I have an old 80's type Specialized Sirrus road bike frame. Nice frame, lugged, good shape.

I'm building it up from nothing but a frame, fork and headset.

The plan is build it buying parts each payday, as much as possible from 6600 series Ultegra.

I've acquired the following parts so far:

• SHIMANO ULTEGRA 6500 30x42x52 172.5mm crankset.
• Shimano BB-7703 Dura Ace Bottom Bracket, 118mm Triple, 68mm.
• SHIMANO LX RD-M580 REAR DERAILLEUR.
• SHIMANO HOUSING STOP.
• Shimano Ultegra FD-6603 Triple Frt Derailleur 34.9.
• SHIMANO ULTEGRA FD6600/3 CLAMP ADAPTER 28.6mm.

Please note the last two items...

I bought the FD and an adapter, since it's a 28.6mm downtube. They showed up todat in the mail and I scampered of to the bike shed to put them on to make sure it all fit. It didn't.


The clamp adapter was way too thin and even after tightening the clamp would spin freely.

So, I defer to the experts, instead of my usual amateur hacks, I'm seeking advice on how amend this and in a good looking manner.

I figure either the shim is either too small or the seat tube is non-standard. I've not measured it.

So should I try another shim from another vendor? Build my own from sheet metal? Or send back the FD and get the right size. Maybe a braze-on model and buy a proper size braze-on replacement clamp?

???

You definitely need to measure the seat tube. If it is 28.6, you COULD get a different shim, but if I were building up one, I would get the right size FD. Lot less trouble in the long run.

The adapter was probably made to fit a 31.8 not a 34.9 clamp.

Fit aside, you may not be happy combining the 6600 series FD with the 6500 series crank. But then again, you may...

Why a MTB RD? You planning to use a huge cassette? Even with the triple?

I think the 6603 fd is designed for a 39t middle ring. It will not shift past your 42t ring. Also, I can't remember for sure but I think the Dura Ace octalink bb may have a different spline than the Ultegra and others.

Thanks for the pointers. Man there's a lot of stuff I don't know.

I'll need to reconsider the FD choice. The DA BB is Octalink1 as are the cranks, I thought that was the same on both. I am going to put a larger sprocket say 32 on the back. I'm not making a road bike as much as a country bike - riv-bike style. If I decide the big sprocket is unneeded I can upgrade the Altus on my Globe with it maybe.

Yup, the 6603 derailler will not shift properly on a 52/42/30 crankset. The 105 5603 front derailler will, however.

Found this old thread: https://www.bikeforums.net/road-cycling/136183-shimano-ultegra-front-derailleurs.html

No doubt about it.

Thanks guys.

I replied to that thread when I was building up my LOOK (seems like ages ago). At the time, the only available option for a triple front derailler for a 52/42/30 crank was a 9 speed 105 (Ultegra 9 speed front deraillers had gone away with 10 speed coming out). I eventually switched out the 9 speed derailler for a 105 10 speed which works quite nice. It would work even better with a 53/42/30 but I haven't been able to justify the extra money to replace an almost new big ring, yet.

A while ago I had started a thread where I posted pictures of the 6603 and 5603 deraillers showing the differences on the inner cage. I can't seem to get the search function to find it though.

Yeah I read somewhere last night that the 6603 was thinner and also had a deeper "drape" on the inside panel, which caused issues on the 52-42-30.

I have found a source or two for 6503 braze on and the clamp.

I considered changing the middle ring for $25. It's an Ultegra too. But 52-42-30 gears out so nicely in my planned schema.

So, the 6603 goes back on the 'bay in a few weeks.