Mechanical Brake Calipers no good?

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karl

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Just put a new axle setup on the drift beater/ 60' simplex. I ordered a cheap hydraulic disk setup off jungle prime,
and 2 days later the ship date was postponed over a month, and I already had the axle parts. So I had a brand new mechanical caliper
sitting around, genuine knott / thomas unit that I never used, as people had nothing but complaints about poor stopping power.

I decided to give it a shot, on a 8in bmi karts disk. No additional leverage, and hooked to petal with a old shortened motorcycle clutch cable,
using brass 1/8 npt x 1/4 compression fittings. At 30mph , if you hit the brake petal it will lock up both rear 13x6.50x6 slicks on pavement. It works great,
as well as a small hydraulic setup. Very surprised.

Plus the toro 212cc snowblower engine is rippin, shaved head, cl1 cam, 18lb springs, intake/ exh, ect. 81t rear sprocket.
Will do donuts in a 2 lane road until it runs out of gas. And generally is a drift machine. If on gravel or grass it only moves sideways.

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BaconBitRacing

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Just put a new axle setup on the drift beater/ 60' simplex. I ordered a cheap hydraulic disk setup off jungle prime,
and 2 days later the ship date was postponed over a month, and I already had the axle parts. So I had a brand new mechanical caliper
sitting around, genuine knott / thomas unit that I never used, as people had nothing but complaints about poor stopping power.

I decided to give it a shot, on a 8in bmi karts disk. No additional leverage, and hooked to petal with a old shortened motorcycle clutch cable,
using brass 1/8 npt x 1/4 compression fittings. At 30mph , if you hit the brake petal it will lock up both rear 13x6.50x6 slicks on pavement. It works great,
as well as a small hydraulic setup. Very surprised.

Plus the toro 212cc snowblower engine is rippin, shaved head, cl1 cam, 18lb springs, intake/ exh, ect. 81t rear sprocket.
Will do donuts in a 2 lane road until it runs out of gas. And generally is a drift machine. If on gravel or grass it only moves sideways.

View attachment 136935
Nice! Looks like fun, interesting with the mechanical brake.
 

karl

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I think people are either trying to use them with stainless steel rotors or not adjusting them properly. But what do I know I like and never had trouble with band brakes either.
Good point, im not sure what material the rotor is. Ill have to check it with a magnet tonight. Also, maybe the knock off calipers brake pads are just junk?
 

BaconBitRacing

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Good point, im not sure what material the rotor is. Ill have to check it with a magnet tonight. Also, maybe the knock off calipers brake pads are just junk?
If I had to guess, people buy knock-off (which with go karts is generally fine) and aftermarket is poor quality. Trash rotor, Yak grease pads.

Edit: That is one awesome loop pipe.
 

panchothedog

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I'm wondering if rotor size is helping his kart stop so well. The old fulcrum and lever theory seems to say so. I'm already thinking about putting a bigger one on mine. I think it's about 5" and stopping power is marginal at best.
 

Snaker

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I see people go buy the fanciest rotors with holes drilled in them because the tuner crowd does. But in reality that stuff is junk. Just buy and use the cheapie rotors and you’ll be fine.
Groves, hole and slots have a legitimate purpose on disc brakes.

Groves are good for scraping and removing water and debris.
Any disc can benefit from that. Especially in off-road and mud.

Holes help with cooling of the disc.
That is only needed if the discs are put to the point of overheating

Through slots are kind of a combination of scrapping and cooling.

I think that the notion that the interrupted surface area leads to less pad contact area which leads to diminished braking is not as critical as it may appear seeing as the top racing and high performance metal brakes look like swiss cheese.
I think that the required total pad contact area can be adjusted by upsizing the brake pads.
But keeping the disc's cool is a bigger challenge.

Is it necessary on a home cart or just bling? Don't know
 

BaconBitRacing

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Groves, hole and slots have a legitimate purpose on disc brakes.

Groves are good for scraping and removing water and debris.
Any disc can benefit from that. Especially in off-road and mud.

Holes help with cooling of the disc.
That is only needed if the discs are put to the point of overheating

Through slots are kind of a combination of scrapping and cooling.

I think that the notion that the interrupted surface area leads to less pad contact area which leads to diminished braking is not as critical as it may appear seeing as the top racing and high performance metal brakes look like swiss cheese.
I think that the required total pad contact area can be adjusted by upsizing the brake pads.
But keeping the disc's cool is a bigger challenge.

Is it necessary on a home cart or just bling? Don't know
That's all true, but with our karts we aren't worrying about heat and fade, we just need to stop when we need to. Good on racing an don the road? Yes. Good on karts? Probably not. Our karts are more like tractors than race cars anyway.
 

Denny

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You’re missing the point. The fancy ones with slots and holes are usually made of some exotic substance that does not have a high coefficient of friction like regular old iron or steel. We are not trying to stop a 3000 lb vehicle from 100 mph repeatedly. No need for fancy holes.
 

Snaker

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You’re missing the point. The fancy ones with slots and holes are usually made of some exotic substance that does not have a high coefficient of friction like regular old iron or steel. We are not trying to stop a 3000 lb vehicle from 100 mph repeatedly. No need for fancy holes.
The vast majority of drilled brake discs (performance or pretend performance) are "not-drilled" metal discs that got drilled.
Don't know how that's throwin ya.
Some are indeed made for carts.
People can use them or not use them as they wish.
Assuming comparable quality, they would likely be no worse than solid discs and possibly better.
But again, I think that grooved discs would be the most beneficial of any discs for this activity.
 

karl

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This was not the direction I thought this thread would go lol.

I was shopping for the cheapest plain steel 1in rotor I could find, and nothing was below $35.

I was going to place an order with bmi karts anyways, and they had the billet 1in hub and the drilled rotor , $30 total. Cost less and looks cooler , thats all i cared about
 

BaconBitRacing

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This was not the direction I thought this thread would go lol.

I was shopping for the cheapest plain steel 1in rotor I could find, and nothing was below $35.

I was going to place an order with bmi karts anyways, and they had the billet 1in hub and the drilled rotor , $30 total. Cost less and looks cooler , thats all i cared about
And it locks up the axle! That's a deal for sure. It's nice to know mechanical discs aren't as and as said.
 

karl

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Thanks pearl, unfortunately I had to retire the loop. It just kept cracking, after the 3rd patch job I was done with it

Anyway I ordered another mech caliper, this time an amazon special. Im going to try it with a plain mild steel rotor on the 459cc minibike. Should be a good test
 

pearl111

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Thanks pearl, unfortunately I had to retire the loop. It just kept cracking, after the 3rd patch job I was done with it

Anyway I ordered another mech caliper, this time an amazon special. Im going to try it with a plain mild steel rotor on the 459cc minibike. Should be a good test
Like to see that,....459cc.. doesn't sound so mini to me, anyway sounds like a neat project.
 
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