caddabs Posted March 12, 2010 Report Share Posted March 12, 2010 This is potentially a stupid question, but hey ho. Having recently changed my tyre, i took the opportunity to strip the front wheel down and change the bearings and generally clean it up. I have re-assembled it, but have a strange "knock" each time the wheel goes round. The bearings are brand new and fitted flush with the outside of the hub. Between the bearings, inside there is a spacer with a rubber "o" ring between the bearings which i have cleaned, greased and replaced. I have a large spacer on the right, the wheel then an old speedo drive which acts as a smaller spacer. The speedo drive isnt moving, and its not the disk. I really dont want to push the bearings out again for fear of damaging them. Its definately a knock and not a Clang. Nothing is rubbing and the wheel spins smoothly and doesnt jolt, wobble or anything else. Any ideas ? Its driving me nuts. Have i got the spindle too tight? (wheel runs very freely), is it the spacer in the middle with the "o" ring moving about? Have i inadvertently flexed the right hand fork leg? Its probably simple, but several attempts to find it have failed. Many thanks - Caddabs Quote Link to comment Share on other sites More sharing options...
geebee Posted March 12, 2010 Report Share Posted March 12, 2010 Hi Have you checked the disc? Elongation in the holes can cause this to click when spun Geebee Quote Link to comment Share on other sites More sharing options...
hrcmonty Posted March 12, 2010 Report Share Posted March 12, 2010 Hmmmm, Did you say you still have your speedo drive in as a spacer. Have you checked to make sure this is fitted correctly. i think the drive has locating grooves, if these arn't sat right you may have it crushed. I suggest buying a spacer for here if your not going to use your speedo. Does it 'knock' whilst the wheel is lifted in the air, or just when there is weight on the wheel???? If you take the wheel out, stick your fingers into the holes where the axle goes. Spin the wheel. Does it knock then? If so something is a miss with the bearings. If not and the speedo drive is fitted correctly, It's something that your doing when putting the wheel on. It's hard to tell with out seeing the wheel etc. but try those comments first. Quote Link to comment Share on other sites More sharing options...
hrcmonty Posted March 12, 2010 Report Share Posted March 12, 2010 (edited) Im confussed, Assuming your on about a 2000 Sherco. The schematic Diagram i'm looking at shows, From looking at the bike from the front. Left hand side, your axle goes thorugh the bearing out the other sides bearing into a bush, then bolts into the fork leg. There is no spacer or rubber 'o' ring? If you have your spacer on the right hand side (Disc side) you shouldn't have the speedo drive aswell. http://www.sherco.com/spare_parts/2000_200...ebook_trial.pdf Edited March 12, 2010 by hrc_monty Quote Link to comment Share on other sites More sharing options...
caddabs Posted March 12, 2010 Author Report Share Posted March 12, 2010 Thanks for those thoughts chaps. I had a look at the diagram too and agree, however when i take the speedo drive off, the spacer on the right (disk side) isnt big enough and the spindle sticks out of the threaded fork leg. Its posisble the spacer may have been shortened to allow for the speedo drive. The speedo is defunkt as the tab is broken off and merely rotates as a spacer. Its definately not the disk, which would click, or clang. This is a definate knock. so far i have only had the wheel in the air on a workshop stand, i havnt tried it under load yet on the ground. The spacer between the bearings is a mystery too. I just put back what i found. Its an ally spacer which fills the gap between the 2 bearings. It has a hole drilled in it in the middle (no not the one where the spindle goes!) and an "O" ring which sits in the middle over the hole. should i junk it? I would like to junk the speedo drive so if the middle spacer isnt doing anything i could cut it down. How tight should the spindle be? I assume you tighten it until you get a bit of friction on the bearing and then back it off a shade? Thanks again - Caddabs. Quote Link to comment Share on other sites More sharing options...
hrcmonty Posted March 12, 2010 Report Share Posted March 12, 2010 no it's normal for there to be the spacer within the hub. Try taking the wheel back off again. and sticking your fingers where the axle goes and rotate the wheel. you need to ascertain if the knock is from the wheel or not. Is it not obvious from listening where the knock is comming from. try this. With the wheel in place and tightened up on the bike. Place a screw driver just on the axle opposite side to the brake as near to the wheel as you can. Spin the wheel and stick your ear to the screw driver. see if the knock is coming from inside the hub! Quote Link to comment Share on other sites More sharing options...
chris morris Posted March 12, 2010 Report Share Posted March 12, 2010 It needs the spacer between the bearings to stop the bearings being crushed when you tighten up the spindle. The o' ring is there to hold the spacer concentric in the hub, but also to allow it to pivot out of the way when removing the bearings Quote Link to comment Share on other sites More sharing options...
pete_scorpa3 Posted March 12, 2010 Report Share Posted March 12, 2010 no it's normal for there to be the spacer within the hub. Try taking the wheel back off again. and sticking your fingers where the axle goes and rotate the wheel. you need to ascertain if the knock is from the wheel or not. Is it not obvious from listening where the knock is comming from. try this. With the wheel in place and tightened up on the bike. Place a screw driver just on the axle opposite side to the brake as near to the wheel as you can. Spin the wheel and stick your ear to the screw driver. see if the knock is coming from inside the hub! Just a word of warning. It sounds really stupid now, but I had a rumbling front wheel bearing so I put the bike on a paddock stand and spun the front wheel to se if I could work out where the noise was coming from. I realised that it was the bearing, and something made me put my finger through the hole in the disc..... as the wheel was spinning. Luckily it didn't sever my finger but it was a bloody good cut!!! Quote Link to comment Share on other sites More sharing options...
hrcmonty Posted March 12, 2010 Report Share Posted March 12, 2010 Oh dear. Not best to put fingers in moving parts. Like i said though take the wheel off, and just spin the wheel on your fingers. Quote Link to comment Share on other sites More sharing options...
caddabs Posted March 12, 2010 Author Report Share Posted March 12, 2010 Thanks All - will have a good look over the weekend and try to keep my fingers intact Might be a duff bearing, but difficult to put the old ones back in now as they came off worse from a good wack with a screwdriver/hammer combo. if i cant trace it - might just rev it harder so i cant hear it ! Cheers - Caddabs Quote Link to comment Share on other sites More sharing options...
houseape1000 Posted March 12, 2010 Report Share Posted March 12, 2010 (edited) You say you've changed the tyre........is it seated properly, also you might have left a tyre lever in it.....no........maybe not ! You didn't whack the new bearings in with that screwdriver did you ? When it knocks, is it at a certain point every time, keep an eye on the valve as a reference point. Edited March 12, 2010 by houseape1000 Quote Link to comment Share on other sites More sharing options...
caddabs Posted March 13, 2010 Author Report Share Posted March 13, 2010 Tried the screwdriver to the ear test and it sounds like its coming from the hub. took it out and tried the finger in each bearing test and it still knocked. took the disk off and tried again and it stopped !! Put disk back on, re-assembled, and it still knocks. oh well - at least its not a bearing. i think i can live with it and apologies to those who suggested it was the disk - you were right ! Cheers - Caddabs Quote Link to comment Share on other sites More sharing options...
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