Rear Deraillieur Spring

steelo

I have a Shimano Deore LX rear mech and I struggle to get a regular single shift either up or down through the gears. Down-shifting one gear will usually take a good 20-30seconds. Up-shifting takes far longer unless I up-shift twice which raises the chain 1 gear and then shift back down once.

I have tried tweaking the low and high settings and cable tension and this doesn't improve the overall up and down shifting of the mech. The only thing I can think is that the spring isn't taking up the slack in the cable quick enough for my liking.

What is the most effective way of cleaning the hard to reach spring inside the rear mech? It's currently covered in dirt and grease, which leads me to believe its not working effectively. Should it be re-greased with a particular lubricant after cleaning?

Many thanks.

supersonic

Before you do any of that, check the cables! Clogged cables cause exactly this effect.

steelo

Sorry I forgot to say, I have also thoroughly clenaed the cables. I slide the outers along the cable, clean out all the dirt, grit etc and then rub lube back down along the cables before sliding the outers back into position. It's a bit of a fruitless task though as they seem to clog up after only a few rides despite the rubbe gaters that protect the transition from the outer ends.

It's as though there is a dead point in the initial action of the spring and that it needs an extra pull to get it going, if that makes sense!

Do more expensive mechs have better springs, or are they a common part across the range?

supersonic

The springs are all pretty similar. Could be that its clogged, and needs a clean. I'd take it off the bike and push the mech body by hand a feel the action and tension. You can throughly clean with degreaser, and dry, then add chain lube to pivot points and springs. Put back on and see how it goes. Also check that the top jockey wheel floats from side to side. Make sure the mech hanger is not bent either.

steelo

Aha, mech hanger!!!

I did prang it in Afan, the LBS bent it back out after checking it with a park tool, maybe its been bent back in a bit!

Hmmm!

supersonic

Ah, should be replaced really! bending them back weakens them further, making them more likely to bend with the slightest of knocks or a mangled gear change. Plus they rarely go back to they way they were,