Shimano mechanical disc brake setting

coyote101

I have fumbled my way through setting the brakes up to a reasonable level, however the lever is still not that responsive and I have to pull it in quite a long way to get the bike to brake.

The steps I have been through are:

1 Adjusting the pad that moves so it is close to the rotor but with little or no rub.

2 Undoing the brake cable at the end and pulling it further out so the cable is tighter (if i pull it too tight the pads start rubbing).

Are there any other steps I can take to try and make the levers more responsive?

Thanks

nicklouse

Which brakes? Have you downloaded the manual or read the info on Parktools?

coyote101

Yeah I did look on Parktool, they have info for Avid mechanicals on there. I dont know the name of the brakes, the levers say v-brake on them, but the actual brakes are discs. Thanks

bikaholic

I always setup mechanical disc brakes twice - that is to say, clamp the cable once to seat the ferrules into the cablestops and to observe how the caliper and lever behaves, then re-clamp again to properly install the brake.

Since OP has done the first part, I will detail a version of the second part:

First, centralise the caliper:
1 - Unclamp the brake cable and retract the non-moving inner pad (this is the inboard pad and can be done using an Allen key).
2 - Spin the wheel and observe how the rotor spins, taking note of any wobbles.
3 - Loosen the bolts and center the caliper so that the rotor runs as centrally as possible inbetween the caliper slot (taking into account the wobbles).
4 - Zero all cable tension adjusters (ie screw them in).

Then, adjust the brake:
5 - Adjust the inner pad so that there is just a tiny bit of rub. You do this a little at a time: spin the wheel to check, adjust pad, then spin the wheel again to check etc.
6 - Manually operate the outer pad by rotating the clamp arm. This will give you an indication of the cable travel needed to work the brake, hence the lever travel.
7 - Clamp the cable, making sure that it sits in the groove under the clamp bolt. The bolt needs to be tight but not super tight to the point of breaking the tiny strands of cable - this can be minimised if you put some tension on the cable (ie by pulling on it) whilst tightening the clamp bolt.
8 - Operate the brake using the lever and observe the lever travel. The biting point of the caliper needs to be less than about two thirds of lever travel (eg so that the inside of the lever does not catch on Shimano trigger shifters). Adjust by re-clamping the cable if necessary. Minor adjustments can be made via the tension adjusters later.

Zip-tying or clipping-in the brake housing:
9 - Operate the brake and observe how the housing compresses and flexes. The lever feel will be lightest if the segment of housing to the caliper is straight. If you introduce a sharp bend in the housing, for example, by zip-tying the rear housing along the seatstay, you will notice an increased resistance in the lever caused by cable friction.
10 - I recommend leaving the housing segment as straight as possible if you are using standard housings and cable inners. For super slick cable systems like Gore Ride-On, Alligator iLinks, Nokon etc, tie or clip the rear housing to the seatstay for a neater look.

Bedding-in the brakes:
11 - Take the bike outside, put it into a low-ish gear and ride the bike with the brake half engaged (and gradually increasing the braking power in steps). Do this for one brake at a time for a couple of minutes.
12 - Perform some hard braking (as if you were doing some emergency stops) using one brake at a time. Take care not to skid the rear wheel or fly over the handlebars.
13 - Lift the bike up and spin the rear wheel to see if the rotor still rubs on the inner pad. Adjust a little at a time until there is no rub if necessary.

Minor adjustments:
14 - Use the tension adjusters to dial in lever feel.

Hopefully, this will give the OP a better braking feel through the levers.