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[jawa-enfield]

..As long as i have my bullet, the front break, of the 2 leading type, does not work the way a brake that size should work, tried different braking pad materials, and yes i know how to adjust such a brake...
i made the braking keys smaller in witdth so there's more force at the braking shoes against te drum..
The strange thing is, at slow speed the brake works well, grasps suddenly, but at higher speed, the brake underachieves.. a lot.
does anyone recognise this phenomenon?
Would be gratefull for the golden tip..

[nigelphoto]

A 2LS fr brake can be set up to perform as well as any disc, except perhaps that it will fade quicker under extreme conditions. It should not grab at slow speeds which indicates the leading edges need chamfering. Despite what you say, I'd suspect it isn't set up properly - and they are notoriously difficult to set up, mind. You could start with this from our hosts http://www.hitchcocksmotorcycles.com/pi ... erhaul.pdf

[ric]

Try slackening off the outer brake plate nut by about one flat off finger tight (before the threadlock you've applied sets) and ensure the nut is tight against the left hand fork leg during the fork cap tightening sequence.


If this works for you then you might also wish to consider packing out the rear edge of the brake plate anchor slot on the fork leg with a piece of leather or other slightly compressible material glued/double sided in place to prevent the rattling noises from the (now) floating brake plate and stop the plate from unwanted rotation into the fork leg every time you apply the brake lever as both alloy parts will be held in gentle contact.

[Les H]

I know what you are saying and I was going to suggest most of the problem is getting a friction lining soft or grippy enough to make the brake work but you say you have tried several? I might be then you are not allowing enough time for them to bed in. Although you can try to get both lining s to contact absolutely spontaneously by adjusting the tie rod in practice a minute difference in contact position will see one lining touch and the other way just short of touching or even with flexing of the mechanics, not touching the drum quite as hard, so only wearing in will get to the exact position where they do. It could be of course that the pivot position of the brake is in the wrong position by design (not the cam position which won't make any difference), maybe it could be more in-board (slightly nearer towards the centre radius of the plate) of where it is currently....it would also mean different shoes would be required to match up. If it was then there would be more self-servo action created and a bigger push outwards of the shoes so to speak and a harder pressure created. If this is so then you might be able to modify the plate and the end of the shoes by experiment ....Not sure if Mr H has a better plate and matching shoes?....Les

[Les H]

Apologies for the typing errors on my post above it makes it a tough read...wish one could edit after sending...so I'll resend with some ammendments:



I know what you are saying and I was going to suggest most of the problem is getting a friction lining soft or grippy enough to make the brake work more effectively but you say you have tried several? It might be then you are not allowing enough time for them to bed in. Although you can try to get both linings to make contact with the drum spontaneously by adjusting the tie rod, in practice a minute difference will see one lining touch and the other way one left just short of touching exactly at the same time, even with the normal flexing of the levers etc, one lining won't be pressing quite as hard. However after a period of usage the wearing in process will you will have the exact positioning where they do contact in unison. Furthermore it really takes a long time before the full length of each shoe makes good contact along its length so once again a lengthy bedding is required to fully judge the brakes power.



It could be of course that the pivot position of the brake is in the wrong position by design (not the cam position which won't make any difference), maybe it could be more in-board (slightly nearer towards the centre radius of the plate) of where it is currently....it would also mean different shoes would be required to match up. This newer position would move the shoe further outwards assisted by the self-servo action and create a stronger push outwards of the shoes against the drum. You might be able to modify the plate and the end of the shoes by experiment ....Not sure if Mr H has a better plate and matching shoes?....Les

[Edward]

If your brake grasps suddenly at low speed you may have an oval brake drum. Try applying the brake very lightly and see if you can feel a pulsating at the lever, if you can the drum is oval.

[vince]

Hi, Perhaps a long shot but how is your cable routed? If it takes a convoluted path through the cassette it can affect the braking power, reroute it outside and see if theres any change, same advice for clutch cable. vince

[PeteF]

Your expectations also matter. If you're used to modern disc brakes then the TLS is likely to disappoint unless you get it spot on and I suggest you might have to resort to skimming the drum and shoes to get it as good as it can be. If you're used to 50's bikes then the Bullet TLS isn't too bad and certainly better than some of the SLS ones I had to suffer in my youth.

[Tim NZ]

No disrespect to our host, but the method they advise to (mis) adjust (adjust the link rod randomly) the 2LS fr brake is a simple stop-gap method for the average Joe, and is possibly the worst way to set a mechanical brake?


If the levers are set as ANYTHING other than a perfect parallelogram, (Both opposing sides equal length) the braking effect (leverage) will rapidly diminish into a POS that will need repeatedly resetting again in short order, and continues to be so until the levers are set to 'True and Square'


(One lining will be completely worn-out and when you go to fit a new pair of shoes, one is left wondering WHY only one lining had worn out???)


I have addressed this same topic here several times before, so you could search old messages, OR if any one would like detailed (some what lengthy) instructions on how to CORRECTLY set and adjust the mechanical 2LS brake so that Stoppies are achievable; contact me of list. royalenfield AT clear DOT net DOT nz


Grabbing brakes are due either to insufficient lead chamfer on leading edge of the lining or excessive servo action on one shoe as a result of incorrect link rod length.

[PeteF]

Tim, Email sent.