Adjusting bike disc brakes - can't get to inner adjuster

Forums › Home Workshop DIY › Adjusting bike disc brakes - can't get to inner adjuster

boland

556 posts

Ultimate Geek
+1 received by user: 85

#309412 17-Oct-2023 12:57

I've got an e-bike and have always struggled with adjusting the rear disc brakes as I can't reach the inner adjuster, without removing the whole brake caliper. Guess this is caused by the fact the rear wheel has the electrical motor which takes up too much space. See photo below. I've worked around it by taking the brake out, trying to guess how much to adjust, and then trying to put it back in; aligning with other bolts to adjust horizontally. This is a very time consuming process to ensure it doesn't rub AND it has enough tension.

I'm trying to follow this video which seems very easy, if you can reach the inner adjuster. Any tips? Perhaps would work with a flexible allen key if they exist? There's only about 1cm of space.

thewabbit

135 posts

Master Geek
+1 received by user: 42

ID Verified

#3148404 17-Oct-2023 13:05

Take the wheel off?

Handsomedan

7769 posts

Uber Geek
+1 received by user: 7402

ID Verified

Trusted

Subscriber

#3148416 17-Oct-2023 13:31

The only solution that I can see is to remove the wheel - the problem is that those brakes are clearly designed with a smaller hub in mind (i.e. a standard hub), not the hub-motor unit that you have there.

If I am honest, I haven't seen a set of bike disc brakes that adjust in that way for quite a long time - and on an eBike I'd be pretty reluctant to be using cable-actuated disc brakes too - with the added weight and speeds that they can go, I'd always be going for a hydraulic brake (which can be sourced pretty cheaply and are largely self-adjusting).

Handsome Dan Has Spoken.
Handsome Dan needs to stop adding three dots to every sentence...

Handsome Dan does not currently have a side hustle as the mascot for Yale

*Gladly accepting donations...

RunningMan

9184 posts

Uber Geek
+1 received by user: 4834

#3148418 17-Oct-2023 13:37

Ball headed allen key might do it.

wellygary

8810 posts

Uber Geek
+1 received by user: 5287

#3148425 17-Oct-2023 14:09

Hex Key + Hacksaw the end down might get you a short enough head, -

Batman

Mad Scientist
30012 posts

Uber Geek
+1 received by user: 6217

Trusted

Lifetime subscriber

#3148436 17-Oct-2023 15:01

Don't take the wheel off. Without the wheel you have no idea where to place the brake caliper

boland

556 posts

Ultimate Geek
+1 received by user: 85

#3148447 17-Oct-2023 15:16

Handsomedan:

The only solution that I can see is to remove the wheel - the problem is that those brakes are clearly designed with a smaller hub in mind (i.e. a standard hub), not the hub-motor unit that you have there.

If I am honest, I haven't seen a set of bike disc brakes that adjust in that way for quite a long time - and on an eBike I'd be pretty reluctant to be using cable-actuated disc brakes too - with the added weight and speeds that they can go, I'd always be going for a hydraulic brake (which can be sourced pretty cheaply and are largely self-adjusting).

Yeah, I think it's a design issue. Not so keen on taking the wheel out.

Perhaps a good idea to get hydraulic brakes as I use my bike mainly to get up & down a ~150 meter hill, so have to brake a lot going downhill to stay under 50km/hour. I have to adjust them every couple of months as the pads wear down quickly.

Doesn't look very easy to install, so guess I'll leave that to a mechanic.

Samsung

Shop now on Samsung phones, tablets, TVs and more (affiliate link).

boland

556 posts

Ultimate Geek
+1 received by user: 85

#3148459 17-Oct-2023 15:39

Quick update: Going to drop it off now at a mechanic to get hydraulic brakes installed! Didn't know they were self adjusting, thanks everyone.

Handsomedan

7769 posts

Uber Geek
+1 received by user: 7402

ID Verified

Trusted

Subscriber

#3148472 17-Oct-2023 16:28

boland:

Quick update: Going to drop it off now at a mechanic to get hydraulic brakes installed! Didn't know they were self adjusting, thanks everyone.

A wise choice. I have almost zero issues with my hydraulic brakes on my Mountain Bike and it gets a pretty rough life.

Handsome Dan Has Spoken.
Handsome Dan needs to stop adding three dots to every sentence...

Handsome Dan does not currently have a side hustle as the mascot for Yale

*Gladly accepting donations...

mdf

3566 posts

Uber Geek
+1 received by user: 1519

Trusted

#3148481 17-Oct-2023 16:44

I think it is a moot point now, but you can get stubby allen wrenches. I had a set from a cycle shop, so would guess that your problem wasn't unique.

Oblivian

7345 posts

Uber Geek
+1 received by user: 2117

ID Verified

#3148482 17-Oct-2023 16:56

At a hazzard of a guess that plate should only maybe come off to replace the pads. Not adjust.

The barrel adjustment on the entry point should normally takes care of wear slack and cable stretch. Bringing in the calipers.

Unlike Normal hydro sets that have easy access drop in slot. However looks like noth have a separator pin in the middle to push them out away from rotor.

Do note you'll need to take more care with mineral oil bleeding and keeping the pistons clean with a hydro set.