Shimano Gearing Question , Experts please

[Smiley]

Got a client that wants to use 9 speed MTB gearing 12-32 rear cassette BUT loves the hood shape of the new 10 speed grouppo. Can he block out one shift , use an XT rear derailure with 10 speed brifters on a TRIPLE set up. Many thanks as I know some of you have done this. Smiley

[Jeremy]

Got a client that wants to use 9 speed MTB gearing 12-32 rear cassette BUT loves the hood shape of the new 10 speed grouppo. Can he block out one shift , use an XT rear derailure with 10 speed brifters on a TRIPLE set up. Many thanks as I know some of you have done this. Smiley

Smiley,

The center to center cog spacing of a stock 9sp cassette is wider than that of the 10sp cassette. So, the clicks will not line up properly with each cog. An XTR (XT, LX, etc...) rear derailleur will work properly with the 10sp shifter and a 10sp chain, as long as you have 10sp spacing at the cassette. There is a relatively inexpensive and simple way to do what you want. The cheaper cassettes like the Sram PG970 or the Shimano HG50 don't use an alloy carrier. These cassettes are a group of individual cogs held togeter by 3 riveted or threaded pins. These pins can be removed and the cassette can be re-spaced with 10sp spacers. The stack does not need to be pinned together again. You will need to put a 3mm spacer behind the modified cassette so that it fits properly on the cassette body. You won't need to do anything to the shifter because the low position set screw will prevent the shifter from moving to the last click. I know that these cassettes are available in an 11-32, I don't think that a 12-32 is available. Another option is the J-tek shiftmate. I havn't used one of these, but many on the forum have and seem to like them. A third option is to buy a custom 12-32 10sp cassette from Cycle-Dynamics. The difference between 9sp and 10sp is the spacing at the shifter and the cassette. An MTB rear derailleur WILL shift a 10sp Shimano system perfectly.

Jeremy

[Smiley]

Thanks Jeremy , So if this client gets a 10 speed rear cassesste and uses a TRIPLE were good for the MTB long cage rear derail. and using the 10 speed brifters ? No need to go to 9 speed then right ? Thanks Smiley

[Jeremy]

Smiley,

10sp cassette, 3X10sp brifters, 10sp chain, MTB long cage derailleur, triple crankset.

Jeremy

[Smiley]

Graci Jeremy

[Marcusaurelius]

Got a client that wants to use 9 speed MTB gearing 12-32 rear cassette BUT loves the hood shape of the new 10 speed grouppo. Can he block out one shift , use an XT rear derailure with 10 speed brifters on a TRIPLE set up. Many thanks as I know some of you have done this. Smiley

Well it can be done with a jtek shiftmate adapter. I used one for a couple of months with my 10 speed campagnolo shifters and ultegra rear derailleur and cassette and it worked very well.

[Ray]

Well it can be done with a jtek shiftmate adapter. I used one for a couple of months with my 10 speed campagnolo shifters and ultegra rear derailleur and cassette and it worked very well.
Check the jtek site - I know that Campy 10 to Shimano 9 works well but not sure if they have one for Shimano 10 to Shimano 9 yet. If they do, this is a simpler solution that rebuilding the cassette.

-Ray

[Dave]

There are shimano users who swear that the 10 speed shifter will operate properly with a 9-speed cassette, merely by moving the cable to the top side of the clamp bolt, rather than below it. I have no personal experience with this (I'm a Campy-only guy).

If that doesn't work then the J-tek shiftmate model #2 would be a better option than trying to respace cassettes.

You can't use 10 speed spacers with 9 speed cogs because the cog thickness is also different (1.6mm /1.78mm). The 10 speed spacers are: 3.95-1.6 = 2.35mm. Combine a 2.35mm spacer with a 1.78mm cog and you get 4.12mm, which just happens to be Campy 10 spacing! It's certainly closer than 4.32mm 9 speed spacing, but the correct spacer would need to be 2.17mm.

[Jeremy]

Cycle-Dynamics makes Shimano 10sp cogs in 1 tooth increments from 11T-34T (except 29,31 and 33). You can specify whatever cogs you want and they are spaced properly for 10sp. It seems that the simplest thing to do is to buy a 10sp cassette in the gearing that he wants. They cost a little more than an XTR 9sp stack but you can replace individual cogs if necessary.

Dave is right about the stock 10sp spacers. You need 2.15mm (approx) spacers to respace a 9sp stack properly. I don't know why, but I have a bunch of them.

The outer cable routing is an interesting idea. This was the fix for using older Dura-Ace shifters (pre 1994 I think) with a newer rear derailleur.

Jeremy

[BarryG]

There are shimano users who swear that the 10 speed shifter will operate properly with a 9-speed cassette, merely by moving the cable to the top side of the clamp bolt, rather than below it. I have no personal experience with this (I'm a Campy-only guy).
Yeah, an account (http://forums.thepaceline.net/showthread.php?t=8009&highlight=ultegra) of my own clueless rediscovery of this technique.