|Posted on Thursday, August 21, 2014 - 05:04 pm: ||
Hey guys, I was rebuilding my caliper last week and noticed the extruded seal in one of the bores.
I know this is pure speculation, but does anyone think this could have caused a temporary lock up of the front brake? As some of you know, I crashed last Decemeber and I don't exactly know the cause. The only facts I know for sure: I was applying the brake to slow for a right hand corner and the next thing I know, the handle bars are vibrating badly (like when you are braking over a very rough surface) and then the bike flips as I am tossed over the handlebars before I could say "Oh shit."
Serviced brake caliper with new pistons, O-rings & pads.
|Posted on Thursday, August 21, 2014 - 05:16 pm: ||
In case anyone wants to read up on O-rings. LOTS of reading here. SOme of it is very interesting. Anyone know what kind of rubber O-rings are in the EBR kit?
I gathered from reading the handbook linked below, most brake seals are made from Ethylene Propylene (EPDM).
|Posted on Thursday, August 21, 2014 - 07:55 pm: ||
if you look at other disks brake calipers...and you may know this... the Oring is square on purpose, the square O-ring kinda "rocks" in the groove ( called a gland) the rocking is used to retract the piston slightly when you release the brakes...hopefully the pads follow and the wheel turns with little or no friction.
if your front wheel locked...I would be more suspicious of the front wheel bearings...they weren't too good in the early production run.( most ball bearings are made in China now...hopefully they have got their metallurgy figured out.)
there was a "notice" on the front brake line in the early days...the routing took it close to the front wheel/tire
|Posted on Friday, August 22, 2014 - 02:25 pm: ||
I would be more suspicious of the front wheel bearings
Would it be obvious if the wheel bearings are bad? The don't *seem* to be bad, but I have never had bad wheel bearing on any bike I have owned....any simple tests to diagnose?
|Posted on Friday, August 22, 2014 - 03:28 pm: ||
I just pulled my bearings FR/RR since i was getting a second set of tires setup. I spun them to feel for "notchiness" - ie not smooth spinning.
Even though they spun easily, mine had some rust on the inside surface which i was surprised to find. Rear was pretty grungy/rusty:
FR not bad. Getting rims powder coated and installing new bearings when they get back anyway...
|Posted on Friday, August 22, 2014 - 03:45 pm: ||
installing new bearings
What is your source and cost, please?
I know from the outside my bearings look great. I don't ride in foul weather and we have a low humidity desert climate in Central Cal. I will put the wheels on the balancer tonight to get a feel for smoothness and check the runout as well.
|Posted on Friday, August 22, 2014 - 06:12 pm: ||
here is a link on source:
Koyo is supposed to be built in Japan...and is a supplier to Toyota...this is from the internet not from personal data...I have these in my bike...if you're in central coast... you may want to look for a town where oil wells are present (Bakersfield)..as they may have an industrial bearing supplier somewhere near by...
here is a post on how to change out the rear (scroll down):
these are sealed bearings...some external rust would be acceptable, but if and when the seals fail (heat and load buildup) ..grease will leave the building and the water will replace it
(Message edited by nuts4mc on August 22, 2014)