Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Vintage Campagnolo clamp on DT shifter issue

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Vintage Campagnolo clamp on DT shifter issue

Old 05-07-21, 06:56 AM
  #1  
sovende
Senior Member
Thread Starter
 
Join Date: Jul 2017
Location: Western WI
Posts: 336

Bikes: TNTL (Too numerous to list)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 104 Post(s)
Liked 75 Times in 63 Posts
Vintage Campagnolo clamp on DT shifter issue

I recently came across and acquired a vintage Campagnolo clamp on DT shifter assembly found in a parts box at a "flea market-like" event. It was by no means NOS but the aluminum levers were in nice condition. The steel parts had some rust but I figured that a bath in EvapOrust would remedy much of that. I should note that neither of the levers would move but again hoped that the time in the EvapOrust would help fix that issue. Before going into the EvapOrust, I did as much disassembly as possible which amounted to removing the bolts securing the levers to the clamp on body, the Campagnolo logo'd outer keyed disk and a thin, keyed washer. I could not remove the levers from the bosses as they seemed to be "fused" together. Perhaps this is why the shifter was in the parts box. Anyway, I was hopeful that the EvapOrust would do its thing and clear some corrosion from the bosses allowing the levers to be removed. No such luck ! The rust on the steel parts of the clamp on assembly was mostly removed but I'm guessing another bimetallic fusion process was holding the aluminum levers to the steel bosses. I tried several penetrants to no avail. The final solution was to apply some (actually a lot ) of heat with a hot air paint stripper to the base of the levers while prying the levers off of the bosses. To be sure, there was a fair amount of corrosion on the underside of the levers and rust on the mating surfaces of the bosses. Steel parts went back into the EvapOrust and the corrosion on the aluminum levers cleaned up nicely with steel wool. Now comes the issue. I'm not completely sure that this lever assembly had all of the OEM parts and can't be sure that the previous owner had it assembled properly. I've Googled it and found numerous photos of numerous lever assemblies and see that most have washers on both the inside and outside of the levers and many have a "nylon" washer too. I'm attaching a photo below of how things came apart i.e. where the single thin washer was in the assembly.

From the internet photos, it seems like there should be a washer between the boss and the inside of the lever. Also, since the outside of the lever is slightly concave and the inside of the Campagnolo logo'd outer disk is slightly convex, a washer between those two surfaces might interfere with the "friction" action. I do suppose though that washer actually provides the "friction" action.
So, I guess my question is, do I have the proper assembly shown in the photo? If it is, do I need a washer between the inside of the lever and the mating surface of the boss? Thanks
sovende is offline  
Old 05-07-21, 07:28 AM
  #2  
55murray
Senior Member
 
55murray's Avatar
 
Join Date: Apr 2017
Location: Lafayette, Indiana
Posts: 429

Bikes: 1955 20" Murray modified cruiser, 2007 Trek 7.3 FX, 1980 Miyata 610, several other vintage coaster brake machines

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 196 Post(s)
Liked 70 Times in 37 Posts
That looks like it cleaned up real nice, eventually! I do suspect you might be missing some washers. The classic and vintage folks would know for sure, you should move this there.
55murray is offline  
Old 05-07-21, 09:42 AM
  #3  
sovende
Senior Member
Thread Starter
 
Join Date: Jul 2017
Location: Western WI
Posts: 336

Bikes: TNTL (Too numerous to list)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 104 Post(s)
Liked 75 Times in 63 Posts
Originally Posted by 55murray View Post
That looks like it cleaned up real nice, eventually! I do suspect you might be missing some washers. The classic and vintage folks would know for sure, you should move this there.
Yes, it did clean up nicely! If I am missing a washer, it would have to be VERY thin since the outer Campagnolo logo'd disk would not fit into the concave recess of the lever. I did consider posting in the C & V section but thought this was more of a "mechanical" issue and assumed that a moderator would move it if that was an appropriate thing to do. I'm sure that plenty of bike mechanics have C & V interests but will concede that many if not most C & V enthusiasts are actually very mechanically inclined. I'm hoping for a definitive answer from either group .
sovende is offline  
Old 05-07-21, 10:24 AM
  #4  
sovende
Senior Member
Thread Starter
 
Join Date: Jul 2017
Location: Western WI
Posts: 336

Bikes: TNTL (Too numerous to list)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 104 Post(s)
Liked 75 Times in 63 Posts
So what I’ve done is lightly grease the inner mating surfaces between the bosses and levers, lightly grease the thin keyed washer, the outer convex logo’d disk and threads on the fixing bolt then reassembled in the order shown in the photo. With only a small amount of torque on the fixing bolt, there seems to be sufficient friction to allow lever movement and perhaps prevent unwanted movement RE: derailleur spring return tension. That would have to wait until I actually install the levers on a bike and run cables to the derailleurs. If I assume that the shifters had never been disassembled , it’s the way it should be. If they had been disassembled, I’ll have to rely on the knowledge and experience of the “experts” here on the forum .
sovende is offline  
Old 05-07-21, 12:02 PM
  #5  
JohnDThompson 
Old fart
 
JohnDThompson's Avatar
 
Join Date: Nov 2004
Location: Appleton WI
Posts: 22,542

Bikes: Several, mostly not name brands.

Mentioned: 133 Post(s)
Tagged: 0 Thread(s)
Quoted: 2574 Post(s)
Liked 1,204 Times in 763 Posts
Is the other lever with similar parts, i.e. no more or fewer than those you've shown disassembled?

The Record shift levers went through several iterations. It does appear that you are missing the plastic friction plate with the convex surface to fit into the lever. The tension bolt may not be original, as it does not have the D-loop.

These are a later version than yours, and have a split washer under the tension bolt:
Attached Images
File Type: jpg
camp-clamp-shifter.jpg (97.0 KB, 35 views)

Last edited by JohnDThompson; 05-07-21 at 12:06 PM.
JohnDThompson is offline  
Old 05-07-21, 01:24 PM
  #6  
sovende
Senior Member
Thread Starter
 
Join Date: Jul 2017
Location: Western WI
Posts: 336

Bikes: TNTL (Too numerous to list)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 104 Post(s)
Liked 75 Times in 63 Posts
Originally Posted by JohnDThompson View Post
Is the other lever with similar parts, i.e. no more or fewer than those you've shown disassembled?

The Record shift levers went through several iterations. It does appear that you are missing the plastic friction plate with the convex surface to fit into the lever. The tension bolt may not be original, as it does not have the D-loop.

These are a later version than yours, and have a split washer under the tension bolt:
Each side was assembled exactly the same! The outer Campagnolo logo’d keyed disk is actually quite thick and the underside is convex shaped. When I did the Google search, the photo gallery that pops up did show several assembled shifter sets that had the same exact tension bolts as mine. I’m thinking that the one I have is an early design and that the later designs had the plastic friction plate and the D-ring’d tension bolts. While it would be possible to place a washer between the inner surface of the lever and the mating surface of the boss, I don’t think it is necessary since the inner edge of the lever does not come in contact with the mounting band. The thin washer that lives between the concave outer surface of the lever and the convex inner surface of the logo’d disk appears to look like spring steel which would make some sense as it would perhaps eliminate the need for a split washer to prevent the tension bolt from loosening.
sovende is offline  
Old 05-07-21, 01:50 PM
  #7  
Mad Honk 
Senior Member
 
Join Date: May 2019
Location: Bloomington, IN
Posts: 1,487

Bikes: Trek 770, Trek 760, Schwinn Paramount, Patelli Professional, Othon Ochsner

Mentioned: 30 Post(s)
Tagged: 0 Thread(s)
Quoted: 636 Post(s)
Liked 528 Times in 397 Posts
That set of levers is assembled correctly! It is a second generation Gran Sport set. The lever stops were pressed on the clamp and then the steel spacer is pressed on the lever boss holding the two plates in place. The bosses are held on the clamp by the spreading of the boss body like a rivet and the pieces then become one. Same process for both sides. The outer thin spring steel washer is what holds the tension on the shift lever because the convex chrome plated washer deforms the spring steel washer into the concave section of the lever. The tighter you make the screw into the boss , the more pressure is applied to the spring steel washer. HTH, smiles, MH
Mad Honk is offline  
Old 05-07-21, 03:52 PM
  #8  
sovende
Senior Member
Thread Starter
 
Join Date: Jul 2017
Location: Western WI
Posts: 336

Bikes: TNTL (Too numerous to list)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 104 Post(s)
Liked 75 Times in 63 Posts
Originally Posted by Mad Honk View Post
That set of levers is assembled correctly! It is a second generation Gran Sport set. The lever stops were pressed on the clamp and then the steel spacer is pressed on the lever boss holding the two plates in place. The bosses are held on the clamp by the spreading of the boss body like a rivet and the pieces then become one. Same process for both sides. The outer thin spring steel washer is what holds the tension on the shift lever because the convex chrome plated washer deforms the spring steel washer into the concave section of the lever. The tighter you make the screw into the boss , the more pressure is applied to the spring steel washer. HTH, smiles, MH
Excellent information! I was definitely hoping that was the proper assembly sequence. Looking at the inside of the clamp on band, it does seem like the act of tightening the clamp bolt would press the “rivet-like” portion of each boss firmly against the sides if the down tube and really tighten things up . Thanks so much for the clarification!

Last edited by sovende; 05-07-21 at 05:42 PM.
sovende is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.