A new shift return spring question....

[Crooz]

I have been wondering, but alway forget to askk until I'm out riding. Obviously the Return Sprint in the Transmission is just that, a RETURN spring!

My question is... at what point during operation does the spring have the most tension on it? Being in any particular gear create more tension? Is there more tension while your shifting? What's the scoop?

[Dan M]

I have been wondering, but alway forget to askk until I'm out riding. Obviously the Return Sprint in the Transmission is just that, a RETURN spring!

My question is... at what point during operation does the spring have the most tension on it? Being in any particular gear create more tension? Is there more tension while your shifting? What's the scoop?

 

 

Hey Crooz,

 

The spring acts on the shift lever. It is always tensioned some but the tension increases when shifting one way and decreases when shifting the other. I'd have to look at the manual to see which way (upshift or downshift) increases tension. One way the lever is pulled, increasing the tension and the other it is pushed relaxing the spring. It doesn't matter what gear you are in.

 

Edit: it is under the most strain when downshifting

[Crooz]

So it's more likely to break while in the process of downshifting, as that is when it has the most stress on it?

 

Is it logical to think that if you jammed your downshifts hard every time vs being a light as possible on the shifter that your likelyhood for breakage is more?

[Jim in NZ]

Hi Crooz,

 

I'm assuming you are talking about the spring that holds the ratchet arm against the selector wheel, not the spring that returns the gearshift lever to the central position after each gear change.

 

I don't see that how you shift has any effect on the spring (well, either spring actually). The gearshift lever, spring and ratchet arm all move exactly the same amount whether you shift quickly or slowly, light or hard.

 

When I replaced my spring 5000km ago, I put a bit of a bend in the long arm to reduce the spring tension. My logic was that because the ratchet arm has hooks that engage with the selector wheel, it doesn't need a lot of force from the spring. It might be that by bending the spring I have put a weak point in it which might cause it to break earlier, which would be a bugger. But all's well so far.

 

Have you had a previous breakage, or are you trying to prevent one? I don't think you can prevent it, assuming you have the 15mm spring boss (see http://www.v11lemans.com/forums/index.php?showtopic=1633). Just carry at least a spare spring with you on your travels so that the nearest bike shop can replace it. Or if (like me) you don't trust them, carry the tools to do it yourself.

 

Cheers,

Jim.

[Guest Nigelstephens]

Has anyone tried re-tempering the the spring to make it less brittle?

[Dan M]

Has anyone tried re-tempering the the spring to make it less brittle?

 

 

I'm always afraid to apply heat to a spring.

If you watch the action of the lever and how tight the spring gets on the down-shift. You can see that if you bend the tang on the spring slightly to have less tension against the lever it is much less likely to break. The function of the spring it just to keep the lever against the pins. There is no need for excessive pressure. I bent mine when replacing and it works fine. I'd be very surprised if it broke again.