Re: [CR]Toe-clip overlap - even on "Good" bikes?


Date: Mon, 30 Oct 2006 16:16:45 -0800
To: classicrendezvous@bikelist.org
From: Jan Heine <heine94@earthlink.net>
Subject: Re: [CR]Toe-clip overlap - even on "Good" bikes?


> I wonder, is this really that much of a problem?
>
>Up until then, in actual use, it's darn near impossible, while
>underway, to turn the bike's front end enough to actually contact
>the toe or clip. At faster than a very slow walking speed, it is
>almost impossible to turn the front fork more than a very few
>degrees...
>
> But maybe I am wrong? Any of you have actual experiences that
>indicate this toe clip clearance thing is a big problem?

I have two experiences to share that came close to disaster...

I lent my Rivendell, which has copious amounts of foot overlap, to a friend. Starting from a light, he wobbled a bit (the copious amount of wheel flop on this long-trail geometry did not help), and got his foot stuck on the wrong side of the fender/front wheel. With no way to turn the front wheel back to straight, down he went. He did not have to go to the emergency room, but blood was spilt. And the fender was bent, attesting to the efforts of my friend to get the wheel past his foot.

A few years ago, I was riding the same bike in town. Even though I instinctively align my cranks correctly during slow-speed turns (even on my bikes that don't have toeclip overlap), there will be a point when one forgets or thinks it unnecessary: I was waiting for a gap in traffic to make a left turn. A gap opened up, but it was a small one - enough for a quick dash across the oncoming traffic. Even though I am "left-legged" and thus started the move with my left crank, my front wheel still was turned enough that the right foot upon completion of the first pedal stroke came down on the wrong side of the wheel. A terrible wobble ensued, but I managed to stay upright and complete my dash across the oncoming lane. But it was a close call, and a crash in front of a delivery truck would not have been pretty. They might have been able to stop - or maybe not.

Toeclip overlap is unnecessary on bikes in my size (57 cm top tube length). It is the result of current bikes having higher trail figures than they used to have. If you look through the archives, you find that Chuck Schmidt measured racing bikes, and until maybe 1970, most had about 40-55 mm trail, usually with head angles of 72-73 degrees. No toeclip overlap with that in most sizes, even with fenders. Once tires got narrower, trail figures had to increase to make up for the decreased pneumatic trail. So they did. But somewhere, somebody came up with the simplistic, inaccurate notion that "More Trail = Stable Handling," and touring bikes began to have even more trail than racing machines, despite their wide tires. And with wide tires and fenders, toeclip overlap becomes a real problem. (If somebody had examined the old bikes and thought about how they were ridden on poor roads at lower speeds, they might have questioned the "more trail = more stability" mantra, but instead most concluded that the old makers simply had no clue how to make well-handling bikes!)

These issues were discussed in detail in an 8-page article in VBQ Vol. 3, No. 3, which goes into detail why bikes handle the way they do, and how trail-induced stability is but one component that affects handling. That article included 13 examples of bicycles that I have ridden. All but 3 don't have toeclip overlap. Their geometries were very different, and examining them all had interesting results.

Because the main difference between these bikes is the amount of fork offset (rake), some intrepid readers of Bicycle Quarterly have had their forks re-bent to increase the offset (rake) and thus eliminate toeclip overlap. Others had new forks built. All so far have been very pleased with the results, which closely mimic the geometries of the older bikes that so many riders like. Several follow-up articles discussed these, and tested bikes with different forks to highlight the differences. (A J. P. Weigle Randonneur with two forks and a Kogswell 650B bike with three forks.)

Maybe toeclip overlap isn't a problem for some riders... but even as an experienced rider, I prefer my bikes without. On track bikes, I don't think it is a problem. Neither on racing bikes that are not ridden in town. But all other bikes can and should be designed without it.

And don't get me started on excessive wheel flop (the result of too much trail), which I think is even more dangerous, as it makes it hard to ride in a straight line. Unfortunately, passing cars don't always give enough room for a sudden weave... -- Jan Heine Editor Bicycle Quarterly 140 Lakeside Ave #C Seattle WA 98122 http://www.bikequarterly.com