Pulley/jockey wheels issue

[rbike]

Re:

Thanks for all replies.

I agree Muddy paw, I should throw away the chain once a year...however using three different bikes, chain never wears the same on all three...depends which one I use most at the time. I never changed jockey wheels though. Is that necessary?

OK legrandefromage, so chain width should not be the problem. I agree.

I adjusted the b-tension screw, since my bigest cog is 32 teeth and seems to be the upper limit that this derailleur can handle, thanks Thias. No problems on the other bike with same set, however.

Since grinding was most (almost all) on the lower jockey, I switched the lower jockeys - put from XTR to STXRC and vice versa. The XTR on STXRC was ok (newer chain). On STXRC jockey that was now on XTR, however, had some grinding (older chain) - not so much as with XTR jockey, however from this I assume that chain is worn.

It is strange however - according to Sheldon B. chain is OK if the distance between 20 centers is 25.5cm or less. Mine is almost as new - between 25.4 and 25.5cm.

Will change the chain(s) as soon as the bikeshop will pass me

One more question - I attached photo of lower XTR jockey, to ask you for opinion if is worn out or not. I got this derailleur in the spring, so I have no experience with this group. My all other jockeys (mostly alivio/STX) were never this worn...The upper jockey seems OK.

 

[Muddy paw]

Hi rbike , well i normally just use 1 bike all year round but when it boils down to it what you mainly use the bike for as i do mainly road and a bit off road on ocassion so if you do mainly off road in varying conditions then wear and tare will happen fairly quick as for those jockey wheels the top one is fine but the bottom is only fit for the bin looking at the tooth wear ..

 

[FluffyChicken]

Re:

It sound to me like worn out jocky wheels, the cannot sit correctly and pull it around fine.
They are ball bearing pullies so also check it runs smoothly not adding to it ramping up the teeth a bit.

For some reason I cannot see the picture posted.

Edit can see it now, bin it that's worn and one tooth is really gone

 

[Thias]

the pics show the same jockey wheel...
And it is worn, but still usable. Provided the bearing is OK.

 

[legrandefromage]

Mud and grime kill chains cassettes and jockey wheels. Jockeys can last years if the rest is kept clean. Chains can last years or 5 minutes (seemingly) depending on use. Cassettes can sometimes last 5 minutes or go on for years. Many wear on just the one sprocket - that comfy one that you churn away on everyday to work.

I run my own bikes very dry and keep it all fairly clean. My neighbour sprayed his every ride without cleaning and used a heavy sticky oil. He needed new jockeys/chain/cassette/rings because that black sticky paste wore everything down prematurely on a 2 year old bike.

I still have serviceable chains and cassettes that are 25 years old - theres no reason to replace them yet as they are clean and still usable without showing obvious damage or wear.

 

[rbike]

Yes, sorry I didn't mention it - photos are of the same jockey - the lower one. However you figured it out yourself. Will change chain as soon as possible.

But I remember at the beginning - I had a low end mountain bike and everything was running smooth until one day I decided to change the chain (out of precaution and, yes, curiosity...). And that was the beginning of then changing the cassette ... and since I was always wondering when to change the chain. Don't want to spend money for measuring tools since they work the same as meter. I think I just need figures and then measure and compare...So I found some figures on the internet, however many different mechanics stick to different tolerances. I guess there is some experience involved...

 

[We_are_Stevo]

Re:

I rather think you're over complicating the issue...

Pay more attention to LGF: what he doesn't know you don't need!

I once had a similar problem after I fitted a couple of fancy alloy jockey wheels: LGF pointed out that there was probably no 'float' in the new 'wheels but I swore black was white it wasn't that...

...he was right!

The 'wheel in your pboto is FUBAR'd, replace it!

 

[FluffyChicken]

Re:

I would still look to replace it, it is being dragged by the chain and if it starts riding up the edge (its profiled parts have been worn out, you'll get a chink as it drops down. Also that one particular tooth that has gone will not be helping
This has no float as it is just the tension pulley but it's the one that stops the mech chattering back and forth.

What's the top guide pully like, they floating bearing pullies and that the one that makes the shifting work well.

These are not cheap to replace with the nos or equivalent modern ones. But they are an important part of the XTR level. Cheaper will work though.