Martin Reynolds Posted August 27, 2012 Report Share Posted August 27, 2012 Problem Solved? 3 Link to comment Share on other sites More sharing options...
dngr2self Posted August 27, 2012 Report Share Posted August 27, 2012 At the moment I'm trying to get the local council to cushion all walls, curbs, pavements and rocks to make them safer. I've also just bought an outfit similar to the one pictured above. I'm still not completely happy though so if anybody has any suggestions how to make trials safer please let me know. 1 Link to comment Share on other sites More sharing options...
eskimo Posted August 27, 2012 Report Share Posted August 27, 2012 Good work. You only but learn from your mistakes. I once spun my wheel when drying the rim. Remember to press your finger in the same direction Ouch. 1 Link to comment Share on other sites More sharing options...
Topsy Posted August 27, 2012 Report Share Posted August 27, 2012 but the torque spec is serious on those, and longer bolts and adding material to the join, would probably require some re-engineering. I'm pulling my rotors off in the next couple of days since I've got a torque wrench to bolt them back on I have seriously never ever seen a bicycle mechanic working on a bike with a torque wrench. None at. and I've seen them so pretty much everything..^^ So I don't think that it should be a big concern. 1 Link to comment Share on other sites More sharing options...
Pazu Posted August 27, 2012 Author Report Share Posted August 27, 2012 Firstly, no it is a childrens tv character called Basil Brush. Secondly, longer bolts is an easy task. You can pick up some bolts from any half decent hardware store or engineering firm, not sure what you mean by adding material to the join though??? Basil Brush, huh. He looks just like Star Fox. I mean that adding material between the rotor and the bolt head might affect the performance or shear resistance of the rotor assembly on the hub, depending upon the material. Aluminum as you suggested would probably be less of an issue than epoxy and carbon fiber. The bolts might have to be tighter - but then the aluminum of the hub will only handle a certain torque before the tapped threads weaken or strip. And adding more dimension between the bolt head and the hub than what was originally there, might lessen the shear resistance of the assembly. Also the bolts could loosen with the addition of softer material in there. And, as the distance between the bolt head and the threads that it screws into increases, the lateral strength of that bolt is going to decrease. Would that matter in this instance? I don't know, what do you think. Link to comment Share on other sites More sharing options...
onza pro series guy Posted August 27, 2012 Report Share Posted August 27, 2012 3 Link to comment Share on other sites More sharing options...
dngr2self Posted August 27, 2012 Report Share Posted August 27, 2012 This is a serious question. Why worry about people losing fingers when the act of riding trials is a lot more dangerous? 3 Link to comment Share on other sites More sharing options...
Pazu Posted August 27, 2012 Author Report Share Posted August 27, 2012 I can see the point about rotors being potentially dangerous, but so are drop offs, gaps and other trials obstacles. Valid point to be sure. Trials is dangerous and those moves compound the danger. Still it is so worth the risk to try. I think it also worth mitigating unnecessary risk. Chain/sprocket jambs, also risky and I'm not doing anything about that. All I'm working on is denying brake rotors a free lunch for 2 trials bikes. And having fun with people here, working out the bugs in an hypothetical product idea. This is one of those things, isn't gonna be worth it for everyone but so far it's worth it to me. Link to comment Share on other sites More sharing options...
dngr2self Posted August 27, 2012 Report Share Posted August 27, 2012 I'm not saying it's a bad idea but it strikes me as strange thats all. A bit of a contradiction. Link to comment Share on other sites More sharing options...
Pazu Posted August 27, 2012 Author Report Share Posted August 27, 2012 (edited) I have seriously never ever seen a bicycle mechanic working on a bike with a torque wrench. None at. and I've seen them so pretty much everything..^^ So I don't think that it should be a big concern. Fair enough. Barnett's manual cites 55 in-lbs in a sequence of 1, 3, 5, 2, 4, then 6 for rotors with Loctite 242 on used bolts. I was citing best practice. Probably not difficult to hit that torque by feel, once you have stripped out a few rotor positions in practice. A torque wrench is not terribly expensive, I use a small Venzo VPT socket wrench. It came with allen key heads & a T25. It is NM so I have to look up the in-lbs in a chart however. Edited August 27, 2012 by Pazu Link to comment Share on other sites More sharing options...
Pazu Posted August 27, 2012 Author Report Share Posted August 27, 2012 I'm not saying it's a bad idea but it strikes me as strange thats all. A bit of a contradiction. I respect your position on this, and I do see the irony of it. My shins are all cut up and I'm not going on about a need for pedal guards. The spokes are dangerous, but I'm not taping them off. Part of this is opportunism I suppose; There's a slim chance that this is a niche product that could keep itself afloat, in some circles. Mostly though, it's about possibly saving some fingers. Why not beat up the idea a bit, to see how it holds up. Would saving a few fingers, be worth the effort? How would we ever know that the fingers were really saved? Would the visual deterrent of the guard, be sufficient? Let me get back to you on this. Link to comment Share on other sites More sharing options...
dngr2self Posted August 27, 2012 Report Share Posted August 27, 2012 I've never used a torque wrench, never stpipped a hub thread and never had a loose rotor. And I'm not alone. Manufacturers guidlines are all good but the implication that it'll all go wrong if you don't follow them is a bit far fetched. I also still have all my finger tips. If you spent half the time creating a solution to this supposed problem as you have to replying to peoples sarcastic replies then this thing would have been proto'ed, tested and put into production by now. 6 Link to comment Share on other sites More sharing options...
Topsy Posted August 27, 2012 Report Share Posted August 27, 2012 I'm still all for neon coloured translucent plexi snap-on things for the kids Link to comment Share on other sites More sharing options...
Pazu Posted August 27, 2012 Author Report Share Posted August 27, 2012 I've never used a torque wrench, never stripped a hub thread and never had a loose rotor. And I'm not alone. Manufacturers guidlines are all good but the implication that it'll all go wrong if you don't follow them is a bit far fetched. I also still have all my finger tips. If you spent half the time creating a solution to this supposed problem as you have to replying to peoples sarcastic replies then this thing would have been proto'ed, tested and put into production by now. Okay. Best practice, is what it is. Doesn't imply anything else. I am reading a lot of suggestions along the lines of, "Trials is inherently dangerous therefore lessening the danger of one minor aspect of trials, is pointless." This is logical fallacy. The fact that trials is inherently dangerous, does not in any way make pointless a lessening of the dangers involved. Not that I mind the criticism. I value learning what others think of the idea, particularly when there is detail. The thread began as a warning to newbs like me and it has served that purpose. I can't move further forward until the Gflex epoxy arrives. That should be tomorrow. I have already created the solution and it is on the bike. It just needs mega-refinement. It's working already. Link to comment Share on other sites More sharing options...
dngr2self Posted August 27, 2012 Report Share Posted August 27, 2012 I am reading a lot of suggestions along the lines of, "Trials is inherently dangerous therefore lessening the danger of one minor aspect of trials, is pointless." I wouldn't say it was pointless, and I think your idea looks quite good. As you pointed out yourself, it's ironic that you should be concerned about losing a finger when I would have thought that somebody so safety concious wouldn't even consider riding trials in the first place. 1 Link to comment Share on other sites More sharing options...
Pazu Posted August 28, 2012 Author Report Share Posted August 28, 2012 (edited) I wouldn't say it was pointless, and I think your idea looks quite good. As you pointed out yourself, it's ironic that you should be concerned about losing a finger when I would have thought that somebody so safety concious wouldn't even consider riding trials in the first place. Well thanks for that, man. I do see your point. I am learning trials to save my life. So that something can matter again. Anyhow it's personal. I wear some protective gear but I'm not concerned about getting injured falling off of a bike, I'm rugged, I just don't think it fair that I have to keep in mind those dual spinning meat slicers. The guard idea is a passing thought to follow through with for my personal bikes. Some little guy may lose a fingertip at the skate park but tell you what it is not going to be on one of my rotors. Me 1, fate zero and I want for it to stay that way. I have great respect for people with trials skills. Trials bikes are amazing, fine machines. Not sure how wise it is to run one without a guard though. They are something to admire, pretty fierce, with or without a guard. And something to respect. There is a discipline to the sport. Knowing disc brakes and their use, is a part of that, I get that now. It wasn't great to get bit by that rotor, could have been a lot worse. LIke if it had happened to one of my children. I'll leave fate no quarter there. Edited August 28, 2012 by Pazu Link to comment Share on other sites More sharing options...
onza pro series guy Posted August 28, 2012 Report Share Posted August 28, 2012 Soooo.... when are you gonna carbon wrap every knife in your house? Put sponge on every sharp corner of the furniture, set up saftey nets at every window and on the stairs? When ypu leave the house do you wear armour in case you ge hit by a car?..... It goes on and on, things are dangerous, its nature, yes we should do things to make stuff more safe, but un-expected and fatal dangers, not stuff like this. If your gonna be dumb enough to make the mistake again, or to try it out to see if the danger is still there, you absolutely deserve to have hands like Sir Ranulph Fiennes! Considering there is this pointlessly long thread about it I highly doubt that you will make the mistake again, so all of your effort to make a solution to the, pretty pathetic, problem has been rather pointless. If it's to stop your kids doing it tell them not too, if they still do (which juding by the hoo har you have made out of it I don't think they will) it's their own fault and they will learn from their mistakes like you, and everyone else on the planet has. Or if you really want to make sure it doesn't happen do what you would with other sharp blades, like knifes, and put the bike somewhere they can't get to it, like say a locked shed. Danger exists learn from it and deal with it. P.s I am sorry about this snappy and quite angry reply but this thread has been raping my notifications for days on end. 1 Link to comment Share on other sites More sharing options...
Ben Gosden Posted August 28, 2012 Report Share Posted August 28, 2012 these look to be the safest ones around really, but not great for trials as the rivets could come loose. yeah i had one of these a little while back and it only lasted a while before that center peice became loose. Link to comment Share on other sites More sharing options...
dngr2self Posted August 28, 2012 Report Share Posted August 28, 2012 It's just damage limitation I guess, like wearing a lid or pads. Worrying about your kids is only natural too. The whole tone is a little dramatic though. 1 Link to comment Share on other sites More sharing options...
Pazu Posted August 28, 2012 Author Report Share Posted August 28, 2012 Soooo.... P.s I am sorry about this snappy and quite angry reply but this thread has been raping my notifications for days on end. No problem and thanks for your opinion on the matter. It's not rape when you can choose to unfollow the thread. Seems to me that you are making a much bigger deal of it than I am. You're going off on hypotheticals, I'm trying to stick with the detail of the exercise. Link to comment Share on other sites More sharing options...
Martin Reynolds Posted August 28, 2012 Report Share Posted August 28, 2012 Gotta say, it does look good. Guessing you couldn't make the diameter larger due to it catching on the caliper? 1 Link to comment Share on other sites More sharing options...
Pazu Posted August 28, 2012 Author Report Share Posted August 28, 2012 It's just damage limitation I guess, like wearing a lid or pads. Worrying about your kids is only natural too. The whole tone is a little dramatic though. You nailed it. Obviously I'm trying to write persuasively, to influence people to see this in the way that I do. Can you blame me? It isn't about disc guards, it's about riding, balance, technique, planning, etc. This guard is a small thing. A few guys have a passing interest in what I'm doing so I'm still posting. I hear what you are saying, I call it "risk management." It is part of the responsibility of a father. It doesn't stop with "what did I tell you!" blaming them in some sort of angry tone after the fact just because you thought to mention it once. That doesn't avail you of responsibility for everything that happens to your kid. When there's nobody else around but you or the 10YO to blame, guess what - it's your fault Link to comment Share on other sites More sharing options...
Pazu Posted August 28, 2012 Author Report Share Posted August 28, 2012 Gotta say, it does look good. Guessing you couldn't make the diameter larger due to it catching on the caliper? Thanks. That's right, also the carbon fiber is super slippery so it's hard to cut a straight line, so the circle kept getting smaller... It ended up a bit smaller than necessary. I will impregnate the cloth with epoxy first on the next try, so it will be much easier to cut a perfect disc. The disc fits within the caliper space but it seems like my pads are hitting too low on the rotor. I am hoping to adjust that. The thickness of the CF disc is about 1mm so it won't fit between the pads but passes through the caliper fine. The next one will be something like .5mm because I am going to press the disc flat as the epoxy sets up. Link to comment Share on other sites More sharing options...
Pazu Posted August 28, 2012 Author Report Share Posted August 28, 2012 Hey if anyone knows if an Avid BB5 brake caliper can be moved on its' mount or otherwise adjusted to ride higher on the brake rotor I would appreciate learning that, if possible I would rather make a larger disc but as MR says, at this point the brake pads contact just below the innermost edge of the braking circumference and slightly into that space that I am trying to close. It isn't critical. I've looked it over and haven't found an adjustment, seems like it's a function of the lug position on the frame. Thanks! Link to comment Share on other sites More sharing options...
isitafox Posted August 28, 2012 Report Share Posted August 28, 2012 From a health and safety point of view I'd say moving the caliper higher up is a bad idea, it was designed to hit the disc at a certain point for a reason. You do realise the quick and easy solution to this whole ludicrous thread would be to ditch the discs and run rim brakes. 1 Link to comment Share on other sites More sharing options...
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