Twin leading shoe braking issue

Drum out of round?.

Hi, wonder if the link rod needs adjustment shoes not contacting at the same time.

Poor adjustment usually just makes the brake inneficient,but it could be a combination of both problems.

I found the same when I was running a 2LS front brake, in fact the only time the brake worked properly was after it had just been soaked and dried out. I think the linings absorb moisture and only after a few applications do they dry out. It has nothing to do with poor adjustment, you could maybe try yet another set of linings or just accept what you have.

Mine didn't have the stiffening kit but I couldn't live with the poor braking (and probably wouldn't have for much longer) so converted to disc. That cost me as much as I paid for the bike in 1975 !

They all do that, Sir!

The inner drum is cast iron so will form a thin layer of rust very quickly which will then jam up the brake.My trick is to ride off cautiously, not using the front brake until I come to an open stretch of road, then get up to at least 30mph and gently brake a couple of times. Everything is fine after that. In summer I use the bike to go to work so do this virtually every day.

Braking at low speeds is dangerous! The front wheel will lock up instantly and, yes, I have laid the Commando on its side at less than walking pace at the end of our street once, to my great embarrassment!

Far worse is the twin-TLS drum on my 1960 Manx (1962 brake on it), which is plain dangerous at anything but racing speeds, but a joy to use on the track.

The SLS brake on my 99 was poor even after O/S linings turned to fit. I decided to do what the manual said and increase the plate/axle clearance to aid centering . This completely ruined the braking ,luckily I had a scruffy old plate that i thought was scrap. This works fine! . No logic to any of it.

This doesn't seem to affect original Ferodo linings. The SLS with NOS brakes shoes on my 99 is pretty effective in all conditions. I have encountered this phenomenon on bikes with new asbestos-free linings. I now have matching clavicles to show for it.

Previously mark_oliver wrote:

Hello all,

My commando has a 2Ls front brake and it works well but if it has got damp or moisture in the air when i start out it grabs very violently almost enough to throw me off. Although after a few uses its works perfectly again. It has always done this and i have replaced the shoes and used different linings. I was advised to file the leading edges but this has made no difference. Any advise would be welcome.

My 750 used to do this and it would easily lock the front wheel the grab was so violent. Even applying the brake slowly it would grab if it was damp. I lived with it like this for 25 years trying different shoes and set ups. The solution was getting the drum skimmed and it's been fine for the last 10 years. So I would say it had nothing to do with what type of lining the shoes had as I have tried old and new.

The first place I took my wheel to could only fit the hub on their lathe as the wheel was too big. I didn't want to take the wheel apart to have it skimmed so had to find someone with a lathe with a removable bed so the wheel could fit in. The firm I used was Allcap engineering, Gloucester, it was a long time ago so you'd have to phone them to see if they could do it. But this is not much use to you if you're in Ireland.

Ironically I have just had the hub on my 650SS skimmed this week by SRM in Aberystwyth. They have a specialised machine lathe specifically for large diameter wheels. No need to remove the tyre even. I booked it in prior to visiting and went and had an ice cream on the sea front and two hours later collected all done. A helpful bunch of guys too. http://www.srmclassicbikes.com/