Specialized Diverge Disc brake issue

[Peat]

I bought myself a Diverge in September 2014 and have been very happy with the bike. I have only just done 400km on it and the front disc has an annoying shudder under load when slowing down. It has the SPYRE-C TRP mechanical discs fitted. Only happens on the front and the bike shop doesn't seem to interested in the problem. Have had disc brakes on my mountain bike and have never encountered this problem.

Any ideas?

[Calvin27]

Hard to say without the bike in front of me but I've had this a few times on various bikes. Try check these:
- is the headset loose?
- check all caliper and rotor bolts
- did you bed the brakes in properly? If not find a massive hill, ride to the top and give your brakes hell, they should start gripping soon
- check for contamination on the rotor or pads - even the slightest bit of road crud somehow managed to kill my fresh set of brake pads!
- check fork and wheel to make sure all is stiff, no crack etc

I will admit I went through the motions on one of my bikes (MTB though) and just couldn't fix it. In the end I just got new brakes and rotor and all fixed. Some bike frames just resonate with a certain brake combo - my specialized did that for a while - had to change the rotors for that.

[Jesmol]

I will admit I went through the motions on one of my bikes (MTB though) and just couldn't fix it. In the end I just got new brakes and rotor and all fixed. Some bike frames just resonate with a certain brake combo - my specialized did that for a while - had to change the rotors for that.

I had the same issue, could not stop the front end sounding like someone throttling a goose, clean pads and rotors, good for 30s, new pads, new rotor , all good.

[Peat]

Thanks for the info......Did use the bike on the last 3 days of the great vic bike ride. I rode down the Black Spur with the brakes on thinking that it would fix the problem....the disc clicks at speed and as you slow down becomes a shudder. I think I'm going to have a hard time getting the bike shop to replace the pads and rotor under warranty (bike is 5 months old)

[Jesmol]

Thanks for the info......Did use the bike on the last 3 days of the great vic bike ride. I rode down the Black Spur with the brakes on thinking that it would fix the problem....the disc clicks at speed and as you slow down becomes a shudder. I think I'm going to have a hard time getting the bike shop to replace the pads and rotor under warranty (bike is 5 months old)

Something not right, disc brakes should be noise less until you actually brake. Could be a warped rotor, if you're going to replace it, get AVID HS1 , great rotors.

[Calvin27]

Something not right, disc brakes should be noise less until you actually brake. Could be a warped rotor, if you're going to replace it, get AVID HS1 , great rotors.

That was actually the one I replaced. I have these rotors on 3 bikes and it's now only on one of them. But yeah, I agree, they should not be making noise while not braking. Possibly a clearance issue or out of true.

If that doesn't work, I would recommend buying cheaper rotors that are heavier and have less cutouts. I've been through just as many shimano low end and avid g2cs rotors, none of them have given me grief.

[PiratePete]

I bought a Diverge expert carbon nearly a fortnight ago, and have noticed that the brake alignment will vary depending on how tight the axle bolts are.

Ensure that you've torqued the through axle bolts to somewhere close to the spec. For the carbon diverge 12nm for front and 15nm at the rear. I have gone to 12nm at both ends. I've only done just under 300km, but the brakes have been silent after being bedded in.

[PiratePete]

3000km later and the only issue I've had with the Diverge is that the factory forgot to grease the BB.

The Shimano BR785 brakes are silent, the only time they make a noise is when the discs are wet, I've learnt to do one short application of brake to wipe the water and grime of the discs, then release then re-apply and they are silent. Feel has improved greatly as the KM have piled on, however they're not the strongest brakes. Possibly due to the rotor sizing, but my Avids on my Reign feel far more powerful, that said, there is nothing wrong with them, they pull the bike up well enough that you can do a stoppy with the rear wheel off the ground.

Can't get enough of this bike, so practical, I just love it.

[trailgumby]

Not sure if this is directly relevant, but hopefully this anecdote might provide some useful insight.

I had a set of Avid x9's with HS1 rotors on my Scalpel when i first got it. There was a fault with the front rotor, where a section of the brake track about an inch long had a *twist* in it, the effect of which was as though the rotor had a thick spot in it. In other words, brake pulsing. Annoying on the back, potentially deadly on the front.

I had naively thought I could straighten it out, or the rotor would wear in. Instead, the problem got worse. After 6 months I had had enough. The LBS, which I had formerly respected as being one of the better ones, was unhelpful. Their excuse was öh, the rotor has a warp in it and it has been rubbing. This despite the marks on the rotor clearly indicating the nature of the problem, and the "high point"being well away from where the supposed rubbing was occurring. Turns out they hadn't actually bothered to look (which pissed me off) they just called the Avid rep. My response was "wth? We/you bought the bike from Cycling Sports Group (the late and unlamented dysfunctional C'dale distributors)"

Long story short, I flogged the brakes on eBay (with appropriate disclosure) and switched to XT. This added around 160g to the bike but the sublime braking performance has well been worth it.