any tips for removing stuck b adjustment screw

johnbhoy

Left my commuter with gunk on it for several weeks and did not clean it. Now paying the price :roll:

Its all cleaned up and i am good to but i need to adjust the b adjustment screw as derailleur is now sticking when in 1st. The screw is very close to threading at the head but it just does not want to move. I have now sprayed a good bit of wd40 at the screw and left it overnight. With a bit of luck it might shift in the morning. Failing this. Does anyone have any advice for loosening this screw

Cheers

John

sungod

which rear mech? if it's a steel screw in aluminium it may be corroded, wd40 won't help

aluminium expands more than steel, so you could try heat, trickle boiling water over that area or use a (small) blowtorch to warm it up

if the head is damaged, you may get a better grip with pliers

ride_whenever

I wouldn't recommend pliers, i usually slot the head with a dremmel and use a good screwdriver as that tends to work a lot better.

Or file both sides flat and use adjustable spanner.

owenlars

The b screw controls the gap between the top jockey wheel and the cassette. I don't see how tweaking this will help with a sticking 1st gear (I assume you mean the smallest cog). The problem is probably more likely to be an indexing one. Try tightening the gear cable a smidge and see what happens.

barrie h

I had an old campag rear mach that everything had seized solid, I managed to get the jockey wheels of, then I put the rest in a clean tin and filled it with diesel and heated it up to flash point and let it cool down every day for a week
It came apart like new after that

Barrie

johnbhoy

Thanks all. Its an SRAM rival 10 speed.

By 1st. I meant the largest cog at the back.(i always get 1st - highest and lowest back to front !!) I have had to replace my rear wheel and the derailleur is now sitting too close to the cassette when in the largest cog on the rear wheel. It then sticks there.

The screw does not look rusted or corroded but it obviously is.

Filing sides down and attacking with adjustable spanner seems the way to go. Will give that a bash

ride_whenever

i'd start with slotting the head, then spanner.

Usually the sram ones have inserts.

johnbhoy

quick update.

Turns out i had not seated the wheel correctly and it had slid down out rear drop out slightly bya couple of millimetres when it was in the stand......

So this resolves the issue. When its seated properly i have just the right amount of clearance for the b adjustment so might get away with having to adjust this.

I now have a new problem though. I have loosen cable bolt so there is no tension in the derailleur. I have wound out the H screw so that it should just sit in the smallest cog at the back. (its quite far out).When i push the pedals the chain keeps trying to jump into the 2nd smallest cog. I have taken the wheel off and taken the casssette off and reseated it making sure everything it down tight. This is a new wheel however. Will adjusting the bolts on the axle shift the relative position of the cassette against the derailleur.

So if i am looking at the wheel standing behind the bike. I loosen the axle on the left hand side and then screw it further in on the right hand side (cassette side). Will then then move the cassette further to the left and help with my alignment issue? I have removable drop outs. They look pretty straight. I have gently bent it out a bit just incase this is impacting. The only other thing i can think of trying is putting a spacer in between the frame and the derailleur to bring the derailleur further out.

ride_whenever

good god, take it to a shop and get the hanger alligned now you've bent it.

If you can't get the cassette out far enough to get into the 11t sprocket then you'll need to move the hub on the axle.

Pics?

johnbhoy

haha.

I have not actually bent the hanger. Its very straight looking . i just put gentle pressure on it to make sure it was not bent inwards so beleive this is fine.

But you 2nd point is exactly what i am wanting to clarify. So you can move the freehub along the axle and this will help alignment.

ride_whenever

it can be done on some hubs, but you really shouldn't have to.

Have you put an 11spd spacer where no needed?

antsmithmk

barrie h wrote:

I had an old campag rear mach that everything had seized solid, I managed to get the jockey wheels of, then I put the rest in a clean tin and filled it with diesel and heated it up to flash point and let it cool down every day for a week
It came apart like new after that

Barrie

Sorry but that is bloody dangerous advice to be giving out.