Rear Brake Modification

[guzzijack]

I've started a new thread for this one as the 'V. hot brake caliper' one would swallow it whole in the debate about the laws of physics and Noether's Theorem

 

Following my own dragging rear caliper and burnt disc scenario - no debate about what was the cause please gentlemen - I thought the return of the lever to the 'at rest' position could do with a bit of beefing up.

 

Here's what I did:

 

 

Consists of a 6mm stainless washer above the lower rose joint; a reasonably stiff spring in extension which neither binds on the actuating rod nor requires any noticeable force to overcome it; a further 6mm washer above the spring with an 8mm washer above that which, it so happens, just bears on the outside rim of the master cylinder. Both of the top two washers fit neatly and are held in place under the rubber boot.

 

Seems to work well and might even prevent dragging caused by those with Charlie Chaplin feet who rest on the lever while riding

 

GJ

[BrianG]

Nice idea!

 

I too, do not like the light return force on the brake pedal.

[dlaing]

That is brilliant!

Way to thing outside the box.

I wanted to ask you for a photo, but did not want to drag you in.

I was contemplating how to hook a spring to the lever, but this does the trick much more elegantly.

[Baldini]

Beats my bit of inner tube hooked round pedal!

 

KB

 

PS (How you getting on w the Sport Demons on the Tonti GuzziJack?)

[guzzijack]

Beats my bit of inner tube hooked round pedal!

 

KB

 

PS (How you getting on w the Sport Demons on the Tonti GuzziJack?)

 

Well I had to improvise because all the bikes have tubeless tyres of course

 

I'll let you know about the Demons when we get back from the run down to the Troffeo Rosso week after next

 

Cheers

 

Graham

[luhbo]

... but this does the trick much more elegantly...

 

 

No, not , it's technical nonsense. The spring works against the brake main piston.

 

Hubert

[dlaing]

No, not , it's technical nonsense. The spring works against the brake main piston.

 

Hubert

GuzziJack wrote "...with an 8mm washer above that which, it so happens, just bears on the outside rim of the master cylinder."

As I understand it the 8mm washer placement on the rim allows for the added spring to assist the internal spring, and more importantly it assists it past the point of negative free-play, so that there truly is free play.

[guzzijack]

GuzziJack wrote "...with an 8mm washer above that which, it so happens, just bears on the outside rim of the master cylinder."

As I understand it the 8mm washer placement on the rim allows for the added spring to assist the internal spring, and more importantly it assists it past the point of negative free-play, so that there truly is free play.

 

Exactly. The upper washer is the bearing plate for the spring and as it, (the washer that is), is only in contact with the bottom of the master cylinder BODY it can have no influence plus or minus on the piston - only to assist the return of the rod and lever. Certainly seems that some people feel that something like this will help the less than perfect O/E setup.

 

GJ

[Skeeve]

 

... a reasonably stiff spring in extension...

 

A very sweet mod, & not to criticize but that looks like a compression spring to me, not extension.

 

FWIW, I hope that spring is in stainless or phosphor bronze, 'cause any regular carbon steel spring is gonna rust like a motherf****r exposed to the weather like that. Keep it covered w/ LPS3 or Boeshield (or better yet, find a rubber bellows that'll fit over it & fill up w/ grease...)

 

Anyway, like I said, a very sweet mod: I suspect that there's going to be a flurry of these showing up on V11s everywhere.

[luhbo]

Yes, you are right, Dave. Sorry, GJ.

I indeed overread the small but important 8mm washer detail.

 

Hubert