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I'm juat about to send my front brake arm off for engraving, I intend to use it as a reverse pull.
Am I correct in thinking the arm gets flipped for reverse pull?

So from this


To this?

No, it stays the same way. Bottom photograph is right.

Storkfoot wrote:No, it stays the same way. Bottom photograph is right.

Nice one, cheers for that.

What does it involve then?

Is this for disc or drum brakes?
May be of interest.
viewtopic.php?f=22&t=11819

you could also use a clutch lever, longer than brake one, larger pivot

landybretta wrote:Is this for disc or drum brakes?
May be of interest.
viewtopic.php?f=22&t=11819

Yeah it's drum, don't want to risk it being too sharp/dangerous.

Will just leave it I think

http://www.ilambretta.co.uk/reverse.html

Im using reverse pull on drum on two bikes and like it. Will be doing the same on the new project

I'm a big fan of a reverse pull drum. WAY better than any other cable brake.

However, I have found that LI cams are better than GP type. The GP type give too much shoe movement for lever travel and make the brakes too harsh for me.

Using a longer lever like a clutch or better still, a late Spanish one will give more power and reduce the any harshness.

To point out the bleeding obvious...

The brake lever doesnt know whether it is being pulled from the right or pushed from the left. The brake mechansim itself is completely unchanged so isnt suddenly going to 'grab' more when used in reverse pull (ie push).

The only difference to changing to reverse pull is a more direct cable routing leading to lower cable friction and therefore a smoother more sensitive 'feel' for the brake, with less pulling effort needed on the handlebar brake lever.

If the shoes are worn out, and there is a risk of the cam locking, that's the same either way you route the cable.

But if you want to keep loads of friction in the cable route thats up to you. If you like to pull harder for less braking effort, then keep the original. Why not introduce a whole extra 360 degree loop in the cable if its better that way?!

tv175lambretta wrote:To point out the bleeding obvious...

The brake lever doesnt know whether it is being pulled from the right or pushed from the left. The brake mechansim itself is completely unchanged so isnt suddenly going to 'grab' more when used in reverse pull (ie push).

The only difference to changing to reverse pull is a more direct cable routing leading to lower cable friction and therefore a smoother more sensitive 'feel' for the brake, with less pulling effort needed on the handlebar brake lever.

If the shoes are worn out, and there is a risk of the cam locking, that's the same either way you route the cable.

But if you want to keep loads of friction in the cable route thats up to you. If you like to pull harder for less braking effort, then keep the original. Why not introduce a whole extra 360 degree loop in the cable if its better that way?!

In any case, the preferred outer cables should be wound with a rectangular section wire, not round as is the case with speedo cables.

Besides the mechanical advantage pointed out, there is yet another advantage to the shorter, more direct reverse pull. It has been referred to as a 'servo' effect for want of a better term, but it is nothing of the kind. What actually occurs is that as the suspension compresses, the whole cable from where it exits the fork crown gets bent. This has the effect of pulling the coils of the outer cable slightly more apart on the larger radius side, which in turn means the inner cable is stretched within it even more.

For that reason, the reverse pull cable set up, whether disc or drum, is best assembled with as straight a run from crown to lever. It almost wants to be 'too short' to gain the best result though rebound of the suspension needs to be taken into account as that will result in the brake operating unintentionally when cresting hump back bridges or popping wheelies outside the local Wimpy....

On a related solution, I see Steelweasl the YouTuber that posts about Lambretta's, mostly good stuff, posted about putting a small pulley wheel near the hub lever to aid the braking. It looked to work on the video but I don’t quite understand the physics.
The best front brake set up I’ve ever had was using a reverse pull with a reshaped clutch level.

GExS wrote:On a related solution, I see Steelweasl the YouTuber that posts about Lambretta's, mostly good stuff, posted about putting a small pulley wheel near the hub lever to aid the braking. It looked to work on the video but I don’t quite understand the physics.
The best front brake set up I’ve ever had was using a reverse pull with a reshaped clutch level.

+1

GExS wrote:On a related solution, I see Steelweasl the YouTuber that posts about Lambretta's, mostly good stuff, posted about putting a small pulley wheel near the hub lever to aid the braking. It looked to work on the video but I don’t quite understand the physics.
The best front brake set up I’ve ever had was using a reverse pull with a reshaped clutch level.

I've seen most of his videos including the pulley. As front braking is the topic, he recently posted a video showing his solution to an overheating hydraulic caliper. I doubt that the racing lads have their fluid boil simply because they'll be using something like https://msdspds.castrol.com/bpglis/Fusi ... BGV7RW.pdf as I used to which completely eliminates fade.

What the pulley achieves in the video is halving the cable pull but it doubles the power from the 'bar lever. Theoretically it should endow the brake with more feel, but that has been discussed in this thread & fitting the longer crankcase cover clutch lever is a far easier option, if that is what is required. IMO the longer lever option completely overcomes the frictional losses of the pulley system & is not a complex solution by comparison.