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PostPosted: Fri Mar 01, 2013 12:56 pm 
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Joined: Sun Jul 05, 2009 11:55 am
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Location: Swansea/Birmingham
Noticed last night that when the rear brake is locked on there is backwards/forwards play of a few mil in my Hope floating rotor. The front has no play at all :shock:

I'm sure I read on here that I might be able to fix it by placing the rotor on a flat surface and gently hammering the circular brackets that hold the brake surface to the rotor body as they can come lose. Did I imagine it or will that work??? Have done a quick search but couldn't find anything :?:

Cheers ;)


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PostPosted: Fri Mar 01, 2013 9:30 pm 
Gold Trader / rb Rider / Special
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Location: Rurally close.
Sounds like that would recrush the rivets? These dont actually move so thats what you want. Be interested if it worrks as i have a loose rivet one one of mine.

Edit: Id say put a nice flat bolck on top of each and hammer that.


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PostPosted: Fri Mar 01, 2013 9:46 pm 
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Thats what I thought and I was sure I read someone on here had a similar problem but I can't seem to find the thread.

I'll give it a go over the weekend, worst scenario is I will need a new rotor which I am gonna need if it doesn't work anyway :D


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PostPosted: Fri Mar 01, 2013 10:42 pm 
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Location: Herts UK
I had similar problem with a formula r1 disc - simiular construction to the Hope - but nowhere near the 1 or 2 mm play you describe. I put the disc on the bed of a vice (a flat steel surface) and smacked the rivets with a punch to flatten them a bit - it took a bit of play out but not all of it - I doubt you will be successful coz i imagine that once thay are able to move, they will wear the alloy carrier quite quickly.

but let us know how you get on.


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PostPosted: Sat Mar 02, 2013 1:58 pm 
retrobike rider / Gold Trader
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Location: Getting fitter, I will beat the Surrey Hills....
Go ahead and just twat it with a hammer, some kid says its how to fix a rotor so it must be true...

https://www.youtube.com/watch?v=W5XyDv1 ... ata_player

:lol:


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PostPosted: Sat Mar 02, 2013 2:33 pm 
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Location: Antwerp, Belgium
The rings aren't supposed to just clamp both sides of the rotor in place. In fact the braking surface is supposed to expand when it heats up, making it come loose from the center piece and the rings.
This prevents sideways distortion, but if you keep pumping and/or over-using the brakes when they're hot, it's easy to wear out the contact points of the disc and develop the kind of play you have.

So IMO they're toast anyway. Even if you manage to clamp everything firmly in place and stop the play, when they get hot they won't function as intended anymore.


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PostPosted: Mon Mar 04, 2013 8:48 am 
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I wouldn't bother overly much about a little bit of play - all the movement is taken up in one direction when you're actually riding the bike and you'd have to have a hell of a lot of wear for the rotor to actually disengage from the carrier.
Anyway, unless you've actually measured it, I would suspect that your "1-2mm" of movement is really a lot less than that.
In other words, it feels more than it really is. I've currently got a 160mm rotor which exhibits the same play and although it feels more, it's only 0.50mm measured at the disc periphary.


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PostPosted: Tue Mar 05, 2013 2:03 pm 
Gold Trader / MacRetro rider
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Stick to a solid rotor.Unless youre horsing it down the alps its unlikely you'll get that big a heat build up ( and then DOES it actually make a difference :?)
I think the floating are heavier also :?


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PostPosted: Tue Mar 05, 2013 2:50 pm 
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dyna-ti wrote:
Stick to a solid rotor.Unless youre horsing it down the alps its unlikely you'll get that big a heat build up ( and then DOES it actually make a difference :?)
I think the floating are heavier also :?


The 180mm Hope Saw rotors on my Bulls each weigh 145g, or 37g more than the bike's original one-piece Formula RX rotors (108g)

As for making a difference, yes they do. When a one-pice rotor heats up, it'll start to warp. A 2-piece rotor won't have that problem.


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PostPosted: Tue Mar 05, 2013 4:20 pm 
Gold Trader / MacRetro rider
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Raging_Bulls wrote:
dyna-ti wrote:
Stick to a solid rotor.Unless youre horsing it down the alps its unlikely you'll get that big a heat build up ( and then DOES it actually make a difference :?)
I think the floating are heavier also :?


The 180mm Hope Saw rotors on my Bulls each weigh 145g, or 37g more than the bike's original one-piece Formula RX rotors (108g)

As for making a difference, yes they do. When a one-pice rotor heats up, it'll start to warp. A 2-piece rotor won't have that problem.


Im not sure youre correct in that RB ? Just because its attached to an alloy carrier is not goin g to prevent it from moving,alloy is a metal too you know ,also affected by heat
Strange then that they did away with the 5 bolt rotor on it's alloy carrier. I do remember quite clearly how they 'proved' that the new 6 bolt rotors were cooler :roll: seems now that that was a pile of poo.

Personally i think its a whole thing is a huge pile of steaming nonsense, designed to sell new bits to you when you dont really need them :wink:


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