PDA

View Full Version : Disk Brake Material



GunnySnow
09-29-2003, 08:07 PM
Hello All,

I am building a little mini-bike for my son and want to put disk brakes on it, any recomendations for disk material? What about pad materials? I think I pretty much have the caliper licked. Could a regular pad from say an automotive pad be cut down to size then possibly turned to make a round puck? Then I could just weld on my fitting to the back to make it work?

thoughts?


Gunny

Evan
09-29-2003, 08:15 PM
Go have a look at the disk brakes on mountain bikes, I'm sure you'll get some ideas.

darryl
09-29-2003, 09:18 PM
Clutches are cork-faced, maybe that could do the job for you, any size you want to cut it to. I don't know the effect of water on it, or the wear rate, but clutches last well enough.

G.A. Ewen
09-29-2003, 10:38 PM
If you can find a deceased snowmobile it will likely have everything that you need, disk, calipers, cable and hand control. http://bbs.homeshopmachinist.net//wink.gif

jfsmith
09-29-2003, 10:51 PM
Gunny,
Some of the disk brake pad sets have a smaller forward brake pad than the rear pad, you may want to check with an auto parts place for what the sizes and for what make car, then maybe look at the junk yard. I don't think you will get the same amount of wear as the car does on this mini bike.

Jerry

CCWKen
09-29-2003, 11:59 PM
You can get the pucks for $1.99. Hardly worth the trouble to make them. But if you must, just take an old brake pad from a truck and use a hole saw. Remove the pilot drill so it cuts a puck. I would let the puck float in a receiver. If you try to weld a mount to it, it might release the bond.

Look here for ideas. (Under go-karts & mini bikes)

http://www.mfgsupply.com/m/c/index.html


Also, cast iron would make the best disk. If you use SS, you'll have to slot it to keep it from warping into a bowl.


[This message has been edited by CCWKen (edited 09-29-2003).]

ibewgypsie
09-30-2003, 12:02 AM
Northern Hydraulics had a cable operated go cart disc brake for about $10. Why engineer something so cheap?


The last mini-bike I built I used a metal paddle to press against the rear tire.. Worked great.

[This message has been edited by ibewgypsie (edited 09-29-2003).]

Thrud
09-30-2003, 03:19 AM
Gunny

You could get a gnarly front disk brake off a real motorcycle from a motorcycle recycling yard cheap - If it was my kid I would want the best possible brake I could put on it. The front brake has the greatest stopping power as the weight transfer during hard stops mozes ot the front wheel - this is why most motor bikes have one disc on the back wheel and two upfront. On an pick-up truck the rear brakes are only used for backing up and when heavily loaded or dragging a trailer.

GunnySnow
09-30-2003, 03:26 AM
Hello All,

I am thinking that the disk should be about 4-6 inches in dia.

I think a front disk from a streetbike might be serious overkill

plus i am trying to keep the weight down, and no hydraulics

if possible


Gunny

abn
09-30-2003, 03:47 AM
Just for trick factor I'd grab a nice late model sport bike caliper off ebay...but if you don't want to mess with the hydraulic hassle of arranging for a master cylinder I have a Wilwood mechanical spot caliper that I'd sell you cheap...like $5 plus shipping from Los Angeles CA area. Probably be about $10 all together via Fedex ground.

http://www.wilwood.com/products/calipers/msc/index.asp

As far as rotor material...I'd use a rear disk from a motorcycle. Most of my rotors are cast iron, but my EBC replacements on my bike are forged steel. For a mini bike, unless it is for racing, I think you could get by with regular steel plate. But I think a surplus motorcycle rear caliper w/ a home shop made carrier would be best.

ibewgypsie
09-30-2003, 05:44 AM
Gunny...

I just happen to have a yard full of JUNK JAP bikes at the moment. Brakes on all.

This Kawa two cylinder with disc brake, mas cyl, and lines

Most items off these will ebay, I'd just as soon save the ebay fees. Brake, caliper and master cylinder will bring $35 on there at most. That'd be the safe way to build the bike. Cut the disc down on a lathe. I would but time is premium around here.

I used a conduit bender on the last mini-bike frame I made. worked great. was a 1" bender and 1" tubing. Forks were made rigid with 1 1/4 tubing.

Where are you? I am in North Georgia, Tunnel Hill to be exact.

GunnySnow
09-30-2003, 08:03 AM
Hello All,

Ibewgypsie,

I am in Ontario, Canada. I am not sure the disk would work. I am thinking that its would be way too big even with turning it down as well as the caliper. I am trying to avoid hydraulics as well if I can, although I do appreciate the offer.

I am curious as to your paddle brake description though. This minibike will only have 9-10" diam tires (from a heavy duty handtruck) its only going to be able to run around 11-15 mph tops.

Gunny

Paul Gauthier
09-30-2003, 08:40 AM
This is where you want to go. Everything you need for go-karts and minibikes.

http://www.northerntool.com/

------------------
Paul G.

mbensema
09-30-2003, 09:34 AM
I had the paddle brake on my mini bike when I was a kid, it used a foot lever, but when turning it was possible for the lever to hit the ground, flipped the bike a couple times doing that. If you go with something like that, then make sure it will stop the bike without having to be depressed very far. I would recommend the disk brake.

Herb W
09-30-2003, 10:18 AM
Gunny
Princess Auto sells a small disc brake assembly that might be just right...and the caliper is mechanical.

ibewgypsie
09-30-2003, 09:44 PM
My rear brake never malfunctioned or flipped the bike. It did wear the tire kinda fast.
It was just a pivot with a paddle on it slick from rubbing the tire.. It had I remember two go cart wheels.

I'd be interested to build a two wheel drive scooter.. I remember one they sold when I was a kid... ROKO?? anyone remember them?

Possible to use one of the motorcycle engines I guess?
I kinda remember it having shaft drive down the side of the forks..

David..

[This message has been edited by ibewgypsie (edited 09-30-2003).]

Dr. Rob
10-01-2003, 02:40 AM
Totally OT, but:

YES, ibew- I remember. I've had those on my mind recently, for no reason. Was just trying to remember the name. Should have asked you.

I think it was an American thing, mid-50's to mid-60's, two-wheel drive motorcycle with gigantic tires, called the Prospector or Navigator or something. ROKO, is that it?

Yamaha did something similar a couple decades later. (BW-200?)

Thrud
10-01-2003, 09:18 AM
there was reference to the machine you speak of in the "pictures of my bike" thread near the end.

I wonder if they had a torque steer problem?

ulav8r
10-01-2003, 11:32 AM
http://www.rokon.com , the two wheel drive two wheeler.

How do you turn on HTML in replies?