Hi Everyone,
David Lahey wrote:Grassy wrote:I was given the opportunity to swap bikes with Greg TL-climax yesterday at the end of the trial.. The brakes not only worked, they were perfect.
So please Greg, and all you other regular contributors to this epic thread, help a novice out and spill the beans on the secrets
Cheers,
Jeremy
I witnessed your surprise regarding the working brakes on Greg's TLahhhh yesterday. I don't know what's wrong with yours but the usual causes for weak drum brakes on trials bikes are:
Lining radius not matching drum radius.
Lining material choice not ideal.
Drum surface not flat.
Rarer causes include:
Shoes not centered.
Play in wheel bearings.
Contaminated linings.
Cable drag.
You may be surprised to know how many of the people you rode with on the weekend were riding bikes that had drum brakes prepared to maximise performance. The usual method for worn drums is to machine the drum surface flat again. Then the shoes are relined with thick brake material that is then machined down so that the radii of drum and lining match. The lining material chosen is important too and modern non-asbestos lining material is available with fabulous friction properties.
Thankyou Jeremy for the ride on your
TLR 200, it is always good to compare bikes and yours is a very nice example! TL-climax
OK, so I will try and answer yours and David's questions. David, Jeremy's 200 has TLR 250 wheels fitted and the brakes were a bit lacking. The rear pedal had quite good feel so I don't think the shoes were not centered or mismatched in diameters and likewise the bearings did not feel loose riding the bike. There was no pulsing so I am pretty sure the drums were round and my most likely conclusion without pulling them apart is contaminated linings, some photos of the inside would help here Jeremy?
The front was pretty much the same in feel but the feel was slightly springy and I didn't have a close look at the cable (riding over rocks) but I suspect it was a 2.0 mm cable. Again if you could measure this Jeremy, 2.5 mm cable has less stretch in the inner and less compression of the outer giving a more direct feel and better feedback. Avoid buying a 2.0 mm front brake cable especially the ones designed to go over the headlight as they add an unnecessary extra bend robbing you of feedback. The front was more effective than the rear and likewise photos disassembled would help? My assumption is the same as the back, most likely contaminated but there could be a dusting of debris working like little marbles or maybe beans in this case inside the drums?
As for the
Basically the brakes are off bikes designed to go faster and therefore have more effective brakes. A mate of mine is always wheeling and dealing in bike parts and we have done some weird and wonderful swaps, I always like going to his place to check out the latest scores and he is always keen to come to my place. Sometimes he will even detour to my place before going home just to show me what he has picked up and is always keen to swap for any of my bargaining chips. The negotiations are the best part as we both always want win win! Anyway he is a
nut and most of the components except stainless steel spokes and TL 125 rear rim came from him in dribs and drabs. They are all
parts and I am hoping some
fans can help identify them for me?
As for brake shoes, I just use off the shelf EBC grooved shoes at about $30.00 a pair from our local
dealer. As David said, there are all sorts of different lining materials available but when you can get effective brakes for $60.00 and a little effort, I have not felt the need.
Here are some more photos starting with the controversial log jam shot next to the Orara River :
- 1595241396934.jpg (147.84 KiB) Viewed 2081 times
This one has the TLR 200 front brake arm as I was waiting for the TLR 250/TLM 200 front arm to turn up that was fitted just before the weekend:
- 1595241445433.jpg (231.18 KiB) Viewed 2081 times