Shiimano compatibility questions (from a Campy guy)

[flydhest]

Prolly dumb questions, but I haven't had a Shimano equipped bike in close to 20 years.

We bought a used bike on our trip to CO so we could have a bike out there for my wife to ride. (Ever since my wife and I got serious, I have kept a Serotta CSi in my mother-in-law's basement). The hills are tough for flatlanders, and my wife doesn't ride more than 2000 miles a year, so we got a triple (mix of 105 and Sora). it is a triple 9-speed. The cassette is a 12-25. For those familiar with Ft. Collins, she did Maniac and was good with it, but if we wanted to do all the dams along the reservoir in one ride, a little lower gearing would be useful, at least mentally. We only get to CO 2 or 3 times a year, and it usually takes half or more of our time there to get used to altitude and climbing, so an even smaller gear is sought.

I have nosed around online for Shimano 9-speed cassettes, and it seems the ones that go to or above 30 teeth are mountain bike cassettes.

Q: Is that conclusion I came to correct or are there Shimano 9-speed road cassettes that go to 32?
Q: Is there a compatibility concern using 9-speed MTB cassettes on a road bike apart from chain length considerations?

[eddief]

the 9 speed Shimano road rear derailleur can be pushed to 30 teeth fairly easily, but the road rear d does not allow for more than that. install a 9 speed mountain rear derailleur and that cassette can go up to 36. You can also install a 26 granny on the front in place of the 30 and that will let you climb most telephone poles.

one o these:

http://www.chainreactioncycles.com/u...prd%7C139443US

and one o these. cheaper models available:

https://www.excelsports.com/main.asp...MTYaApiI8P8HAQ

bigger yet:

http://www.chainreactioncycles.com/u...prd%7C431532US

small up front:

http://www.ebay.com/itm/Sugino-26T-7...0AAOSwtZJY9JXk

[jruhlen1980]

As far as I can figure out there's no difference between "mountain" cassettes and "road" cassettes other than the range. In other words, the cog spacing is the same so you don't have to worry about derailleurs.

I think Shimano MTB derailleurs and road shifters were mostly compatible up until they went 10-speed, but I'm not entirely certain. I know I got a deore (non-shadow) 9 speed RD to work with 105 10-speed shifters at one point though, with an 11-36 cassette.

[oldpotatoe]

Originally Posted by flydhest

Prolly dumb questions, but I haven't had a Shimano equipped bike in close to 20 years.

We bought a used bike on our trip to CO so we could have a bike out there for my wife to ride. (Ever since my wife and I got serious, I have kept a Serotta CSi in my mother-in-law's basement). The hills are tough for flatlanders, and my wife doesn't ride more than 2000 miles a year, so we got a triple (mix of 105 and Sora). it is a triple 9-speed. The cassette is a 12-25. For those familiar with Ft. Collins, she did Maniac and was good with it, but if we wanted to do all the dams along the reservoir in one ride, a little lower gearing would be useful, at least mentally. We only get to CO 2 or 3 times a year, and it usually takes half or more of our time there to get used to altitude and climbing, so an even smaller gear is sought.

I have nosed around online for Shimano 9-speed cassettes, and it seems the ones that go to or above 30 teeth are mountain bike cassettes.

Q: Is that conclusion I came to correct or are there Shimano 9-speed road cassettes that go to 32?
Q: Is there a compatibility concern using 9-speed MTB cassettes on a road bike apart from chain length considerations?

9s shimano/sram MTB and road cogsets are the same spacing. Triple rear der, up to 28-32 should be no problem as long as the chain is proper length.

As for shimano 9s rear ders, all are intercompatible, road or MTB. 10s MTB rear ders are not.

[alterergo]

Originally Posted by oldpotatoe

As for shimano 9s rear ders, all are intercompatible, road or MTB. 10s MTB rear ders are not.

oldpotatoe got it all figured out! That is the beauty of Shimano 9s! Road and MTB Shimano groups use the same pull ratio on shifters and actuation ratio on RD. Cassette the same cog spacing. They use slightly different actuation ratio on FD, but even then most people are able to make road shifters work with mtb FD, it is just a bit more finicky.

To get lower gearing, you can either go:
A. MTB RD (long cage) and cassette on the rear, say 11-32 or 11-34 (I don't think there is -36 Shimano 9s cassette)
B. put a smaller aftermarket granny chainring on the front. I put 24T Salsa on 9s triple crankset, and it works fine with ultegra 9s FD. 24-39 is a bit of jump, but it shifts just fine. Chaincatcher is a must. I use Deda.

I have both A. (commuter and Costco grocery hauler) and B. (road bike). B. is more economical and I think your wife will like it more for the purposes you describe.

[oldpotatoe]

[That is the beauty of Shimano 9s! Road and MTB Shimano groups use the same pull ratio on shifters and actuation ratio on RD./QUOTE]

Too bad it didn't carry over to 10s, not 11s either.

[rkhatibi]

I worked on a friend's Klein Quantum Race here in SF to solve some of the same issues. He had a nice 8sp Shimano Tricolor that we both liked the looks of, but 11-26T and 39/53T was a bit much for the hills around town.

Added an 8sp HG51 11-30T cassette and 9sp silver RD-M591 long cage RD. Worked perfectly with his existing 8sp shifters. Should be the same with 9spd as the pull didn't change.