H: Hubs, Wheels and Tyres Brake Shoes and Linings
- Thread starter Eric
- Start date
I believe that they are available from the Spares Co. They have already been developed.
This appears to be a good design and I would not put a lining of less than .50 coefficient of friction. Historically, linings that are too low in friction have been used on Vincents, in my opinion.
David
This appears to be a good design and I would not put a lining of less than .50 coefficient of friction. Historically, linings that are too low in friction have been used on Vincents, in my opinion.
David
Hi David,
They do look well designed, but also very expensive. Club store says it is due to the expense of designing and manufacturing a new item, which I can certainly believe. What brake lining have you found with a .50 coefficient of friction? Aren't the GGW linings rated less (IIRC 0.44)? You have found something better? Didn't you post recently that going that high might cause another problem (too grabby or something) and were going to test them?
In 100 years of cars and motorcycles, I am surprised no one has stumbled across a set of brake shoes from another vehicle that would fit and work well (small car, perhaps). May need to be from something with mechanical brakes, to have an eye and a flat at the ends, Wishful thinking, perhaps.
They do look well designed, but also very expensive. Club store says it is due to the expense of designing and manufacturing a new item, which I can certainly believe. What brake lining have you found with a .50 coefficient of friction? Aren't the GGW linings rated less (IIRC 0.44)? You have found something better? Didn't you post recently that going that high might cause another problem (too grabby or something) and were going to test them?
In 100 years of cars and motorcycles, I am surprised no one has stumbled across a set of brake shoes from another vehicle that would fit and work well (small car, perhaps). May need to be from something with mechanical brakes, to have an eye and a flat at the ends, Wishful thinking, perhaps.
Green Gripper Woven is .52 cold and .43 hot. AM4 is .44 cold and .41 hot. It has been used by Vincent owners for a few years.
http://www.scanpac.com/cm/pdfs/tds-GGW.pdf
I would think this would be the minimum you would want.
Yes, I have been doing a lot of work on this and David Tompkins has done some low speed testing on a .61 lining that I put on some stock Vincent shoes. I have six shoes, two 7" and four 8" shoes that are being relined right now with the .61 lining. If I get them to David in time for the next race at the end of May I will have some good feedback.
I originally thought that the high friction linings would mitigate the softness of the shoes on the Vincent and provide more braking power with less squeeze. It looks like that may be true based on David using only about 30% of the lever travel to come to a complete stop, but I decided that the this was not a good solution for the racers or performance bikes.
I am not sure that I would characterize my efforts as "stumbling across", but I went looking for a shoe I could use on the Vincent. I chose a Honda brake shoe:
This shoe was reasonably close, but metric and a little big. The width is 30 mm instead of 7/8". The diameter is 180 mm instead of 178 mm. The pivot needed moving to make this brake work without compromising the very thick lining bed.
Here it is slimmed down with the pivots moved. I wanted to remove the lining and arc the bare shoes to the proper diameter. I milled most of the lining of with a rotary table and fine tuned them on a sander. I did this until I got the exact same contour on the new show as an unbent stock shoe.
This can be done with a 1/2" bolt and a square block on the cam end to check your work.
The finished shoes above have been sent for lining, as mentioned.
Several notes: I did not need to machine the brake shoes for fitting a speedo. I have not drilled the shoe for the cotter pin, yet. Finally, I had to mark the shoe so that the lining would be bonded only on the 90 degree section from the center of the shoe. The stock shoe has those dips to prevent extending the lining. I simply transferred marks from the dips on the stock shoes. This replicates the 90 degree arc and the 35 degree heel angle that Vincent wanted.
As I have mentioned before, there is no serious harm in using extended linings. They need to be clearanced much more at the heel and toe ends so the lining does not touch the drum easily. The dips in the original shoes prevented the linings from being bonded to the low pressure areas of the shoe and getting in the way of the harder working middle. As a test, I felt it was best to stay close to stock on the geometry. Stiffness of the shoes aside, this means the coefficient of friction is the only change. I am hoping the combination will provide much better stopping.
David
http://www.scanpac.com/cm/pdfs/tds-GGW.pdf
I would think this would be the minimum you would want.
Yes, I have been doing a lot of work on this and David Tompkins has done some low speed testing on a .61 lining that I put on some stock Vincent shoes. I have six shoes, two 7" and four 8" shoes that are being relined right now with the .61 lining. If I get them to David in time for the next race at the end of May I will have some good feedback.
I originally thought that the high friction linings would mitigate the softness of the shoes on the Vincent and provide more braking power with less squeeze. It looks like that may be true based on David using only about 30% of the lever travel to come to a complete stop, but I decided that the this was not a good solution for the racers or performance bikes.
I am not sure that I would characterize my efforts as "stumbling across", but I went looking for a shoe I could use on the Vincent. I chose a Honda brake shoe:
This shoe was reasonably close, but metric and a little big. The width is 30 mm instead of 7/8". The diameter is 180 mm instead of 178 mm. The pivot needed moving to make this brake work without compromising the very thick lining bed.
Here it is slimmed down with the pivots moved. I wanted to remove the lining and arc the bare shoes to the proper diameter. I milled most of the lining of with a rotary table and fine tuned them on a sander. I did this until I got the exact same contour on the new show as an unbent stock shoe.
This can be done with a 1/2" bolt and a square block on the cam end to check your work.
The finished shoes above have been sent for lining, as mentioned.
Several notes: I did not need to machine the brake shoes for fitting a speedo. I have not drilled the shoe for the cotter pin, yet. Finally, I had to mark the shoe so that the lining would be bonded only on the 90 degree section from the center of the shoe. The stock shoe has those dips to prevent extending the lining. I simply transferred marks from the dips on the stock shoes. This replicates the 90 degree arc and the 35 degree heel angle that Vincent wanted.
As I have mentioned before, there is no serious harm in using extended linings. They need to be clearanced much more at the heel and toe ends so the lining does not touch the drum easily. The dips in the original shoes prevented the linings from being bonded to the low pressure areas of the shoe and getting in the way of the harder working middle. As a test, I felt it was best to stay close to stock on the geometry. Stiffness of the shoes aside, this means the coefficient of friction is the only change. I am hoping the combination will provide much better stopping.
David
Very interesting David. What model of Honda are the shoes off. Do you have a part number?
Simon
Simon
I always thought there would be a Japanese shoe that would "almost" fit, would it not have been easier to mount the shoe on a dummy Honda brakeplate and machine the outside first then reposition the eyes ??
Are there any of the relining companies that will fit Green Gripper in the UK or supply it in suitable sizes ??
Chris.
Are there any of the relining companies that will fit Green Gripper in the UK or supply it in suitable sizes ??
Chris.
I wonder if Green Gripper is available in Australia or NZ? Any takers??
Simon,
Yes. The brakes are made by EBC, which is a neighbor of the Spares, Co.
Unfortunately they are not "free motorcycle brakes", but "asbestos free motorcycle brakes." I know Bill was excited for a few seconds. But, they are readily available in the UK on Ebay. If you intend to buy some on-line, they may ask you for a model number. I have been using Honda 1972 CB550K. Just make sure the EBC316 pops up.
Chris,
The Honda brake plate is too big and it is not really necessary. Moving the pivot does two things, it lets you center the cam face as close as possible to the stock shoe while not running out of meat between the pivot and the inside of the shoe. That is, it is difficult to center the cam ends and leave the wall of the pivot thick enough. But, ultimately, you are also trying to move the lining bed, which is three times the thickness of the Stock shoes, inside the drum far enough so that you don't have to thin them to fit in the smaller Vincent drum.
I did it by eye for the ones above. It is not difficult as long as think of lining up the Vincent shoe on top of the Honda shoe and getting all of the outer edge of the Honda shoe within the edge of the Vincent shoe just like in the third photo above. On the next shoes I machine I will place them with the DRO:
This is what I came up with, but you may choose to do it differently.
Thinning the shoe to stock size is easy if you have a good stock shoe and a DRO. Put the stock shoe in the vise, run the cutter up to it and set the DRO to zero. Take the new shoe and cut it back to zero, then flip the shoe 180 degrees and cut to zero.
Once the lining bed is centered and the correct stock width, put the stock shoe in the vise by gripping the lining bed and bring the cutter to the pivot or cam. Zero the DRO and do the same. I plug the pivot hole first so it gets machined to the proper width.
Regarding the lining, get it off any way you are able. I used a rotary table to get it down to very thin and used a sander for the final finishing to stock shoe size. A little more meat comes off the ends of the shoe because it is a little larger in diameter.
The lining bed does not have to be super precise as the new lining will be mounted and then arced to size. Because these are rear brakes I believe the mu is .35, which is very low. Considering that the linings are very low friction I would put something .50 or higher like Green Gripper, at a minimum.
David
I'll try our local Race Brakes in Auckland to see if they can supply.