6th Gen. Rear Brake.

Hey!

I've got a 2007 with 11,000 km (shy of 7000 mi) and notice over the last couple of rides (particularly in the city) a bit of a shudder from the rear end under braking. I'm pretty sure I've narrowed it down to rear brake, but is there anything else someone can think of that would cause this?? Fluid is good, no scoring on the disc and they "feel" normal.

Out of curiosity, how involved is a rear brake job on the VFR? Is it the kind of job a reasonably competent driveway mechanic can handle or strictly a dealership job.

 

Hey BrandSpankinVFR, I'm not familiar with your problem but I wanted to subscribe to the thread in case this issue comes up. I've got an '07 VFR 25th Ann VFR800 with only about 2,500 miles.
I'm sure someone will be able to help. Good Luck.

 

Not to spread paranoia, but an issue with bent/cracked rear axle has been identified.
If the brakes and rotors are confirmed to be OK, I would look to the axle next.

 

I have noticed this on my 6th gen model. I had thought it was some anomoly with the linked brakes. To be clear: If I'm trail braking on the "rear" brake whilst going at around walking pace, I get the shudder.

(strictly IMO) What I thought was happening:

1. Applying pressure to the pedal causes the proportional control valve to send some brake pressure to the middle piston of the front left caliper
2. This then causes the caliper to pivot and apply a small amount of pressure on the secondary master cylinder on the caliper mount.
3. That pressure is then sent back through to the rear brake adjusting the amount of force exerted by the rear caliper.

I suspect this gives you some sort of feedback loop. You can (also) feel the shuddering back through the brake pedal and I find it most noticable when accelerating against the braking force. Sometimes backing off the brake pedal is sufficient to "break the cycle"
Off course, I could be completely wrong!
Blatant plug:
If you're unfamiliar with how the linked braking fits together on the VFR, I wrote it up on my blog at one point:
nerdrider.com » Honda’s Dual Combined Braking System

 

I too have noticed this once or twice. Can never seem to repeat it, just rendomly happens, usually going about 10-15 mph. Did it before and after new pads, and fluid change. I'll be taking my bike in soon for the wiring recall, I'll ask about it then.... As for brake pad change, it's a very simple and straight forward job. Any garage mechanic can do it.

 

You guys nailed it dead on, its just intermittent (odd that twice this week, twice in the city on different rides) and I can't reproduce it. Now that its in my mind I think I feel it more due to paranoia about riding about with worn out pads.

Because I've never felt it, what would some indications be on a bike its time to replace pads?

I went about 22,000km on my last bike, and I know the current owner and its now got about 30,000km and still original pads, so it worries me that I could after only one season be looking at needing brakes.

 

if the rear disc is loose or just slightly warped it can cause those problems, not sure if this info helps but i would check if i was you.

 

Well, I'm at a loss about the cause of the shuddering. I took it around the neighborhood after a good looking at and nothing. I can't reproduce it, but I know I'll be riding along and -BAM- it'll strike again. Pads are fine, disc is straight/not scored, rear wheel turns freely, brake fluid is fine... even lubed and adjusted the chain for good measure and checked over all the bolts out that end and just perfect.

I'll post again when this strikes again, but for now I guess its a quirk of the bike.:unsure:

Thanks for the reply's!

 

I get the same on my '07. As far as I can remember it has done it since new, so I just chalk it up to the nature of the beast.

 

I have noticed a similar problem with car disc brakes over the years. It turns out the steel in the rotors can vary around the disc due to recycled steel in the mix causing the friction to vary as the pads rotate around the rotor. Trouble shooting this problem can make you crazy. The dealers / manufacturers won't admit this. I have found this problem in quite a few cars that I have owned over the years turning the rotors solves the problem for a while but it comes back after hard usage / heating the rotors real hot. I have solved this problem in all cases by purchasing high quality rotors Decelerotors brand they brag on their advertising about the steel quality and the drilling and slots in the rotors help to cool them. Maybe honda got some bad ones.