Brakes!

[Captainwoot_imp]

Hello to all from Ontario Canada! hope everyone is enjoying the summer ! I have a question about front brake rotors. My 2016 cb had just under 20,000 km and I am in need of a set of replacement rotors. This will be the second set. I now have a brake vibe under moderate to heavy braking from highway speed. The first set were o.e.m replacements that were close to $800 cdn. That really hurt and I don't want to pay that again lol. I found a trw mst278 replacement , has anyone used these?

Thanks for any input
Brent

(on an unrelated note, my plastic headlamp bucket fell apart. I replaced it with a metal one and fitted it with a "trucklite" led headlamp)

 

[GoldOxide_imp]

$800C - yikes! Strange to be wearing/warping(?) through discs?

RE headlamp bucket: How did it fall apart? Fasteners just dropped out? Plastic disintegrated?

 

[ohiorider_imp]

Hello to all from Ontario Canada! hope everyone is enjoying the summer ! I have a question about front brake rotors. My 2016 cb had just under 20,000 km and I am in need of a set of replacement rotors. This will be the second set. I now have a brake vibe under moderate to heavy braking from highway speed. The first set were o.e.m replacements that were close to $800 cdn. That really hurt and I don't want to pay that again lol. I found a trw mst278 replacement , has anyone used these?

Thanks for any input
Brent

(on an unrelated note, my plastic headlamp bucket fell apart. I replaced it with a metal one and fitted it with a "trucklite" led headlamp)

Have you personally, or had a shop, check the front rotors for lateral run out with a run out gauge? My front brake generate a slight amount of buzz and slight vibes occasionally, but until I re-tweak the Race Tech valving, I'll attribute my issues to front suspension that isn't dialed in properly.

 

[pekingduck]

As Ohiorider says, have a shop check the runout on the discs with a dial indicator. Only need to check the outside surfaces, no need to check both sides. This is common practice on car brakes, and could show only one disc is out of true. Absolutely no reason to replace both if one is good.

Back in the late-'70s early-'80s Suzuki and Honda big bike rotors would warp from hard use, and replacements were no better. We used to have a machine shop surface grind them, and they wouldn't distort again. I would rather pay to have them surface-ground than try new ones. There is a saying that a new part is an untested part.

More complete machine shops will have them - similar to a milling machine, but a grinding wheel is used instead of a rotating bit, and the surface is much smoother and more precise. The process is to grind the mounting surface first, the outer surface next, then the inner surface.
(A shop I used to work at had one, and they would also grind valve shims if they didn't have the right size)

I can't think of any reason short of impact that a rotor(or rotors) can get bent in normal use. I've seen discs galled and blued that were still straight.

If you had the wheels painted or powdercoated, the disc mating surface needs to be masked as well as the bolt holes.

 

[dave]

I've had to replace both front rotors on my VFR800, (at separate intervals) but I have over 108,000 miles on this bike. I don't know how or why they got warped (I checked them myself with a dial indicator). Here's something to think about: Could a mechanic, who was replacing your front tire, have damaged them removing the old tire, or installing the new one? I always wonder this about my VFR.

 

[pekingduck]

I've had to replace both front rotors on my VFR800, (at separate intervals) but I have over 108,000 miles on this bike. I don't know how or why they got warped (I checked them myself with a dial indicator). Here's something to think about: Could a mechanic, who was replacing your front tire, have damaged them removing the old tire, or installing the new one? I always wonder this about my VFR.

I've changed a lot of tires using different machines, and I can see there are many ways using one less than carefully can impact the disc. I can even see how a front wheel, just resting against something gets tipped over and could damage a disc.

 

[Captainwoot_imp]

$800C - yikes! Strange to be wearing/warping(?) through discs?

RE headlamp bucket: How did it fall apart? Fasteners just dropped out? Plastic disintegrated?

I will check the runout with a dial indicator to verify. The plastic headlamp just cracked in all directions from the fasteners.

Just as strange as my brakes.. Never had a bike do these things lol.
Still love the cb though!

 

[pekingduck]

Honda always uses steel flanged spacers on plastic headlight cases so the screw does not tighten against plastic. Was yours missing those? Just curious.

 

[Captainwoot_imp]

Honda always uses steel flanged spacers on plastic headlight cases so the screw does not tighten against plastic. Was yours missing those? Just curious.

No nothing missing. When unbolted those spacers just fell out and bucket fell apart.

 

[Nortoon_imp]

Hello to all from Ontario Canada! hope everyone is enjoying the summer ! I have a question about front brake rotors. My 2016 cb had just under 20,000 km and I am in need of a set of replacement rotors. This will be the second set. I now have a brake vibe under moderate to heavy braking from highway speed. The first set were o.e.m replacements that were close to $800 cdn. That really hurt and I don't want to pay that again lol. I found a trw mst278 replacement , has anyone used these?

Thanks for any input
Brent

(on an unrelated note, my plastic headlamp bucket fell apart. I replaced it with a metal one and fitted it with a "trucklite" led headlamp)

When new, the rear disk on my 2017 CB1100 EX dragged when I spun the wheel to wax the chain. I complained to my dealer about it and they said I must be riding with my foot on the rear brake. I told them I seldom use the rear brake, and I do not rest my foot on the pedal. They told me to use the rear brake more.

A month or so later the disk was discoloured from being over heated. Honda Canada had them replace the disk and brake pads under warranty. The rear brake still drags at a certain point when I spin the wheel, but it yet to discolour. I assume the rear discs on the new CB1100 EXs are warped from the factory.

To make things worse the Honda engineers placed the brake fluid cup under a frame brace so it is impossible to remove the cap without removing the cup. Morons! When I got my CB back the rear brake was mush and almost useless. Obviously the mechanics did not bleed the brake fluid.

The front brakes also squeal just before stopping, but at least they work.

Really annoying that a Honda motorcycle that cost me about $16,000 Canadian out the door has faulty brakes. The brakes on my $6800 CB500XA had none of these faults.

I tried the other Honda dealer who installed my new tires. But they ignored my request to check the rear brake and bleed the line. They also ignored my request for new spark plugs.

Too bad we now pay more money for poor service.

 

[max]

If you look at the rear brake line routing you notice that the line has a high point at the master cylinder, to bleed this line and remove air in this line the new brake fluid has to be flushed quickly so that no air can remain in the high part of this line.
Or the caliper has to be removed and held up high in such a way so all the air in the line can slowly rise to the caliper and bled in the traditional way.

No such issues exist in the ( non abs ) front brake system, it lets air escape over time because the master cylinder is at the highest point and the ports in the master cylinder are designed so any air in the line can surface at the reservoir.

To me it is possible that disks can develop rust spots if left wet after a ride, this may influence the surface friction at that spot, the rotor is still true but can feel uneven when braking, this may take quite some time to reduce in intensity.
This happened to me and the intensity changed ( reduced ) when the front brake pads were replaced.

To see if the rotor is warped or the wheel mounting is not true the rotor could be measured and marked if a high spot is found and rotated 90 degrees and measured again, if the high spot moved with the rotation the disk needs attention, if the spot remains in the same place it may be the wheel is somehow affecting the runout.

 

[GoldOxide_imp]

Fortunately, many of those latter tasks you can still do yourself, if up to it.

 

[Captainwoot_imp]

Hello all, just an update if anyone requires brake rotors as i did. TRW MST278 is a direct replacement for front rotors. considerably cheaper than oem. I installed a set last week and now the cb is as smooth as silk again!

 

[baxtercat_imp]

captain--what was the metal headlight bucket you used as a replacement? was it a direct fit?

 

[Rocky_imp]

Hello all, just an update if anyone requires brake rotors as i did. TRW MST278 is a direct replacement for front rotors. considerably cheaper than oem. I installed a set last week and now the cb is as smooth as silk again!

Thanks for the update, but the place you got them would also have been helpful.

 

[GoldOxide_imp]

Hello all, just an update if anyone requires brake rotors as i did. TRW MST278 is a direct replacement for front rotors. considerably cheaper than oem. I installed a set last week and now the cb is as smooth as silk again!

Thanks for the update, but the place you got them would also have been helpful.

Thanks for the update, but the place you got them would also have been helpful.
Very good to read Captain.

(+1) What Rocky said.

 

[Lord Popgun]

Thanks Captain! I’m putting that number in my service manual for future reference.

 

[Cormanus]

Start here, https://www.trwaftermarket.com/ap/catalogue/product/mst278/

 

[peterbaron]

Captain, good to hear, but would like to have your feedback again after few thousand kms, please. Was the run out checked after replacing them?
TY

 

[Captainwoot_imp]

captain--what was the metal headlight bucket you used as a replacement? was it a direct fit?

Hello. it was a universal bucket from amazon (looks like a vintage Kawasaki one) . Used the bucket and the honda attaching hardware. only addition was a stainless "toothed" washer between the bucket and the mount ears.

https://www.amazon.ca/gp/product/B073PXW...UTF8&psc=1

Hello all, just an update if anyone requires brake rotors as i did. TRW MST278 is a direct replacement for front rotors. considerably cheaper than oem. I installed a set last week and now the cb is as smooth as silk again!

Thanks for the update, but the place you got them would also have been helpful.

Thanks for the update, but the place you got them would also have been helpful.
Very good to read Captain.

(+1) What Rocky said.

Thanks for the update, but the place you got them would also have been helpful.
Very good to read Captain.

(+1) What Rocky said.
I actually sourced them on ebay. vendor named uk motors

Captain, good to hear, but would like to have your feedback again after few thousand kms, please. Was the run out checked after replacing them?
TY

I will try and update when I get some miles on, only about 5ookm so far. I did not check the run out, after it was braking so smoothly I just called it a job well done!