750SF shifter shims

LV71H

New member
Location
Germany
Hi!

On the diagram of the 750SF shifter mechanism, there would appear to be a shim-O-ring-shim combination on the shaft between the spring and the cover.
I've only ever seen the one shim on my bikes. Is the shim-O-ring-shim combnation correct?

Cheers

Esben
 

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Thanks!
I have 1 washer inside the cover and rhe O-ring between the cover and the lever, but no washer.
As long as the o-ring doesn't have sufficient gap that it can dislodge then no need for the outer washer. I play with the internal 'washering' to get a good fit that also prevents the heavy spring 'leg' from getting jammed under the eccentric adjusting screw and the plate that strikes it at max gear change limit. I'm actually considering a thin sheet that will fit over the eccentric screw and prevent the spring from ever being able to drift inwards and block the shifting - dead simple fix.

Also super important is to make sure the shifter cylinder (with the pins at one end and the toothed gear at the other) slides in or out with zero resistance but no play. If it's sloppy or tight, loosen the four bolts securing the larger inner cover and tap it either east or west until you achieve the sweet spot. Also important to check the outer triangular cover to ensure that it doesn't bind the lever shaft when tightened - I check clearance without the gasket. It it's close to touching the inner mech then it will be fine with the gasket in place.

A few things to think about but get it right and it'll shift beautifully 9as long as your eccentric screw is also in tune!!).
 
Q if you come up with that shield design think about making a few, they would sell. Occasionally I get a blocked sensation on a change, back off the pedal and go again and it slips in. Andy Wagner in his huge paper catalogue suggests bending the spring leg to avoid this. I tried that once but it twists the spring off square and that's not a good fix.
 
The mounting of the lever not being a piece of precision engineering, some levers are close enough to hold the O ring in, others aren't with the ensuing oil weep. Some of my bikes need washers, some thicker than others, some not. The washer does figure on the parts diagram above.

Paul
 
Q if you come up with that shield design think about making a few, they would sell. Occasionally I get a blocked sensation on a change, back off the pedal and go again and it slips in. Andy Wagner in his huge paper catalogue suggests bending the spring leg to avoid this. I tried that once but it twists the spring off square and that's not a good fix.
It looks like about 5 minutes work, Vince. Small rectangle of sheet metal of a size that once fitted won't rotate into trouble, a hole the size of the eccentric adjuster, fit before spring. Then the spring can be as close as it likes to the main selector arm.

Interestingly, when setting the SFQ shifting up I discovered that I had the exact same prob you had: I could get a nice shift going in one direction, but then the hooks would foul on the pins in the pins in the selector cylinder on some gears and not return to engage with the pin. I gently ground the hooks a tiny bit but ended up using the whole mech from my SF - worked perfectly! Just that tiny diff can have that much effect. I also fit on or two washers behind the spring to help prevent it fouling the shiftplate-eccentric screw.
 
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