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Is it possible to use any STI systems that are designed for 8 or 9 speed rear derraileurs with an older 7-speed system? If I want STI, do I have to have an 8 or 9 speed rear derraileurs?
(sorry for the spelling of the shifter-thingys. not going to look it up, but you know)
I am not a bike mechanic, but here is what I have on a beater Cannondale. I have Campy Athena 9 speed derailleur and ergo shifters. This is used with an 8 speed freewheel in the back. I believe when the shop did this they put a spacer on the freewheel to make up for the difference.
If you have the 9 speed STI set up, you might be better off and order a cheap rear wheel from Nashbar or someone like that. You can get a rear wheel with a 105 9 speed cassette hub for less than a 100, possibly close to 50.00. You'll save yourself some hassle and have access to the 9 speed. I am probably going to do exactly that and order an inexpensive rear wheel with a cassette for the beater.
Woops, I misread your original post. It appears that you have a 7 speed rear derailleur. It is likely that it would not be compatible with the 8/9 speed STI levers. What type of hub/cassette do you have?
You could find a compatible derailleur for cheap.
I'd better defer to a mechanic.
ok i have zero road bike knowledge, but from mt bikes:
shift indexing is done in the shifter, the derailleur doesn't know if it's a 7, 8 or 9 speed as far as the number of clicks. there might be funniness with cable throw amounts/leverage ratios and you might have to fiddle with limit screws, but most likely you'll get something that works just fine. maybe one shift might be a little off, btu if you're asking if this can be done, you're doing it because you want to save money, so give it a shot.
over the years i've run many different combos of shifter and derailleur with minimal problems. some people will probably turn their nose up at it, but you will most likely be fine, and you won't know unless you bolt it on and try.
Shimano 600 cassette with Ultegra hub.
Thing is, I'm not sure if I can actully fit a bigger cassette between the stays, and they're carbon so they're not getting bent.
My impression is like Bills, I think. I feel like the indexing is in the shifter, so maybe I'd have the ability to shift in to a phantom gear or something. But, if the limit screws are set ok, it seems like the shift lever would work just fine for the 7 gears I need it to.
It may be an expensive lesson to learn, though, if I buy the STI from somwhere and it doesn't work.
i didn't realize you also had a 7spd cassette. go reading.
this is a trickier ghetto rig than adapting a 7spd derailleur to an 8spd rest of the bike because the indexing is in the shifter, so you're going to have 9spd shifting with only 7 gears.
youll basically have to bring one of your limit screws so far in that you're hitting it one gear early. if you screw up and try to push past it, it won't be the end of the world, but it won't be great.
so you want to run nine speed shifters with a 7 speed cassette? If so you will likely get poor results. 7 speed cassettes are spaced (ie the spacing between the cogs is different) differently from 9 speed so it won't work well. if you're talking about using a 7 speed derailluer on a 9 speed you'll likely run into problem with its range so it probably won't work well.
You could run 8 speed shifters and then just set in the limit screw. 7 and 8 have the same spacing.
NOW we're talking!!Quote:
Originally posted by UTdave
You could run 8 speed shifters and then just set in the limit screw. 7 and 8 have the same spacing.
Everyone is right. I have a 7 speed cassette, and I can't change it because I have stays that don't fit the longer rear hubs. So, I'm stuck with my 7-speed cassette.
The spacing is exactly the problem I didn't know I would have, but knowing the 8 and 7 speed spacing is the same, I may see the light.
If I can use my existing 600 derailluer, I could get an 8-speed STI shifter that would work (it would have an extra shift at one end that just wouldn't do anything).
If this doesnt' work, I could get a new 8 spd derailluer and then IT would have an extra shift on one end that didn't do anything.
If this doesn't work, I've wasted several hours and a few hundy bucks.
the deraileur is really not the issue here. i currently have a ghetto rigged beater that is using 7sp STI (mountain) shifters and a 7sp derailleur on a 9sp cassette. i have full use of #1 cog and #9 cog, but it is sketchy inbetween. the derailleur, however, does span the range no problem.
i think its a little ambitious to spend $$ on nice new STI shifters only to use them on a ghetto rig. the point of ghetto rigging is not buying stuff. if your going to drop a couple hund on shifters, you may as well get the new wheel.
as far as i know, rear wheel spacing has not changed for a few millenia. to fit the newer larger 9sp cassetes on the freehub, the distance between spoke flanges was reduced making more dish on the wheel. i don't think they changed spacing on frames.
I think you already have the answer you're loking for; so, other than trying to coble together an STI set-up on a downtube shifter bike, are you enjoying the Allez?
It's awesome. I put a solid 200 miles a week on it, or more, and it's been great. I'm getting a new stem-- is your friend a big dood?
I rode it from Cleveland to Marietta, OH in a 200 mile endurance adventure race last weekend. I was in the saddle for 13 hours overall. Lots of complements from Colnago and Serrota and other fancy-pants riders, which makes me smile.
I'm thrilled to hear that you are enjoying the bike; I'll pass it along to my friend. Is he big? No, not at all, he's 5' 8" maybe 5' 9".Quote:
Originally posted by Cornholio
It's awesome. ... is your friend a big dood?
Don't bother spending money trying to get STI. You'll spend way too much and it'll never work right.
The best option is to put on barcons (bar-end shifters).
On this page, they have what you need: http://rivendellbicycles.com/webalog...s_derailleurs/
-Downtube cable stops, so you can run cable housing from where your shifters used to be.
-Bar-end shifter mounts, to put your current downtube shifters on the bar ends.
Or if you can root around and find 7-speed barcons, they'll probably be cheap. Ask your local race bike shop if they have any in the parts pile.