New bike, front brake not so good! Any tips? (Juicy 5's)

apoc_reg

Hi Guys,

Just brought my first serious mountain bike after existing on a £600 halfords job since 2001(!)

Its a Scott Genius MC-20. Everything has been great in my first couple of days of ownership apart from the front brake which is pants!

The brakes are Avid juicy Five's and the back brake is brilliant. Unfortunatly the front is not and if im on a slope with four fingers braking it will continue to roll forward ever so slightly!

I brought an avid brake bleeding kit and bled the front brake but no change

Any tips? this is my first set of disc brakes so know NOTHING about them lol (although followed the bleeding guide with no problems).

Thanks guys and hi from me to the forums!

P.S have done 50-60 km on the bike so should be worn in and the manual offers no troubleshooting tips!

nicklouse

either still needs to bed in. Or more likely pads are contaminated.

dav1

Bedded in properly? you need to do 30-40 hard stops on the pads before they get to 100% of power.

apoc_reg

I suppose if i buy some new pads and its the same at least id have a spare set!

Could i try the pads from the back or would they likely be different?

I would think theyre bedded in as i did about 40-60km in kielder water on it which is incredibly hilly (Coming from a guy who lives in Cambridge that may not be saying a lot though!!)

Thanks guys

nicklouse

Ok lets have a look at the alignment of the caliper then.

while watching the disc from the edge when you pull the brake does the disc get moved? if should not be distored as that will reduce the brake feel.

But if it the lever has good feel abut you have no power then contamination is 99% the cause.

remove pads clean disc and caliper with meths or isopropyl alcohol and bed in new pads.

I would not bother with swapping the rear into the front as you will have 2 sets of pads to bed in and if you put the old fronts in the rear you may have to then decontaminate the rear disc as well.

Surf-Matt

Just ride through a load of cack - seems to bed the brakes in MUCH quicker!

Re-align pads if needed though - it's very very easy on Juicys.

apoc_reg

Thanks for the suggestions, i'll have a play when i get home from work and report back!

apoc_reg

Would you mind explaining what you mean by contaminated by the way?

Is it something i could have done or would i be able to go back to the shop (had it less than a week) for new pads??

Thanks again

nicklouse

contamination.

well anything that got on the pads or disc.

have you cleaned the bike? what did you use.

have you lubed the bike? did any lube get anywhere near the brakes/disc?

did you touch the discs/pads......

did things leak when you bled the brakes?

Have you read the manual?

apoc_reg

Thanks that gives me an idea, yes i have read the manual but there was no section on problems etc or reference to possibly contaminating the pads.

I have cleaned it with a bucket and sponge and then used GT85 which i was told was good to spray the bike with after washing. Could that be a problem?

I bled the brakes although that was only because the brake wasnt performing very well.

Thanks

nicklouse

apoc_reg wrote:

I have cleaned it with a bucket and sponge and then used GT85 which i was told was good to spray the bike with after washing. Could that be a problem?

if it was while the brakes were uncovered or fitted to the bike them yes.
ant lube anywhere the brakes is bad news.

clean the discs and new pads in the front.

apoc_reg

ah that'll be in then!

Thanks youve been a great help.

Regards

nicklouse

From the owners manual

Do not allow any brake fluid to come in contact with the
brake rotors. If this occurs, clean the rotors with isopropyl
alcohol.
Do not allow any brake fluid to come in contact with the
brake pads. If this occurs, the pads are contaminated and
must be replaced.
Do not touch the braking surface of any rotor with your
bare hands, because the oils from your fingers will degrade
its performance. Always wear gloves, or handle the rotor by
its spokes.
Disc brakes become very hot during use. Do not touch the
caliper or rotor immediately after use. Make sure the brake
has cooled down before making any adjustments.

oils from hands and lubricating oils do the same thing.