cdwhite

Hi,

I recently got a 1985 Univega Gran Rally (Shimano 600 components) with a dysfunctional rear wheel/cassette but in otherwise great condition. The original RD was used with the original 7-speed cassette/shifters. I'm wondering if it will be compatible with a new 9-speed cassette and 9-speed downtube shifters. I don't plan on getting a cassette where the largest cog has more teeth than the largest cog on the original (23T), but am not quite sure if the derailleur will be able to move enough laterally to be able to accommodate a 9-speed cassette.

Any help would be much appreciated!

thanks

Al1943

Try it and see. Pretty good odds it will work, if not it will be an easy upgrade.
You'll need a 9-speed chain.

FastJake

1985? I think that was pre-indexing for the 600 group. So it may or may not work. Doesn't hurt to try it and see. A more modern replacement RD will not be expensive if you need to go that route.

cdwhite

Indeed, the original shifters are not indexed, but that shouldn't affect the derailleur should it? Also, I forgot to mention that one of the shifters is broken, and since I need to replace the cassette and shifters anyways, I thought I might as well try to go for 9-speed if it's possible.

oldskoolwrench

Fancy filigree around the "Shimano 600", or is it plain? Either way those DR's won't work because:

1) No floating upper pulley.
2) No adjusting barrel for index adjustment (the Arabesque model has a spring loaded adjusting barrel but it's too short, and the current one uses different threading).

Best bet is to find a Sora or Tiagra that's 9 speed compatible.

coupster

I don't know the Model year but. I've been using the same RD ,branded Shimano600, from a original 7 spd system up to my current 10 spd. When I switched from 8 to 9, I replaced the jockey wheels with an 11 tooth set from Tacx - the top pulley has no float. I've had no issues with it. (wish I could say the same for the rest of my component mix). Currently it is on a 2003 Trek 2300 frame paired with an Ultegra 6600 10 spd brifter, a Tiagra 12-30 cassette and a Sram chain. The drive train is a little noisy on the smaller sprockets, but it shifts just fine.

Borrow a wheel with a 9 spd cassette, install it without the chain, loosen the limit screws and manually move the RD across the cassette. (If you can separate the chain from the RD, it'll be a bit easier.) If it cover all the sprockets, you're probably fine. I don't know about the indexing adjuster, never had an issue with mine.

As a related aside, I just threw a Sram 11-32 cassette on it (borrowed from a friend's new Synapse) and guess what? It worked too. Chain's a little short but it shifted across the entire range without complaint.

FastJake

1) Some people actually don't like Centeron-G, claiming quicker shifting can be achieved without it. I don't mind it, but I once had a 9-speed bike setup with non-floating pulleys and it worked just fine.
2) More of an issue, but not impossible. An adjusting barrel could probably be added somewhere like on the shifter bosses. But since the OP is planning on using DT shifters, it's still an issue.

oldskoolwrench

Really? I was always told that the float compensates for any irregularities in the drive train. That's a good tip to file away; did you just use a lower pulley in its place?

Just caressing a 600 tri color and was noticing the indents on the adjusting barrel; the post Arabesque 600 just has a cable stop on the back. I suppose one could drill it out and try to tap the opening with an adjusting barrel but it seems like a lot of work.

FastJake

They do, but if you're particular about your drivetrain setup it can work well without the floating pulley.

In my case I just had an RD without any pulleys so I used some ancient Shimano pulleys from a crappy derailer pre-indexing.