Maxx Posted December 30, 2010 Report Share Posted December 30, 2010 Hi everybody, I was wondering if anyone here know why Benito put his front brake disk in the wrong way ? this pic : http://www.benitoros.es/blog/wp-content/uploads/foto.jpg thanks Quote Link to comment Share on other sites More sharing options...
Sam Moss Posted December 30, 2010 Report Share Posted December 30, 2010 (edited) i dont think it would matter what way it it. my mates got his front disc one way and his rear disc the other way. Edited December 30, 2010 by Sam Moss Quote Link to comment Share on other sites More sharing options...
Cresswell_d Posted December 30, 2010 Report Share Posted December 30, 2010 Hi everybody, I was wondering if anyone here know why Benito put his front brake disk in the wrong way ? this pic : http://www.benitoros.es/blog/wp-content/uploads/foto.jpg thanks Could it be his 'good side' is to the right and don't want to bend any discs if he messes up. Daz. Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted December 30, 2010 Report Share Posted December 30, 2010 I was wondering if anyone here know why Benito put his front brake disk in the wrong way ? Looks 'correct' on that photo... Quote Link to comment Share on other sites More sharing options...
Little Yoshi Posted December 30, 2010 Report Share Posted December 30, 2010 Could it be his 'good side' is to the right and don't want to bend any discs if he messes up. Daz. Did you even look at the pic? And I ran my disk backwords.More out of rushing to get riding than anything. Never noticed a difference. Quote Link to comment Share on other sites More sharing options...
Cresswell_d Posted December 30, 2010 Report Share Posted December 30, 2010 (edited) Did you even look at the pic? And I ran my disk backwords.More out of rushing to get riding than anything. Never noticed a difference. Nope. It will teach me for not lookin at photos. Edit: wow I would'nt have a clue why he hasn'nt got it the wrong way. Daz. Edited December 30, 2010 by Cresswell_d Quote Link to comment Share on other sites More sharing options...
Maxx Posted December 30, 2010 Author Report Share Posted December 30, 2010 (edited) We can see there are arrows on the surface where the pads brakes and they are in the wrong way. I have the same disk on my Sky 2 but I don't known in which direction I must fix it so I can't ride ... (no others indications on the disk) Here the arrows are more visible : http://www.al4bikes.com/b2c/index.php?page=pp_producto.php&md=0&ref=TB6105036000 Edit : an another pic here, it is also the wrong sens : http://img151.imageshack.us/img151/8435/32671133.jpg Edited December 30, 2010 by Maxx Quote Link to comment Share on other sites More sharing options...
6ft-midget Posted December 30, 2010 Report Share Posted December 30, 2010 It's the right way in that picture too. Quote Link to comment Share on other sites More sharing options...
Maxx Posted December 30, 2010 Author Report Share Posted December 30, 2010 How do you know this ? There is no indication on the disk, just holes which are like arrows Quote Link to comment Share on other sites More sharing options...
j-bonham@hotmail.com Posted December 30, 2010 Report Share Posted December 30, 2010 We can see there are arrows on the surface where the pads brakes and they are in the wrong way. I have the same disk on my Sky 2 but I don't known in which direction I must fix it so I can't ride ... (no others indications on the disk) Here the arrows are more visible : http://www.al4bikes.com/b2c/index.php?page=pp_producto.php&md=0&ref=TB6105036000 Edit : an another pic here, it is also the wrong sens : http://img151.imageshack.us/img151/8435/32671133.jpg The disk is correct in both photos. the "arrows" on the rotor need to point backwards.... Quote Link to comment Share on other sites More sharing options...
Maxx Posted December 30, 2010 Author Report Share Posted December 30, 2010 The disk is correct in both photos. the "arrows" on the rotor need to point backwards.... Ok thanks for the answer, but how do you know that the arrows must point backwards ? Quote Link to comment Share on other sites More sharing options...
aener Posted December 30, 2010 Report Share Posted December 30, 2010 (edited) In about four years of having a disk, I've never had an issue, so it's either an entirely theoretical issue - or only if you use the same rotor for a very long time (hardly the case, in this area of cycling ), but the spiral should lean "forwards". Ie - the way they are pointing in the picture is correct. I'm no materials engineer, but it's something to do with different strengths of the material. It's stronger when being compressed than stretched, and in the idea that most of the time a brake will be used when rolling forwards, it compresses the spiral arms into the centre, rather than pulling them away. I've seen a couple of those floating rotors rend themselves apart under heavy load, and whilst I'm sure it's happened - I've never seen a "normal" rotor do it. That's my very sketchy understanding of it, anyway. Hopefully someone with some actual knowledge instead of a dodgy memory of something I never properly knew can provide a better answer. I'd be rather interested in the specifics, if anyone fancies a good, long type Edited December 30, 2010 by aener Quote Link to comment Share on other sites More sharing options...
Greetings Posted December 30, 2010 Report Share Posted December 30, 2010 How do you know this ? There is no indication on the disk, just holes which are like arrows Why do you assume it's not? The arms should expand in the rotational direction which is why some people ride rear discs installed backwards believing that in trials the rear brake stops the bike from rolling backwards rather than forwards. Quote Link to comment Share on other sites More sharing options...
j-bonham@hotmail.com Posted December 30, 2010 Report Share Posted December 30, 2010 In about four years of having a disk, I've never had an issue, so it's either an entirely theoretical issue - or only if you use the same rotor for a very long time (hardly the case, in this area of cycling ), but the spiral should lean "forwards". Ie - the way they are pointing in the picture is correct. I'm no materials engineer, but it's something to do with different strengths of the material. It's stronger when being compressed than stretched, and in the idea that most of the time a brake will be used when rolling forwards, it compresses the spiral arms into the centre, rather than pulling them away. I've seen a couple of those floating rotors rend themselves apart under heavy load, and whilst I'm sure it's happened - I've never seen a "normal" rotor do it. That's my very sketchy understanding of it, anyway. Hopefully someone with some actual knowledge instead of a dodgy memory of something I never properly knew can provide a better answer. I'd be rather interested in the specifics, if anyone fancies a good, long type Correct, see in this pic how the rotor arm lean forward like a circular saw blade...... ( the red bits ) Quote Link to comment Share on other sites More sharing options...
Maxx Posted December 30, 2010 Author Report Share Posted December 30, 2010 Ok thanks alot ! So on this pic, the front disk brake is really in the wrong direction, why benito does this ? http://img17.imageshack.us/img17/3397/bicisaltarbascula.jpg some people ride rear discs installed backwards believing that in trials the rear brake stops the bike from rolling backwards rather than forwards. And does it really works ? Quote Link to comment Share on other sites More sharing options...
j-bonham@hotmail.com Posted December 30, 2010 Report Share Posted December 30, 2010 Ok thanks alot ! So on this pic, the front disk brake is really in the wrong direction, why benito does this ? http://img17.imageshack.us/img17/3397/bicisaltarbascula.jpg And does it really works ? indeed it looks to be wrong way round. not a clue what difference it make, if any. personally, i don't think it would make any differance to performance..... Quote Link to comment Share on other sites More sharing options...
SamKidney Posted December 30, 2010 Report Share Posted December 30, 2010 (edited) shouldnt they make a rotor with symetrical arms then? If the rotors are designed to take forces when moving forwards but not backwards, surely the stress on the rear rotor ( when going up to back wheel, gaps ect. ) would mean it would crack over time? I had a monty rotor that had been put on the wrong way round, and that cracked quickly. But with another the right way it was fine for ages. I think theres a rotor with symetrical arms that comes with the Try-All edition Hope Mono Trial. That would take up the stress both forward and backwards. And the rotor in the photo is the correct way round. Edited December 30, 2010 by Echo Lite 09 Quote Link to comment Share on other sites More sharing options...
aener Posted December 30, 2010 Report Share Posted December 30, 2010 shouldnt they make a rotor with symetrical arms then? If the rotors are designed to take forces when moving forwards but not backwards, surely the stress on the rear rotor ( when going up to back wheel, gaps ect. ) would mean it would crack over time? I had a monty rotor that had been put on the wrong way round, and that cracked quickly. But with another the right way it was fine for ages. I think theres a rotor with symetrical arms that comes with the Try-All edition Hope Mono Trial. That would take up the stress both forward and backwards. And the rotor in the photo is the correct way round. Some of them do. If straight arms could be made as strong as curved (maybe they are - I don't know) it'd be a minor weight saver, too Quote Link to comment Share on other sites More sharing options...
Krisboats Posted December 30, 2010 Report Share Posted December 30, 2010 I'm no materials engineer, but it's something to do with different strengths of the material. It's stronger when being compressed than stretched, and in the idea that most of the time a brake will be used when rolling forwards, it compresses the spiral arms into the centre, rather than pulling them away. This. Same principle as old brick built bridges and archways. The material being forced in on itself helps to reinforce the arms where as it's far easier to sheer them apart when applying the force from the opposite direction. Quote Link to comment Share on other sites More sharing options...
chris4stars Posted December 31, 2010 Report Share Posted December 31, 2010 (edited) so....peoples opinions here....(it may be different depending on the styles of riding) is the braking forces on the front wheel rotor in trials similar to regualr riding? ie slowing the wheel when rolling forward same question about the rear? id think that on the rear anyway, the wheel (and therefore rotor) is more likely to experience the same force as it would if the rear wheel was rolling backwards... all in all in terms of the forces experienced most....is the front brake stopping you going forwards, and the rear stopping you going backwards? Edited December 31, 2010 by chris4stars Quote Link to comment Share on other sites More sharing options...
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