 By richclydesdale on 8/26/2007 Hello! I was wondering if it was possible to wind up with a mis-matched shifter and derailer. Let me explain: I have a Mongoose XR-200 (I know, I know, but if it weren't for a cheap bike, I wouldn't have one at all), it came with this funky Sram long-cage plastic rear derailer and Sram grip-shift shifters. The inevitable happened, the plastic gave out around 200 miles. Thanks to Mongoose's fearless warranty, they sent me a Shimano TZ-30. I followed the instructions carefully to adjust it. No matter what I do, I can't get it to put the chain on all 7 sprockets. It will ALWAYS miss two of them. I can adjust it so that it skips 2, 4 and 6 or just 4 and 6. I can force the shifter to go between its natural detents and then I can get all 7 sprockets. What it seems like to me is that the derailer needs a different shifter that will hold it in the right spot. Am I barking up the right tree here? |
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Rear Derailuer/Shifter Combo Bad? |
MikeG says:
 It sounds like it may be a confusion between two different shifting ratios. I know that I had to get a SRAM derailleur for my new SRAM shifters. When shopping, I knew that it needed a 1:1 ratio, whereas shimano uses a 2:1 ratio. It sounds like your derailleur and shifter don't share the same ratio. I thought Grip shifters have a 2:1 ratio, because my old bike had them with a shimano derailleur too. I *think* I have that right. Hopefully someone else can verify this? MikeG Either riding or Thinking of Riding... The madness of MTB, I love it! |
MikeG says:
There are different SRAM Twist style shifters, some have 1:1 ratio, and some have 2:1. Your shifter is giving twice the movement that your derailleur is expecting. You have to specify the exact type of shifter you have. Sometimes the easiest way to find info is to *shop* for your stuff on ebay to find out more about it. Strange sounding, but it works! MikeG Either riding or Thinking of Riding... The madness of MTB, I love it! |
richclydesdale says:
Thanks MikeG! I knew I wasn't going crazy! You know, the funny thing is that Mongoose sent me the the new derailluer (Shimano TZ-30) to replace that monster-mega caged plastic SRAM derailluer...maybe they didn't know that the shifter ratio is different... |
richclydesdale says:
UPDATE: I called Mongoose with the intention of getting a little more info on adjustment, shifter replacements, etc., and they are sending me a new derailluer and shifter...go figure! |
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