[Help] Formula RX Hydraulic Disk Brakes

BCBorn

Cruising
May 11, 2011
25
0
11
Tokorozawa
#1
Hi All,
I bought a Canyon MTB a couple years ago with Formula RX brakes, without realizing that the included Formula brakes weren't supported in Japan. About a month ago I started having some trouble with the rear brake. Sadly, the LBS was unable (unwilling) to help.I tried to solve the problem myself with a brake pad removal, but that didn't help...Probably made matters worse :)

Anyway, I am looking for someone that might have some experience with AVID style hydraulic disk breaks.

The rear break has no give or modulation. The rotor is rubbing, and the brake cylinders themselves don't seem to be returning. I am guessing that a rebuild is in order, but I have no idea how to do it. The Formula brakes use the avid bleed kit, but I have no experience with hydraulic brakes.

Is there anyone on the forum with experience using formula or hydraulic brakes? Anyone willing to make a trip out to Tokorozawa? I am willing to pay you for your time. PM me if you are interested.

I guess the other option would be to replace them with a mechanical brake like the Avid BB5 or BB7.

Any help would be appreciated.
Really want to get back on the bike now that things are cooling down a bit.

Thanks.
 

FarEast

Maximum Pace
May 25, 2009
5,528
538
193
Yokohama
#2
Myself and a few others (Alan) have alot of experience with hydraulic brakes.

However you location is a little to far out from me - Im in Yokohama.
 

GSAstuto

Maximum Pace
Oct 11, 2009
945
242
103
tokyo
www.roadfixie.com
#3
Sounds like the rear brake piston is frozen. That could happen from just sitting around and not being used. Try hitting the Avid site and walk through the installation and maintenance guide - http://www.sram.com/service/avid . Honestly, if the piston is frozen, you should be able to free it with some WD-40 and then replace all the seals. Then bleed it and adjust. I use a very fine Scotchbrite pad typically to cleanup any roughness. If the piston itself shows any sign of corrosion - junk it. You can get a service kit for about 2000 yen and the Avid Bleed Kits are about 4000 yen on various online e-tailers. The mechanical brakes are no way as strong as the Formulas! They are good for CX or Road - but I wouldn't recommend them for XC or DH at all.
 

kiwisimon

Maximum Pace
Dec 14, 2006
2,629
447
103
Japan
#4
You tube has a ton of videos on bleeding brakes. The formular site also has downloadable instructions on bleeding but with a sticky caliper you are better off rebuilding. Maybe probikemechanic can help you here. https://tokyocycle.com/bbs/member.php?u=1060

You really need a lot of time and a spacious work area to do a god job. but it's not impossible. I wouldn't go to mechanical brakes, they are a bit weak as GSAstuto said.
 

FarEast

Maximum Pace
May 25, 2009
5,528
538
193
Yokohama
#5
Also if you do upgrade I would go to Shimano, easilly available in Japan lots of parts and upgrades all at very good prices.

I currently use the XT system rotors as well and love it.

btw - Prorace mechanic is out in Nagano so even further out than me ;)
 

BCBorn

Cruising
May 11, 2011
25
0
11
Tokorozawa
#6
Thanks for the feedback guys.

I will look for a bleed kit and check the instructions on the formula site. I guess I can't make them any worse than they already are. Learning to bleed them is going to have to happen eventually I guess :)

GSA - Would the bleed process for my formulas be pretty much the same as the video on the SRAM site?
 

FarEast

Maximum Pace
May 25, 2009
5,528
538
193
Yokohama
#7
If you bleed them I suggest getting a wedge the will hold open the brake pads. otherwise you might find that its impossible to get the rotor back in or if you bleed with the rotor in that its pinched and rubs.
 

kiwisimon

Maximum Pace
Dec 14, 2006
2,629
447
103
Japan
#8
If you bleed them I suggest getting a wedge the will hold open the brake pads. otherwise you might find that its impossible to get the rotor back in or if you bleed with the rotor in that its pinched and rubs.
A disposable chopstick rubberbanded in does nicely, it's soft enough so it won't damage the caliper.