Bicycle Mechanics - 10 speed to 9 speed conversion for touring

I now have a 10 speed rear cassette with a 12-27 cluster. I would like to use a 9 speed cassette with a 12-34 range for touring.

I know I need to change my RD (now a Shimano Ultegra short cage). Do I also need to change my STI Brifters (now a 10 speed 105 model)?

Can I use a Shiftmate to keep from changing brifters?

Michael

A Shiftmate Model #2 will let you use Shimano 10-speed brifters and any Shimano rd with a Shimano 9-speed cassette.

I'm doing about the same thing using Campy 10-speed Ergo brifters with a Shimano rd and a Shimano 9-speed cassette and it works extremely well.

I am pretty sure that there are aftermarket 11-34t 10 speed shimano spaced cassettes. That would let you change your RD and cassette and leave everything else the same. I think IRD makes some.

EDIT: here (http://www.bikemania.biz/ProductDetails.asp?ProductCode=IRD_WR_Shimano_30963) is one for sale.

EDIT2: here (http://www.interlocracing.com/cassbreakdown.html) are all the cassettes they offer.

Note: I have never actually tried any of these.

I am pretty sure that there are aftermarket 11-34t 10 speed shimano spaced cassettes. That would let you change your RD and cassette and leave everything else the same. I think IRD makes some.

EDIT: here (http://www.bikemania.biz/ProductDetails.asp?ProductCode=IRD_WR_Shimano_30963) is one for sale.

EDIT2: here (http://www.interlocracing.com/cassbreakdown.html) are all the cassettes they offer.

Note: I have never actually tried any of these.

Yes, I could keep a 10 speed chain and my 10 speed brifters. But what RD should I use? A long cage Ultegra or a 9 speed XT?

Michael

Yes, I could keep a 10 speed chain and my 10 speed brifters. But what RD should I use? A long cage Ultegra or a 9 speed XT?
Michael
You will HAVE to use an MTB rear derailleur if you want to go with the 34T big cog. It's not the cage length that eliminates the Ultegra or any other road derailleur, it's the ability of the jockey pulley to clear the large cog.

Shimano says their road rd's are limited to a 27T big cog. Other riders who have tried them report they will nearly always work with a 28 or even a 30T and sometimes with a 32T but nearly never with a 34T.

Will the 9 speed XT MTB rear derailleur shift all 10 gears?

Michael

Will the 9 speed XT MTB rear derailleur shift all 10 gears?

Michael
Yes. The indexing is in the shifters. The rear derailleur just follows orders.

Thanks,

Michael

I don't get why this mod is being done. 10-speed sutff isn't inherently weaker, or less reliable than 9. I mean if you were cocerned about that you'd go to 8, or even 7. Please... explain.

I don't get why this mod is being done. 10-speed sutff isn't inherently weaker, or less reliable than 9. I mean if you were cocerned about that you'd go to 8, or even 7. Please... explain.
The OP was looking to get a much wider range cassette and the widest range 10-speed cassette Shimano makes is 12x27. To get a 32T or 34T big cog he needs to go back to 9-speed to stay with Shimano.

IRD does offer 10-speed cassettes with larger big cogs but a Shimano road rear derailleur probably won't handle it.

IRD does offer 10-speed cassettes with larger big cogs but a Shimano road rear derailleur probably won't handle it.

Yes, but a Shimano mountain derailer should work just fine.