Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

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.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 08-19-07, 04:09 PM   #1
RunJumpHop
Junior Member
Thread Starter
 
RunJumpHop's Avatar
 
Join Date: Aug 2007
Location: Texas
Bikes: Vitus 979, Panasonic road bike, Triax Mtb
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
How to fix the Phantom shift!

Hey guys, I am riding a recently built up late 80's Vitus 979. It is originally a 6 spd with Shimano 600 components, but I have recently put on a new set of Bontrager Race wheels that I assumed couldn't take the old 6 spd freewheel (right?). So, I now have an 8 spd cassette but the same old shimano 600 shifters and derailleurs. I am running the shifters in friction mode and I am able to switch from gear to gear fine. BUT, when I get out of the saddle and really pump hard or climb a hill the bike will shift into a higher gear, which can be problematic obviously when climbing a hill.

Is this simply because the Vitus is so 'flexy' and puts tension on the cables when I really push it? Or is it my 8 spd cassette not interacting well with my 6 spd components? how can I alleviate this?

Thanks.
RunJumpHop is offline   Reply With Quote
Old 08-19-07, 04:57 PM   #2
mike
Senior Member
 
mike's Avatar
 
Join Date: Jul 2000
Location: Snowy midwest
Bikes:
Posts: 5,392
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Friction shifters?

If yes, tighten the friction cups via the bolt at the side of the levers.
mike is offline   Reply With Quote
Old 08-19-07, 10:06 PM   #3
melville
Senior Member
 
melville's Avatar
 
Join Date: Jul 2007
Bikes:
Posts: 486
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Look in your other three threads about this neat old bike.

1. make sure the cable is lubricated where it runs through the housing in back

2. crank the friction adjustment down (on SIS shifters, done with a screwdriver)

3. get some 8S downtube shifters

4. get some Simplex Retrofriction shifters like the Europros used in the 80s

5. friction bar-end shifters are another good cure

6. 8S index bar-end shifters are another fix (but then you'd be copying ME!)

7. STI, but you may have front derailleur and brake compatibility issues

Good luck

Mel
melville is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -6. The time now is 10:03 AM.