2023 Subscriptions robster82 Posted December 31, 2017 2023 Subscriptions Report Share Posted December 31, 2017 I put a new chain on tonight in prep for tomorrows run, all gears running smooth on the big chain ring but when in the small everything goes really wonky! Looks like chain jumps off bottom jockey wheel. Paul Mcd wants local hills tomorrow now I'm stuck in big ring, please help? P.s. I did clean dirt from the jockey wheels and there is a bit of sideways movement, not sure if this is normal. Cheers Quote Link to comment Share on other sites More sharing options...
2023 Subscriptions George Posted December 31, 2017 2023 Subscriptions Report Share Posted December 31, 2017 How old is your cassette? if it’s a bit worn it’ll cause a new chain to jump. Quote Link to comment Share on other sites More sharing options...
Life Members chung Posted December 31, 2017 Life Members Report Share Posted December 31, 2017 That's a bummer, Robbie! It's always difficult to diagnose bike issues on the forum, but it's fun nonetheless :-) 1. Have you cut the new chain to the right length? When one small chain ring (front) & smallest sprocket (rear cassette), the chain should still be tension, with around 10-15mm gap between the chain & the upper jockey wheel! 2. Does you lower jockey wheel's (the one in question)" teeth" still good, by that I mean it haven't worn out? 3. Does the chain want to come off in all the sprocket selections or is it just when chain is on the lowest one? I'm sure others will be along soon to chip in :-) Good luck & if all fails, just stick it on the big ring & smash it up those hills :-) Cheers Chung Quote Link to comment Share on other sites More sharing options...
2023 Subscriptions robster82 Posted December 31, 2017 Author 2023 Subscriptions Report Share Posted December 31, 2017 This is the second chain on the cassette George, I've had that problem before but this seems very different. Chung, the chain was measured against the old one so should be ok and the jockey wheel teeth look fine. Yes the chain is coming off all sprockets very quickly! 1 turn of crank then chain is off jockey wheel and all out of line. Quote Link to comment Share on other sites More sharing options...
2023 Subscriptions robster82 Posted December 31, 2017 Author 2023 Subscriptions Report Share Posted December 31, 2017 There is a wee bit of lateral movement on the jockey wheels, not sure if this is normal, I'm thinking when in wee ring there's not as much tension and with this movement chain jumps off. Should j.wheels be solid? Quote Link to comment Share on other sites More sharing options...
2023 Subscriptions George Posted December 31, 2017 2023 Subscriptions Report Share Posted December 31, 2017 A wee bit of movement is normal. if your previous chain had stretched a bit, as they all do eventually, it starts to wear your cassette & chainrings. This affects your shifting. could also be you haven’t fitted it right and you have a stiff link that’s causing it to jump. Quote Link to comment Share on other sites More sharing options...
2023 Subscriptions robster82 Posted December 31, 2017 Author 2023 Subscriptions Report Share Posted December 31, 2017 Cheers George, I was pretty sure it was jockey wheel problem but to be sure I'll test another wheel/cassette on bike tomorrow. Quote Link to comment Share on other sites More sharing options...
Galeb Posted December 31, 2017 Report Share Posted December 31, 2017 A bit of jockey wheel movement is normal...they also last quite a bit. I would say either small front ring or most probably cassette worn out (signs of teeth wear are normally shark fin/sharp edge appearance). You can always put back the old chain and see if that works for a temp solution. Quote Link to comment Share on other sites More sharing options...
2023 Subscriptions XXX Posted January 1, 2018 2023 Subscriptions Report Share Posted January 1, 2018 Have you put the chain on right , have you adjusted the b screw, take them off and clean then note which one goes to the top and correct direction of travel. one of the wheels are designed to move to keep the chain in the right place Quote Link to comment Share on other sites More sharing options...
2023 Subscriptions P McDonald Posted January 1, 2018 2023 Subscriptions Report Share Posted January 1, 2018 Just read this Robbie, this is a long shot but happened to me once. Tighten the very small Allan screw that holds the outer rear mech plate to the inner plate. Other than that my suspicion would be rear mech knackered but worked with stretched chain ok. suggest try your rear mech from summer bike ? Quote Link to comment Share on other sites More sharing options...
2023 Subscriptions robster82 Posted January 1, 2018 Author 2023 Subscriptions Report Share Posted January 1, 2018 Cheers guy's, put my summer wheel/cassette on and still same problem. Narrowed it down to jumping off only in gears 1-5. Chain is definitely on ok as everything runs sweet on big ring, no stiff links either. I've not adjusted any screws at all. Thanks for the suggestions I'll have another play about tomorrow. Quote Link to comment Share on other sites More sharing options...
Life Members chung Posted January 1, 2018 Life Members Report Share Posted January 1, 2018 Robbie, If all the above points have been checked & it's fine as far as you can see! Then have you recently dropped your bike landing on the drive side? Or that the rear mech have had impact (knock) against it? I suspect that your rear-mech hanger (the detachable part screwed onto the drop-out which your rear mech is attached to) might be very slightly bent. Unfortunetly, the only sure & accurate way to check & fix it is with an "rear mech alignment tool", all good bike mechanic should have one :-) http://www.chainreactioncycles.com/park-tool-derailleur-hanger-alignment-gauge-2-2/rp-prod149800?gs=1&pgrid=36427643173)&ptaid=pla-272543305852&utm_source=google&utm_term=&utm_campaign=Chain+Reaction-UK-PLA-PLA-All-DT-SE-Shopping+QLB+Generic+Desktop&utm_medium=base&utm_content=mkwid|sBeMgJ9J4_dc|pcrid|161850070953|pkw||pmt||prd|546386UK Good luck! Cheers Chung Quote Link to comment Share on other sites More sharing options...
Committee Alan McLean Posted January 2, 2018 Committee Report Share Posted January 2, 2018 (top(pulley) jockey wheel has more side-to-side wobble to allow gear change. lower(tension) has less) Chung may well be correct re. hanger. It sounds like your chain line may be too extreme from front little ring to rear small cogs. This would matter if the lower jockey wheel is pointing outboard a little. Can you post a photo from directly behind the bike in small/small? Our enormous minds may come up with an explanation which makes at least partial sense. Also post lateral shot of the cassette teeth. Overhead shot of small/small would be supercool too. Also (apologies if you have done so ):?directional chain/correct chain speed/?removal and accidental swap of jockey wheels. What's the groupset? Alan Quote Link to comment Share on other sites More sharing options...
2024 Subscriptions Darryl Gunson Posted January 2, 2018 2024 Subscriptions Report Share Posted January 2, 2018 Hi Robbie I've only just seen this so hopefully you have now sorted it out. If you haven't sorted it, check the jockey wheels again. Some lateral play is normal, however the bushes can wear out. This results in too much play which could affect the chain, in certain gears. If your jockey wheels are the type that have bearings ( eg SRAM) check they are all there - missing bearings can have same effect as above. It happened to me recently. If it turns out to be a bent hanger, I have the alignment tool should you need it. Alternatively, replacements are cheap. Quote Link to comment Share on other sites More sharing options...
2023 Subscriptions robster82 Posted January 2, 2018 Author 2023 Subscriptions Report Share Posted January 2, 2018 Thanks again for the info and suggestions men, as soon as I get time my plan is to remove and inspect/clean the jockey wheels and take it from there. Everything has been kept the same, 11 speed kmc chain I have used before, no jockey wheels removed or any screws adjusted it was a straight swap. Groupset is 11 speed Shimano 105 5800. Quote Link to comment Share on other sites More sharing options...
Committee Alan McLean Posted January 2, 2018 Committee Report Share Posted January 2, 2018 (edited) excellent plan. My jockey wheels were totally seized after cross racing so they can malfunction. Shimano pulleys should be marked "guide" for top and "tension" for bottom with directional arrows for correct replacement. Cheap replacements available on line. but have you checked hanger alignmnent first? we await with baited breath...... Edited January 2, 2018 by Alan McLean pulley should read guide Quote Link to comment Share on other sites More sharing options...
2023 Subscriptions robster82 Posted January 3, 2018 Author 2023 Subscriptions Report Share Posted January 3, 2018 I now have 'Jockey wheel induced insomnia' couldn't sleep with all these solutions going round in my head, so up first thing and started to tinker. Hanger, to the eye looks in line, theres been no bumps to my knowledge. Small chainring teeth look fine also, this doesn't get a lot of use being by hammered by the boggers. All screws were tight and in place. Cassette looks also in good nic. So stripped j.wheels to inspect and clean, the wee bush/roller thingy inside bottom jockey doesn't sit quite snug, re-assembled everything and there is a fair bit of lateral movement on both wheels. It looks like the bush has worn on bottom wheel allowing movement, the tension is then lost on chain causing it to jump off, Dooleys in the morning. P.s I'm now running late for a wedding with a pregnant angry wife growling at me! George 1 Quote Link to comment Share on other sites More sharing options...
Life Members chung Posted January 3, 2018 Life Members Report Share Posted January 3, 2018 1 hour ago, robster82 said: P.s I'm now running late for a wedding with a pregnant angry wife growling at me! Good news Robbie, look on the bright side, at least now you have a functioning bike! :-) Quote Link to comment Share on other sites More sharing options...
2023 Subscriptions robster82 Posted January 5, 2018 Author 2023 Subscriptions Report Share Posted January 5, 2018 Fitted new jockey wheels this morning and everything seems to be running good, cheers for all the info. Richard 1 Quote Link to comment Share on other sites More sharing options...
2023 Subscriptions George Posted January 5, 2018 2023 Subscriptions Report Share Posted January 5, 2018 Good news, Robbie although I note that your wife was initially just angry. She is now pregnant & angry. busy few days? KennyS and robster82 2 Quote Link to comment Share on other sites More sharing options...
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