Viewing 40 posts - 41 through 80 (of 89 total)
  • On one Parkwood rear disc help please !!
  • bigjim
    Full Member

    I’ve got another 160mm disc on the way to try.

    A ruler or measuring tape would probably be cheaper.

    I’ll have a look at mine tonight anyway.

    thisisnotaspoon
    Free Member

    I doubt the post mounts are out by any significant amount, looks like a one piece cast/forged part with the dropout.

    Ask On-One, and if you don’t have any joy I’ll look at my fatty (which is also 160mm and IIRC shares the same dropout).

    renton
    Free Member

    A ruler or measuring tape would probably be cheaper.

    I’ll have a look at mine tonight anyway.

    Sorry what I meant is that I think the disc I have isnt compatible with the caliper.

    Its an rt54 alivio disc.

    Northwind
    Full Member

    The cheaper discs are made out of monkey metal so they’re not recommended with sintered pads but the radiuseseses should be the same.

    (OK, like a lot of people I think, I found out about the sintered pads thing after using one of the discs for about a year- it seemed fine, I’ve had faster wearing discs)

    mrmoosehead
    Free Member

    http://roweroweporady.pl/pobierz/shimano-compatibility.pdf page 25?

    BR-M615 is not listed as compatible with the RT54, if that is what you are using. (But that might just be the pad material)

    bigyinn
    Free Member

    renton – Member

    A ruler or measuring tape would probably be cheaper.

    I’ll have a look at mine tonight anyway.

    Sorry what I meant is that I think the disc I have isnt compatible with the caliper.

    Its an rt54 alivio disc.

    Unless the RT54 disc is bigger than any other 160mm I doubt thats your problem (it may be the metal in the disc isnt suitable for use with sintered pads, but thats another issue).
    The problem is either the post mount is too tall or the disc is too small.
    Either shim the caliper to raise it so it works with an 180mm disc or take a file to the post mounts to lower the caliper. (filing not recommended)

    mrmoosehead
    Free Member

    Gah. The suspense is killing me…

    andyl
    Free Member

    They are probably off the peg drop outs that are machined down to what is needed, eg could be 180 or could be 160, 140 etc and in this case they’ve been machined badly. The top surfaces don’t look parallel with each other.

    bigjim
    Full Member




    bigjim
    Full Member

    Have you checked the pads to see if they are fully contacting the rotor or not? I wonder if you’ve just been thrown by the rotors being for a different brake and looking like something is wrong when it isn’t

    There is something a bit odd about these frames in that I can’t seem to use a 180 adapter though, but mine engages fine with the slx rotor

    mrmoosehead
    Free Member

    Just eyeballing the difference between the OPs picture and those pictures, you can see that the overall disc diameter looks pretty much the same, and the position of the caliper is the same.

    The difference, however, is in the wear line on the OPs disc – it’s much further out.

    So, this implies either the pad contact material is not fully formed on the pads (i.e. doesn’t cover the fully pad surface), or you have the wrong pads in there…?

    bigjim
    Full Member

    So, this implies either the pad contact material is not fully formed on the pads (i.e. doesn’t cover the fully pad surface), or you have the wrong pads in there…?

    Fairly sure the new pads have a bevelled edge at the bottom which would give the appearance of less contact on the rotor until they wear down a couple of mm

    superstu
    Free Member

    Did you get this fixed Renton?

    renton
    Free Member

    In a word no.

    I’m still none the wise with it….

    I got a new disc to try and there is a difference between the pad contact surface ….

    It’s still squeaky.

    I’ve tried to measure the distances one of the posters above measured…..

    I think it May be the same ?

    What do you think, time to call on one ?

    andyl
    Free Member

    That “new” disc looks like an old LX one so might be aimed at the lower spec discs and be slightly different. It certainly looks as though it’s intended for a pad contact area slightly further out. Maybe the lower spec ones have a slightly smaller contact area to increase the pressure to get the friction higher but at the expense of higher heating.

    otsdr
    Free Member

    If the outer edge of the disc is at the edge of the pad (which seems to be the case), you’re ok. As bigjim mentioned, the pads have a taper on the bottom side (which supposedly prevents squeaks and other noises), it takes while for that to wear down.

    thisisnotaspoon
    Free Member

    Right, I had a play about yesterday with the fatty’s brakes, didn’t get the trail out so this may be wrong, but:

    The Fatty comes as standard with Is mounts and a IS-Post +20mm adapter, Avid DB3’s, a 160mm disk and NO conical washers. My other Avid brakes (elixirs) look to have identical calipers but with **5 rotors.

    I swapped to shimano brakes and 180mm rotors and have the same problem as the OP. Tried it with all the ~185mm addapters I had and none would work, all put the caliper ~2mm too high. An avid 185mm rotor fit perfectly on all bar the Hope ‘B’ adapter which is a nominal 183mm. Even a +0 IS to post adapter mated to a 203mm post-post front adapter was too tall.

    So, a bit of googling suggests shimano adapters are 180mm, so that’s the next thing to try.

    In terms of helping the OP, I think the only solution is to try a shimano post-post 180mm adapter and matching disk, and if that doesn’t work aftermarket 165mm or 185mm rotors.

    bigjim
    Full Member

    renton I think the only problem is you are still using the wrong rotor for the brakes you have, that as mentioned above looks like an old LX rotor. Also brakes squeaking isn’t anything to do with the frame.

    richardthird
    Full Member

    RT54s are shit anyway. Get some Centrelock to 6-bolt adaptors and proper rotors on there.

    renton
    Free Member

    Its doing my nut in now.

    FWIW Ive fitted a shimano RT63 rotor now and it looks better but its still squealing like a muthertrucker !!

    some pics…….

    Apart from the uneven pad which I have now flattened I cant see owt wrong with it yet the squealing and mushy feel persists??

    STATO
    Free Member

    Apart from the uneven pad which I have now flattened I cant see owt wrong with it yet the squealing and mushy feel persists??

    That angle means you bolted up your caliper wonky. The slots on it are to allow you to adjust it to get it straight.

    renton
    Free Member

    How come the other pad is perfectly level then ?

    I’m sure it was parallel too.

    Is it worth trying another set of pads ?

    bigjim
    Full Member

    Yeah caliper is badly set up, the pads have been hitting the rotor at an angle so will feel weak and will squeal like a stuck pig

    bigjim
    Full Member

    because that one pad has been hitting the rotor first. I think you will need new pads and set up the caliper properly.

    emac65
    Free Member

    Annoying rear brake aside, how you finding the Parkwood ?

    renton
    Free Member

    Really good actually.

    I’ve built it up as a new bike and I find it really nice to ride.

    Are you considering one as this one will be for sale as soon as the disc issue is sorted.

    coomber
    Free Member

    From renton saying he has just built it up (without getting the brakes sorted) and already trying to sell it on, he might not be the most impartial of views.

    Emac they are really nice. I have one now for 2 years, nice and solid. Not super modern and long but not that short. Think they are only £130 at on one in their never ending sale at the moment.

    Renton just take it to someone to sort it surely?

    renton
    Free Member

    Coomber. This was always going to be built up and sold on regardless of the disc issue or not. I did say I will not sell it before it’s sorted or did you miss that but ?

    I don’t want to take it to anyone as I’ve never taken a bike to a shop before in my life as I pride myself on being able to investigate online and then do the work myself.

    emac65
    Free Member

    Are you considering one as this one will be for sale as soon as the disc issue is sorted

    Cheers, but I only buy frames & prefer to spec myself. As Coomber mentioned, I’ve been eyeing the frames on the On One site

    renton
    Free Member

    No probs.

    It’s a great frame and I’m sure you won’t be disappointed.

    coomber
    Free Member

    My point was its hard to make a judgement on any bike unless it’s all working properly. You might decide to keep it when it’s done then.

    Would take a pic of mine but don’t know what it would do to help

    Nobeerinthefridge
    Free Member

    I don’t want to take it to anyone as I’ve never taken a bike to a shop before in my life as I pride myself on being able to investigate online and then do the work myself.

    Maybe time to swallow your pride as you’re not setting the heather on fire here. This is basic fitting, are you not a RAF fitter? Fit the 180, shim the caliper so that the pad sits at the right place on the rotor and align properly. It’s not rocket science.

    renton
    Free Member

    I don’t want to fit a 180mm rotor as that would mean buying a new rotor and adapter kit.

    It’s not rocket science you are right. I’ve just been waiting to see if anyone else has had the issue before.

    Maybe thinking of taking the paint off the post mount mounting surfaces next.

    ghostlymachine
    Free Member

    BTW if the tops of the posts aren’t square to the axis of the wheel it will also be mushy and lack power and squeal like a pig. They might need facing.

    I guess you don’t have the tools to do that.

    renton
    Free Member

    Facing will be one thing I do pay to get done :mrgreen:

    bigjim
    Full Member

    Renton

    You don’t need to be facing or removing paint

    Just get some new pads and read up how to align the caliper, and watch the pads when you are done to see if they look in line and contacting nicely at the same time

    Neither of those rotors are designed for your brakes so you might still have problems. I am using those lx rotors with the newer xt brakes on my commuter without dying but they are quite likely to have different sizes of contact area as they aren’t designed to work with each other

    scotroutes
    Full Member

    Removing paint will often reduce/remove the squeal.

    renton
    Free Member

    This is the first brake I’ve ever had bloody issues with.

    I thought I had aligned it correctly and it seems strange that one pad is wrecked yet the other is perfectly fine.

    Just out of interest why do you think the rt63 rotor isn’t suitable as its listed as a deore disc.

    bigjim
    Full Member

    The name deore has been around for donkeys years, different models come out every few years under the name deore but with different model numbers. Those rt63 rotors are an old style, I have them from a bike that was bought in about 2008. Since then the brakes and pads have been redesigned, so it is possible the contact area is not the same, ie the pads in your new deore brakes are a different width from the ones your rotor was designed to use. It might be OK, but seeing as the previous wrong rotor has already confused you it might not help.

    renton
    Free Member

    Cool.

    I’ve got a new deore centrelock rotor and a new set of deore pads on the way.

    Fingers crossed that will sort it out.

Viewing 40 posts - 41 through 80 (of 89 total)

The topic ‘On one Parkwood rear disc help please !!’ is closed to new replies.