Manual brake issues HELP!!!

[GeorgeG4]

Hello
George here from Maine. I got an old vintage go kart frame and decided to restore it as a project over the winter months. I’ve recently completed it. It game out well. I’ll post pictures. Everything is new or restored. 1” live axle. Predator 212cc with stage 1 performance kit. 30 series torque converter, disk brake with manual caliper. Heavy duty brake cable. Etc.
Before

After

my problem is no matter how I adjust the brake it doesn’t work well at all. I can push as hard as I can and it BARELY slows you down. Can’t lock the wheels at all. I’ve checked and double, triple checked everything I can think of. Everything is brand new. Alignment is good. Caliper floats in the holder a touch like it is supposed to (tried with no play, no difference)
It’s as if I do not have enough leverage.
do the new disk and pads need to wear some to work better?
I’ll post better more specific pics when I get a chance to see if anyone sees anything I do not.
I’m at my wits end…..

 

[Denny]

The kart looks great! Yes pads do need to bed in before optimum braking is achieved. I am not a fan of using cables with brakes. The problem with using a cable is it will stretch when you press on the brake and act like a giant rubber band. Not goood for brakes, you should have used a solid rod.
With that said I also can’t see what kind of pedal ratio you have. You want the lever for the pedal to be longer than the lever for the caliper.

 

[panchothedog]

Nice job on the kart. Looks good. I have a mechanical disc on a Manco kart. It is original to the kart. It doesn't work very well at all. As mentioned by Denny in the previous post a rod would be better than a cable. Mine has a rod. Where it attatches to the bottom of the caliper I took a piece of steel about 3 inches long and bolted it to the stock piece to increase leverage. It helped. Kart won't even come close to locking up the wheels, but it's not as scary as before.

 

[pearl111]

The kart looks great! Yes pads do need to bed in before optimum braking is achieved. I am not a fan of using cables with brakes. The problem with using a cable is it will stretch when you press on the brake and act like a giant rubber band. Not goood for brakes, you should have used a solid rod.
With that said I also can’t see what kind of pedal ratio you have. You want the lever for the pedal to be longer than the lever for the caliper.

Denny, I may have this same issue in the near future with a build that's already InProgress.
Can you explain, in a little more detail, the last sentence... (you want the lever for the pedal to be longer than the lever for the caliper.)
I keep going over it but, I don't understand it.

 

[pearl111]

Nice job on the kart. Looks good. I have a mechanical disc on a Manco kart. It is original to the kart. It doesn't work very well at all. As mentioned by Denny in the previous post a rod would be better than a cable. Mine has a rod. Where it attatches to the bottom of the caliper I took a piece of steel about 3 inches long and bolted it to the stock piece to increase leverage. It helped. Kart won't even come close to locking up the wheels, but it's not as scary as before.

Do you mean, you made the brake pedal longer so you could push down on it harder/farther?

 

[Denny]

Yes! You got it! But the only problem being the extra length of the longer pedal stroke. The trick would be to find the optimum lever length for both the caliper and and the pedal.
You have to remember you do not get optimum braking by locking up the wheels. Optimum braking is achieved just before locking the wheels.

 

[pearl111]

Hello
George here from Maine. I got an old vintage go kart frame and decided to restore it as a project over the winter months. I’ve recently completed it. It game out well. I’ll post pictures. Everything is new or restored. 1” live axle. Predator 212cc with stage 1 performance kit. 30 series torque converter, disk brake with manual caliper. Heavy duty brake cable. Etc.
Before
View attachment 136512
After
View attachment 136511View attachment 136510View attachment 136513
my problem is no matter how I adjust the brake it doesn’t work well at all. I can push as hard as I can and it BARELY slows you down. Can’t lock the wheels at all. I’ve checked and double, triple checked everything I can think of. Everything is brand new. Alignment is good. Caliper floats in the holder a touch like it is supposed to (tried with no play, no difference)
It’s as if I do not have enough leverage.
do the new disk and pads need to wear some to work better?
I’ll post better more specific pics when I get a chance to see if anyone sees anything I do not.
I’m at my wits end…..

Welcome to DIY. The kart looks great, nice job.

 

[Functional Artist]

Howdy &

Kart looks great!

I agree, your brake issue is probably leverage related.

You need to increase the leverage of the pedal over the brake.

How about post a couple of pics of (mainly) your brake system?
...& maybe we can come up with some suggestions as to "how" ta do it

 

[GeorgeG4]

Thank you all!

I’m not sure if I can say this or not but the brake and throttle pedal and brake kit are from go power sports. Also the brake cable.
I did in the beginning, have a threaded rod as my break rod, but I noticed it would bend and flex too much. Plus I can’t do a straight shot to the caliper arm. So I figured the cable would be a better solution. I guess not.
I’ll post more/better pics soon.

 

[BaconBitRacing]

Your go kart is beautiful! Everyone here is happy to see a kart like that around.

 

[GeorgeG4]

Your go kart is beautiful! Everyone here is happy to see a kart like that around.

Thank you!
Now, if I can get the brakes to work properly, so it’s safe. The only other thing I want to do is add fenders what little bit I’ve driven it. I’m completely covered in everything Lol. it’s definitely not perfect. The paint isn’t perfect. My painting conditions weren’t ideal being winter here in Maine etc. but mechanically I think it’s pretty sound.
I also need a bigger tires on the front. The ones that are on there. I thought were bigger than they actually are.

I also stretched it 9”. So can easily fit an adult pretty comfortably.

 

[BaconBitRacing]

Thank you!
Now, if I can get the brakes to work properly, so it’s safe. The only other thing I want to do is add fenders what little bit I’ve driven it. I’m completely covered in everything Lol. it’s definitely not perfect. The paint isn’t perfect. My painting conditions weren’t ideal being winter here in Maine etc. but mechanically I think it’s pretty sound.
I also need a bigger tires on the front. The ones that are on there. I thought were bigger than they actually are.

I also stretched it 9”. So can easily fit an adult pretty comfortably.

Maybe a little less muddy in the summer lol. Safety #1!

 

[Functional Artist]

I’m completely covered in everything

Getting covered with "nature" depends on how & where you ride it
...& some folks even consider "it" as "Free Bonus"

Kinda like this:

 

[Snaker]

Pretty much what others have said.
Cable brakes aren't the best but I don't believe they're useless
I had a Suzuki ATV with factory cable rear only brakes and doughnut rear tires. It worked.

Your photo's don't show any good shots of the brake?
One thing I do notice is the mounting tab for the cable at the front.
Look at that very close, and the rear, for any flex with brake action.
That would affect the cable flex
Might need to angle brace those.

 

[GeorgeG4]

What is I made the brake lever longer?
can’t in crease the pedal length.

 

[panchothedog]

GeorgeG4. Leverage can be added at either end. The pedal or the caliper. Down beneath the kart, on the bottom side of the caliper, there's a metal tab that your cable connects to. The part that actually moved back and forth when you step on the pedal. That's where I lengthened mine, giving me more leverage, more pulling power when I step on the pedal. My brake rod also has a couple of slight bends in it like you described that yours does. I took a couple of pieces of steel appx. 8" long, x 1 /2" wide x 1 /8" thick and had it welded across from one side of the bend to the other. This stopped the rod from flexing
when pressure was applied. Not real pretty, but it's down under the kart and not noticeable at all. Both of these things helped. Like I said in my 1st post, they are still not what you would call good brakes, but before I did those two modifications it was downright scary.

 

[GeorgeG4]

Hey all

little update. I messed with a longer l ver at the rear. It helped, now I need to make it better and prettier. I’m annoyed I frigged with so much stuff dealing with this brake issue, that I need to grind down, clean up disassemble and paint areas again.

I’ll update again when complete.

 

[Denny]

Just think of all the fun you had while getting an education!

 

[Karttekk]

Not familiar with the type of caliper you have but with the Airheart style you can run the adjustment screw in until the pad in front of the screw is lightly touching the brake disc. This will allow the most effective braking with the least pedal travel.

Airheart Brakes - calipers

 

[Karttekk]

Airheart caliper adjustment procedure.

https://mail.tolomatic.com/archives/PDFs/3999-0015_01_LiningRPLkitPS.pdf