ghosts_cloak Posted September 23, 2005 Report Share Posted September 23, 2005 Hi guys, I have had my trials bike for a couple of weeks now, and I just gave it the once over checking bolts hadnt worked loose etc and the wheels were true. I checked the crank bolts and one of them (right) tightened up quite a bit. They are Middlesburn Pro trials crank on a Square taper UN53 BB. I just read on the net that you shouldnt re-tightnen crank bolts once they have been installed properly or you will spilt the crank? Mr Leeson really put them on tight when we built the bike. So, are you supposed to keep the crank bolts as tight as you can or once there on should I just leave them well alone? I was using a LONG allen key from Tartybikes by the way for plenty of leverage. Thanks guys, I cant afford to damage my cranks so advice is appreciated! ~Gaz Quote Link to comment Share on other sites More sharing options...
RicH_87 Posted September 23, 2005 Report Share Posted September 23, 2005 never had a set of burns myself but i thought it was common knowledge that all crank bolts should be kept tight at all times. It's loose bolts that are gonna lead to your cranks getting rounded or whatever. I personally check and tighten my crank bolts before every ride, (so i don't have to carry the fat 8mm allenkey around mainly). But yeh, if they were mine, i'd be tightening them too, and making sure they stayed tight at all times. Quote Link to comment Share on other sites More sharing options...
Tomm Posted September 23, 2005 Report Share Posted September 23, 2005 Yeah, I've not heard of cracking the cranks or anything, it would be far worse to ride them loose! Having said that, you don't want to go tightening them up so much that you shear the bolt head - That would not be good. But that's very unlikely, and probably very hard to do. Just keep them moderately tight, and check they're not loose. If they keep coming loose, get some loctite on the bolts. Quote Link to comment Share on other sites More sharing options...
JIX Posted September 23, 2005 Report Share Posted September 23, 2005 (edited) Once you have ridden it a few times you should check they are tight, and tighten where nessecery as tight as you can with your hand and the long allen key. Once middlerburns are done up tight they wont come loose very often if at all. Just give it a check once in a while and they will be fine. Good to see you went for the middleburns :sleeping: EDIT: Sorry wrong person I was think of B) Edited September 23, 2005 by JIX Quote Link to comment Share on other sites More sharing options...
Littleharrys Posted September 23, 2005 Report Share Posted September 23, 2005 Hey Man, I have middleburns. My bolts don't loose very often, you can tell usually because as you pedal you will here a little squek each time the cranks go round. When it does happen I tighten the bolts as hard as I can with a park tool allen key which is fairly long. They are about 3-4 years old and not split yet. When you do them up, make em tight, ie solid power. But dont jerk the allen key or hit it with a hammer cos the sudden pressure will snap the bolt. Its a bit of common sense, do em up tight but don't go for a strong man contest, cos if there not quite tight enough then you can always do them again, but if you snap the bolt the you stuffed. You can get a torque wrech otherwise which measures how tight the bolt is and set it to the recomended level by middleburn, but there not the cheapest tools. H Quote Link to comment Share on other sites More sharing options...
Canned Posted September 23, 2005 Report Share Posted September 23, 2005 I have the same thing happening to my TRex.... I keep an allen key with me most times and if it works loose and I've forgotten it, I'll stop cos it's just not worth it. haven't tried the locktite yet - intend to give it a go soon though. I think I'll go for an Isis BB if any failure happens at the crank... Quote Link to comment Share on other sites More sharing options...
andyroo Posted September 23, 2005 Report Share Posted September 23, 2005 A rubber mallet is good for tightening the bolt, because you can get it tight, but being rubber its absorbs some of the shock so doesnt allow you to suddenly snap the bolt or do it too tight. Rubber mallets rule :) Quote Link to comment Share on other sites More sharing options...
Mark W Posted September 23, 2005 Report Share Posted September 23, 2005 Allen key > Rubber mallet. Typically, new parts need to bed in, and new cranks/BB's love the whole "Let's get loose" game. Just tighten it up good 'n' proper, and repeat whenever it feels like the axis of your crank spinning goes "funny". It'll feel like it's dropping away. Anyway, yeah, just tighten it whenever it does that, and after some time it'll go away. Alternatively, you can just threadlock it in place :) I've never, ever heard of a crank 'splitting' because of over-tightening. The bolt is gonna go waaaaaaay before the crank arm. If you're super paranoid, take it to your local bike shop, and ask them to do it up with a torque wrench. Typically, manufacturers seem to recommend 35-40fl/lbs (or whatever the crap the imperial measurement is), but 40-45 always does it for me. Quote Link to comment Share on other sites More sharing options...
Tom Booth Posted September 23, 2005 Report Share Posted September 23, 2005 Ive had my burns about 4 month and only tightend them about 4 times in the first few weeks, then after that the bolt stayed solid. Im preety happy about it aswell, i think the rust just holds the bolt in place lol. Good luck Gaz, keep riding dude (nice bike btw!!!) Cheers Tom Quote Link to comment Share on other sites More sharing options...
ghosts_cloak Posted September 23, 2005 Author Report Share Posted September 23, 2005 Hiya :lol: Thanks for the advice everyone! Yeah, I am a little over-cautious with my bike with it being new, and also because its the first bike I have ever looked after myself! (used to be serviced for me) I thought that the bolts might work loose initially, which they seem to have done, so its a good job I checked - and I will keep checking! I dont think (touch - wood) I would break the bolt by over tightnening - Im not exactly bulging with muscle :) Thanks Tom, I think its an awesome bike :P ~Gaz Quote Link to comment Share on other sites More sharing options...
MesaMan Posted September 25, 2005 Report Share Posted September 25, 2005 A rubber mallet is good for tightening the bolt, because you can get it tight, but being rubber its absorbs some of the shock so doesnt allow you to suddenly snap the bolt or do it too tight. Rubber mallets rule (Y) Think about that for a while! If the rubber absorbs some of the shock then it's also absorbing some of the energy required to tighten the bolt - so it's counterproductive. It's like a boxer's gloves. Unless you're a little 6yr old girl you should be able to tighten the bolt with a nice smooth but powerful hand turn. If you're Mr Universe you might sheer the bolt but that's a bit extreme unless a shock force is applied. Quote Link to comment Share on other sites More sharing options...
Simpson Posted September 25, 2005 Report Share Posted September 25, 2005 Ever since my crank arm fell off in london without an 8mm i decided that i would never let this happen again, there only duro cranks and a wank BB, so if i changed id change it all. I got a 6 foot lead pole and lock tight and made sure that bitch wasnt coming off again!!! Quote Link to comment Share on other sites More sharing options...
ghosts_cloak Posted September 25, 2005 Author Report Share Posted September 25, 2005 Ever since my crank arm fell off in london without an 8mm i decided that i would never let this happen again, there only duro cranks and a wank BB, so if i changed id change it all. I got a 6 foot lead pole and lock tight and made sure that bitch wasnt coming off again!!! (Y) You dont say?! The leverage must have been immense!! Im surprised that didnt break something! Is it still working okay then? ~Gaz Quote Link to comment Share on other sites More sharing options...
andyroo Posted September 25, 2005 Report Share Posted September 25, 2005 Think about that for a while! If the rubber absorbs some of the shock then it's also absorbing some of the energy required to tighten the bolt - so it's counterproductive. It's like a boxer's gloves. Unless you're a little 6yr old girl you should be able to tighten the bolt with a nice smooth but powerful hand turn. If you're Mr Universe you might sheer the bolt but that's a bit extreme unless a shock force is applied. I only got a lickle alan key (Y) Quote Link to comment Share on other sites More sharing options...
Simpson Posted September 25, 2005 Report Share Posted September 25, 2005 (Y) You dont say?! The leverage must have been immense!! Im surprised that didnt break something! Is it still working okay then? ~Gaz Yep! not going to come off again are they! was just a case of i'd had enough and they were GOING to stay on or snap off and thread something, but hey it worked, want to get new cranks soon though (Y) Quote Link to comment Share on other sites More sharing options...
pashley pro Posted September 25, 2005 Report Share Posted September 25, 2005 i wouldnt put locktite on as they will be hard to remove. use PTFE tape that should stop it coming loose Quote Link to comment Share on other sites More sharing options...
Simpson Posted September 25, 2005 Report Share Posted September 25, 2005 Its a mechanics locktite which my dad took from the work shop to do studs up with, its like hard to undo but then it cracks and will come off easy its a more mild formula still called locktite though Quote Link to comment Share on other sites More sharing options...
george_bush Posted September 25, 2005 Report Share Posted September 25, 2005 On my cranks i put some thick greace on the threds of the crank bolts and they now rairly come loose. However this might just be my bike. Quote Link to comment Share on other sites More sharing options...
Simpson Posted September 25, 2005 Report Share Posted September 25, 2005 On my cranks i put some thick greace on the threds of the crank bolts and they now rairly come loose. However this might just be my bike. But greese is a lubricant :D not saying i dont belive you because im sure its true but...... grease? Quote Link to comment Share on other sites More sharing options...
CurtisRider Posted September 26, 2005 Report Share Posted September 26, 2005 grease is fine for me i rarely tighten my sqr taper cranks on my mod, just do them up a few times when new, and they seem to stay happy, i check them every so often and they dont seem to have budged :D just give them a proper tighten, really go for it, and then go ride and you should be able to forget all about it..... Quote Link to comment Share on other sites More sharing options...
Mark W Posted September 26, 2005 Report Share Posted September 26, 2005 Don't forget with square taper cranks though you can and will stretch the tapers on them if you over-tighten them. That killed my last set of cranks off, anyway. I'd overtightened them too much, so even with a 127.5mm BB, I couldn't get an ACS Claw on up front, tabs or no tabs :D Problems of being He-man I guess. Quote Link to comment Share on other sites More sharing options...
Littleharrys Posted September 26, 2005 Report Share Posted September 26, 2005 Or just that you don't know what your doing? Either way, funny!! :P Quote Link to comment Share on other sites More sharing options...
Mark W Posted September 26, 2005 Report Share Posted September 26, 2005 Or just that you don't know what your doing? Either way, funny!! :P No, it's just that I overtightened them once when I wasn't using a torque wrench, and lo, the die was cast. I wouldn't say I "Didn't know what I was doing"... Quote Link to comment Share on other sites More sharing options...
spangler Posted September 27, 2005 Report Share Posted September 27, 2005 (edited) I tighten mine loads and the always creek no matter what i do, but i prefer them to be tight anyway. Edited September 27, 2005 by spangler Quote Link to comment Share on other sites More sharing options...
T-Limburn Posted September 28, 2005 Report Share Posted September 28, 2005 if the cranks bb and crankbolts are new then they do need a little while to bed themselves in, so after a short while they will stop coming loose - or atleast they should do. Quote Link to comment Share on other sites More sharing options...
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