b_dubz

Hey all,
I'm building up a sweet bike and unfortunately found (the hard way) the Shimano 600 front derailleur I have has a 1" clamp size whereas the seat tube on my frame is 1 1/8". Bummer. I was looking around online and it doesn't seem like these were made with 1 1/8" clamps. Does anyone know if they were, or how to solve this issue?

Also, I was able to find a Shimano part (SM-AD11) designed to convert a braze-on FD to a clamp. I'm wondering if this same or similar part can be used to convert a 1" clamp to 1 1/8" clamp. Thoughts?

Your input is appreciated-

Cheers.

ThermionicScott 

Most 600 front derailleurs were 28.6mm (1-1/8") clamp -- perhaps your seat tube is actually 31.8mm?

bobotech

Just use a derailleur with a 31.8 clamp or any braze-on road front derailleur with a 31.8 braze-on clamp. Any good bike shop should have braze-on adapters in various sizes.

Kimmo 

Solution:

FastJake

I think they actually made that FD in a 31.8mm, but yeah the easiest solution is a braze-on FD with a 31.8 clamp.

HillRider

Yes, in those days Shimano made clamp-on front derailleurs only in 28.6 mm and 31.8 mm clamp sizes. The one size they didn't make as a stock item was 34.9 mm and you had to use a braze-on derailleur and an adapter clamp.

Shimano did make a special run of 34.9 mm clamp-on 8-speed 105 and RX-100 front derailleurs for Trek in the early 1990's. I was able to get it as a special order item through my LBS (who was a Trek dealer) for my 1996 Litespeed.

b_dubz

How embarrassing - I double checked the seat tube and measured it to be 1 1/4" (31.8mm)...and the clamp is 1 1/8" (28.6mm). Argh.

So the problem of not fitting is still there. I'm still wondering if the derailleurs can be detached from the clamp and re-attached to a different size clamp (SM-AD11 at 31.8mm).

Or hell - maybe I'll just pick up a new Ultegra FD...

bobotech

If the derailleur is a braze-on derailleur with no clamp, then yes, that derailleur can be attached to the SM-AD11 braze-on clamp adapter. If the derailleur is a standard clamp-on derailleur, then there no, there is no way you will be able to attach it to a braze-on clamp adapter since your derailleur is NOT a braze-on derailleur. If your derailleur clamp is too small for your seat post, the only solution is to acquire a different derailleur. If your derailleur clamp is too large for your seat post, you can shim it down.

HillRider

Bobotech is correct that Shimano front derailleurs with built in clamps cannot have the clamp size changed or be converted to a braze-on type. Shimano braze-on front derailleurs can be attached to whatever size adapter you need.

Some Campy fd's could be converted from braze-on to clamp-on and back but the conversion parts were priced to make buying a complete new derailleur about as attractive.

Kimmo 

Say you acquired a busted 600 FD with the 31.8 clamp, it would be possible to swap the mechanism onto the other clamp, since it's just held on with circlips.

But I wouldn't recommend it. The last Shimano FD I reassembled was such a hair-tearing exercise I did a happy dance when I succeeded... that little spring is damn strong, and you have precious little purchase.

b_dubz

THANKS for all of your responses.

Now the question is - I have a Shimano 600 friction FD lever. Looking at the Shimano website for the Ultegra FD (https://bike.shimano.com/publish/cont...-.fd_road.html), the FD-6700-G-B features dual SIS index shifting. So, is a friction lever compatible with an index FD?

Thanks again.

bobotech

Friction works with everything. Indexing means that the derailleurs have the proper cable pull and ratio to match their respective shifters but its a moot issue when it comes to using a friction shifter since a friction shifter can shift anything pretty much.

b_dubz

Fantastic. So that explains why older DuraAce shifters typically don't work with other older Shimano derailleurs - because the pulls and ratios were different (from what I gather on other forums).

One more question - The wheelset I found (600 hub with hyperglide cogs) has a cassette with 8 cogs, and the RD shifter I have (purchased as part of a group, separate from the wheelset) has 7 indexes. Can I just assume that only 7 of the 8 cogs will be in use? Or will this be another issue?

Obviously this is my first bike build, and I really appreciate the help!

bobotech

Yes as to the rear Dura Ace derailleurs. For the most part, most all modern Shimano rear derailleurs will index fine with any Shimano or compatible indexed shifter. In otherwords, you can use a 9 speed rear shifter with any common Shimano rear derailleur that is index capable except for the 7400 series Dura Ace and newer 10 speed Dyna Sys stuff. If you are doing friction, anything goes.

So your rear wheel has 8 cogs and the rear shifter you have only has 7 speeds? You can use 7 of the 8 cogs with careful use of the limit screws. I would lock out the smallest cog on the cassette.

Ronno6

Does yoiur shifter 'click" 7 times? If so, than it IS an 8 speed shifter. If it is a 7 speed, it will only click 6 times. In either case, you are fine with the 8 speed cassette. The spacing is the same whether it is 7 or 8 speed.

b_dubz

Great question - I'm 90% certain that I gave that some thought and counted '1' before the first click. But now that you bring it up, I'm second guessing myself. I'll double check when I get home from work.

I'll go ahead and try to set it up locking out the smallest cog. It'd be a lot easier to adjust if I had a proper work stand...it seems I'll have to rig something up to keep the rear wheel off the ground while making the adjustments. Woo-hoo.

Kimmo 

No, it's not, unless it's Campy, who use 5.0mm for both. Shimano uses 5.0mm for 7s and 4.8mm for 8s.

Close enough to get it to work, but it won't be perfect. Alternate 'hubbub' cable clamping method should improve it, I think.

It'll shift all eight cogs if you do it the other way; you don't need a click for the biggest cog... you can just pull the lever past the last click.

Anyway, locking out the small cog would likely result in an overshift to the second-smallest cog, because shifters generally let out more cable for the last click to help the RD make it onto the smallest cog; the limit screw is what holds the RD in place for that one.

Ronno6

Geez, right you are! I stand corrected. Can't believe I've labored under that supposition all these years. Thanks!

b_dubz

Wow you guys seem on point. So, here's the deal. The 600 group I got came with a FD (wrong size), RD, 7 cogs + lock ring + spacers, brakes, shifters, etc. The wheel set has a rear hub that has 8 cogs. The hub/cassette body is also threaded on the outside (last 1/2 inch or so). Im thinking I can use the 7 cogs w/ included spacers (assuming 5mm) to match the 7 speed shifter, then thread a track lock ring on the end. I think there would be some fine tuning to do with the RD, would that work alright? OR...buy a spacer (or 2) to stick between the hub (spokes) and largest cog effectively pushing the cogs outward allowing me to use the 'externally threaded' lockring?

b_dubz

And what's hubbub cable clamping?