Bicycle Mechanics - Replacing my 1972 Campagnolo Valentino RD
Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.
So, I recently did a head over heels flip on my road bike (It was a disaster) and in the process completely wrecked my RD. So, I'm looking for a quality, inexpensive replacement I can get off of ebay or something. Most of my bike is from the mid 70's, but I recently replaced the rear wheel and cassette, so that's modern. I'll update this thread later tonight after I go check specifically what I've got back there. In the meantime, though, any tips/suggestions/whatever? I'm thinking of turning this into a project, actually, repainting her, cleaning her up, and generally just making her presentable again. She's got a lot of miles on her.
Almost anything will be an improvement from (straight parallelogram, stamped parts, unreasonably short cage for some reason) Valentino. Presumably you need something with an adapter claw, which means either Shimano Tourney (ugh! red pulleys...) or something used. See if your local bike co-op or friendly neighbourhood LBS parts bin has any old Suntour derailleurs, which will have a proper slant parallelogram (which Shimano and Campy didn't adopt until Suntour's patent expired in the 80s). I am in the process of building up an ex-Valentino bike with a Suntour Honor RD, which uses an adapter claw like the Valentino.
It might also be possible to hack something together using a modern non-Tourney derailleur and an older adapter claw, but no guarantees there.
You could also take this opportunity to replace what I'm pretty sure will be a weird sliding low-end Campy FD -- a swinging cage works much better, especially when the chainrings are a bit farther apart in size. Any FD from the last 30 years or so should work better.
If you have a modern cassette, this could be your chance to upgrade to indexing, which would probably mean buying some cheap SunRace downtube shifters (or finding NOS ones, if you'd prefer to keep everything older-looking).
If you have original 70s (somewhat ineffective) stamped metal sidepulls, you could take this opportunity (while you have everything apart) to replace the levers and calipers.
Finally, you could upgrade to a cotterless square taper BB and crankset. I'm guessing that any bike from that era with low-end Campy parts will use cottered cranks on an Italian threaded BB. You could pick up a cheaper cartridge unit (make sure it's Italian thread, which is right-hand thread on both sides and slightly wider and longer than a normal English BB) or try to find an Italian square taper spindle to fit the existing cups (! -- this will be even more difficult, as hardly anybody makes non-cartridge square taper BB parts anymore). You might be okay with cottered cranks, but I find them a real pain to deal with.
Whoops... I re-read what I've written, and I just told you to replace most of your bike. By the time you're done, you might have spent rather a lot of money. Whether this is worth it depends mainly on how nice the frame is (stamped vs forged dropouts, nice lugwork, fancier brand, etc.). It would be quite a bit cheaper to do a low-budget SS conversion (you can replace the cassette with a single cog and spacers) if you're okay with that. Local bike co-ops and used-parts-oriented LBSes are probably the best route to go with this sort of project, if you don't want it to get money pittish.
I hope that's somewhat helpful. I'm currently in the process of upgrading an Italian bike of the same vintage in pretty much the way I described.
If you live somewhere flat you shouldn't worry too much about the FD...
Also I think I remember seeing a claw once that was just a claw, that went to a derailleur hanger. Shouldn't be imposible to find one, I imagine.
This would let you use any old decent RD from the last 25 years, which I'd recommend. Look, NOS 600 for $23 (http://www.ebay.com/itm/Vintage-New-Shimano-600-Rear-Derailleur-RD-6208-NOS-/250876632302).
And you can switch it to a nicer frame with a hanger down the track.
10-17-11, 09:00 AM
Here is a source for a "claw type" rear derailleur hanger for use on frames without a built in one. Using it you could mount nearly any modern rear derailleur.
I didn't realize anybody made those. That's fantastic!
Ya'll are super helpful, especially Dave. You've definitely given me a general framework for my little project. I really don't want to replace the frame- this bike has a lot of sentimental value, and the paint job is gloriously awful (The latest technology in theft prevention). What I'll probably end up doing is replacing the derailleurs and possibly going to index shifting, if I can find some good parts for a relatively low price. I'm talking to some guy on craigslist about this set of Suntour AR friction Derailleur
Rear Derailleur (http://i.imgur.com/LYazB.jpg)
Front Derailleur (http://i.imgur.com/dqy5M.jpg)
Is this a solid piece of hardware?
10-17-11, 11:46 AM
The Sun Tour AR series were solid units and if they are in good condition should give very satisfactory service. My first "good" bike, an '85 Bridgestone 400 came with Sun tour ARX front and rear derailleurs and they worked well for thousands of miles. They are not, however, suitable for use with index shifters.
I'm talking to the guy via email. He's willing to sell them both for 15$, which sounds like a solid deal. Arranging a pickup is problematic, though. Index shifting is a low priority- it's more "if I find a good deal on a derailleur, and it happens to be index, I'll go for it" than anything else. Would that claw hanger work for this set?
Also, I'm looking at this. (http://www.ebay.com/itm/Vintage-Shimano-Dura-Ace-RD-7402-Dura-Ace-8-Spd-Rear-Derailleur-/320775390154?pt=Cycling_Parts_Accessories&hash=item4aafb403ca&autorefresh=true#ht_546wt_1269) This appears to be indexed, though, and there are compatibility issues with older Shimanos. What sort of shifters would I need to get to make this work?
10-17-11, 12:53 PM
Dura Ace 8s derailleurs will only index properly with Dura Ace 8s shifters. All other Shimano 8s can be mixed and matched at will, same for 9s.
10-17-11, 12:56 PM
If for some reason you want a period Campy Gran Turismo derailleur to replace your Valentino, PM me, I have one in good shape you can have for cheap or trade.
If I'm reading Sheldon Brown's chart correctly (http://sheldonbrown.com/dura-ace.html), you can use standard Shimano spacing nine-speed shifters (the cheapest of which are probably Microshift or Sunrace bar ends or clamp-on downtubes) with an old 7/8sp Dura Ace RD and a standard 8sp cassette -- supposedly 8sp DA and 9sp other Shimano have the same cable pull. Your mileage may vary with this set-up. If it doesn't work, you can go back to friction.
I just finished my quick-and-dirty SS conversion by shortening removing the derailleur and shortening the chain until it wasn't going anywhere. It should work as a stopgap until I find a real derailleur. I did have a minor issue, though... The rear axle would deform and bend whenever I put a lot of torque on the pedals, and the wheel would rub up against the frame. I tried to tighten up the axle, and the damn thing snapped in half! I've never seen a screw snap in half because of longitudinal forces like that. Thankfully, I had a spare lying around, so it wasn't a huge deal. This one is super old, though, and it seems to be a lot sturdier. Is there any reason for this?
Axles can snap, but there's normally a good reason. 8-speed freewheels with quick release axles were very bad for this, so nobody makes them anymore. A solid axle (I'm assuming that Valentino and QR are not technologies found on the same bike) snapping under normal use is really weird, though. Could you post a picture? I'm quite curious.
Powered by vBulletin® Version 4.1.12 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.