bultacorock Posted November 10, 2014 Report Share Posted November 10, 2014 (edited) Hello ...... if you have a bit of free time it would be great to get some feed back on my chain jamming My Chain jammed full of clay, sand and started to jump and jammed with a small stone just at the right time to get a 5, some one spotted the stone and managed to get it out for me, the chain was sat almost on top of the teeth on the back sprocket and trying to do the same at the front. I readjusted the rear wheel so the chain was much slacker to try and give it space to clear its self which it did ( a tip a rider gave me on the day ) and then needed reajusting when enough of the mud had gone so that the chain was sitting right. because was now way too lose ,any way it was never really right after wards. Has any one had this kind of thing happen to them, It was very wet an the event was in a sand quary it seems like a mix of liquid clay & sand which bulids up and drys on the bike, it happend a bit in the same place in the summer. Is the a chain lube that works better at muddy events to help stop the mud sticking to the chain. Thank you all for your help with this BR Edited November 13, 2014 by bultacorock Quote Link to comment Share on other sites More sharing options...
woody Posted November 10, 2014 Report Share Posted November 10, 2014 If you haven't got a chainguard, that is the reason. A chainguard needs to completely block off the tyre between the top and bottom chain run, otherwise the tyre just deposits mud on the top of the chain on the bottom run which then gets dragged between the chain and sprocket. The guard will also stop mud being carried onto the front sprocket. Slackening the chain won't stop mud building up If you have a guard fitted make sure it is effective and blocks off the tyre from the chain. 3 Quote Link to comment Share on other sites More sharing options...
bondy Posted November 10, 2014 Report Share Posted November 10, 2014 sorry for butting in woody wasn't there an extra piece off chain guard at the front to cover the front sprocket? Quote Link to comment Share on other sites More sharing options...
sirdabalot Posted November 10, 2014 Report Share Posted November 10, 2014 The worst examples ive had on the subject were in mx and enduro. Most events were muddy and it was wise to run the chain slack in anticipation of the mud embedding itself into the chain. I had a chain snap due to a stone doing as you describe, the stone was sitting between the gearbox sprocket/casing and had a witness mark on it from the chain/sprocket. Ive seen it at mx races too. Fitting chainguards may help, my enduro bike had one, but it didnt stop the stone on mine. I did try using dry graphite lubricant but it didnt seem any better than just running the chain dry or using wd40, normal chain oil turned the sand/mud into grinding paste, so not recommended. Hope this helps. 1 Quote Link to comment Share on other sites More sharing options...
dadof2 Posted November 10, 2014 Report Share Posted November 10, 2014 You need mud relief grooves in your sprockets, sometimes new sprockets can be supplied with these already in. Rig up sprocket scrapers for both front and rear sprockets, most MX bikes have these integrated with a chain guide for the rear sprocket. 1 Quote Link to comment Share on other sites More sharing options...
geniejlg Posted November 10, 2014 Report Share Posted November 10, 2014 Hello Bultacorock, I have experienced this only once, I entered a trial to give my recently built cub it's first run out and was dismayed 1/2 way round the 2nd lap when a similar thing happened, the cub is the only bike I have with 420 chain fitted but I suspect the problem was a combination of new chain, new sprockets very tight tolerance's and the consistency of the mud and importantly the 'sand' taking up the space so preventing the chain fitting on the sprocket. Only needs the odd grain on the odd tooth to prevent the chain dropping in to the sprocket. Only sussed it when I had packed up and gone home. Regards 1 Quote Link to comment Share on other sites More sharing options...
pschrauber Posted November 10, 2014 Report Share Posted November 10, 2014 The main issue to the Bultacos are the gap between airbox and swing axle, there a lot of mud will be piled up when riding under muddy circumstances and some of this debris will fqall over to the chain as there is a longer distance between swing axle and front gear. The mud there will be collected by the shaft of the kicker and stay there too. Easiest way to protect the chain and keep it cleaner is to mount an additional rubber flap at the lower end of the airbox that works as a mudguard / fender extension. Then there was an protection plate for the chain mounted in the gap betqween swing arm and front sprocket to the Sherpa which was needed for some countries to make the motorcycle road legal but difficult to find or you make your own. Additional you can use dry chain lube that isn't sticky this helps too a lot. 1 Quote Link to comment Share on other sites More sharing options...
wobbler Posted November 10, 2014 Report Share Posted November 10, 2014 Move up north !!! Then just rocks to smash it on. Sorry I can't be of more help!! Cheers The wobbler 1 Quote Link to comment Share on other sites More sharing options...
woody Posted November 10, 2014 Report Share Posted November 10, 2014 It's pretty straightforward... if you ride in deep stodgy mud, the mud will stick to the tyre sidewall and get carried around as the tyre rotates. If the build up of mud is thick enough, and you haven't a chainguard, or one of the right depth, the chain will act as a scraper and slice the mud off the tyre which will then sit on the chain as it goes onto the sprocket. If the mud is thick enough or has stones or grit in it, expect trouble as it will unseat the chain Running the chain slack won't prevent this, it's impossible, as the stone or grit will still go between the chain and the sprocket. Running the chain slack will just increase the chances of it jumping off the sprocket if the suspension rebounds quickly On motocross / enduro bikes it's not such a problem as there is a lot more clearance between tyre and chain Bondy, I've no idea as I've never had an original guard fitted. 2 Quote Link to comment Share on other sites More sharing options...
twinnshock Posted November 10, 2014 Report Share Posted November 10, 2014 (edited) When I bought my brand new 198 in 1978 it was fiited with a flimsy sheet metal guard over the front sprocket. This fitted to the engine using the retaining bolt of the clutch cam in the magneto cover and bolted to the frame near the foot rest. This guard was more of a finger guard and would not have stopped the mud/stone issue being dicussed. Almost the first thing I did when I got this bike was to take this guard of and throw it away. I can not ever recall seeing a bike being ridden with one fitted. Stuart Edited November 10, 2014 by twinnshock 1 Quote Link to comment Share on other sites More sharing options...
jon v8 Posted November 10, 2014 Report Share Posted November 10, 2014 Obviously its harder on a bike with rear suspension as everything moves.But the chainguard on my AJS is the most effective on any bike I've ever had,unless there is really deep,sloppy mud I often don't need to even clean or lube the chain for 2 or 3 trials. 1 Quote Link to comment Share on other sites More sharing options...
woody Posted November 10, 2014 Report Share Posted November 10, 2014 Probably a little more substantial than I was thinking....... but illustrates the point nicely about masking off the tyre Looks very much like a Bultaco guard Quote Link to comment Share on other sites More sharing options...
bultacorock Posted November 12, 2014 Author Report Share Posted November 12, 2014 (edited) Thanks to every one for your feed back it all helpful to me Thanks again Woody, i have what i think is the standard soft plasic Bultaco chain gard, may be it has a bit cut off the bottom it only covers the top run of the chain, i can see what you mean about the tyer dumbing mud on the chain, now that you have pointed it out to me. I have orderd a alloy chain gard from BUK. the one i have is way past its best. Thanks again Pschrauber I fitted front wheel mud flap to the bottom of the air box like you told me in a tip you gave just after i finish rebuilding my bike it really works well thanks. Thanks againg for all your feed back BR Edited November 13, 2014 by bultacorock Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.