I have two issues I've noticed on my bike. Granted I had to fully rebuild it after receiving a new frame so it's not something I can say has developed over time as I don't remember it previously, and it may have started due to me not setting something correctly in the rebuild. Anyway,
1) When shifting the front mech, as I pedal, the chain links sit on the top of the teeth of the chainring for a few seconds, before settling in between the links as they should. What causes this? I'll double check the chain, but I'm pretty certain it's not stretched nor old. I'm running an 10sp/8sp Shimergo set up.
2) I've noticed when I pedal slowly and lightly, I can detect a rattling/roughness (almost like something is loose) in the chain as I pedal, can feel it in the pedals. It only happens on mid range gears on the rear cassette, none of the others. And it goes away when I apply power. I've checked the chain over and nothing is rubbing against anything. I did fit some new jockey wheels. Apart from it being the jockey wheels I can't for the life of me figure out what it is!
I know the above is a bit vague but wondering if anyone has come across such issues with their bikes...
Tranmission issues
Re: Tranmission issues
I'm experiencing almost the same myself after putting a new crankset and nearly new BB on a bike today. I've checked the chainline and it's pretty good. The chain shows no sigh of stretch. The bike's not been used for a while and I can't say whether the roughness existed with the old crankset or not. It's a 9 speed bike and the new crankset is supposedly the TD-2 from Spa. I say supposedly because it looks like and XD-2 and the recommended spindle size of 107mm was certainly not correct on my bike. I'm using a 116mm spindle and the centre ring is lining up with cog number 6.
Re: Tranmission issues
Ah interesting. I'm using the Spa XD2 TA chainset and it's pretty much new as well. Combined with a 118mm spindle which lines it pretty much perfectly with the 4th (of 
gear.
I'm just not sure if something needs bedding in, or if there's an issue. Usually though, I find this sort of thing to be an issue. I always like the bike to run perfectly smooth. I'll ride it to work tomorrow to see if I can figure out what it is.
gear.I'm just not sure if something needs bedding in, or if there's an issue. Usually though, I find this sort of thing to be an issue. I always like the bike to run perfectly smooth. I'll ride it to work tomorrow to see if I can figure out what it is.
Re: Tranmission issues
My all silver TD-2 does have 5 visible arms, but I had the impression the XD-2 was now made this way too? I have stronglight rings. My shifters are the dura ace bar ends, so the front is friction shift.
It might be easiest for me just to get a shorter spindle and try that. Current BB is a Truvativ 116 which is JIS tapered. I tried a TA Axix 107mm (also JIS I think) which was too narrow. Might get a Shimano UN55 110mm to try. The frame is 130 OLN and originally came with a 7 speed triple and Shimano LP-27 110mm BB.
It might be easiest for me just to get a shorter spindle and try that. Current BB is a Truvativ 116 which is JIS tapered. I tried a TA Axix 107mm (also JIS I think) which was too narrow. Might get a Shimano UN55 110mm to try. The frame is 130 OLN and originally came with a 7 speed triple and Shimano LP-27 110mm BB.
Re: Tranmission issues
Ok a little more context.
1) When I mentioned the chain doesn't align, the links actually sit on the teeth rather than the teeth going between the chain links. Could this be caused by the rear mech? Or is it the front mech simply not shifting cleanly/fast enough?
2) It feels as if the rear mech isn't indexed perfectly (the clicking/rubbing) but I've checked and it's pretty much perfect. I can notice it on all gears, but 3rd and 4th more than anything else. It's most notable when cycling very slowly and not applying too much pressure to the pedals.
I'm going to hazard a guess and say it's the rear mech. It's a different 8sp one I put on. And I put new jockey wheels on. I'll just have to keep riding and try to diagnose it.
1) When I mentioned the chain doesn't align, the links actually sit on the teeth rather than the teeth going between the chain links. Could this be caused by the rear mech? Or is it the front mech simply not shifting cleanly/fast enough?
2) It feels as if the rear mech isn't indexed perfectly (the clicking/rubbing) but I've checked and it's pretty much perfect. I can notice it on all gears, but 3rd and 4th more than anything else. It's most notable when cycling very slowly and not applying too much pressure to the pedals.
I'm going to hazard a guess and say it's the rear mech. It's a different 8sp one I put on. And I put new jockey wheels on. I'll just have to keep riding and try to diagnose it.
Re: Tranmission issues
OK you should really say
-what chain you are using
-what cassette you are using
-what rear mech you are using
-what exact type of XD-2 you are using
-what chainrings you are using
The chain skating normally only happens if you are using a skinny (9s/10s) chain on an 8s chainset and/or the chainrings are badly spaced and/or have the wrong chamfers on them. Once a chain starts skating it will definitely carry on until it has worn itself a groove. You need to fix that, and the only way to fix it is to use different parts. You will find that some outer rings have shoulders pressed into them that throw the chain inwards so that it can't easily do as you describe. I would expect you to perhaps need one of those.
If you are using a poor combination of skinny chain and slightly thicker cassette sprocket these will often work but just be noisy all the time. Chains are nominally all about the same width internally but in reality this varies slightly and with it goes noise, shift quality and a load of other things. I have found that 0.05mm appears to make a different sometimes.
If any of the parts are already worn even slightly the net effect can be slight noise and slight rough running until it settles down. If you are using a worn chain (even slightly worn) it won't skip, it will just (rather noisily) wear the sprockets and chainrings out at double-quick speed.
cheers
-what chain you are using
-what cassette you are using
-what rear mech you are using
-what exact type of XD-2 you are using
-what chainrings you are using
The chain skating normally only happens if you are using a skinny (9s/10s) chain on an 8s chainset and/or the chainrings are badly spaced and/or have the wrong chamfers on them. Once a chain starts skating it will definitely carry on until it has worn itself a groove. You need to fix that, and the only way to fix it is to use different parts. You will find that some outer rings have shoulders pressed into them that throw the chain inwards so that it can't easily do as you describe. I would expect you to perhaps need one of those.
If you are using a poor combination of skinny chain and slightly thicker cassette sprocket these will often work but just be noisy all the time. Chains are nominally all about the same width internally but in reality this varies slightly and with it goes noise, shift quality and a load of other things. I have found that 0.05mm appears to make a different sometimes.
If any of the parts are already worn even slightly the net effect can be slight noise and slight rough running until it settles down. If you are using a worn chain (even slightly worn) it won't skip, it will just (rather noisily) wear the sprockets and chainrings out at double-quick speed.
cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Re: Tranmission issues
Yeah sorry, here's the bits.
Chainset - XD2 (TA) Triple 24/36/46T
Cassette - 8sp SRAM 11-30T
Rear Mech - 8sp XT cage
Front Mech - 8sp Triple XTR
Chain - 9sp Shimano (with a powerlink)
So everything 8sp, except a 9sp chain.
Ah yes, I know the shoulder you mean, remember it on a lot of my Shimano stuff. I'll have a look at the XD-2 chainrings, can't remember if they have it or not.
I also have a second bike with an 8sp XT rear mech and exact same Shimergo set up (exactly!) and it doesn't suffer from the noise/rubbing/roughing. But it does suffer from the chain skating. So there's definitely something wrong with the combo.
My previously built Soma never had any of these problems. It differed with a 9sp Shimano cassette, and 9sp XT shadow rear mech. Other than that, it was exactly the same.
So from judging by the above, an 8sp chain might be worth trying (shame, I can't remember powerlinks being compatible with 8sp).
Chainset - XD2 (TA) Triple 24/36/46T
Cassette - 8sp SRAM 11-30T
Rear Mech - 8sp XT cage
Front Mech - 8sp Triple XTR
Chain - 9sp Shimano (with a powerlink)
So everything 8sp, except a 9sp chain.
Ah yes, I know the shoulder you mean, remember it on a lot of my Shimano stuff. I'll have a look at the XD-2 chainrings, can't remember if they have it or not.
I also have a second bike with an 8sp XT rear mech and exact same Shimergo set up (exactly!) and it doesn't suffer from the noise/rubbing/roughing. But it does suffer from the chain skating. So there's definitely something wrong with the combo.
My previously built Soma never had any of these problems. It differed with a 9sp Shimano cassette, and 9sp XT shadow rear mech. Other than that, it was exactly the same.
So from judging by the above, an 8sp chain might be worth trying (shame, I can't remember powerlinks being compatible with 8sp).
Re: Tranmission issues
I don't know about "powerlink" but KMC do a variety of 8 speed chains either come with or can be used with a "missing link" or "quick link".
Re: Tranmission issues
was just researching a bit more, and came across thisviewtopic.php?f=5&t=72632
Took me about 30 seconds before I noticed I was the OP!
Re: Tranmission issues
I've discovered the strange rattling/rubbing noise. It's the jockey wheels! The one new part I introduced. The chain and the wheels aren't quite interconnecting properly. I'll need to check they're the right ones. I bought 10T wheels. Anyway that's one issue diagnosed.
Re: Tranmission issues
In the 8sp XT rear mech I originally put some new 10T jockey wheels (it came 2nd hand without jockey wheels, so I guessed 10T was correct... put in the right way round!), but the chain doesn't seem to align properly with them. The jockey tooth is hitting part of the the link, pushing the chain out slightly, before the chain slots in and meshes correctly with the teeth. Is this normal? I guess not.
So, I tried a Shimano 11T set of jockey wheels from an old Deore mech I have. These run smoother and seem to mesh better, but still not perfect.
It seems to be worse when in 4th gear on the 8sp cassette. I've yet to figure out why. I may try reseating the cassette when I get home. The 4th gear is part of the main body of gears, so odd it's affected more than any of the other gears.
Other things I've tried, all manor of ranges on the b-screw. And checking everything is set correctly (indexing is perfectly smooth and aligned) and tightened properly.
I've not looked at shortening the chain. It's already just about the right length. With the chain on the 30T rear, and front 46T chainring, everything is very stretched (I know you shouldn't really ride that combo but as an example). But I worry that taking some more links out won't help and I'll just be left with a shorter chain.
I could also get an 8sp chain. But I can't see how that would fix the jockey wheel meshing issue. It would solve the chain skating issue, but at the moment that's a lower priority.
Any ideas?
The other bike with the same XT rear mech (M739 or M740) is on the other side of London, so I'll have to wait until I can check it, see how many teeth the wheels have etc...
So, I tried a Shimano 11T set of jockey wheels from an old Deore mech I have. These run smoother and seem to mesh better, but still not perfect.
It seems to be worse when in 4th gear on the 8sp cassette. I've yet to figure out why. I may try reseating the cassette when I get home. The 4th gear is part of the main body of gears, so odd it's affected more than any of the other gears.
Other things I've tried, all manor of ranges on the b-screw. And checking everything is set correctly (indexing is perfectly smooth and aligned) and tightened properly.
I've not looked at shortening the chain. It's already just about the right length. With the chain on the 30T rear, and front 46T chainring, everything is very stretched (I know you shouldn't really ride that combo but as an example). But I worry that taking some more links out won't help and I'll just be left with a shorter chain.
I could also get an 8sp chain. But I can't see how that would fix the jockey wheel meshing issue. It would solve the chain skating issue, but at the moment that's a lower priority.
Any ideas?
The other bike with the same XT rear mech (M739 or M740) is on the other side of London, so I'll have to wait until I can check it, see how many teeth the wheels have etc...
Re: Tranmission issues
Well solved it all. The 10T jocket wheels were fine.
Solution was a new chain!
I measured the old one (using the park tool). It was still ok, but slightly stretched, so I just bit the bullet and replaced it with a nice Ultegra one I had spare.
It solved both the jockey wheel noise and the chain skating.
Solution was a new chain!
I measured the old one (using the park tool). It was still ok, but slightly stretched, so I just bit the bullet and replaced it with a nice Ultegra one I had spare.
It solved both the jockey wheel noise and the chain skating.
Re: Tranmission issues
glad it is sorted out; that is kind of what I expected.
Just out of interest, how worn was the chain in %?
cheers
Just out of interest, how worn was the chain in %?
cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Re: Tranmission issues
Hmmm I'd say 70-80% worn, so arguably still life in it. I didn't measure exactly but the bespoke Park tool could almost fit between the links. Could have sworn the chain was newish but it's easy to forget. Always worth checking I guess rather than assuming.
Re: Tranmission issues
My problem was the chain too I think. New chain on, and no rattling. I laid the old chain along side the new one and the old one was maybe 3 or 4 mm longer, not much. So the stretch was less than 0.4%. The only other thing I did was to clean up a slightly stiff lower jockey wheel. I think it must have been the chain.