Wheelman Brake Drum Refinishing Fail

Trying to get your Spree/Elite to run, or run better? Post your questions here.

Moderator: Moderator

Post Reply
User avatar
Wheelman-111
Moderator
Moderator
Posts: 11319
Joined: Wed Oct 22, 2008 5:09 pm
Location: Deepinnaharta, Texas

Wheelman Brake Drum Refinishing Fail

Post by Wheelman-111 »

Greetings:

Recently Flash's brakes have come under scrutiny for a distinctively J*erk-y operation. Maybe it's the racy Malossi pads, or maybe because the various Flashes have gone about TWICE as fast as the brakes are designed to handle. Whatever the reason, application of either brake lately has resulted in eyeballs jiggling crazily in their sockets, and several dental fillings coming loose. That can mean only two things:
A. Wheelman has a seizure disorder, or
2. The drum section of both rims has overheated causing them to become ovals instead of perfect circles.

You can buy brand-new Metropolitan rims for about $125, but my left kidney hasn't completely grown back since my Vespa purchases. Also, I'd have to dis- and re-mount the Conti tires, something I dislike intensely to do.

Nobody I know refinishes old-school brake drums anymore, mainly because drum brakes have gone the way of other quaint traditions like Steam power and the iPhone 6. Even if there was a resurfacing machine anywhere near Deepinnaharta, I'm not sure they could accommodate the 10" rims and roughly 4" drum surfaces. What is a cheap bastich like myself to do?

After much Wheel-reflection, I came up with a possible solution: What if the brake shoes themselves were abrasive enough to remove material? A steady application of very light lever pressure - one click at a time - would perform the same function as the service station's drum lathe, only Sanding instead of cutting material away. A little more thought and I came up with this Idea:
Al-You-Minnie-Yum Oxide paper?  Check.<br />Scissors?  Check<br />Contact Cement?  Check.<br />Old and worn (Not Enough) stock shoes?  Check
Al-You-Minnie-Yum Oxide paper? Check.
Scissors? Check
Contact Cement? Check.
Old and worn (Not Enough) stock shoes? Check
BrakeRefinishPrep.jpg (198.6 KiB) Viewed 8417 times
Cut strips to match the area of the brake pads pretty closely. Next painted up with the Contact Cement:
The hardest part is walking away until the CC is really dry and non-tacky.  I'm pretty sure I waited long enough, but the paper + glue layer added a lot of thickness to the pads.
The hardest part is walking away until the CC is really dry and non-tacky. I'm pretty sure I waited long enough, but the paper + glue layer added a lot of thickness to the pads.
BrakeRefinishGlue.jpg (172.83 KiB) Viewed 8417 times
and finally pressed and rolled the sandpaper onto the pads, making sure the paper wrapped around the leading edge of the pad so it wouldn't be stripped off as the drum spins.
BrakeRefinishReady.jpg
BrakeRefinishReady.jpg (126.97 KiB) Viewed 8416 times
I planned to spin the rim by pressing a drill chuck against the tire like an old Whizzer moped. That part worked, briefly.

Seems like a sure-win, right? Is Wheelman not the smartest human ever to inhabit this mudball? Uhh, not so fast...

Problem 1: It was a coax to wiggle the brake panel back into position over the drum on the wheel. It seems paper and cement thickened the overall dimension of the brakes, and it had to be "walked" over the rim's lip into position against the friction surfaces of the drum. If the stock brakes were more worn than mine were, things might've worked better. As it was,

Problem 2: Contact between the sandpapered shoes and the drum lining was a bit firm, even with the brake cable adjusted to slack. I could turn the tire easily for about 3/8ths of a revolution, but the drum was SO oval that it was hard to turn through the tight spot, every half-spin. I soldiered on, finding the tight spot and using a Back-and-Forth motion, got it to spin all the way around, still "catching" a bit every half-spin. One half turn of the cable adjustor and the same issue arose and was overcome. I repeated this about 6 times until...

Problem 3: Contact cement evidently lacks the heat tolerance of whatever Voodoo they use to bond ceramic lining material to the steel (aluminum?) shoes. It would appear the sandpaper wore out, and the cement let go causing the sandpaper to curl and leading to....

Problem 4: It took me about 30 minutes before I was able to pry the brake panel back out of the drum. The sandpaper was almost worn through in spots, and one leading edge had lifted and retroflexed, resulting in the Paper Jam from *.

One bright spot: After cleaning up the stock shoes and the grit in the drum, I reinstalled the wheel and test drove. It's definitely a LOT better than it was. Maybe good enough to try it on the rear rim if I can find a set of REALLY worn stock shoes somewhere. It sure will be easier to spin the rear wheel: Engine Power!
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
User avatar
Meatball
CB900F
CB900F
Posts: 2320
Joined: Sat Jun 04, 2016 10:45 am
Location: seattle

Re: Wheelman Brake Drum Refinishing Fail

Post by Meatball »

You may be onto something here, Wheel. If there was a way to adhere something much more abrasive/durable to the shoe than sandpaper it may yield better results. Sanding stone? Small carbide teeth in a cross-hatch pattern? Create a pair of shoes with replaceable grinding surfaces tough enough to grind the drum and you could begin a small enterprise.

Spin the wheel and slowly tighten the adjustment screw until theres intermittent resistance...stop when you get constant resistance.
I need to find some new haters...the ones I have are starting to like me.
User avatar
Wheelman-111
Moderator
Moderator
Posts: 11319
Joined: Wed Oct 22, 2008 5:09 pm
Location: Deepinnaharta, Texas

Re: Wheelman Brake Drum Refinishing Fail

Post by Wheelman-111 »

Greetings:

Yes, right now I'd settle for an old set of brake shoes if anyone has them collecting dust.
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
User avatar
motormike
Moderator
Moderator
Posts: 5488
Joined: Wed Dec 29, 2010 10:58 pm
Location: Glasgow, KY

Re: Wheelman Brake Drum Refinishing Fail

Post by motormike »

I suspect that removing drum molecules from the narrowed diameter in order to achieve a diameter equal to the widened diameter left by warping will increase newly formed diameter by a factor that will require brake shoe linings to be simliarly increased in order to attain adequate contact duration during the immediate future of your periodic brake engagement.
RideRed
<Gyro S><MB5><Honda Navi><Helix><Sym Wolf><Yamaha Razz><Honda CH150 Deluxe>
"Live Large - Ride Small"
1man8scoots
CB900F
CB900F
Posts: 1485
Joined: Wed Mar 18, 2015 11:49 am
Location: usa

Re: Wheelman Brake Drum Refinishing Fail

Post by 1man8scoots »

I have a good condition stock wheel once you give in. I'll be going to austin then Brownsville tx to drop off a sb50 and visit the island. If you've given in by then you're more than welcome to it for no cost. I'll be down there may 6th to 9th I believe.
User avatar
Wheelman-111
Moderator
Moderator
Posts: 11319
Joined: Wed Oct 22, 2008 5:09 pm
Location: Deepinnaharta, Texas

Re: Wheelman Brake Drum Refinishing Fail

Post by Wheelman-111 »

Greet - uuhhh, Whut? Dangitall Mike, be talkin' thet-thar Inglish.

It was a long time ago, but I have actually observed a drum-turning machine, first-hand, when my misbehaving Maverick (1971 Mercury Comet with a 302 V8 and All-Wheel Drums!!) got its drums resurfaced. Worked like a charm. Yes I had to adjust the brakes out a hair, but really not much material was removed.

1Man your are a champ. But Corpus is WAY out of your way from Austin to Brownsville. Also, at the risk of sounding like I'm looking a Gift Horse in the Oral Cavity, is it a Met rim? I have Conti 90/90s that don't fit particularly well on Elite 1.85s...
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
1man8scoots
CB900F
CB900F
Posts: 1485
Joined: Wed Mar 18, 2015 11:49 am
Location: usa

Re: Wheelman Brake Drum Refinishing Fail

Post by 1man8scoots »

I have both I'm sure.

I'm fairly certain that I run through corpus Christi between the 2. 77 hits 37 on the far edge of town if I remember right. I'm passing through San Antonio as well to pick up a ns50 engine for a customer on the way back also. Might see if sanjuro is ready for me to pick up his af34 as well
User avatar
ped
CB900F
CB900F
Posts: 1783
Joined: Sun Sep 29, 2013 9:54 pm
Location: northeast usa

Re: Wheelman Brake Drum Refinishing Fail

Post by ped »

Hi wheelman.
I had to remove the malossi brakes because of squeak.
I used OEM metro brake pads and they work good.
they do get hot. I may have to drill vent holes on the side hub to keep pads cool?
the metro pads seem to work fine up to 60mph. after that they get hot and lose grip. after 70+mph forget it. lol.
try the OEM metro pads. I think you will be fine. :thumbwink:
Life's a trip enjoy the ride.
94 elite SR, 86 spreedio, polini corsa, keli variator, 8.4, jet. speed 65 mph
spreedio video. https://www.youtube.com/watch?v=BZr46_-douQ
User avatar
motormike
Moderator
Moderator
Posts: 5488
Joined: Wed Dec 29, 2010 10:58 pm
Location: Glasgow, KY

Re: Wheelman Brake Drum Refinishing Fail

Post by motormike »

I've operated automotive brake-lathes.
Access to a machine shop lathe that would chuck-up the wheel
seems to me the likeliest way to achieve desired result.
There's always the small shop somewhere willing to do it,
but the cost feasibility weighed against the swapping to Met wheels
is something you will have to consider.
RideRed
<Gyro S><MB5><Honda Navi><Helix><Sym Wolf><Yamaha Razz><Honda CH150 Deluxe>
"Live Large - Ride Small"
MrJumps
CB900F
CB900F
Posts: 1453
Joined: Thu Dec 25, 2014 11:12 pm
Location: Tennessee, Maryville

Re: Wheelman Brake Drum Refinishing Fail

Post by MrJumps »

Reminds me of this time I had a set of drilled and slotted rotord that were warped... dont ask. I asked a freidn that got a lapping/surface machine secound hand and when it started lapping the rotors it started acting like it was catching, about 20 secounds later the surface of it caught into a spot and threw it up and the "chuck" bent the rotor right in half and ruined his machine.

Use CA glue, its pretty d*** good for s*** like this.

Or tike to swap some disk brakes into the barrel. Ms. Wheelman may agree since it makes you safer and you can have the added bonus of the looks of those fancy disk and rims, plus ots easy af to change disk breaks.
1993 ch80, swapped with a ch250
2021 DRZ400sm :worship:
User avatar
Wheelman-111
Moderator
Moderator
Posts: 11319
Joined: Wed Oct 22, 2008 5:09 pm
Location: Deepinnaharta, Texas

Re: Wheelman Brake Drum Refinishing Fail

Post by Wheelman-111 »

Greetings:

Uhh, whut's CA Glue, Jumps? Ms. Wheel-person would not endorse the cost of a disc swap, and I lack the welder and the skills to accomplish the task.
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
MrJumps
CB900F
CB900F
Posts: 1453
Joined: Thu Dec 25, 2014 11:12 pm
Location: Tennessee, Maryville

Re: Wheelman Brake Drum Refinishing Fail

Post by MrJumps »

Cyanoacrylate(superglue), bonds harder than Marley and Me

http://www.caglue.com/ either the thin or medium, they also have it on amazon.

Goes on harder than a broekn heart, dont get it on anything you dont want to have to bury. Best superglue ive gotten my hands on used it to glue down a microwave handle, the handle broke in the middle before it gave up again bond lasted 3 years plus daily microwave usage.
1993 ch80, swapped with a ch250
2021 DRZ400sm :worship:
Post Reply