i realize this is rapidly becoming the cycling equivalent of “does my ass look fat in these jeans?” . . .but, here we go:
i’m riding a 2004 cervelo soloist (aluminum) with an ultegra 9-speed rear derailleur. i’ve got a half ironman coming up with ~3000m of climbing (!!) and want to give myself every chance of finishing with a bit of dignity. i’ve found a Sora-grade 11-30 cassette online that would give me lots more range than my current (11-23, i think).
it’s a short-cage derailleur, yes, and i think shimano’s literature indicates something like 28 max. but. . . i also read lennard zinn (or maybe the park tools guy? anyway, someone wise) saying that shimano is always way conservative with tooth limits to cover their butts and account for bikes with weird rear triangles/hangers.
does anyone have theoretical knowledge or personal experience cramming a big cassette into this bike/drivetrain?
But it probably will take a 30 if the chain is set slightly long, meaning while in the small/small combo there is one extra link in the chain.
yeah, that was the tech document i’d read. but then i read this from lennard zinn, and it made me think maybe it’s worth trying a bit larger. i’ve found a cheap old sora online for 15 bucks, which seems like a low-risk experiment. the ultegra-level cassettes i’m finding so far are only as big as 12-27, and i think i’ll want a bit more grunt than that!
A few years ago I was doing a similar sort of equation and came to the conclusion the best solution was to go to a triple chain set (horrific I know). On a 9 speed systems you start to get some pretty big jumps on a wide spaced cassette and that will hurt over the longer distances. You also don’t want to sacrifice the higher gears for descending as its nice to have something to push against even if you aren’t applying much power. Finally the cost of a NOS Shimano triple was only marginally more than a new set of front rings. The biggest hassle was tracking down the appropriate matching triple shifter although the latest generation of shimano 9-speed brifters are cheap and better than anything produced in 2004 so buying new won’t be a massive negative.
I use the setup with both an 11-25 and 11-28. Cross-chaining is an issue in the granny (30) and big (53) rings. If you accidentally find yourself in small/small or big/big the bike makes a lot noise to remind you to chose a better gear but never should be in these combos to begin with. By the time you need the granny you should be well up the cassette and similarly if you are in the 53 you shouldn’t be near the 25 at back.
Overall I like the triple and I definitely thinks its worth considering. Its overkill for everyday riding but a 70.3 with 3000m of climbing isn’t everyday riding.
Not sure if my memory is any good at this stage either…
Back in the day, I had a Cycle Dynamics 12x30 that worked well with DuraAce 7800. It worked with the original SRAM Force too, but the B screw was all the way out. Yeah those are 10 speed, but at the time it made me think that Shimano underestimated their rear derailleur capacity.
slapped that 11-30 on the other day, and it runs very well. my first ride had about 750m of climbing and it was a relief to have that much more range. the sad part was realizing that, even at a good cadence, my littlest gear (34x30, i think) is really slow. but maybe climbing at 8km/hr is the price to pay for comfort when i’m a few hours into a long race and looking up another mountain . . ,