metisse Posted February 18, 2020 Report Share Posted February 18, 2020 2 hours ago, b40rt said: Hi Hamish, was going till about Thursday, then with the weather and 5 hours each way, chickened out. Sorry to have missed you, hope you enjoyed it ? The original poster, siht stirred that he is, is a friend of long standing, I look upon him as a long term project, care in the trials community, as it were..... Yep it was good, but after a while I get trials bike blurredness.... some nice stuff as usual and nice to catch up and say hello, a tad windy on the way home.. hats off to our driver we all got home safely and just in time to keep the family happy, who didn t know I had penciled it in till the last minute.. 1 Quote Link to comment Share on other sites More sharing options...
baldilocks Posted February 19, 2020 Report Share Posted February 19, 2020 23 hours ago, b40rt said: So by your calculation, twin leading shoe brakes are less effective than single leading ! That'll be why multi leading brakes were developed ..... The other advantage with turning the arm forward is a far better cable run, and shorter outer which compresses less, absorbing less energy. I think the cable run is the advantage. Also some torque arms are worn and can shift under braking if the hole is elongated. If the brake arm is forward of the fork leg it takes slack up in the cable as it moves. Quote Link to comment Share on other sites More sharing options...
midlife Posted February 19, 2020 Author Report Share Posted February 19, 2020 (edited) Thanks folks So if there is a benefit to having the arm in the forwards position it is marginal BUT there is less or no chance of the arm getting damaged by a rock or any anything else we might find or our merry way round if pointing to the rear. Edited February 19, 2020 by midlife Quote Link to comment Share on other sites More sharing options...
midlife Posted February 19, 2020 Author Report Share Posted February 19, 2020 Oh I take it by the change of subject I have came up with the answer why the lever points to the rear. Next topic FARMING 3 hours ago, b40rt said: Though you were being rude, not commenting, but your excuse that it was date night holds water. Please, stop asking advice, I really have no experience in dealing with the chaff marks caused by the leather harness, or the bruising on the abdomen caused by the chalk . I've heard raddle powder works fairly well. Quote Link to comment Share on other sites More sharing options...
steve Posted July 9, 2020 Report Share Posted July 9, 2020 I spent hours trying to work out the forces etc.... Came to the conclusion that the leverage from the cam would be slightly weaker by moving the arm to the front. But I did it anyway on my Armstrong, mainly for the cable run. I was wearing a hole in the bottom yoke. On braking forks compress and you can feel the effect on the lever as the cable is bent. Fitted some new forks as my old stanchions were knackered, so I needed to make some bits anyway. I made a custom mudguard risers with a cable pull anchor (drilled and hollowed for weight saving). Custom fork brace which is flatter and helps reduce twisting. Also made a nice strong torque arm. I tried to keep all the angles optimum for best efficiency, which meant a new brake arm with slot at a different angle. Less outer cable = less flex and no deflection on fork travel. I used 2mm Cable, but I also have a 2.5mm to make up to try. Tested it Saturday. Overall result = Awesome Works better that I'd hoped, lever feels so solid, not too vulnerable for damage and I think it looks good too. What do you think? Sorry to muddy the SWM forum with pics of an Armstrong! 1 Quote Link to comment Share on other sites More sharing options...
section swept Posted July 10, 2020 Report Share Posted July 10, 2020 8 hours ago, steve said: I spent hours trying to work out the forces etc.... Came to the conclusion that the leverage from the cam would be slightly weaker by moving the arm to the front. But I did it anyway on my Armstrong, mainly for the cable run. I was wearing a hole in the bottom yoke. On braking forks compress and you can feel the effect on the lever as the cable is bent. Fitted some new forks as my old stanchions were knackered, so I needed to make some bits anyway. I made a custom mudguard risers with a cable pull anchor (drilled and hollowed for weight saving). Custom fork brace which is flatter and helps reduce twisting. Also made a nice strong torque arm. I tried to keep all the angles optimum for best efficiency, which meant a new brake arm with slot at a different angle. Less outer cable = less flex and no deflection on fork travel. I used 2mm Cable, but I also have a 2.5mm to make up to try. Tested it Saturday. Overall result = Awesome Works better that I'd hoped, lever feels so solid, not too vulnerable for damage and I think it looks good too. What do you think? Sorry to muddy the SWM forum with pics of an Armstrong! Very nicely done, brake operating lever looks to be well protected ? Quote Link to comment Share on other sites More sharing options...
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