georgebest

Hi Chaps

I've just bought a Rockhopper & purchased some Mono Minis seperately which the shop fitted (on to the Manitou Elites?).

I've got it home & when I peddle with any power & the bike is tilted to the right (disc is on the left), there's quite a loud 'pringing' sound. Something is rubbing but what I know about bikes isn't worth knowing!
Has anyone got any ideas that may help?
Cheers

dirtbikedude

If they did not set the caliper up just right you are probably hearing the disc hit the caliper because of a small amount of flex in the fork. When the front is unsupported can you spin the wheel with no problems?

georgebest

Yeah

When I spin the bike over, the wheel spins ok (a tiny bit of friction between the disc & pad). It's when I peddle hard & the bike is angled to my right that there's quite a lound ringing sound? It doesn't sound heathly but I couldn't spot any major signs of friction?

dirtbikedude

I know the sound. Look closely at where the disc passes through the caliper. If it is at even the smallest angle or a mm or two to one side it can cause this to happen. Hopes are great brakes, that is all i use but they are a biyatch to set up at times.

Are you a clydesdale rider (200+lbs)? That will also increase how much the fork will flex

dirtbikedude

Might seem silly to ask but did you make sure the qr is snug and that the wheel is in the dropouts stright?

georgebest

Nah, I'm a between 11 & 12 stone (160ish pounds?). It's just a bit annoying because the bike shop gave me their spiel that I needed the brakes fitting by them, & they'd do an A1 job etc....
Do you reckon I need to take it back in?

georgebest

Yeah, I think so (QR + straight).... I pulled the wheel off & put it back on

dirtbikedude

I would say yes. If you tell the shop the caliper is not on stright and they see it is only off a very very tiny amount they might just think you are just an anal arse (depends on the shop though). So just tell them the problem, see what they say and if they can correct it. You should be able to recreate the sound riding in the parking lot to show them what you are talking about.

Also, if you have a very stong legs then you could just be flexing the fork alot.

georgebest

It must be the legs!!

Good stuff. Thanks for the advice

dirtbikedude

Just another thought, before you ride again make sure the bolts on the disc are tight. That is another cause and can put you in the emergency room quite quickly

stapfam

I have Hope Mono M4's and they do take some setting up. Make certain that all the bolts are tight. Even go as far as putting threadlock on the bolts. All bolts tight,Centred correctly, Still Getting the sound, then perhaps the Caliper is not far enough out from the Discs,

Too many options to go through on where the noise is coming from so take it back.

Hopper

Ok either the caliper is a little bit offset, it is possible that there are a few burs on the fork mount or caliper spacer which could be doing this. Also it is quite likely that somethig is flexing, your hub, your fork, your skewers, your rotor even (but very unlikely). When you put the bike on an angle there are gyroscopic forces trying to push you upright, these forces will cause some very minor flex in your bike and even the smallest amount of flex can cause a rotor to rub.