omgnoseat Posted June 4, 2009 Report Share Posted June 4, 2009 Hello, I build up my complete bike a few days ago and noticed some (what felt to me) flex in the rear wheel. So I checked everything and it was alright.Then my girlfriend noticed that it wasn't actually the wheel flexing, but it were the brake pads. I tried to film it but it wasn't very clear, so I made this up quickly http://www.imagedoll.com/show.php/2268_padwobble.swf.htmlI'm using a booster with koxx browns on a grinded try-all rim. The bike is top shape, no flex at all. The caliper remains still but the padd just wobbles around when I hop on the back wheel, or put any force on the back wheel whatsoever.Hope anyone can explain why this is happening and how I can fix it ofcourse Thanks in advance. Quote Link to comment Share on other sites More sharing options...
Shaun H Posted June 4, 2009 Report Share Posted June 4, 2009 Could be a snapped piston nipple? Quote Link to comment Share on other sites More sharing options...
Simpson Posted June 4, 2009 Report Share Posted June 4, 2009 Could be a snapped piston nipple?Yarp check that 1st, if you have you can just press some blue tack in there. (although this is probably a steriotypical Simpson bodge that does f**k all but makes me feel better) Quote Link to comment Share on other sites More sharing options...
omgnoseat Posted June 4, 2009 Author Report Share Posted June 4, 2009 Could be a snapped piston nipple?Very unlikely.. but I'll check later.Thanks for the response Quote Link to comment Share on other sites More sharing options...
psycholist Posted June 4, 2009 Report Share Posted June 4, 2009 Movement up to about 1mm is perfectly normal. If there's a lot more than that the pin on the end of the brake piston is likely to see loading and get snapped off. Ordinarily it takes no side load at all and just holds the brake pad onto the piston. If there's loads of play your brake pads may be out of tolerance or the forks that locate the pads in the brake may be worn/broken. Quote Link to comment Share on other sites More sharing options...
Rob/Mitch Posted June 4, 2009 Report Share Posted June 4, 2009 It's the pads! They dont quite fill the reccess of the piston. allowing them to move back and forth.My Koxx browns are exactly the same, you get used to it after a while!Got them from trialsman shop on ebay. Quote Link to comment Share on other sites More sharing options...
omgnoseat Posted June 5, 2009 Author Report Share Posted June 5, 2009 Movement up to about 1mm is perfectly normal. If there's a lot more than that the pin on the end of the brake piston is likely to see loading and get snapped off. Ordinarily it takes no side load at all and just holds the brake pad onto the piston. If there's loads of play your brake pads may be out of tolerance or the forks that locate the pads in the brake may be worn/broken.it's more than 1mm I did notice that there is a little bit of pad material broken of the pad, but that doesn't seem likely to cause the wobble in the pad..It's the pads! They dont quite fill the reccess of the piston. allowing them to move back and forth.My Koxx browns are exactly the same, you get used to it after a while!Got them from trialsman shop on ebay.I don't want to get used to it Never noticed this on my previous bike aswell, so it seems quite weird.But it does seem like the pad doesn't really fit in the piston..Also checked the pistons nipples btw, they seem perfectly fine and are definatly not broken of Thanks for the response everyone. Quote Link to comment Share on other sites More sharing options...
psycholist Posted June 5, 2009 Report Share Posted June 5, 2009 I'd try different pads or different backings - sounds like the pads you have are too loose a fit between the locating forks in the Magura slave piston. The danger with too much movement is that it could break the tip off the slave piston so no other pads would hold in either. Quote Link to comment Share on other sites More sharing options...
Scoox Posted May 14, 2012 Report Share Posted May 14, 2012 (edited) My 2011 HS33s do the same, however I disagree with the above replies that this is normal. It is not. I've owned two sets of HS33s previously (pre 2005 version) and I never noticed any wobble or play whatsoever. The Echo TR rim brake that came with my Echo 24 bike dind't have any wobble either, and it's supposedly a cheaper brake. But recently I bought a 2011 HS33 and it had this problem. However I am using it with the Echo pads as it was supplied without official Magura pads (cheaper this way), so maybe the Echo pads are the problem? Will have to wait till I get new pads e.g. TNNs. When you apply the brakes, the pad backing suddenly clanks against the slave. This in mechanics is called "dynamic loading" (fast), as opposed to "static loading" (gradual and slow). Dynamic loading is more likely to cause things to crack or snap. Therefore technically it shouldn't be like this. So if all HS33 brakes are like this then it is normal in the sense that all brakes are manufactured to very poor tolerances, in which case I hope (and I am sure) Echo will come up with a much better alternative very soon. Edited May 14, 2012 by Scoox Quote Link to comment Share on other sites More sharing options...
williams Posted May 14, 2012 Report Share Posted May 14, 2012 It's the pads! They dont quite fill the reccess of the piston. allowing them to move back and forth. This. I had the same problem before, and it's the pads. Quote Link to comment Share on other sites More sharing options...
Andeee Posted May 14, 2012 Report Share Posted May 14, 2012 Sounds like snapped clip on the backing where the piston goes. Happened to my old zoo pads years ago did not notice until one ride it decided to pop out! Quote Link to comment Share on other sites More sharing options...
dann2707 Posted May 14, 2012 Report Share Posted May 14, 2012 Yeah my plastic backed pads wobble like shit mad. Quote Link to comment Share on other sites More sharing options...
Scoox Posted May 19, 2012 Report Share Posted May 19, 2012 Sounds like snapped clip on the backing where the piston goes. Happened to my old zoo pads years ago did not notice until one ride it decided to pop out! Unlikely, like Psycholist said above, the nipple-clip coupling "...just holds the brake pad onto the piston" and nothing else. This means that the lateral forces i.e. the actual braking forces are transferred to the slave through other parts of the backings. I bought 4 different sets of brand-new pads two days ago (to try different compounds) and they all have the same wobble problem, so maybe it's not the pads. Maybe it's meant to be like this... Yet I have a cheap bike with cheap vees and they don't wobble at all, kind of annoying I might stick two bits of plastic to the backings to fill up the gap, will post back once it's done. Quote Link to comment Share on other sites More sharing options...
dann2707 Posted May 19, 2012 Report Share Posted May 19, 2012 Did you try metal backed pads though? Tnns are a really really tight fit. Quote Link to comment Share on other sites More sharing options...
Scoox Posted May 19, 2012 Report Share Posted May 19, 2012 Did you try metal backed pads though? Tnns are a really really tight fit. Haven't tried yet but thought about it. The problem is that here in China they are quite expensive. I can get them from Tarty but P&P is about as much as the price of the pads, so I am waiting for something to brake so I can warrant an order haha. Maybe I will order a pair when I go back home in the summer. In the meantime, if anyone using TNNs has a Vernier calliper at hand could they please confirm the relevant measurement, and possibly do the same for normal plastic pads? Thanx Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.