Minion Posted June 6, 2011 Share not sure that i agree... why is the BB thread the way it is? "right side is wrong and left side is right" and it has been tapped by a single threadItalian thread BBs have two sets of RH threaded cut, so they have been tapped with a single thread. English BBs have a left and a right thread, so need different thread cutters for each side. Right hand thread follows the right hand rule: make a thumbs up sign with your right hand, if you turn a RH threaded fastener in the direction of your fingers (anti-clockwise), it will move in the direction your thumb is pointing. Using your left hand, you can see that a LH threaded bolt moves up when it is turned clockwise. To illustrate that cutting thread from the other side won't change the direction, think of a nut and bolt. Both are RH threaded. Put the nut on the table and mark the facing-up side. Pretend this is the side from which the thread was cut. Screw the bolt into the nut - it goes in. Now flip the nut over, so that the mark is on the table (in other words, the nut has been threaded from the other side). The bolt will still thread into it. Link to comment Share on other sites More sharing options...
MacDaddy Posted June 6, 2011 Share How about drilling the hole out, tapping a right-hand thread and fitting a right-hand thread helicoil and just find another right-hand pedal, take the axle from that pedal and fit that to your original left hand pedal.... Shooo, im even confusing myself here (but you get the picture) Link to comment Share on other sites More sharing options...
Dylan Solms Posted June 7, 2011 Share HiI had the same problem, I almost bought a new crank until I got some awsome advice. They told me to take the crank off and take it to an aluminium welder where they filled it with aluminium (of your crank is made of aluminium). The only problem is that they did not have the right drill though,however the bike store did so they drilled the hole and sprayed by crank illuminous green. I also got the other one sprayed and they look awsome.In total, it only cost 200 bucks which is a lot less than a 800 rand crank.So just find your nearest aluminium welder, they fill it and mabye they even have the drill bit, otherwise your local bike store has!Hope it helps and good luck! Link to comment Share on other sites More sharing options...
Tankman Posted June 7, 2011 Share Maybe this will help you remember:Whenever removing pedals, keep the crank in a vertical position like in the photo.Have the handle of the spanner or Allen key point towards the rear of bike (same for both sides) then apply downward force not the best photo but it is all google could find so early in the morning Edited June 7, 2011 by Tankman Link to comment Share on other sites More sharing options...
Johan Bornman Posted June 7, 2011 Share not sure that i agree... why is the BB thread the way it is? "right side is wrong and left side is right" and it has been tapped by a single thread am i being a stupid wannabe? You ask why BB thread (and pedal thread for that matter) is the way it is?If it wasn't, it would unscrew itself through a mechanism called precession.Precession is when a body (in this case the BB itself) rotates around a point that is not in the centre of the body. Thin of a large man and small child. The man holds the child's hands and he swings her around in a circle. If you look at the man's feet you'll notice that he's not rotating exactly around the centre point through his body. His feet actually tap out a small circle around him. This is precession. The earth and the moon does the same. The moon doesn't rotate around the earth with the earth's two poles offering a perfect axle. Earth actually moves in a small circle itself. A car with an unbalanced wheel does the same. The same happens with a BB in the frame's BB shell. The BB spins around its axle, but the axle, thanks to the unbalanced weight of the crank, moves in a small circle. This circle is allowed by the flexibility of the BB shell. We're talking small here. Now, if the two items - the BB shell and BB, are screwed into each other, that movement unscrews the two from each other if the thread is not adjusted to make them screw tighter, not looser. Italian threaded BBs are not adjusted for this phenomena and thus have a tendency to come loose. They have to be extra tight. The same is true for pedals. There is precession in there. In the case of the BB, the two sides are not tapped with the same tool. The right and left side tool are opposites of each other. Link to comment Share on other sites More sharing options...
Captain Fastbastard Mayhem Posted June 7, 2011 Share It does the job, Tankman... Link to comment Share on other sites More sharing options...
dirtrider Posted June 7, 2011 Share If you want another arm pm me . Collect only . Link to comment Share on other sites More sharing options...
TNT1 Posted June 7, 2011 Share A left hand thread started from the back or the front is still a left hand thread. Think about it. A glass of red wine may assist the process. What? As in "a glass of red wine is the same from the top to the bottom or the bottom to the top"? Link to comment Share on other sites More sharing options...
patches Posted June 7, 2011 Share Idiot me stripped the thread of my one SLX crank arm (where the pedal attaches to the crank arm; had no idea the one pedal's thread is opposite direction). Is it possible to dril it out, tap it and retread it? If so, where can this be done, and what can I expect to pay? ~ I hope my terminology is right... Which side is it? Drive or nonn drive? (sorry, I could figure it out by your opposite thread on the pedal detail, but I'm feeling lazy today). I ask, because if it's the non-drive (left side) then you can purchase another one from CRC for about R480 (Excl. shipping and VAT). They seem to only sell the 170mm length and currently don't have stock untill 22/06/2011, so not as good an option as if dirt-rider has what you need... but an option none the less. http://www.chainreactioncycles.com/Models.aspx?ModelID=41814 Link to comment Share on other sites More sharing options...
Captain Fastbastard Mayhem Posted June 7, 2011 Share If you want another arm pm me . Collect only . You carrying a spare? Or are you on the black market? Does the original owner know he's going to be giving this arm away? Link to comment Share on other sites More sharing options...
dirtrider Posted June 7, 2011 Share Not yet but he sure find it missing when he goes for his ride tomorrow morning . I got a room so full of bike sheeet that I cannot find half the stuff . Been looking for a DHX5 Air shock now for 3 days and still haven't found it . But did see a crank when I looked ,. Link to comment Share on other sites More sharing options...
zaShadow Posted June 7, 2011 Share Maybe this will help you remember:Whenever removing pedals, keep the crank in a vertical position like in the photo.Have the handle of the spanner or Allen key point towards the rear of bike (same for both sides) not the best photo but it is all google could find so early in the morning And do you press down to release the pedal then? Link to comment Share on other sites More sharing options...
TNT1 Posted June 7, 2011 Share What happened to lefty-loosey, righty-tighty? Link to comment Share on other sites More sharing options...
AndreZA Posted June 7, 2011 Share What happened to lefty-loosey, righty-tighty? Works on pedals (Right is right but left is wrong) but BB is the other way around. Link to comment Share on other sites More sharing options...
The Drongo Posted June 7, 2011 Share And do you press down to release the pedal then? Link to comment Share on other sites More sharing options...
The Drongo Posted June 7, 2011 Share What happened to lefty-loosey, righty-tighty? The same thing that happened to sense, and sensibility. Link to comment Share on other sites More sharing options...
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