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Discussion Starter · #1 ·
So I have been running these for about 2 months. Fantastic power, modulation, etc.

Only issue is that there is no contact adjust and the lever comes WAY back to the bar before you get full bite. Only on the rear break though. Front it perfect. Note:

- Not worn out rotor
- New or newish pads
- Fresh bleeds multiple times with no air escaping

I can't find anything online, but it just seems like a thicker rotor or something would eliminate this. Running shimano rotors that are 1.8mm when brand new. Have tried "top off" lever only bleeds etc to try and overfill the system, but it doesn't help.

Anyone else?
 

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I have the same situation, rear brake pulls really far...going to re bleed soon and may also change pads to see if this improves things.

Did you use a bleed block?


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Discussion Starter · #3 ·
I have the same situation, rear brake pulls really far...going to re bleed soon and may also change pads to see if this improves things.

Did you use a bleed block?

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Yep, used the bleed block from the TRP "shop" bleed kit with the super nice syringes.

One thought was to shave down the bleed block about .3-.5mm, but then I bet I would have rotor rub at all times.
 

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Interesting that you say it only happens to the rear brake, and not the front. Because, the calipers are the same, its just hose length/routing differences that make them different.

In my mind, that means you have pretty much 2 likely issues.

1) The longer hose, and more complicated routing for the rear means more bleed issues are possible (again, as the calipers are the same either way, and the fronts are fine).

2)There is an outside chance that you could have different thickness rotors front and rear. Seems unlikely... but not sure what else could cause the issue.

Here are a few random questions for you.

When you installed the rear brake, did you have to disconnect the hose? And if so, did you do it at the lever, or caliper end to get the routing correct? If it was the caliper end, and depending on how you bleed it, it could take a long time for a bubble there to work its way up, particularly if the routing is long and curvy.

Does yours have a bleed nipple on the caliper end, or does it have a plug, and then require another adapter like at the lever end? TRP changed the fitting a while back, because of feedback from Aaron Gwins mechanic, who said he was removing the nipple entirely for better bleeds.

I've got a set of quadiems, and mine feel identical front and rear. When I installed mine, I disconnected the lever end, and performed a giant lever bleed (for a very long time, as my bleed kit didn't have 2 TRP adapters, as mine doesn't have the bleed nipple at the caliper end, so I had to improvise).

I think if it were me, I'd be assuming there is some renegade bubbles in the rear hose at this point. Maybe its worth hanging the bike, or mounting it in a stand that makes the lever end much higher than the caliper, and then doing a full bleed (bottom up)? I'd also probably be tapping/jostling the hose the whole time, just to try to get it out.

If that didn't work, I'd swap rotors between the front and rear for a minute, just to check to see if its somehow a rotor thickness issue.

Good luck :).
 

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Also try removing the wheel (and therefore rotor) then giving the lever a squeeze or two so the pads reset closer together. If it’s too close then you’ll have to spread the pads apart with some kind of gapping tool.
 

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I've got 2 sets of Quadiems and been dealing with the same problem. What's more or less worked for me is the following. Before bleeding, pull on the lever without the wheel (or even pads possibly) in place to get the pistons closer together. The idea is to push them out a bit so you can overfill the system. Of course this means you won't be able to use a bleed block because it won't fit.

Then do a bleed only from the lever using the syringe. Take note of how much oil you have in your syringe. Pull on the syringe to get air out, it will take multiple tries to get most of it out, and also holding the syringe pulled to allow air to flow up. Once you're satisfied with the lack of air coming up, Push the syringe back to roughly the same place where it was before you started pulling on it. This is the most frustrating part to get just right. If you don't push enough, there won't be enough oil in and the lever will pull to far back. If you push too hard, there will be too much pressure and a bunch of the oil will leak out when you remove the syringe, also resulting in too much pull in the lever. So it may take a couple tries of removing and putting back the syringe to get it full but not gushing out.

Once the system is closed, you'll have to push the pistons back in (without the pads on of course), otherwise the rotors won't fit. You may still end up with brake rub though. But after straightening the rotor and riding a few times, my brake rub went away.
 

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Discussion Starter · #10 ·
Have you guys figured out the problem?

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I sort of did was nemesis posted, but a little different. I found two pieces of hard/thin plastic (cut out of the clear little box that a sram chain comes in) that when sandwiched were ever so slightly thicker than a rotor. Instead of pulling the pads I just stuck the plastic in there as my pad spacer and then did a lever bleed using the pull/push method with the syringe nemesis used. Worked well. Definitely an improvement, but not perfect.
 

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I have the same issue (rear brake only also) and I usually just push in the pistons and overfill the lever body. It works for a while but then the issue comes back. And it doesn't seem like the right thing to do. My guess is that the pistons are stuck so it takes more force (lever throw) to get them to activate. I've been wanting to do this, but haven't gotten around to it:
 
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