A4 scale = 70%
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A4 scale = 70% |
Cycle transmission notes page 7 ... Indexing continued
You can use these 'drop handlebar' shifters with Campag or Shimano-compatible rear mechs by swapping an internal ratchet, as follows. For example, 'Shim 8sp' means 'use a Shimano-compatible freehub and 8 speed cassette'. (Note: pull your gear cable tight enough to eliminate redundant clicks in top gear.)
| 8 sp Ergopower |
C20th 9 sp Ergopower |
C21st 9 sp Ergopower |
10 sp Ergopower | ||
|---|---|---|---|---|---|
| rear mech: |
Shimano Shimano (mod 4) C21st Campag C20th Campag |
x all 6sp x all 7sp, Camp 8sp |
all 6sp all 7sp, Camp 8sp Shim 8sp Camp 9sp |
x Shim 8sp Camp 9sp Shim 9sp |
Shim 8sp Shim 9sp Camp 10sp Shim 10sp |
| ( mod 4 : pitch of mech modified by turning its anchor-plate by 90° - method 4 below ) ( x : non-standard pitch - respace your cassette with Highpath spacers ) | |||||
(With thanks to Chris Juden for his 'Shimergo' articles in the CTC magazine.)
Tricks like these alter the pitch of a rear mech by changing the route the cable takes across its parallelogram. They are useful if you mix equipment from different makes and vintages.
| 1: Normal | 2: Wide pitch | 3: Wider pitch | 4: Narrow pitch | 5: Adjustable narrow pitch |
|---|---|---|---|---|
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2 and 3 : Clamping the cable on the wrong side of the anchor-bolt (3) results in more movement. If this is too much, drill a small hole through the bolt (not an easy task!) and thread the cable through that instead (2).
4 : For less movement, turn the anchor-plate 90° and bend the cable around the outside of its bent tab. You may need to enlarge the plate's hole first or, if there isn't a tab, make your own bent plate instead.
5 : Replace the cable adjuster with a much longer one to make the pitch adjustable. It is normal when the adjuster is fully out, less when halfway, and even less when screwed in all the way. (The adjuster now does two jobs - large changes affect the pitch but small changes continue to fine-tune the indexing as before.)
For even more possibilities you can combine a long adjuster (5) with one of the other methods (2, 3 or 4).
Remember that a rear mech shifts best when adjusted to be close to, but not touching, the rear sprockets. Its exact position can be adjusted by turning the hanger adjuster screw.
Manufacturers are cautious with their specs and you may be able to push mechs further than they say. Maximise your rear mech's capacity by minimising the length of your chain - see Modern gears and chains.
To check if you can fit a smaller inner chainring, put the chain on the smallest rear sprocket and measure the gap between it and the bottom of the front mech cage. You can reduce the size by one tooth for every 2mm.
| © Chris Bell, 2004 |
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| HIGHPATH ENGINEERING Cornant, Cribyn, Lampeter, Ceredigion, SA48 7QW, Wales, UK phone / fax: +44 (0)1570 470035 (UK office hours only) email: 
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