Karl Von Posted May 23, 2009 Share Posted May 23, 2009 Well, I finaly got around to swap out the rearend in my brothers Roso Mandello. He snaped the pinion at bike week. Here are the photos Link to comment Share on other sites More sharing options...
Greg Field Posted May 24, 2009 Share Posted May 24, 2009 Small consolation, I know, but that's the only snapped pinion I have ever heard of, even on race bikes. Link to comment Share on other sites More sharing options...
dlaing Posted May 24, 2009 Share Posted May 24, 2009 Could that be a result of not having the U-joints lined up correctly? (ignoring the painted on alignment marks?) Link to comment Share on other sites More sharing options...
pete roper Posted May 24, 2009 Share Posted May 24, 2009 My thought exactly Dave. The forces exerted on the shaft and universals is enormous if the trunnions aren't alligned. It could be a manufacturing fault as well though. Pete Link to comment Share on other sites More sharing options...
Karl Von Posted May 24, 2009 Author Share Posted May 24, 2009 My thought exactly Dave. The forces exerted on the shaft and universals is enormous if the trunnions aren't alligned. It could be a manufacturing fault as well though. Pete The painted marks were lined up when I took it apart. My brother also, babied this bike, no burn outs, wheelies, etc.. I would say it was a defect. Maybe the same guys who are in charge of hardening the cams on the EVs & Griso did pinion shafts also ? Link to comment Share on other sites More sharing options...
richard100t Posted May 24, 2009 Share Posted May 24, 2009 Thats exactly the same place that my Rosso Mandellos pinion snapped. I however admit to trying a wheelie when it snapped. Lesson learned...no wheelies or burnouts with a shafty. Link to comment Share on other sites More sharing options...
richard100t Posted May 24, 2009 Share Posted May 24, 2009 Heres mine Link to comment Share on other sites More sharing options...
Karl Von Posted May 24, 2009 Author Share Posted May 24, 2009 Heres mine He was sitting at a stop light and we all went to leave. I saw he was having trouble and notoced his drive shaft was spinning but the bike was not moving. Strange that it was two Rosso's that had the pinions snap. Maybe it was the sonic wave from the ratteling single plate clutch that broke it Link to comment Share on other sites More sharing options...
dlaing Posted May 24, 2009 Share Posted May 24, 2009 He was sitting at a stop light and we all went to leave. I saw he was having trouble and notoced his drive shaft was spinning but the bike was not moving. Strange that it was two Rosso's that had the pinions snap. Maybe it was the sonic wave from the ratteling single plate clutch that broke it Interesting. I wonder if there is something he can do to reduce the chance of a recurrence. Obviously no wheelies, but some other things might help like, drilling the rubber in the cush drive, and making sure the cylinders are balanced, more frequently, and maybe some other things are critical like swing arm alignment, and suspension sag, maybe paint the bike black, so it will no longer be a Rosso Perhaps the mechanical veterans on the forum have some ideas on the matter? Link to comment Share on other sites More sharing options...
luhbo Posted May 25, 2009 Share Posted May 25, 2009 ....The forces exerted on the shaft and universals is enormous if the trunnions aren't alligned. .... No, that's not correct. It's not as it should be this way, but it won't damage anything. Hubert Link to comment Share on other sites More sharing options...
pete roper Posted May 25, 2009 Share Posted May 25, 2009 No, that's not correct. It's not as it should be this way, but it won't damage anything. Hubert Jesus Hubert. Do you have to disagree with everything I say just on principle? If the trunnions aren't aligned as the suspension moves up and down the shaft winds up like a bloody great torsion spring. The forces are considerable and WILL damage stuff. Sorry but as usual you're talking worrying piffle. If it is so unimportant why the hell do you think every manufacturer since the dawn of time who uses Hookes couplings in driveshafts, (Like all rear wheel drive, front engined, cars.) build their driveshafts with the trunnions alligned? Because it looks prettier? Gimme a break. Pete Link to comment Share on other sites More sharing options...
luhbo Posted May 27, 2009 Share Posted May 27, 2009 Jesus Hubert. ... Here a Hubert only will do, thanks. Anyway, my posting has nothing to do with you personally or with any principles. How come? It's only what you write. The content is wrong, that's all, not the name below it. We had this once already. If you had really understood what's going on at the ends of such a misaligned driveshaft you'd be more carefull with bringing this in context with a snapped off pinion, wildly guessing about enormous forces. Remember, the beemers always used one u-joint only, and they did go up and down, especially under load. What did they do to eliminate those "enormous forces" you're talking off? Hubert Link to comment Share on other sites More sharing options...
pete roper Posted May 27, 2009 Share Posted May 27, 2009 Here a Hubert only will do, thanks. Anyway, my posting has nothing to do with you personally or with any principles. How come? It's only what you write. The content is wrong, that's all, not the name below it. We had this once already. If you had really understood what's going on at the ends of such a misaligned driveshaft you'd be more carefull with bringing this in context with a snapped off pinion, wildly guessing about enormous forces. Remember, the beemers always used one u-joint only, and they did go up and down, especially under load. What did they do to eliminate those "enormous forces" you're talking off? Hubert Smallblocks also only use one coupling. They have a very soft cush drive in the rear wheel. BMW's have a shorter suspension travel and a longer shaft and the forces imposed on a driveline by a single Hookes coupling working at an angle are very much less than the forces imposed by two that are misaligned. Whether you believe this or can understand I give not a fig but I DO worry that your comments may lead people to think that driveshaft alignment is unimportant and not something that should be treated with care. A few years ago there was a bloke who posted here who was having handling problems with his Balablio. He was at the point of selling the bike but just happened to drop past my workshop and I noticed that his shaft was misaligned by only one spline. we fixed it on the spot and he saw fit to mention here how suddenly the bike's handling had been transformed. The forces imposed by misaligned trunnions ARE susbstantial, more than enough to seeriously upset the handling of a 200KG+ bike with a 100KG rider on board. as the shaft winds up and unwinds as the suspension moves those forces will work on the rorque arm and, because every action has an equal and opposite re-action, on the driveline of the bike. I understand FULLY what is happening in that situation and how dire the consequences can be. As usual Hubert, you're wrong, and as in so many cases your statements could have dangerous outcomes for people who choose to listen to them. Pete Link to comment Share on other sites More sharing options...
luhbo Posted May 27, 2009 Share Posted May 27, 2009 ....as in so many cases your statements could have dangerous outcomes for people who choose to listen to them..... Some really have problems with reading a text and understanding it as well. So far I thought this was more a problem of nowadays' youngsters. Hey Pete, I never told anyone to drive around with a misaligned shaft. It's all just about this semisense of huge forces killing this or that. Such things just don't happen. Hubert Link to comment Share on other sites More sharing options...
pete roper Posted May 28, 2009 Share Posted May 28, 2009 Some really have problems with reading a text and understanding it as well. So far I thought this was more a problem of nowadays' youngsters. Hey Pete, I never told anyone to drive around with a misaligned shaft. It's all just about this semisense of huge forces killing this or that. Such things just don't happen. Hubert Errr? Well? the way I read it was, "No, it's not right, but don't worry about it. It won't do any harm." In my humble opinion this is incorrect an dangerous information so I'll argue against it till I'm blue in the tits. Please don't tell me that you're now going to get up on some pompous high horse about me being 'Common' and using 'Bad Language'. That would simply be the icing on the cake Pete Link to comment Share on other sites More sharing options...
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