Originally Posted by
Wogsterca
I don't understand the lots more front shifting on doubles, you have low range for uphill and flats (with wind), high range for flats (no wind) and downhill, with a double instead of losing 2 gears on each end, you lose only one. If you really need to do a lot of shifting, then maybe you have the wrong cassette on there. Which I think is a large part of the problem in general. Cassettes are still marketed as if we had 5 speed freewheels where you choose which 5 cogs you want and need to have knowledge of which cogs are best, this is why today we still refer to gear inches as if that explains it all. I think it would be better to have different cassettes based on the crank size and riding style, to give you a reasonable gear range for different uses.
With my original cassette (a SRAM 12-26), I could go down to about 12 mph in the big ring at a reasonable cadence - but I'm cross chained. To avoid using the biggest 3 cogs and maintain 80 rpm I'd have to be going between 16 and 17 mph. So, anything slower than 16 mph or so and I'd either be spinning below 80 rpm or cross chained. On the other hand, in the small ring @80 rpm at around 16mph andI'd be in one of the 3 smallest cogs (which is a worse cross chain condition, IMO - at least it makes more noise, and the SRAM shifters only have trim on the large ring).
No matter how you slice it, if you are cruising along between 15 and 17 mph with that cassette and a compact, and you're maintaining a cadence of around 80 rpm, you'll either be cross chained or shifting a lot. I prefer to shiift a lot rather than be cross chained.
FWIW with the new 11-32 cassette, the wider gaps actually work better for me, giving me some options right in that hole. I've also been working the last 18 months on increasing my cadence, getting comfortable spinning at 90 - 100 rpm for long periods of time, which has increased the speeds I'm riding at and reduced my dependence on finding just the *right* gear. However, I'm not the first person to complain about a hole in the gearing with a compact at those kinds of speeds.
I think part of the issue too is that you and I have a different definition of cross chaining. Not saying mine's correct, but I have to believe that bending the chain at the kind of an angle just isn't doing it any favors - although I'll be the first to admit that my choice of not using the 3 biggest cogs with the big ring is arbitrary at best.
JB