# 9 or 10 speed



## switchbacktrog (May 10, 2013)

Is any one using 10 speed on their tandems or is it not robust enough? I would like a clutch mech on my next build and they only seem to come with 10 speed.


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## ds2199 (Sep 16, 2008)

switchbacktrog said:


> Is any one using 10 speed on their tandems or is it not robust enough? I would like a clutch mech on my next build and they only seem to come with 10 speed.


We have been using 10 speed for the past 3-4 years. Two different tandems. No issues. We are a lightish team (270 lbs) and put a lot of miles on the mtb tandems.

Let me know if you have any specific questions.


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## switchbacktrog (May 10, 2013)

I've had some local UK feedback to suggest using a Deore cassette as lighter ones tend to collapse.


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## Dr. Paul Proteus (Sep 26, 2004)

We've been running 10-speed as well. Originally with an XT cassette, then the SRAM X0 (pinned) & XX cassettes. We're also a lightish team (270-280, depending upon our recent beer & ice cream intake), but also put on a good amount of miles in less than ideal, wet German weather.


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## TandemNut (Mar 12, 2004)

I'm not sure there's any reason not to use the clutch-style rear derailleur with a 9 speed cassette. The derailleur is not indexed; the shifter is.


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## TigWorld (Feb 8, 2010)

Pull ratio is different on Shimano 10 spd mtb RD. If you want 9 spd clutched RD then you have to use a shimano clutch RD in conjunction with a SRAM 9 spd (1:1) shifter. You may need a small 5mm spacer at the derailleur cable clamp if you shifting doesn't index perfectly.


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## switchbacktrog (May 10, 2013)

TigWorld said:


> Pull ratio is different on Shimano 10 spd mtb RD. If you want 9 spd clutched RD then you have to use a shimano clutch RD in conjunction with a SRAM 9 spd (1:1) shifter. You may need a small 5mm spacer at the derailleur cable clamp if you shifting doesn't index perfectly.


So what you're saying is that................The pull ratio on the 10 speed Shimano is 1:1, and that you need the Sram 1:1 shifter to operate a Shimano RD. I thought that ALL Shimano RD's were 2:1 pull ratio.

Either I've completely misunderstood your post, or It's wrong information..............

EDIT: After seeing the post below, and doing some Googling it, does appear that TigWorld is correct about the pull ratio's and compatibilities.........my apologies.


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## shiggy (Dec 19, 1998)

switchbacktrog said:


> So what you're saying is that................The pull ratio on the 10 speed Shimano is 1:1, and that you need the Sram 1:1 shifter to operate a Shimano RD. I thought that ALL Shimano RD's were 2:1 pull ratio.
> 
> Either I've completely misunderstood your post, or It's wrong information..............


Shimano MTB 10-sp uses a different pull ratio and is not compatible with any other Shimano derailleur or shifter.


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## TandemNut (Mar 12, 2004)

SRAM 9 and 10 speed derailleurs both use 1:1 pull ratios, and Shimano uses 2:1. So I don't see why you couldn't use a 10 speed SRAM Type 2 rear derailleur with a 9 speed SRAM shifter, unless something else is going on. We don't use Shimano stuff unless specifically requested by the customer, so I don't know if the 10 speed Shimano stuff is different, but if it's not 2:1 like the rest of Shimano, that's news to me.


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## shiggy (Dec 19, 1998)

TandemNut said:


> SRAM 9 and 10 speed derailleurs both use 1:1 pull ratios, and Shimano uses 2:1. So I don't see why you couldn't use a 10 speed SRAM Type 2 rear derailleur with a 9 speed SRAM shifter, unless something else is going on. We don't use Shimano stuff unless specifically requested by the customer, so I don't know if the 10 speed Shimano stuff is different, but if it's not 2:1 like the rest of Shimano, that's news to me.


Actually, no. SRAM 9-sp and 10-sp RDs use different cable pull ratios. Can not use a 9-sp shifter with a 10-sp RD or vice versa.

The 1:1 ratio (and the Shimano 2:1) is a marketing approximation, not a precise description.

All of this has been discussed ad nauseam over several years on the drivetrain board


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## patineto (Oct 28, 2005)

We have 9speed shimano XTR/XT in our two tandems (one "Road" one mountain), but sometimes I do wonder about 10 cogsets do to the extra 2teeth in the back for extra climbing, plus you can install the "Mega range" 40 and 42t in the back..


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## TandemNut (Mar 12, 2004)

I stand corrected on this. We had built up a 9 speed bike with the 10 speed T2 derailleur, and it seemed to shift fine, but a discussion with the SRAM tech folks confirms what's stated above. SRAM seems to be following Shi*mano in the non-compatibility direction nowadays.


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