Shimano LX M570 rear derailleur problem

[teddyuk]

I have Shimano LX Brake/Shifter Pods - M570 and a rear derailleur LX m570. The shifter is not able to go from the bigger to the fourth sprocket, and the shifter lever is completely without resistance to its moving as in the other sprockets (sorry if I am expressing myself so badly, but english is not my native language).


What to do? Which could be the problem?

 

[Charlieboy28]

it may be knackered or it may be gunked up so that the pawls are not engaging the ratchets.

buy some cheap turps ( turpentine or white spirit is a good degreaser) , take your shifter off the bike and remove all cables.

take the bottom casing off with 2 or 3 little screws and immerse in the turps. leave immersed over night or a good few hours and cycle the shifter ( click it up and down).

let it dry squirt with WD40 to blast out any remaining grit then use a small amount of light oil ( 3 in 1 bog standard bike lube chain lube or anything ) on the moving bits and reassemble.

 

[teddyuk]

it may be knackered or it may be gunked up so that the pawls are not engaging the ratchets.

buy some cheap turps ( turpentine or white spirit is a good degreaser) , take your shifter off the bike and remove all cables.

take the bottom casing off with 2 or 3 little screws and immerse in the turps. leave immersed over night or a good few hours and cycle the shifter ( click it up and down).

let it dry squirt with WD40 to blast out any remaining grit then use a small amount of light oil ( 3 in 1 bog standard bike lube chain lube or anything ) on the moving bits and reassemble.

Thanks so much for your guidelines.

Can I also ask wich is my bottom brackets? it kreks a lot, all the time. In a bikes shop they said it is normal for the model, but I forgot to ask which one ii is... but I m starting to get mad with the noise. Is it LX BB or Deore

 

[Anthony]

Can I also ask wich is my bottom brackets? it kreks a lot, all the time. In a bikes shop they said it is normal for the model, but I forgot to ask which one ii is... but I m starting to get mad with the noise. Is it LX BB or Deore

It doesn't really matter which model of bottom bracket you have, it isn't normal for it to creak. Creaking is usually due to either the bottom bracket not being tightened enough in the frame, or else the crank arms not being tightened enough on the bottom bracket tapers. I would suggest you take the cranks off and take the bottom bracket out, check that it seems to be turning smoothly and has no play, clean everything, regrease the bottom bracket threads and reassemble. There are different views on whether you should grease the bottom bracket tapers before fitting the crank arms, but I do personally and I think it may be advisable for you to try it in this case, to see whether it cures the creaking. You shouldn't just put up with the noise, because if it is caused by anything being loose, that can cause damage over time.