Bill Curtis wrote:
>> Roller chains are not appropriate for lightweights. They belong to the
>> fat-tire-crowd. The whole point of block chain was that the solid links
>> stretch, but would transfer power...just what a racer needed. When he came
> out of
>> retirement in his mid-fifties, Reg Harris said, "I have every confidence
>> the new alloy cranks, but a sprinter must use block-chain! Incidentally,
> on 30
>> days of training, Harris was able to win the British Empire Sprint title
> on a
>> bike fitted with archaic inch-pitch-block-chain.
Bill, with all due respect, I don't think it will make a hill of beans difference.in real world performance today, although I enjoy the myths of yore as much as anyone does. And, if thinking it made a difference helped Harris, so be it. But, please let me make a few observations and speculate a bit.
1) "Topologically," the two are equivalent, in that the paired rollers and inner plates exactly substitute for the block. You would observe that more parts means more potential failure possibilities, and I'd agree. Unless the block doesn't have bushings, which roller chains of that vintage had.
2) Over the past 100 years, there seems to have been a consistent trend toward narrower roller chains, from the 1/4" block chain (or was it 5/16") on my Davis Triplet of the 1890s to the chainsaw blades of the modern 10-cog set-ups. Metallurgy and manufacture have improved so we get enough strength with current chains. I don't follow racing closely, but I'm not aware of races frequently being decided by broken chains. In my 40 years of riding pretty hard, the only time I broke a chain was a 3/32" on a triplet, with three pretty strong adult riders -- and that was not a pure tension failure.
3) So, I'm not a wagering man, but if I were I'd lay a pint on the idea that the 1960s inch-pitch roller chain, a more modern design, would take a lot more pull before breaking than the archaic block chain.
4) Of course, if this is a beauty contest, block wins, hands-down, for many people, and may have been more popular with the sprinters. For me, given the choice between hundreds of dollars for block chain (as suggested by Larry Black) or actually getting chain that will work on a bike I love but won't ride all that much, it's an easy choice.
(BTW, I am selling the inch-pitch chains on behalf of a charitable organization, and buying one for myself. I won't make a dime off this).