How do I adjust these rear brakes!? Confused.

galwayguy85

Putting my old bike back together (just to be used for commuting/very short rides, it's training days are over!). Rose Gran Fondo, orignal group set SRAM Force 22. The replacement components for the drivertrain are mostly Shimano 105 parts. No hassle there, although the internal cabling broke my heart.

It is just the rear brakes. To be very specific, 105 BR-R7010-R Direct Mount Rear Brake Calliper (it sits close to the bottom bracket)

Many conflicting results when one googles that part. Some have an integrated barrel adjuster, others not. The one which I have is shown on the right. The arrow shows the alignment of the brake cable. It and the cable housing feeds into a small rotatable shot. No ferrules etc are involved (which surprised me a little). A small allen bolt holds the cable under tension.

What puzzles me is how do I apply adjusts to the tension, for example when taking the wheel off for service and/or cleaning?

Won't loosing/tightening the allen bolt make the cable fray over time? The other alternative is to deflate the wheel when things need to come out. Not very practical.

The last set of rear brakes were some cheap junk (which were fitted by the LBS) - not the OEM part. Those replacements had a small wheel one could rotate to make easier tension adjustments.

I've also bought the Shimano SM-CB90 Inline Quick Release Brake Cable Adjuster but have had no success there either. It seems not to be compatible, according to the PDF manual.

Please help before I make any more adjustment fails! Thanks!

CoffeeImpala

The dealer manual for that brake caliper is at the bottom of this page.

https://bike.shimano.com/en-EU/product/component/shimano105-r7000/BR-R7010-R.html

Part of the product description on that page notes "Need Inline cable adjuster (SM-CB90) for cable adjusting and quick release feature." This is further emphasised, with SM-CB90 installation instructions, on page 17 of the dealer manual.

"The cable adjustment nut and the quick release lever are not equipped on BR-R9110-R/BR-R8010-R/BR-R7010-R; be sure to use SM-CB90 (cable adjuster)."

galwayguy85

Super. Thanks for helping out. Shimano really need to make the names of their products a little less ‘arbitrary’. ‘7000’ vs ‘7010’ can be little hard to distinguish.

I have a new SM-CB 90 cable adjuster and used it on the last (brand new) brake cable. All it seemed to do was put a nice ‘bend’ in the cable and housing. I used the previous cable to determine where and how long to make the cut on either side of the adjuster. I suspected (maybe falsely) that this was the cause of the bad braking performance - the brake lever was coming almost all the way back to the drops.

The last one was about 7 years old and seemed to no more function when opened and closed.

I guess that the adjuster is in the ‘closed’ position during the installation and fastening of the rear brake cable?

The only YouTube video I can find is in French. Do you know of any better online resources?

Starting to run out of brake housing st this stage. Too bloody mean to give the LBS any more cash for what might be a 10 minute job.

galwayguy85

The video in question. It might also be the case the clowns in the LBS cut the housing (near the bottom bracket) too long which caused a drop in tension? Practically zero 'bite' when pulling back the brakes.

https://youtu.be/zL3PH-jwJuQ

hesker

It should be really easy to see if your cable housing is too short as you will have exposed cable. Maybe post a few photos.

I’ve never fitted direct mount brakes but imagine the same principles apply. Your housing must come up against a hard stop at both ends. Not much to it really

galwayguy85

Grand out. Will take a look at things and maybe post some photos tomorrow. I hope the local bike shop can show a bit of compassion and fling 50 or 60cm of cable housing in my general direction. 😀