cat-i Posted April 26, 2009 Share the bicycle mechanic appie was at work again today. she managed to fix the problem (she thinks) but a few questions remains: Q1 - what on earth could have caused the rotor to bend so badly? it was fine on the boven-weekend - although i possibly might not have noticed, because the last day of riding was mainly downhill at high-ish speeds with some concentration needed (and shuttles back up) - so it could have been bent and i didn't hear it. Rode the disks on my hardtail for more than a year without any rotor-buckling incidents. i just took a pair of pliers and bent it back where it caught on the brake pads. with an old tube between the pliers' jaws. softly at first, but with no luck, so with quite a bit of force when i realised softly is not going to do it. Q2 - why did i need so much force to bend it back? i was pulling the rotor far beyond where i wanted it, released it, and then it would still wobble in the same wrong direction than before Q3 - how much of this can a rotor take, before snapping? and how often can i true a rotor before it needs replacement? Q4 - at some stage i was considering swapping the front brakes with the hardtail's. The giant got juicy-something, the hardtail got hayes something. the 2 forks are different - looks like there's an adapter on the hardtail's fork to make the hayes fit. would that adapter be brake-specific, or fork-specific? that is - would i be able to use the same adapter on a different set of brakes on the same fork? cat-i2009-04-26 10:40:21 Link to comment Share on other sites More sharing options...
Serendipity Posted April 26, 2009 Share Buy a new rotor. It is like a hanger for the deraileur. You can bend it back and it will work fine for a while but the metal is never quite the same again. For interest sake - a lot of people have the quick release of the front wheel on the same side as the rotor - and invariably you tend to use the rotor to grip on while you tighten the wheel. This can easily bend your rotor. Link to comment Share on other sites More sharing options...
Kranswurm Posted April 26, 2009 Share I can understand what you are talking about.Its a toss up between my major crash in Nov or the rock I hit about a month later.Either way i am amazed at how easy it is to bend it but how difficult it is to staighten.I have tried but I think the tolerance is so fine that its a better bet to just buy a new one.Problem solved.No more cheep cheep Link to comment Share on other sites More sharing options...
Capricorn Posted April 26, 2009 Share Q1:a high speed impact could have done it. Check the edges for dents and gashes which might prove the supposition of an impact. Q2: rotors are normally made of steel, which are quite stiff, but not so stiff they become brittle. remember, they going to get quite hot, and should function under severe braking even in cold conditions, and thus be able to withstand relative extremes of temperature. Q3: Adapters tend to be brand specific because of slight differences in mounting holes. However, it wont hurt to check if it fits your juicy brakes. At the end of the day, I would agree with Kranswurm and recommend u simply spend some $$$ and buy a new rotor. Link to comment Share on other sites More sharing options...
Daxiet Posted April 26, 2009 Share Juicy's normally pair up with Avid Clean Sweep rotors. These are so far the best rotors I have ever owned, but they sell for ~R360-R400. You can get cheaper rotors, but I would recommend sticking to the Clean Sweeps. On how do they bend very badly, could only be an impact, eg. flying rock, etc. You should be able to switch the Hayes with the Avid's, so far the brackets I have used have been much of a muchness. But I would stick with the Avids, the brake mechanism can't be blamed for a rotor bending. On the fork, does you Giant have a Fox post mount - eg. brake caliper mounts directly on to threaded holes on the fork. Your HT fork is "IS" mount, it screws into a bracket that the brakes on screwed onto? If your Giant has post mounts on the fork, you just eliminate the little bracket. You can steal the rotors from you HT and stick them on your Giant provided they are both the same mount - eg. Center Mount or 6-bolt.Daxiet2009-04-26 14:18:44 Link to comment Share on other sites More sharing options...
darnijl Posted April 26, 2009 Share There are quite a few discs for sale on the hub aren't there..? Link to comment Share on other sites More sharing options...
cat-i Posted April 27, 2009 Share Juicy's normally pair up with Avid Clean Sweep rotors.... but I would recommend sticking to the Clean Sweeps. You should be able to switch the Hayes with the Avid's' date=' so far the brackets I have used have been much of a muchness. But I would stick with the Avids, the brake mechanism can't be blamed for a rotor bending. On the fork, does you Giant have a Fox post mount - eg. brake caliper mounts directly on to threaded holes on the fork. Your HT fork is "IS" mount, it screws into a bracket that the brakes on screwed onto? [/quote'] thank you, daxiet, you were spot on with what the HT and the giant's forks look like i got the rotor fixed enough to manage a 70-kay ride in chickenpie-area, so i hope it would be ok for sani2c. with the switch, i was thinking of switching them over permanently (cos it's just too much trouble to switch back, so the juicy's would have to go on the HT and then i could fix the rotor later - i still use the ht very often. don't know what i have, ther's lots of writing on (size, bolt torque, rotation direction, but the only branding is 'avid') ... i love the name cleansweep .... sounds like the broom the wizards play quidditch with - might just get myself one of those to improve my flying haha no i wasn't blaming the brake mechanism for bending the rotor ... on tracing back, i realised it might have been from a fall at boven, so i am to blame one more question:do i need to pay attention to the 'bolt torque'? i assume it's got something to do with how tight the bolts must be when you mount the thing? if i do decide to replace the thing (later, when i manage to bend it again), then how would i know when it is too tight? and does it matter what order i tighten the bolts, like a car's wheel, or can i tighten them in any order? Link to comment Share on other sites More sharing options...
Daxiet Posted April 27, 2009 Share I haven't made use of a torque wrench when bolting on my rotors, I think they are meant to be 6NM, which isn't very tight. I use an allen key I got with a set of Hayes rotors, the shaft is short enough to ensure I don't really risk stripping the thread on the hub (softer of the 2). Don't think which order you tighten them is really that important, it's not a cylinder head, but I tigthen them in a criss-cross fashion just incase. Put all bolts in, tighten them a bit, then once all are in and semi tight, start tightening them each gradualy to an estimated 6NM. Rather than swap the brakes swap the rotors!, I am using Hayes 6-bolt rotors with my Avid Juicy's, they work fine together, they did at some stage squeak really bad, but that bad phase has passed. On the Cleansweep, they may have a label G2 or G3, but in short they are good little guys. Daxiet2009-04-27 12:06:08 Link to comment Share on other sites More sharing options...
Guest Big H Posted April 27, 2009 Share You get a tool that you use to bend rotor blades back into shape. I used one on the MTB Tandem and it runs straight now. This is one.... http://www.parktool.com/images/products/productimages/det_DT-2_200598_61713.jpgIf you are handy with your hands and can work metal, I am sure you can make one, or even better, if you know somebody who drives an Alfa Romeo, they have to be technical and work on their own cars, get him to make you one!!!!!!! There has also been persistant rumors that you can place the rotor on a solid stove plate and heat it up with a pot filled with water on it. I do not really believe this and has never tried it but the advice comes up time and again. Link to comment Share on other sites More sharing options...
Daxiet Posted April 28, 2009 Share There has also been persistant rumors that you can place the rotor on a solid stove plate and heat it up with a pot filled with water on it. I do not really believe this and has never tried it but the advice comes up time and again. Yes, the hot stove... I'm not sure if that has ever worked for anyone. But I sheepishly admit I have tried this. Should have know better, metal heated will deform/discolour badly. But the rotor was stuffed, so it was worth the laughter and ridicule from my wife. Check the pic, all that weight and the rotor still warped up, even after letting it cool under this pressure. So in short I won't recommend wasting time on this, plus it discolours the stove top. http://i266.photobucket.com/albums/ii273/daxiet/potandrotor.jpg Link to comment Share on other sites More sharing options...
KevinV Posted April 28, 2009 Share There has also been persistant rumors that you can place the rotor on a solid stove plate and heat it up with a pot filled with water on it. I do not really believe this and has never tried it but the advice comes up time and again. Yes' date=' the hot stove... I'm not sure if that has ever worked for anyone. But I sheepishly admit I have tried this. Should have know better, metal heated will deform/discolour badly. But the rotor was stuffed, so it was worth the laughter and ridicule from my wife. Check the pic, all that weight and the rotor still warped up, even after letting it cool under this pressure. So in short I won't recommend wasting time on this, plus it discolours the stove top. http://i266.photobucket.com/albums/ii273/daxiet/potandrotor.jpg[/quote'] Daxiet, thanks for being the "mythbuster" on this one! Link to comment Share on other sites More sharing options...
cat-i Posted April 28, 2009 Share hahaha you spare me the trouble of trying that out, then. thx again. Link to comment Share on other sites More sharing options...
NotSoBigBen Posted April 28, 2009 Share Cat-i you ready for nonstop? Link to comment Share on other sites More sharing options...
Johan Bornman Posted May 1, 2009 Share Myth busted. At last. Thank you. Link to comment Share on other sites More sharing options...
cat-i Posted May 4, 2009 Share Cat-i you ready for nonstop? hi bigben - got the msg only now and yes, as ready as we could be - hope yo enjoyed yr ride ... will post in the sani2c thread. Link to comment Share on other sites More sharing options...
cat-i Posted May 4, 2009 Share k, so if the rotors are intechangable, i have interchangable front wheels, for all intents and purposes - cool i can just see the fron wheel maintenance going downhill from here ... Link to comment Share on other sites More sharing options...
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