Chain slip in higher gears

lonegringo

I got redirected to the site after a quick google search and think I already have my answer but wanted some confirmation....

I am experiencing a bit of chain slip/chain jump when in the higher gears on the cassette - doesn't seem to matter which chainring on the the front it is on - when applying more force such as going uphill or flat out on the level.

This is a new setup although some parts are old:
Chain - Shimano XT 9 speed - NEW
Cassette - Shimano XT 9 speed - NEW
Rear Mech - Shimano Deore - OLD (10 years) but recently taken apart and cleaned as much as possible.
Front Mech - Shimano Ultegra 3 chainring version - NEW-ish (2 years)
Chainrings - Shimano Deore - OLD (10 years)

All cabling etc is new.

I am erring on the thought that the chain is too long due to the slip happening on the rear cassette. There is no clicking when cycling under normal force so believe I have aligned the mechs correctly.

Should I remove a link to the chain to see if that improves the situation?

Many thanks

lonegringo

so, I took a link out and it is still slipping. Looking again at it today whilst riding and it does appear the rear mech is slightly out of alignment.

Bozman

I've had similar after swapping a cassette and chain, everything ran like clockwork until you got out of the saddle and then i got slip, two quarter turns on the rear mech cable adjuster and it was sorted.

lonegringo

Thanks, I will give that a go. I am doubtful that the derailleur cage or anything is bent either as this was working fine on the old frame and I have not had a knock/fall on it, well, recently.

Monty Dog

Check the chain length (too long) or the pivot spring tension in the rear mech - if you haven't got enough 'wrap' around the small sprocket, the chain will slip

lonegringo

Chain - I set this up with the methodology that when the chain is on and through the rear derailleur, it should be at max length from the big chainring to the second cog on the cassette. That is how I understood it should be set from a number of guides on the net. If anyone can confirm this method is the best to use then we can eliminate that.

Gear shifting itself is relatively smooth, I can find every gear when using normal force and when I have the bike of its wheels.

I tightened the cable with two quarter turns yesterday and physically checked the cable on the chainstay which did seem more tense, but on the commute to work this morning it was still slipping.

Incidentally, it is slipping once I am already in the gear, not during changing.

keef66

You sure it's skipping on the cassette? From your description of new chain and cassette but 10 year old chainrings I'd have thought it more likely it's skipping on the worn chainrings??

I size chains by routing round the big ring and biggest sprocket but not through the rear mech, then add 2 whole links (2 inners plus 2 outers)

lonegringo

Hmm, ok, maybe I misread the methods then. I also have no spare pins at the moment to add the link back in and judging by what I have read the one that I pushed out half way and then back in to remove a link will probably fail at some point in the near future.

NB: it is not skipping as mentioned originally, it is literally slipping in the same gear....gear changes are fine on the road and on the stand. It is literally when I try to put my foot down in larger ratios or going uphill that the problem starts. This is most annoying since I live in the highest point within my city and have a 1km climb at 10-15% gradient at the end of the ride

I have looked down whilst riding and can confirm it is definitely not slipping on the chainrings, even though they are old.

Besides chain length, could it be the cage pulleys being worn out? I have not inspected these fully. I have some spares from a crappy mountain bike with shimano mech for an 8-speed MTB. Can I simply change the cage over? Or would it be better to get complete like for like?

montyburns56

Try adjusting (anti-clockwise) the derailleur angle adjusting screw (dunno what the correct term for it is!) so that the derailleur sits closer to the sprockets.

lonegringo

Cage pulleys are not so worn, probably in the middle of their life. The LBS fitted the new cables so I'm thinking to just take it back and get them to do it as their free 2-week tune-up.

@montyburns56 - I think that is called the B-tension screw. So your saying it should be looser? I will take a look at that tonight, but I have it almost as loose as it can be.

Incidentally, slipping has somewhat reduced when going uphill since first seen. It is still slipping in almost every gear on the big chainring though.

plowmar

I had what seems to be a similar problem with slipping on the two smallest cassette rings, which I presume is what you mean by largest gear - although in a way it doesn't really matter.

The fix was that I'd bent the rear derrailleur hanger and it just needed carefully putting back to the vertical.

lonegringo

Hmm, I thought about that, only this is a new frame with a verticle dropout and pretty sure I have not bent it already. Pretty sure I got the derailleur in correctly too as it is flush. There is a little play in the derailleur itself though...

I am gonna take it back to the LBS to see what they say. Hopefully it will be easy to sort out, if not it is a new derailleur for me, about time really.

lonegringo

Man, LBS said they fixed it, it is not fixed. Into the big chainring and crrraaaassssggggsss noises coming from the cassette. Most annoying, especially since they charged me R$40 (10 quid or so) for the privilege.

Any other suggestions people?

lonegringo

So, mud on my face...upon further analysis the slip is actually happening on the front on the big, worn out chainring. Purchased a new one from ebay, 12 quid for a new shimano deore 48T, not bad.

keef66

keef66 wrote:

You sure it's skipping on the cassette? From your description of new chain and cassette but 10 year old chainrings I'd have thought it more likely it's skipping on the worn chainrings??

I refer the honourable gentleman to my earlier statement...

lonegringo

Sincere apologies, your nearing-6000 posts should have been given greater respect.

keef66

lonegringo wrote:

Sincere apologies, your nearing-6000 posts should have been given greater respect.

Don't go confusing quantity with quality; I'm often talking utter b0llocks