Bicycle Mechanics - Shimano 600 SIS Shift levers

Just starting to get into cycling and had a question. I have a mid to late 80's Univega gran rally aluminum frame fully equipped with Shimano 600. I've heard that the down tube SIS shift levers (SL-6208) are notorious for breaking off the tabs inside. Unfortunately when i was taking it apart for the first time and cleaning it, this situation happened to me.

It's a 6 speed rear derailleur (Shimano 600 RD-6208) and apparently they don't make them anymore. I have done some searching around and have found nothing that would work and match up to 6 speed. I kept reading that the levers have two variations, one for steel frames and one for aluminum ones. (please, correct me if I'm wrong) The levers mount directly into the frame and thus far, I have yet to figure out how to get the bases out. Checked some sites and Ebay and all that I could find was clamp on levers.

At this point, I'm not really sure how to proceed. Ive read on other forums that the general recommendation was to replace them. I read on one forum that a good rear derailleur to replace them with is the Shimano Sora but would really appreciate some advice. If at all possible, I'd like to keep the original hardware on the bike, but I realize that that may not be feasible.

Went down to my local bike shop and was told that Dura-ace makes a 6 speed down-tube shift lever but they are quite expensive. Would love some suggestions on how to proceed.

I"m a bit confused. Why do you feel that it's necessary to replace the rear derailleur?


Btw, the Classic & Vintage forum is another good place to ask about older stuff.

I'm just starting to learn about the detailed workings of derailleurs. I was under the impression that you would have to have a shift lever that has 6 positions for the 6 gears in the back. Would a lever that was made for a 7 speed rear derailleur work on this 6 speed?

The number of index positions at the shifter must match or exceed the number of cogs at the rear in order to use them all. But the rear derailleur (RD) has nothing to do with that. All indexing happens at the shifter.

You do have to match shifter pull ratio between shifter and RD, but with a few rare exceptions (*cough*8-speed Dura-Ace*cough*) all Shimano road components use the same ratio.

Here (http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3946) is an interesting read about the topic of compatibility at the rear.

Ok, I read through the article and it did explain a lot of things for me. Still had a couple of questions though.

DMF, If the number of index positions at the shifter must match or exceed the number of cogs at the rear in order to use them all. If the shift lever has more positions than I have cogs in the back will I just be relying on the high/low adjustment on the RD to stop me from shifting into gears that are not there?

What about derailleur range of motion? With having more cogs on the cassette, will the derailleur have the range of motion to shift into all of the available gears?

Yes.

Generally, yes, though some very old RDs might not handle more recent stack heights.

now that we have that settled what exactly is broken? is something on the lever it's self broken or on the parts that go over the bosses? this things should just pull off but you may need a bit of pressure

the posting does not say how many speeds these are but they look like 6speed.

The difference between the "aluminum frame" and "steel frame" SIS shifters is the radius of the plastic mounting piece. If that's not broken on your shifters, you could simply swap those into replacements to make it work.

Otherwise, any friction shifters will work fine on those bosses if you can live without indexing.

now that we have that settled what exactly is broken? is something on the lever it's self broken or on the parts that go over the bosses? this things should just pull off but you may need a bit of pressure

The damage is actually to the part that holds the levers to the bosses and I can only assume that those tabs are important. (see picture below)

A.Winthrop

Thanks for all of the parts suggestions. I think that I might just try out a 7 speed workaround. Might be fun.
However, I have an aluminum frame. Will they work on the mounts that are in the picture below?

http://i170.photobucket.com/albums/u278/dushus1/ShiftLever.jpg
http://i170.photobucket.com/albums/u278/dushus1/LeverMount.jpg

You can use 7-spd levers with your bike. Just put those concave washer pieces back and you're fine. Be sure to tighten the fixing-screw tight. It's the loose screws and wiggling that leads to breaking the shifter pieces like you've shown.