Shifter/derailleur/cassette question
05-31-20, 04:44 PM
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Shifter/derailleur/cassette question
I have a Specialized Hard Rock from the late eighties, it's got the original Suntour 3040 rear derailleur and shifter. The cassette is a 6-speed, there are three chainwheels on the front. I want to replace the derailleur, the only 6-speeds I can find are Shimano Tourneys.
So...if I install the Shimano tourney with a Shimano shifter, will it index with the original 6-speed cassette? HELP!
So...if I install the Shimano tourney with a Shimano shifter, will it index with the original 6-speed cassette? HELP!
05-31-20, 05:18 PM
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05-31-20, 05:21 PM
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As I recall Sun Tour had a wider small->2nd cog spacing from the others, so their shifters pulled an uneven amount of cable for the first shift. You MIGHT be able to finagle it to shift acceptably with a Shimano shifter/derailleur combination. What do you hope to accomplish with the derailleur swap, assuming the derailleur is not worn/broken?
05-31-20, 05:36 PM
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You are likely going to have to switch everything as Shimano and Sun Tour indexing aren't compatible. If you are willing to use friction shifting nearly any components will work together.
05-31-20, 05:38 PM
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If you have a friction shifter, you can use just about anything, but if it’s indexed, you have to stay ‘in the family’ so to speak.
06-01-20, 01:33 PM
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As I recall Sun Tour had a wider small->2nd cog spacing from the others, so their shifters pulled an uneven amount of cable for the first shift. You MIGHT be able to finagle it to shift acceptably with a Shimano shifter/derailleur combination. What do you hope to accomplish with the derailleur swap, assuming the derailleur is not worn/broken?
06-01-20, 01:40 PM
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Thanks for the helpful replies, I really appreciate all the good info. I removed the derailleur and was able to straighten it. I re-assembled everything and set it all up. It was fine except when in the highest gear (smallest cog) if I really stood on the pedals the chain would try to climb the next higher cog and then fall back. The cassette seemed to not be on the same plane as the front chainwheels. I repositioned the rear axle and now the bike shifts great, runs quiet. Next I need to re-cable it.
