Derailleur Problem , I am an idiot with em -

[mooby77]

Hi Guys

Driving me mad , All was good on my giant trance e+ 2 pro 2021 , After a sesh yesterday , decided to give a good seeing to , the bike that its , bled the brakes , all good , removed the chain , good clean , checked wear just over 0.5mm so happy with that. Next took the cassette off , so far so good , 40nm undone all good , into the degreaser each cog, in sequence , as normally just throw em in, then forget the spacers, any way all nice and clean , re-assembled on to the freehub , re-torqued to 40nm all good.

Wheel back in , chain on , quick spin up , initially ok , then when for a quick spin in the woods and now the gears are now way as good as before I started , grr , and biggest problem is cannot shift into the lowest gear , biggest cog , skipping on the middle of the ranges on the way back up from highest to the lowest

Any ideas , I really cant get my head around derailleur adjustments , I guess something has moved , and I need to re-adjust the limit screws, but I don't get why such a change just by removing and cleaning.

It is a Shimano Deore XT, 12-Speed, Shadow+ and Shimano CS-M6100-12, 10-51T, 12-speed

Thanks for any help or opinions.

Also I am thinking going forward to change to a 1x 11 , Primarily on cost but also really do not need the 12 on the E.

Cheers

Paul

 

[Frankenbetty]

Check the chains routed correctly through the rear mech. There’s a little tab on the jockey wheel assembly that’s easy to miss.
then check the cable tension. Check the rear wheels done up tight and straight and check the mech hangers not bent.
don’t mess with the limit screws until you’ve checked everything else as they rarely loosen off on their own. it’s bad initial setting up that makes them a problem generally

 

[Mikerb]

............so have you put the cassette spacers back in their right locations? If you were selecting gears OK before you started stripping and cleaning it is very unlikely any of the derailleur adjustments have changed by themselves ( limit screws/b tension/cable tension) so the most likely cause of your problem is something you have done wrong in reassembling it all.

 

[MrPeaski]

As @Mikerb mentions, Have a look at page 14 of the dealers manual to make sure you have assembled the spacers in the correct positions.

https://si.shimano.com/api/publish/storage/pdf/en/dm/MACS001/DM-MACS001-05-ENG.pdf

 

[Rosemount]

I took off a SRAM 12 spd cassette .
Dropped it ,cogs and spacers every where . Reassembled it . Adjusted the limit screws and rode . Took some head scratching before I realised I only had 11 gears of my 12 speed ! Other cog was hiding under my bed . lol .

 

[urastus]

Trouble in the lowest gear does not point to spacers etc. This is probably easier to check with the bike upside down. 2 limit screws; one is for the lowest gear, one is for the highest. While in lowest gear jockey wheel needs to be lined up with the lowest gear (vertically in line) - that's what you use the limit screw for. While in the highest gear, jockey wheel centre needs to be lined up with the outside of the highest gear (a little bit off set). Then run through the gears - if they hesitate going into lower gears, tighten the barrel adjuster. If they hesitate going into higher gears, loosen the barrel adjuster.

As others have said, you shouldn't have to do the limit screw adjustments, but tension adjustments can and do change especially as chains lose lubrication, and then again when they are newly lubed. Consider Frankenbetty's post above; while you have the bike upside down, pedal it and look to what is causing the noise. If it is as frankenbetty has suggested (very easy mistake to make) you have to re route the chain through the derailer taking note of that tab between the jockey wheels.

 

[mooby77]

Cheers Guy's I'll have a re-check later and thanks to everyone for advise and the manual attachment link .

Paul

 

[mooby77]

Sorted , Cogs and spacers were correct , It was the routing of the chain through the rear mech , wrong side of the tab, re-done , minor adjustment on the barrel sorted everything else out.
Now running smoother than Boris Jonhnson putting wall paper up
I am putting it down to a " blonde moment" AKA old age or more probable just plain incompetence

 

[Rosemount]

Yup, been taking bikes apart for 40 years (god, nearly 50 years) and I still got the chain the wrong side of that tab recently.
Definitely age, can't possibly be incompetence... no...

On the road bike, at the weekend, I was removing the plastic splined packing tube out of a new cassette.
Being really careful, trying my best to keep everything in assembly order.
It was a really tight fit. When it finally gave way, you guessed it, fecking cogs and spacers all over the bastard garage.
Collected it all up, but it wasn't right.
After an hour of searching and cursing, I moved the chest freezer and there, right at the back, was one of the damned spacers.
How something 40mm diameter, rolls under a 20mm gap I will never know. ?‍

A new member of the cassette caterpulters club congratulations !

 

[fenwick458]

Sorted , Cogs and spacers were correct , It was the routing of the chain through the rear mech , wrong side of the tab, re-done , minor adjustment on the barrel sorted everything else out.
Now running smoother than Boris Jonhnson putting wall paper up
I am putting it down to a " blonde moment" AKA old age or more probable just plain incompetence

haha, I've done that before! was in a rush building my mates bike back together, just threw the chain on 5 mins before he came and then we set straight off on a 100km hilly loop around the lakes. he did mention a bit of rattling several times on the way... I said I'd have another look at the gears later for him...
when I found my mistake and told him we both laughed!