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I'm getting more confused about going from 7 to 9 speeds(9 posts)

I'm getting more confused about going from 7 to 9 speedsteacherguy
Mar 23, 2002 5:15 AM
First I'd like to say thanx to the guys that answered and gave their opinions on if I can change from 7 or 8 speed to use 9 gears. I already knew I would have to use a new rear derailer and chain but now someone tells me I need to use a different crank and front derailer. Is this true? Will a nine speed cassette work on a hub that was eight speed? Thanx.

P.S. This site is awesome!
re: more answerscyclopathic
Mar 23, 2002 5:35 AM
No, you can still use your old deraileurs and crank. Front shifting will be marginally better if you replace front chainrings and deraileur.

You absolutely need only 3 things: cassette, 9sp chain and right shifter. I've run mutliple 8/9sp combos also helped friends to convert their drivetrains. 9sp derailuers are the mith Shimano marketing came up with to sell them. 9sp chainrings are marginally wider (.5mm). I was never able to verify it (and I really tried!)

Some old Shimano freehubs may need to be modified here's a link to Sheldon Brown page which talks about it (and 7 to 8 to 9 conversion in general). I've never had to grind freehub

hope this helps,

re: Correct,.......exceptRusty Coggs
Mar 23, 2002 7:11 AM
His current rear derailer has to be shimano index capable and NOT pre 9 speed DA, and the front derailer has to be STI compatible,meaning road and with the arm that the cable attaches to perpindicular to the derailer cage.
OK, this is what I got to work with. . .teacherguy
Mar 23, 2002 1:36 PM
105 Seven speed Index derailer, Front 105 deraler (The left lever was friction shift), 105 double crank. All from a Cannondale R600 Not sure of the date. I have a road wheel with an 8 speed sprocket that I could use too. I'd like to put on ultegra STI shifters or is the 105 good enough. I'd also consider the ultegra rear derailer if it was worth while to do so. Thanx, teacherguy
you'd be finecyclopathic
Mar 23, 2002 4:03 PM
your derailleurs should work with new shifters. Get shifters, new chain and cass. 8sp freehubs are 9sp compatible you can use 8sp rear without mods.

here's another Sheldon article where he covers some of "compatibility" issues take a look
re: Correct,.......exceptcyclopathic
Mar 23, 2002 3:52 PM
this is only true for pre-'97 DA rear der which used shorter cable pull. All other Shimano rear Der use "standard" 1:2 pull. If you think I'a wrong that's what Sheldon says about it

anyways this is mood point 105 is not DA and is not as old
re: Read it againRusty Coggs
Mar 24, 2002 6:43 AM
That's exactly what I said.....
re: Read it againcyclopathic
Mar 24, 2002 8:01 AM
you're right I missed it on first read.. do we speak the same language now? ;)
Double or triple crank?Spoke Wrench
Mar 24, 2002 5:33 AM
I did an 8 to 9 conversion on a tandem. I could get the front shifting to work on the work stand, but it was too marginal to work reliably on the road, the correct, slightly narrower, 9-speed front derailleur fixed it. I don't think that's necessary on a double. The rear derailleur guides the chain by a roller in the center of the chain so the width of the rear derailleur cage doesn't matter.

I've also converted several 7 speed cassette hubs to 8/9 speed. If the OLD (over locknut dimension) is correct (130mm for a road hub), all you have to do is remove the axle, replace the freehub body using a 10mm allen wrench, and redish the hub.