Bicycle Mechanics - Shimano 8 Speed Indexing: Will This Work?

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.



PDA
ColonelJLloyd
09-29-11, 08:19 AM
I cross posted this in the C&V sub forum, but I suppose this question really belongs here.

I'm curious if this will index. I'm going to install the Shimano 8sp bar end shifters (thanks, Brock!) regardless because if it doesn't index to my satisfaction I'll just use the friction setting. But here's what I have.


Shimano 8sp bar end shifters
Shimano 8sp HG cassette
Shimano 130mm freehub
Shimano RD-MT60 (http://www.velobase.com/ViewComponent.aspx?ID=3f73f16c-1a7e-46c5-ab73-f21755e71b08&Enum=108) long cage deraileur (ca. 1988; meant to index with 6sp shifters)
I suppose at the heart of the matter is this: Is the design of the MT60 similar enough to a modern 8sp compatible RD that the cable pull from the 8sp shifters will place it in the right spot over each cog?

The spacing on a 6sp freewheel is something like 5.5mm and is 4.8mm on an 8sp, but all that is related to the pull of the shifter itself, correct?

http://gallery.me.com/justinhughes/100185/Feb062011_1055/web.jpg?ver=12970503930001

http://farm4.static.flickr.com/3494/3911825695_bd8fcc876e.jpg

CACycling
09-29-11, 09:11 AM
...but all that is related to the pull of the shifter itself, correct?[/IMG]
Correct. With very few exceptions, Shimano RDs of the indexed era have the same pull ratios and the indexing is determined by the shifter.
well biked
09-29-11, 09:16 AM
Correct. With very few exceptions, Shimano RDs of the indexed era have the same pull ratios and the indexing is determined by the shifter.

Right, and the exceptions in regard to a different cable pull ratio of Shimano rear derailleurs from the indexing era are eight speed and earlier Dura Ace and the brand new Dyna Sys "10 speed" mountain bike stuff. All other index-compatilbe Shimano rear derailleurs use the same cable pull ratio.

ColonelJLloyd
09-29-11, 09:24 AM
So, well biked, are you saying that the RD-MT60's pull ratio won't jive with the 8sp shifters?
Puget Pounder
09-29-11, 10:16 AM
So, well biked, are you saying that the RD-MT60's pull ratio won't jive with the 8sp shifters?

He's saying it will.

DA 8 speed and the 10s MTB stuff do not have the same pull ratio as the rest of the lineup. You are in the clear.