Improving the front brake

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hydra
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Improving the front brake

#1

Post by hydra » Wed Jan 21, 2009 8:52 pm

I have a drum brake setup on my '58 Pan and it was marginal at best when I got it. There are a few ways to get better braking on the front. The first and most expensive is to install a PM or similar disc brake setup. This involves a new front wheel, adapters, discs, caliper, and hydraulic master cylinder and if you have internal throttle controls there will be issues there as well.
The route I took to make it usable was to re-work the existing brake by doing a few simple things. First, take off the wheel and inspect the drum and shoes. If the drum is dusty/rusty clean it out thoroughly with steel wool and blow it out. Then use mechanics cloth or emery cloth to de-glaze the drum until it has a nice dull finish. Clean the shoes if they are greasy with brake kleen, let them dry and again de-glaze them with the emery and blow them clean with air. This gives the shoes and drum a better mating surface. If you see the brake shoes are shiny in spots where they are hitting and dull in others, they may need to be leveled and I do that by lightly sanding the high spots until the shoes perfectly match the arc of the drum. If the drum is grooved or ridged you can have it turned at a local brake or Harley Davidson aftermarket shop if they have the right holding tools.
When you have the shoes and drum re-surfaced you can re-assemble them, but now there is an adjustment procedure necessary to insure the shoes are centered and hit evenly. With the wheel back on, and before you tighten the the outer nut and axle nut, loosen the anchor nut on the leg that secures the drum to the leg. Now the backing plate should be a bit loose since all the nuts are loose. Have someone squeeze the brake handle a few times and then hold it down tight. Now tighten the big outer nut, the axle, and the anchor nut while they are holding the brake on. This centers the shoes and backing plate in relation to the drum and gives you a much firmer handle since the shoes should be hitting evenly all the way around.
This also gives you a larger surface area in contact with the drum. Adjust the cable by grasping the outer housing above the adjuster, pulling it up until the slack is out, and then spinning the adjuster almost all the way down. Now you should feel the brake engage in the first 1/4 of the pull so that even if there is cable flex you will be able to get stopped without the lever hitting the bars. If you can't get enough slack out you may have to remove the wheel again and pull some slack out of the cable at the attachment point at the end of the internal brake arm.

That's it! The only other thing I've done in the past is to have the shoes re-lined with hi-friction coefficient brake linings at a brake shop. They use it for race car brakes and special applications, but it isn't available in a lot of places. I'd try the procedure above first and see if that makes your brakes easier to live with.



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Re: Improving the front brake

#2

Post by oldschool » Sat Aug 14, 2010 2:12 am

hydra wrote:I have a drum brake setup on my '58 Pan and it was marginal at best when I got it. There are a few ways to get better braking on the front. The first and most expensive is to install a PM or similar disc brake setup. This involves a new front wheel, adapters, discs, caliper, and hydraulic master cylinder and if you have internal throttle controls there will be issues there as well.
The route I took to make it usable was to re-work the existing brake by doing a few simple things. First, take off the wheel and inspect the drum and shoes. If the drum is dusty/rusty clean it out thoroughly with steel wool and blow it out. Then use mechanics cloth or emery cloth to de-glaze the drum until it has a nice dull finish. Clean the shoes if they are greasy with brake kleen, let them dry and again de-glaze them with the emery and blow them clean with air. This gives the shoes and drum a better mating surface. If you see the brake shoes are shiny in spots where they are hitting and dull in others, they may need to be leveled and I do that by lightly sanding the high spots until the shoes perfectly match the arc of the drum. If the drum is grooved or ridged you can have it turned at a local brake or Harley Davidson aftermarket shop if they have the right holding tools.
When you have the shoes and drum re-surfaced you can re-assemble them, but now there is an adjustment procedure necessary to insure the shoes are centered and hit evenly. With the wheel back on, and before you tighten the the outer nut and axle nut, loosen the anchor nut on the leg that secures the drum to the leg. Now the backing plate should be a bit loose since all the nuts are loose. Have someone squeeze the brake handle a few times and then hold it down tight. Now tighten the big outer nut, the axle, and the anchor nut while they are holding the brake on. This centers the shoes and backing plate in relation to the drum and gives you a much firmer handle since the shoes should be hitting evenly all the way around.
This also gives you a larger surface area in contact with the drum. Adjust the cable by grasping the outer housing above the adjuster, pulling it up until the slack is out, and then spinning the adjuster almost all the way down. Now you should feel the brake engage in the first 1/4 of the pull so that even if there is cable flex you will be able to get stopped without the lever hitting the bars. If you can't get enough slack out you may have to remove the wheel again and pull some slack out of the cable at the attachment point at the end of the internal brake arm.

That's it! The only other thing I've done in the past is to have the shoes re-lined with hi-friction coefficient brake linings at a brake shop. They use it for race car brakes and special applications, but it isn't available in a lot of places. I'd try the procedure above first and see if that makes your brakes easier to live with.

Hi Jerry from Denver here! Ok ! The is a Guy in California who has a shop and most of his Biz is rebuilding front and rear Drum Brakes ! When he is finished with your setup it will stop as good as an Factory Early Disc Brake setups! Wouldnt you like to "Chirp" your front brake at 35-45 MPH...I can write all the things he does but just go to his website and read what he can do with Vintage Race bikes and early Harley Drum brakes ! Good Luck !

go to Vintage brake .com His name is Michael "Mercury" Morse

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Re: Improving the front brake

#3

Post by Panacea » Mon Aug 16, 2010 3:24 am

oldschool wrote:
hydra wrote:I have a drum brake setup on my '58 Pan and it was marginal at best when I got it. There are a few ways to get better braking on the front. The first and most expensive is to install a PM or similar disc brake setup. This involves a new front wheel, adapters, discs, caliper, and hydraulic master cylinder and if you have internal throttle controls there will be issues there as well.
The route I took to make it usable was to re-work the existing brake by doing a few simple things. First, take off the wheel and inspect the drum and shoes. If the drum is dusty/rusty clean it out thoroughly with steel wool and blow it out. Then use mechanics cloth or emery cloth to de-glaze the drum until it has a nice dull finish. Clean the shoes if they are greasy with brake kleen, let them dry and again de-glaze them with the emery and blow them clean with air. This gives the shoes and drum a better mating surface. If you see the brake shoes are shiny in spots where they are hitting and dull in others, they may need to be leveled and I do that by lightly sanding the high spots until the shoes perfectly match the arc of the drum. If the drum is grooved or ridged you can have it turned at a local brake or Harley Davidson aftermarket shop if they have the right holding tools.
When you have the shoes and drum re-surfaced you can re-assemble them, but now there is an adjustment procedure necessary to insure the shoes are centered and hit evenly. With the wheel back on, and before you tighten the the outer nut and axle nut, loosen the anchor nut on the leg that secures the drum to the leg. Now the backing plate should be a bit loose since all the nuts are loose. Have someone squeeze the brake handle a few times and then hold it down tight. Now tighten the big outer nut, the axle, and the anchor nut while they are holding the brake on. This centers the shoes and backing plate in relation to the drum and gives you a much firmer handle since the shoes should be hitting evenly all the way around.
This also gives you a larger surface area in contact with the drum. Adjust the cable by grasping the outer housing above the adjuster, pulling it up until the slack is out, and then spinning the adjuster almost all the way down. Now you should feel the brake engage in the first 1/4 of the pull so that even if there is cable flex you will be able to get stopped without the lever hitting the bars. If you can't get enough slack out you may have to remove the wheel again and pull some slack out of the cable at the attachment point at the end of the internal brake arm.

That's it! The only other thing I've done in the past is to have the shoes re-lined with hi-friction coefficient brake linings at a brake shop. They use it for race car brakes and special applications, but it isn't available in a lot of places. I'd try the procedure above first and see if that makes your brakes easier to live with.

Hi Jerry from Denver here! Ok ! The is a Guy in California who has a shop and most of his Biz is rebuilding front and rear Drum Brakes ! When he is finished with your setup it will stop as good as an Factory Early Disc Brake setups! Wouldnt you like to "Chirp" your front brake at 35-45 MPH...I can write all the things he does but just go to his website and read what he can do with Vintage Race bikes and early Harley Drum brakes ! Good Luck !

go to Vintage brake .com His name is Michael "Mercury" Morse
Don't get your hopes up for the early disk brake performance, mine was rebuilt at Vintage Brake a couple years back with modest improvement...Mike

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Re: Improving the front brake

#4

Post by kitabel » Mon Aug 16, 2010 2:44 pm

it will stop as good as an Factory Early Disc Brake setups

He makes no such claim, and it won't.

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Re: Improving the front brake

#5

Post by Sir_Rat » Mon Aug 16, 2010 3:56 pm

Anyone using the Dual Cam front brake? I've got one but my bike wont be finished for another 6 months.
Aloha....Mike

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Re: Improving the front brake

#6

Post by Panacea » Tue Aug 17, 2010 4:27 am

kitabel wrote:it will stop as good as an Factory Early Disc Brake setups

He makes no such claim, and it won't.
As I recall I read that on his website, I know I've heard that before, can't recall where. Like I say, don't get your hopes up...Mike

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Re: Improving the front brake

#7

Post by ozwick86 » Tue Aug 17, 2010 5:59 pm

This is the cut and paste direct from the website.

VINTAGE BRAKE is dedicated to serving the premium/high performance brake lining needs of the Vintage & Classic bike owner. We specialize in drum brake linings suitable for mechanical leverage ratios. Properly done, drum brakes can perform better than ever before, surpassing early disc performance.

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Re: Improving the front brake

#8

Post by kitabel » Tue Aug 17, 2010 7:00 pm

The claim does not state that the H-D 8" single leading shoe brake can be as good as a disc, only that some drums can.

Those would be the Guzzi, Yamaha, Suzuki, Brit 2LS and 4LS.

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Re: Improving the front brake

#9

Post by ozwick86 » Tue Aug 17, 2010 8:40 pm

kitabel,

I was not agreeing to the statement, I was just posting it as a reply to Panacea. Vintage Brake could revise the statement on his website.

:)

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Re: Improving the front brake

#10

Post by kitabel » Wed Aug 18, 2010 10:25 pm

Of course, no criticism of you was intended.
Quoting the manufacturer is always a useful post, and we know it's not an endorsement - just information.
Vintage is an excellent mfg., I just think he should qualify the claim a bit!

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Re: Improving the front brake

#11

Post by RUBONE » Thu Aug 19, 2010 1:08 am

It does not take much to exceed early disc brakes. First generation Brit discs were atrocious. So were most European types. The Japanese were the first to make production disc brakes work. Remember that some of the first types were mechanical, not hydraulic! Nowhere does he claim an H-D drum will exceed an H-D disc, as they did not exist in the same time period!
I don't think any revision to the website is necessary!
Robbie

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Re: Improving the front brake

#12

Post by 58flh » Tue Jun 14, 2011 1:13 pm

A drum brake will always be just that a DRUM-BRAKE. We all who ride on them know the limitations--there have been many times i had to stand on the rear & squeeze that front to get out of a mess!!!. I take good care of my brakes, always break-down the front and back once a year,&check that all should be there do all the adj. -after-all its the olny thing keeping me & the ol-lady alive. I know Im ramblin again,,what im trying to say here we all know our bikes & thier stopping distancees--after all we ride them everyday. I can truly say i can lock-up my rear-wheel with a little pressure on the peddle!. My front brake i can squeeze with both hands if i wanted to & it wont lock-up, but she will stop t-enough for my liking! I have been reworking these beautiful machines for many years now just like alot of us out here! My thing is this you aint gonna get a duel-drum-mechanical Pan-Knuck what have you to stop like if it had discs on it!. I have machined my drums -all new parts,-file to fit the whole nine!-even worked with different shoe matieral,-except for ceramics, i havent tried them yet-but when i do i will let you men know how it works out!.(remember keep her upright 4th gear wide-open & enjoy that bad bike!)58flh

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Re: Improving the front brake

#13

Post by kitabel » Tue Jun 14, 2011 6:10 pm

Assuming that you wish to retain drum in front, and that any repairs etc. have been done, there is a possible mod to improve the leverage.
A “snail cam” (similar to the late Ford Mustang clutch cable mechanism) could be incorporated into the motion path. The idea is that the distance from the bar lever pivot to the cable end is not constant (as it is with stock brakes), but changes length as it rotates.
This can change the leverage from low effort/high travel for the initial cable pull to take up all slack, then gradually change to high effort/low travel to apply maximum force to the brake cam just before shoe contact is made with the drum. The leverage ratio can be anything you wish within the confines of available space, from 1.1:1 to 3:1. This is not a plug-in but an engineering project, and will require considerable development time and fabrication skills.

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Re: Improving the front brake

#14

Post by panfreak » Thu Feb 09, 2012 4:27 pm

I had a glide drum up front on my pan for years and following the setup procedures mentioned above, I was happy with what I was getting. I recently redid my bike and now have a springer drum on, it's absolutely horrible no matter what adjusting I do. I might as well not have it, truthfully. Now I know this will be old hat to any of you guys who've been running this before, but in taking the wheel off and trying to maximize shoe contact through adjusting, they are clearly mis-engineered in my opinion, the cam at the bottom, when actuated, only allows the lower portion of the pad to make contact with the drum as they are essentially stationary at the top. By the time I squeeze the lever into getting them to touch, I'm only using the bottom 10% of the pad? Bear with me here... Has anyone ever tried putting on a thicker than normal set of pads and then chucking the whole setup in a lathe and turning them down to better match the I.D. of the drum? Although new aftermarket, maybe mine are just fucked, but if they made contact alot sooner it seems that I could greatly increase the percentage of pad contact. The only way to do this (in my case anyway) is to start with thicker pads. My last question would be, is this the norm or in buying a reproduction set did I get a drum thats got a slightly larger I.D. than what it should be?

EDIT: My apologies, I see re-arcing is mentioned in other posts and this is essentially what I refer to. But it seems this method would be most beneficial when started with pads thicker than stock and turned down to match, is this how it's done or are they simply working down the stock ones?

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