday thread:

Small wheel bikes are a compromise

Is that true? What are people experiences and opinions?

Now it goes without saying that I have the utmost respect for oldpotatoe but I don't know if that statement is a perpetuation of a myth.

The advocates of small wheels are stubborn to say the least and wheel out the usual records held by small wheeled bikes and the racing pedigree.

I have read a lot about them but I'm undecided. I see the advantages and I see the disadvantages.

I'm on the fence but I would quite like a Moulton TSR 30, if for no other reason than it's elegant utilitarian space frame design.

[EricEstlund]

Yes and no.

Small wheels spin up faster, but don't hold speed as well. Tire selection is smaller. While it can be mitigated, they don't roll over small road debris as well. "Most" groups are designed to work optimally with larger wheels (and in some cases longer bikes, but this is a bike design issue more then a wheel size issue).

I have a Bike Friday I built that mostly hangs out. For a travel or multi-modal commute they are great, but I'm not swapping out my 700c bikes for fixed mini-velos any time soon. 20" wheels are about as small as I can handle (for my own use). Lots of folks are happy on 16" wheels, but it's not my thing.

If you have ridden small wheeled bikes and like it, then it's not a compromise, it's a preference. Choice is good.

[Louis]

I'm on the fence but I would quite like a Moulton TSR 30, if for no other reason than it's elegant utilitarian space frame design.

I've never ridden one, but as they say, variety is the spice of life. If you're interested I say get one and see for yourself if you like it. If $ is not an issue buy a new one. If it is, be patient and find a used model. Have fun.

[branflakes]

this argument is relatively nascent to me. i just haven't given much thought to it over the years.

however, the counter to small wheel bikes being a compromise would be that larger wheel bikes are superior. but where does that argument cease? how big is too big? why? i haven't hit the google-fu button on the mac just yet, so the answer may be out there.

my assumption would be that all things being equal (rubber type, psi, friction coefficient, etc.), over the course of some distance x, a tire has to travel the same distance regardless of size. so a 20, 24, 26, 650, 700, 29 all have to achieve the same distance, but would use varying amounts of rubber to accomplish the feat. in the varying sizes, gearing obviously would play a factor in the effort required to reach said distance.

so, in my very simplistic analysis, i would believe the biggest compromise would be the availability of the appropriate gearing to equalize effort, and the possibility that smaller tires would require quicker replacement due to increased revolutions.

feel free to dispute any of my logic.

[Mark McM]

Maybe you're reading too much into Old Potatoe's comments? All bicycle designs (and wheel size selections) are a compromise of some form another, afterall.

In terms of wheel size selection, smaller wheels have both positive and negative characteristics - small wheels are smaller are smaller and lighter, and for the same construction, are stiffer and stronger as well. But they also don't roll as well, having higher coefficient of rolling resistance and generating higher bump/vibration forces over rough surfaces.

For the best rolling characteristics, the modern 'standard' road wheel sizes (700c, 27", 650b) were selected because they are the largest wheels that would easily fit in frames built for the majority of the target audience - which at the time, were adult males. Wheels smaller than the 'standard' size make a bike more easy to transport and store (which is why they are used on Bike Fridays and other folding bikes), but lose out on some rolling characteristics.

In order to regain some of the better shock absorbing characteristics of larger wheels, many small wheel bikes adopt design features such as suspension or fatter tires - but these features have their own costs and drawbacks - and so have their own compromises.

[palincss]

As Mark says, they're all compromises. Moultons can be terrific fun. The suspension is wonderful on things like manhole covers and tree root bike trail paving heaves, and you find yourself going out of your way to ride over them just to experience it. However, the suspension does exact a toll on climbing, and will really seriously punish a choppy rider. Get out of the saddle and start horsing around and next thing you know, you'll be bouncing up and down like a demented pogo stick. And there's simply nothing else that looks like a space frame Moulton.

Here's mine:
http://farm5.staticflickr.com/4148/5033369267_1862c1efd9.jpg