BMWSportTouring

Adjusting brake pedal height

Posted By: Rex R

Adjusting brake pedal height - 11/08/17 06:38 AM

Anyone know how to adjust the resting height of the brake pedal? I'd like it to sit about 1/4"-1/2" lower
Posted By: AndyS

Re: Adjusting brake pedal height - 11/08/17 10:11 AM

I think it is a case of adjusting the actuating shaft at the forked clevis (where the master cylinder attaches to the rear part of the brake lever).
The clevis attaches to the brake lever by means of a split pin (with a washer), although you shouldn't have to take this off.
The clevis position (and therefore the brake lever angle/height), is dictated by 2 nuts. One above the forked clevis, and one inside the clevis.
It looks as though you can back off the upper nut, adjust the lower nut (up or down to suit and then lock off again with the upper nut.
I don't think you have a lot of adjustment there, but you shouldn't need much.
Posted By: Rex R

Re: Adjusting brake pedal height - 11/10/17 06:28 PM

Thanks for the suggestions. Can anyone confirm or correct this?

Andy's response had a lot of "I think", and "should be" in there. Anyone actually make this adjustment?
Posted By: AndyS

Re: Adjusting brake pedal height - 11/10/17 06:54 PM

Rex, you are right, it us just some observations, but it is such a simple thing to check and try, you could feedback and tell he if that is the way to do it.
It appears to be one of the simpler things to throw a spanner at.
Posted By: lkraus

Re: Adjusting brake pedal height - 11/10/17 08:53 PM

Looking at the Repair DVD, it appears that the Wethead pedal is different from the Hexhead/Camhead(/R1150?) pedal.

The older R1200 has specific adjustment procedures for the pedal stop and piston rod "blow-by" clearances. I think I seem to recall that maybe I've read that a badly mis-adjusted piston rod on those models can cause the rear brake to lockup when applied. Possibly. (Is that vague enough? smile ) The point is, getting it wrong can be dangerous.

The RepROM illustration shows a similar clevis on the RTW pedal, with what might be a lock nut for adjustments, but I found NO procedure or specs for any adjustment.

If you try adjusting the rod, be sure to test the rear brake repeatedly before taking it off the center stand.


Ilium Works offers an adjustable brake pedal, but I think it's a bit pricey for the small adjustment you want.
Posted By: dirtrider

Re: Adjusting brake pedal height - 11/10/17 09:00 PM

Originally Posted by lkraus
Looking at the Repair DVD, it appears that the Wethead pedal is different from the Hexhead/Camhead(/R1150?) pedal.

The older R1200 has specific adjustment procedures for the pedal stop and piston rod "blow-by" clearances. I think I seem to recall that maybe I've read that a badly mis-adjusted piston rod on those models can cause the rear brake to lockup when applied. Possibly. (Is that vague enough? smile ) The point is, getting it wrong can be dangerous.

The RepROM illustration shows a similar clevis on the RTW pedal, with what might be a lock nut for adjustments, but I found NO procedure or specs for any adjustment.

If you try adjusting the rod, be sure to test the rear brake repeatedly before taking it off the center stand.



Evening Larry

The BMW 1150 (I-ABS system) & the early 1200 (again I-ABS) system did need a very special rear brake pedal adjustment procedure & a specific up-stop clearance adjustment as the brake switch leaf was operated by the pedal against the up-stop.

Later 1200RT's with I-ABS gen ii were not nearly as picky about pedal adjustment as they didn't use a dedicated up-stop & don't have a brake light switch mounted at the pedal.
Posted By: lkraus

Re: Adjusting brake pedal height - 11/11/17 03:23 AM

Originally Posted by dirtrider
Evening Larry

The BMW 1150 (I-ABS system) & the early 1200 (again I-ABS) system did need a very special rear brake pedal adjustment procedure & a specific up-stop clearance adjustment as the brake switch leaf was operated by the pedal against the up-stop.

Later 1200RT's with I-ABS gen ii were not nearly as picky about pedal adjustment as they didn't use a dedicated up-stop & don't have a brake light switch mounted at the pedal.


That sounds reasonable, since iABS2 no longer needs the switch to activate the servo motor. I've only worked on my '06 RT's iABS, so I'm looking through the DVD for clues on later bikes. Could the switch have been dropped beginning with the Camhead? I'm still seeing it in the parts fiche and RepROM procedures up to 2009.

No matter. My concern was that Rex's experiments might cause a problem with the piston rod adjustment, if it is adjustable at all on the RTW (and not documented on the DVD).

Surely somebody has attempted to adjust the pedal on a Wethead? It's been out for four years now!
Posted By: KeithK

Re: Adjusting brake pedal height - 11/11/17 03:24 AM

Works exactly as Andy says,adjusted mine to work with peg lowering kit.

Keith
Posted By: dirtrider

Re: Adjusting brake pedal height - 11/11/17 01:09 PM

Originally Posted by lkraus
Originally Posted by dirtrider
Evening Larry

The BMW 1150 (I-ABS system) & the early 1200 (again I-ABS) system did need a very special rear brake pedal adjustment procedure & a specific up-stop clearance adjustment as the brake switch leaf was operated by the pedal against the up-stop.

Later 1200RT's with I-ABS gen ii were not nearly as picky about pedal adjustment as they didn't use a dedicated up-stop & don't have a brake light switch mounted at the pedal.


That sounds reasonable, since iABS2 no longer needs the switch to activate the servo motor. I've only worked on my '06 RT's iABS, so I'm looking through the DVD for clues on later bikes. Could the switch have been dropped beginning with the Camhead? I'm still seeing it in the parts fiche and RepROM procedures up to 2009.

No matter. My concern was that Rex's experiments might cause a problem with the piston rod adjustment, if it is adjustable at all on the RTW (and not documented on the DVD).

Surely somebody has attempted to adjust the pedal on a Wethead? It's been out for four years now!


Morning Larry

The external brake switches were dropped on the 2007 & up 1200 bikes. That is when the braking system switched to the I-ABS gen 2 system. The pre 2007 I-ABS (wizzy) system used external brake pedal & lever switches to trigger the servos, brake lights, & drop cruise control set. The later braking systems (2007 up) used internal pressure sensors to trigger the brake lights & rear servo.

The reason that the rear brake switch being present is very important to brake pedal adjustment is that it includes an external pedal up-stop adjustment. That external brake pedal up-stop position MUST MATCH the rear master cylinder internal piston stop or the cylinder take-up port could remain covered by the piston & prevent full rear brake pressure release. (so on the pre I-ABS gen 2 systems it is very difficult to move the brake pedal position (angle) without causing rear braking issues)

On the later (2007 & up) systems without the external brake switches the pedal adjustment is much easier as there is no external pedal up-stop, so (within reason) a simple clevis adjustment can change the pedal angle/pedal position.

Added: In my BMW parts book it does sort-of show the rear switch for all but if you look closely there is a qualifier at the bottom stating--- "This is a rear brake switch for vehicles with integral ABS".


Posted By: Rob L

Re: Adjusting brake pedal height - 11/12/17 04:28 PM

I adjusted mine. The threaded rod can be shortened by screwing the clevis/fork in after removing the pin. Get on the floor with a light and see the linkage that attaches the pedal to the master cylinder.
Posted By: Rob L

Re: Adjusting brake pedal height - 11/12/17 04:51 PM

https://imgur.com/ZOfgVVs
This is the clevis.
https://imgur.com/outXnMP
I removed the pin and shortened the threaded rod a bit
https://imgur.com/mPpprfh
this is after I shortened and reassembled the pedal
Posted By: Rob L

Re: Adjusting brake pedal height - 11/12/17 05:10 PM

[Linked Image]
The rod may be too long. Remove the clevis and grind off a few threads.
[Linked Image]
I also left the locknut off to shorten the distance between the clevis and the master cylinder even more. Use locktight on the threads instead.
Posted By: AndyS

Re: Adjusting brake pedal height - 11/12/17 09:38 PM

Hi Rob, not keen on the 'no lock nut'. How about drilling a tiny hole in the piston rod UNDERNEATH the clevis...then lockwire it to prevent shaft rotation.
Posted By: Rob L

Re: Adjusting brake pedal height - 11/13/17 01:06 PM

You would need to remove the master cylinder to drill the hole. Not keen on that either........ I did this a year ago when I added the lowered foot pegs. Over 10,000 miles and no problems.
Posted By: AndyS

Re: Adjusting brake pedal height - 11/13/17 01:59 PM

Why would you need to remove the Master Cylinder? Just do it in-situ.
Posted By: Rob L

Re: Adjusting brake pedal height - 11/13/17 11:00 PM

the rod can turn (revolve) and move sideways. It would need to be held stationary (in vice) to drill a hole. The clevis and rod would need to be drilled together. I feel that the lock-nut is a bit of overkill and really not necessary, however, your bike, your decision.
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