On Tue, Mar 10, 2009 at 9:57 AM, John Betmanis <johnb@oxford.net> wrote:
> ...I feel that it's quite possible to build small, if not the
> smallest, frames without toe overlap unless the builder considers a tight,
> upright frame to be more important. Even with toe overlap, nothing really
> bad can happen because it would only come into play at extremely slow
> speeds or standstill.
>
Perhaps the important thing is not the tightness or uprightness, but how the bike rides. My wife rides a 50cm frame and needs a short top tube, and the first time she rode and descended on her on-topic Batavus Professional, she raved about how well it went around curves at high speed, how right it felt, how responsive, and how good the steering felt, how the front wheel felt like it was in the right place, not way out in front of her on remote control. I was surprised because I didn't know what the difference could be, since these were all attributes I expected as a matter of course in my 58cm bikes. But it turns out these attributes were new to her because she'd been riding bikes with geometry that pushes the front wheel out forward with a slacker head angle or fork rake chosen more to avoid toe overlap than for steering response. Her Batavus Pro in an ordinary SL long point bike, but the 50cm was designed to put the front wheel in the same place underneath her, relative to where a good 58cm frame puts the front wheel under me. One result is toe overlap, but this is only an issue in slow maneuvers in parking lots, or a U-turn in the road. She's not crazy about the toe overlap but she wouldn't give up how the bike handles just to get rid of it.
Looking at how builders design small 700c 50cm bikes without toe overalap, I usually wouldn't want to ride the bike that results from those compromises. Like Marcus said, smaller wheels are the only way I or she would consider for a small frame to prevent toe overalap. Not that she couldn't ride those other non-overlap 700c bikes fine, but why would she want to now that she's ridden a bike with the front wheel where it's supposed to be, and knows what a great ride feels like. No doubt some builders are able to build a 50cm 700c frame without toe overlap that somehow doesn't put the front wheel too far out front for good handling, but she hasn't found any yet. One track bike I rode for part of a season was a long tall 60cm with a very long front center. It felt like I turned the bike, then waited a beat, then found myself turning, sort of like driving a long wheelbase truck. The front center on that bike was proportional to the long front center on her earlier bikes without toe overlap, and so I had experienced the kind of ride she'd always had before toe overlap.
In years of riding track, I had some track bikes with overlap, even in my usual 58cm size, and some without. Often older bikes were less likely to have overlap (I remember a 60s Holdsworth track bike with lots of rake), and larger bikes less likely too, although this was not a hard rule. But I don't remember any conversation about toe overlap as a problem.
A rider doing a track stand is aware which foot is going to end up in front and knows which way the front wheel will be turned. Riders may only able to do the stand with a particular foot forward and the wheel turned a particular way, or are much more adept at one orientation over the other. This is probably why most riders don't have an issue with toe overlap when doing track stands--one instinctively knows to put the wheel to the side with the foot to the rear. My favorite 58cm track bike has overlap, and as I became more ambidextrous with my track stand (wheel either side, either foot forward, standing up or sitting down) I wondered whether I'd sometimes forget and put the wheel in the way of my foot, but it doesn't happen for some reason. There is kind of bike stand where the rider swings the wheel back and forth from one side to the other to maintain balance. You see it on the street sometimes, and toe overlap would definitely hinder that movement. While this maneuver is useful to mtb Trials riders in some situations, It's not the way a track rider does a track stand. The only time I notice toe overlap as a problem is riding on the street, U-turns, slow turns in the parking lot, etc., on my track bike or one of my couple of 58cm road bikes with toe overlap.
There are certainly legitimate reasons for builders to try to avoid overlap even in small frames--pleasing the customer's expectations being a main one. My wife if given the choice before she rode 50cm 700c bikes would haved picked the one without overlap, but after riding each kind would always pick the one with overlap, because the ride is not compromised from her point of view. A builder who believes small 700c bikes handle better with toe overlap would have had a difficult time convincing my wife of that before she rode, though. I can see why builders wouldn't want to evangelize for something like toe overlap unless the rider already knows the ride she wanted. Another reason would be personal preference--some people may be more put out by overlap than me or my wife, and may consider handling differences in a small frame a small price to pay.
Another reason may be liability concerns, which is too bad.
Mitch Harris
Little Rock Canyon, Utah, USA