Need to move brake lever closer to bar after 13m MC install

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jimbo

jimbo

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Hi, I have installed the AN 13mm master cylinder ($$$!) and a ss hose. The brake is now super hard right from the start of the movement. I want to bring the stock lever closer to the bar. Should relieve the levers heal where it touches the mc piston? I had to push in the piston to install the lever Or heat and bend the lever itself . If I remove materiel from the lever heal the piston could move out of the bore and cause problems. Or use this RGM one?



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Need to move brake lever closer to bar after 13m MC install
 
jimbo said:
The brake is now super hard right from the start of the movement.
Click to expand...

A reduced diameter master cylinder would normally result in increased lever travel with a lighter action.

jimbo said:
I want to bring the stock lever closer to the bar. Should relieve the levers heal where it touches the mc piston? I had to push in the piston to install the lever
Click to expand...

With the brake released the piston should be able to fully return or the bleed port that allows residual system pressure to vent into the reservoir may not be uncovered which can result in the pads dragging or even the brake locking on under certain circumstances so it sounds as if metal needs to be removed from the "heal" (heel) and enough to include a small amount of free-play.
 
When I installed the Madass 13mm resleeve kit on my stock MC, the kit comes with three different thickness caps to use as shims on the outside end of the piston, where lever heel contacts it. This to fine tune where the piston seal positions with respect to those tiny holes in reservoir floor. There was also guidance to file down the lever heel if needed incases where piston ends up too deep in bore. Apparently not all levers have exact same dimensions.
 
this is what AN said to do

You can try and bend the lever, it is a forging. You can't remove material on the heel of the lever as it will make no difference as the spring will force the lever out to where it sits now.
 
"A reduced diameter master cylinder would normally result in increased lever travel with a lighter action."

yea when used with the old stock rubber hose, not so much with a new SS hose.
 
jimbo said:
yea when used with the old stock rubber hose, not so much with a new SS hose.
Click to expand...

Yes, perhaps not as much as the rubber hose but the lever travel should still be increased. I have a modified (by RGM) 13mm master cylinder with a braided hose and would say it does. When RGM used to do this modification they also requested the lever be sent so they could bend it further away from the handlebar to compensate for the additional movement.
 
maybe its the difference between a modified MC and the as cast 13mm AN sells?
 
jimbo said:
maybe its the difference between a modified MC and the as cast 13mm AN sells?
Click to expand...

I couldn't say but any 13mm piston should travel further than the standard 5/8" piston with no change of caliper resulting in increased lever travel.
The important thing is that the lever shouldn't prevent the piston from fully retracting so not uncovering the vent hole which could be the reason why there is reduced lever movement.
 
Try a Mk3 lever as its a different shape but should fit the earlier M/C. The RGM sleeve kit has an adjustable pusher between the lever and the piston assembly. The earlier RGM sleeves had an unadjustable pusher so they wanted the lever sending with the M/C so they could file the heel to get the piston travel correct. Never heard of them 'bending' the lever. I wouldn't want to do that anyway.
 
jimbo said:
The brake is now super hard right from the start of the movement. I want to bring the stock lever closer to the bar.
Click to expand...
A bit strange. Besides issues with the master cylinder, If the pistons are retracting normally you should have decent movement before they reach the disk and therefore decent lever movement. What is the condition of the caliper seals (old, new, etc.)?
 
dobba99 said:
Never heard of them 'bending' the lever.
Click to expand...

My Mk3 lever returned by RGM (the one below in the picture) I noticed had been bent and also when compared with another standard Mk3 lever (on top) that I had and I'm sure it wasn't like that when I sent it to them.
Need to move brake lever closer to bar after 13m MC install


The only evidence of metal having been removed is from the area arrowed (on the lower lever), not the heel. This was one of the early RGM fixed pusher conversions.
Need to move brake lever closer to bar after 13m MC install
 
Is there concern that bending the cast lever might weaken it? This is a life safety device afterall and can take a fair load when used in an emergency.
 
jimbo said:
this is what AN said to do

You can try and bend the lever, it is a forging. You can't remove material on the heel of the lever as it will make no difference as the spring will force the lever out to where it sits now.
Click to expand...
Don't understand this statement. If you are only trying to make lever closer to bar for comfort, then ok. But if issue is lever has no movement before fully pressuring the MC, that sounds like a problem with piston seal positioned too far down the bore, due to lever heel holding it there, not permitting the pressure vent holes to pass fluid.
 
Tornado said:
Don't understand this statement. If you are only trying to make lever closer to bar for comfort, then ok. But if issue is lever has no movement before fully pressuring the MC, that sounds like a problem with piston seal positioned too far down the bore, due to lever heel holding it there, not permitting the pressure vent holes to pass fluid.
Click to expand...
Sorry I reinvestigated the lever action and there is some movement, so it might not be an issue after all
 
Dirt bike riders have been straightening alloy levers for years without problems.
There is an art to it. The challenge is the lever will initially bend readily, but will often work harden in the process.
In which case you need to relieve the internal stresses from the previous bend.
Heating up the lever helps the bending.
If it resists even with heat, it probably needs annealing.
It might take 5 or more heat, bend, and anneal cycles to get it where you want it.
Depends on the alloy and how bent it is.
 
I bent my clutch lever for a better fit for my hand using a propane torch and a vise.Have used it for 2 years now with no problems.Just be gentle with the process.
Mike
 
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Hi,
I because of a medical condition (Dupyutrans Contracture) I had lost strength in my hand but also couldn't get all four fingers around the brake lever making emergency stops (kangaroos) problematic.
I reduced the master cylinder bore (can’t remember what kit) which largely solved the excessive lever pull issue.
Of course there is more travel on the lever but that is not a problem.
The lever was still a little too far from the grip for me to easily reach so I removed some metal from the heal but also epoxied a small pad to the portion of the lever that limits how far forward the lever resides when not in use.
The result is the lever is closer to the bars making it easier to grab in an emergency and requires less squeeze to provide heavy braking. It has more feel but is more spongy and at full pressure is rather close to grip.
All in all it is infinitely better than the previous iron hard brake that needed a grip like a Scotsman on a fiver to get any meaningful retardation. Yes, twin aftermarket discs would be better but would be expensive and reduce the originality of my very standard bike. (Not that I’m obsessive about originalit, it’s just that changes like discs are so obvious).
Al
 
Alan L said:
Hi,
I because of a medical condition (Dupyutrans Contracture) I had lost strength in my hand but also couldn't get all four fingers around the brake lever making emergency stops (kangaroos) problematic.
I reduced the master cylinder bore (can’t remember what kit) which largely solved the excessive lever pull issue.
Of course there is more travel on the lever but that is not a problem.
The lever was still a little too far from the grip for me to easily reach so I removed some metal from the heal but also epoxied a small pad to the portion of the lever that limits how far forward the lever resides when not in use.
The result is the lever is closer to the bars making it easier to grab in an emergency and requires less squeeze to provide heavy braking. It has more feel but is more spongy and at full pressure is rather close to grip.
All in all it is infinitely better than the previous iron hard brake that needed a grip like a Scotsman on a fiver to get any meaningful retardation. Yes, twin aftermarket discs would be better but would be expensive and reduce the originality of my very standard bike. (Not that I’m obsessive about originalit, it’s just that changes like discs are so obvious).
Al
Click to expand...
That is part of the reason I want to Brembo brake and clutch mc on the Commando. I had Pazzo shorty cam levers on my Duc and they worked great. I have to have them set differently for each hand.

Old school straight or frog-leg levers, not so great. Well, not really at all in a workable way.

Lots of options that fit the Brembo MC (and I assume Nissin).

Need to move brake lever closer to bar after 13m MC install
 
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