Another gearing question...

[dd74]

I have two bikes of which I want to address the gears:

1) A steel bike with Dura-Ace 10-speed shifters, a Rival standard crank, and a Rival 11-26 cassette. Is 12-28 the largest stock SRAM cassette I can place back there while still using the short-cage derailleur?

2) The same goes for my second bike (a Ti frame), but in 9-spd. On that, I have all Dura Ace except an Ultegra standard crank and a 12-27 cassette. Is 27 the largest Shimano gear I can fit back there before I have to worry about switching out the derailleur on this as bike as well?

Thanks!

[Ray]

This has been covered a number of times. You can generally push a short cage derailure beyond its stated largest cog, but how far depends on a bunch of things. I know most Shimano road derailures are rated to 27-28 teeth but they can almost always handle 30. In some cases, they can handle 32, in other cases not. I've never heard of anyone running a 34 with one. I'd assume SRAM is kind of similar, but I have less experience, so I can't say for sure. I don't think 9 vs 10 speed makes any difference in this.

-Ray

[dd74]

Do Shimano or SRAM sell a 12-29, 12-30, or 12-31 cassette? I looked briefly on their websites and saw nothing to that extent.

If not, who does sell them?

[Ray]

Do Shimano or SRAM sell a 12-29, 12-30, or 12-31 cassette? I looked briefly on their websites and saw nothing to that extent.

If not, who does sell them?
Harris cyclery breaks 'em down and puts 'em back together in novel ways. I believe IRD or someone also makes some, but don't have experience with those. Shimano (and probably SRAM) also have mtb cassettes with 32 or 34 large cogs. AFAIK, Shimano and SRAM cassettes are interchangeable.

Here's a link to Harris, just to get you started:

http://sheldonbrown.com/harris/k7.html#9

-Ray

[Mike748]

Look at Harris Cyclery's custom "century" cassettes.

[dave thompson]

I have two bikes of which I want to address the gears:

1) A steel bike with Dura-Ace 10-speed shifters, a Rival standard crank, and a Rival 11-26 cassette. Is 12-28 the largest stock SRAM cassette I can place back there while still using the short-cage derailleur?

2) The same goes for my second bike (a Ti frame), but in 9-spd. On that, I have all Dura Ace except an Ultegra standard crank and a 12-27 cassette. Is 27 the largest Shimano gear I can fit back there before I have to worry about switching out the derailleur on this as bike as well?

Thanks!
Do Shimano or SRAM sell a 12-29, 12-30, or 12-31 cassette? I looked briefly on their websites and saw nothing to that extent.

If not, who does sell them?

The largest road cassette that either Shimano or SRAM make is an 11-28.

IRD makes an 11-30 cassette, which I am using on my 10-speed bikes with the standard 'short cage' rear derailleurs.

[Jack Brunk]

Sram has the new XX mountain 10 speed coming out with cassettes ranging from 30-36. I hear that the DA Rd will handle up to the 34. Word has it that the cassettes work great with DA.

[zott28]

Any info on Campy stuff, I beat myself climbing this weekend to the point of wanting a compact, but it would be cheaper if I could put a lager cassette on. I have a record short cage RD thou.

[thwart]

Any info on Campy stuff, I beat myself climbing this weekend to the point of wanting a compact, but it would be cheaper if I could put a lager cassette on. I have a record short cage RD thou.I run a 13-29 cassette on a Centaur bike with a short RD like yours and a standard crank. I've even done the unthinkable---the 53-29 a couple of times---and lived to tell about it. :D

[Ti Designs]

My opinion remains unchanged since the last time this came up...

[dd74]

I forgot. What was your opinion?

By the way, those IRD cassettes are pricey --- sheesh!

[Dave]

The largest cog size is less of a problem than the RD's wrap capacity. For the most part, you should be able to use a compact crank with any cassette up to 27 or 28T. Some bikes will work better than others due to the chainstay length. There are lengths that produce up to 2T more wrap than others.

With Campy, a 13-29 works for certain if you never shift beyond the big ring and 26T cog, but shifting to the big ring and 29 gets into the chainstay difference. Some bikes will make it and others won't.

With the new 11 speed you can use a 50/34 with a 12-27 and a short cage RD, since that's all they sell.