front brake

[Breetwor]

Front brake on my G12CSR is a little scary if your going much over 60mph. Has anyone tried a change to a different fron brake, for example a Grimeca 180mm double sls? I'm afraid to put a large single sided brake on it because I ounce had the brake stay ripped right out of the fork slider. That was a G80CS with standard brake fitted with AM4 linings. Any input appreciated. Thanks.

[Duncan]

David

Is this ( "CLICK HERE" )the brake you are referring to?

I have one in the shed that I keep threatening to fix on my twin, if you want to make the modification reversible it should be relatively simple, the spindle would require reducing on one side for the fork clamp leaving a raised portion next to the hub and the other side would need a split sleeve. The above site has some torque arms in 2.5mm stainless I do not know if the undrilled one will fit though.

If you do go ahead I would be interested to hear how you get on.

I do know of several bikes that use a hydraulic twin leader based on the original Mini shoes and cylinders (I think there is a picture on the site somewhere), I believe that Malcolm Arnold has a neat mechanical twin leader crafted into a standard hub, in the photo section there is also a modification to fit a Norton TLS and SPRIDDLER’s photos showing how to remove part of the trailing edge to improve braking.

[singleminded]

To improve the braking I fitted a Commando TLS & forks to to standard
1 1/4" AMC yokes
This involved enlarging the holes for the larger diameter Norton stanchions. A small amount has to be machined off the right side fork boss & brake plate retainer as the forks now have a narrower centre than the Commando yokes. The next problem to overcome is now the pinch bolts do not fit. To overcome this both sides of the pinch bolt hole were seperately taped & plugged then redrilled to allow the pinch bolts to fit. (Subsequently when doing this mod for others I found it was easier to use long roadholder sliders as their yoke centres ore much the same as AJ ones.

Been running it for over 30 years & somewhere over 100,000 miles now without a problem & it stops!
Hardest thig now is finding correct shoe material as some of the proported lining material does not work as well as the original stuff.
The other way is to go whole hog & fit the Whole Commando front end yokes & all BUT this involves machining the headstock for the taper rollers.

If you want to see it go to the new pics section & look at the xmas ride pic

Cheers
JT

[rayswadling]

I'm currently working on getting a BSA 8" TLS hub into my 650. It's a heavy thing being all iron, but it's a good brake.
I've had to get the spindle modified as it was too short, but the diameter was OK.
I plan to make up a torque arm to suit and will have to drill a suitable hole (or holes) in the brake plate, as the original fitting uses a boss on the fork leg for this purpose. I think the main thing is to make sure the torque arm mounting points have no free movement as I can see any movement could eventually cause a failure.

Both the bikes I raced years ago used the Seeley double-sided SLS brake and alloy torque arms to the mudguard mounting studs (Triumph and Norton forks). Never had any problems with the torque arms so personally it's the method I'm happy to use.

[Eric]

If you search this forum to find other topics about the front brake it may help. In my own experience careful attention to all details of the existing front brake can improve it substantially.

I guess that's why the design was not changed in so many years as correctly set up and maintained its adequate, not exactly fantastic but adequate.

[wilko]

If you can find one of those 8 inch sls from a fifties BSA it would look more appropriate, with nice wide shoes.

[rayswadling]

I have uploaded a picture of the initial fitting of the BSA 8" TLS into the forks.
This was really to confirm the extended spindle was OK and to start to work out the torque arm.