Skip to content
View in the app

A better way to browse. Learn more.

Trials Central

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Cota 349 Gear box selector drum

Featured Replies

Hi - I have an '83 Cota.  I have had the gear box stripped and it is working on the bench, but there is too much movement in the gear selector drum, so it is vibrating and then jumping into gear.  Does anyone have a picture or diagram showing the selector drum set up pls?

IMG_9971.JPG

  • Author

Thanks very much - I have this already but the guy rebuilding it says it is difficult to match the parts to the diagram.  The main issue is that the bike jumps into gear in neutral, maybe due to vibration, I can try adding some shims to firm it up, but do you think that will work?

4 hours ago, George Cardale said:

Thanks very much - I have this already but the guy rebuilding it says it is difficult to match the parts to the diagram.  The main issue is that the bike jumps into gear in neutral, maybe due to vibration, I can try adding some shims to firm it up, but do you think that will work?

I bought my 348 and the gear selection was awful, on inspection I found there were no shims on any of the shafts. The manual suggests a complicated measurement method involving lots of adding and subtraction. I just assembled the box with its gaskets and tested end float on the shafts then made up a set of shims to take the end float to 0.1mm this helped a lot.

Has your man adjusted the 01302 cam plate carefully enough using eccentric nut 107 so that neutral is selected positivly? The 349 has the aditional roller 11001  that should help positive engagement a little more.

Have you got the manual? 

  • Author

Thanks very much, is the manual in Spanish, if so I have it.  My email address is gcardale1@gmail.com if easier 

Thanks for your help, much appreciated 

bigshineybike reminded me to mention that the 349 and many other spanish bikes of the time use 0.5 mm thick centre gasket, which is not a standard size here, but is available. The thickness of the centre gasket is important for things like the side play in the shift drum

  • 2 weeks later...

Like Bigshineybike I shimmed the shafts and the drum.

I also made a shim to fit under the hex head of the eccentric adjuster 2166.107 (selector group drawing) and that reduced gearchange shaft 'slop'. Also made a bronze bush in the outer cover where the shaft exits the cover (under seal 0099.1424).

 

So far so good.

Edited by dr nosh

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.