AndreyT

A week or so ago I bought a pair of TRP Spyre mechanical calipers (2nd generation). Installed them on my "sport commuter" bicycle, front and rear (160mm and 140mm rotors respectively). The first caliper (front) is perfect: both brake pads are strictly parallel to the rotor. By using individual pad adjustment screws I can reduce the gap between the pad and the rotor to a bare minimum on each side and thus obtain a perfectly tuned mechanical brake.

The second caliper (rear) suffers from one issue though: the pads are not parallel to each other. When I install it on the bicycle the inboard brake pad ends up strictly and prefectly parallel to the rotor, but the outboard pad is not. Here's a drawing that illustrates the problem



Because of poor pad-to-rotor alignment on the outboard side I cannot properly tune the outboard pad: the pad begins to touch and rub the rotor in one spot, while on the other end the gap is still large. To close that gap I need a lot of brake lever travel, which is not good.

I contacted both the vendor and TRP. TRP responded instantly and sent me a replacement caliper. However, the replacement caliper appears to have the same issue. Here's a photo of TRP's replacement caliper taken against bright white background



I sent this picture to TRP a few days ago but so far received no response (in contrast to their immediate response to my first message).

If not for my front TRP Spyre caliper, I would probably end up assuming that this is as good as it gets with Spyre. But the front one is just perfect: everything is square, aligned and parallel.

So, what is going on here? Maybe someone can share their experiences with TRP Spyre. How parallel are your pads? Am I supposed to keep cherry-picking Spyre calipers until I find a good one? Or is there an adjustment trick that I'm missing?

Looigi

In the pic, it appears the pad on the right is not sitting flat against the plunger that pushes on it. Try jiggling it around or pushing on it to see if you can get it to sit flat.

AndreyT

Good eye. If that black flat part visible in the picture is indeed the plunger, then it is definitely strange that there's a visible gap between the plunger and the pad backing. I'll take a closer look tonight.

However, I already tried everything in the "jiggling and pushing" department. I also tried rotating the pads inside the caliper (i.e. swapping inboard and outboard pads), but the problem just does not want to go away. And in the caliper that is currently installed on my bicycle the issue always remains on the outboard side, suggesting that the problem is in the caliper, not in the pads.

fietsbob

Did you take the pads out then put them back in again? ridden and slowly braked several times,
Standard new bike practice, to bed in the pad and the disc to each other yet?

AndreyT

Yes, I tried taking out pads, rotating them between inboard/outboard and between front and rear calipers. The problem is always with the outboard side of that specific (rear) caliper.

I also tried swapping the calipers around (front and rear). The problem follows the caliper.

Yes, I did all that. I have these calipers installed on my bicycle. And I've been riding it for more than a week now. The brakes work. The front is perfect, but the rear is too mushy and requires squeezing the road brake lever (SRAM Force) to the point where it bumps into the drop bar.

The outboard wear marks on the rear rotor are uneven (consistent with the pad misalignment), but I don't believe I will ever be able to "file down" the outboard pad to the point where it will finally become parallel to the rotor surface.

cobba

Probably the pad spreader that's causing the problem.

fietsbob

<Guess> its a 2nd.. send it back to seller and get a replacement..

utoner34

I have got exactly the same problem. Have you managed to sort this?

csport

I had Spyres on my bike, recently upgraded to Juin Tech R1's. It solves the problem with the cable pull, also the stopping power is better. Juin Tech calipers will also automatically re-center the pads because they are semi-hydraulic (cable actuated hydraulic).

I think my Spyres also had a problem with the pads not being perfectly parallel. Did you buy yours separately or did they come with a factory built bike?

Andrew R Stewart 

We see this often enough on low end OEM calipers. As long as we can get the rotor to clear with no noticeable rubbing we're happy. Worst cases have seen a small amount of pad surface grinding to increase gap. Andy

utoner34

I have disassembled mine several times, even tried to play with a metal spring which separated the pads (not sure if this could make a difference), but without success.

Its a shame for what would otherwise be a pretty much perfect and bulletproof disk brake.

utoner34

Some updates. I have emailed sypre and they agreed to send me one caliper for free (which was a nice gesture form them ), but when it arrived it had the same alignment issues as my 2 other calipers that came with the bike (to my dissapotment).

In the meantime I have purchased 2 TRP Spyre calipers from different website for my other bike and these 2 calipers have perfectly paralel pads. The only thing I am not sure if these pads will stay paralel after many riding hours (since I dont ride this bike often). Unfortunaltey since they are post mount and my other bike is flatm ount I cannot put them on my other bike which I ride constantly.

mpetry912 

this seems like a pad return spring problem perhaps ?

I have found the swiss stop return springs, for example, very weak.

The shimanos are way better.

Maybe spreading the return springs to give more retraction force.

/markp

utoner34

If you mean brake pad spring, not using pads and spring for testing, only the caliper. As shown in the pictures above, caliper pistons are simply not paraler. I even disassembled one to see if I can maybe stretch big metal spring but I dont see any difference.