This can be right. 50mph in my yerfdog?

[t0x1k]

Ok, according to the speed calculator, at 3600 rpms without the TC it is 32 mph.
I have a bike speedometer set up for the 18" tires, the magnet on a stem welded to the rim and the sensor mounted within 2mm of the magnet. I put the kart on jack stands and maxed it out at 45 mph! The speedometer has a max speed setting(it had a max speed of 45, from when it was jack stands), I just finished rebuilding the steering spindles and lifted the front end, took it for a ride and came back to find the max speed at 51mph.
Now here's the funny thing, I was going down my street, it's a slight down hill, maybe a 15 degree slope to a bottom straight away of about 100 feet before smacking into a round about. To me I flew by my car at around 40, the engine was maybe around 2500-3k rpms and the TC was in full OD.

My question to everyone is, when you're using the bike speedometer is it critical where the sensor is placed? like closer to center or outside? I have one my my bicycle and it reads accurately no matter where it is. But 50mph seems false, cause I'll be ****ed if a 4" band brake can stop close to 500lbs of me and kart in less then 50 feet in the rain.

 

[TOO FAST]

Band brake is not right for your application. Get rid of it and get a disk or a disk set up
from a mc or sled before you hurt yourself

 

[Kenny_McCormic]

You have 18" rims?

 

[Compnerd88]

No way your doin 50 with the governor still on keeping it at 3600rpm

maybe your speedometer is in kph and not mph

-Logan

 

[Smurph]

You have 18" rims?

x2

If the speedometer is set for 18" bicycle tires, and its on 5-6" kart tires, it'll pulse about 3 times more than it should.... But I don't know if the scale is linear.

Are you sure it's calibrated for the application?

 

[t0x1k]

No, 18" overall diameter. I'm pretty sure it's in MPH, if it isn't i'll sure feel stupid.
I want to switch over to disc, but that requires me to cut out the axle, replace all the bearings, holders, sprocket, since it's all seized up and I welded the sprocket cause it was loose and wouldn't stay in place.

 

[woodmandan2]

well 50km/h is about 20-25 miles an hour so that could be right. Take a picture of this speedo I may have seen it before.

 

[r_chez_08]

50km/h = 31mph

 

[Rickracer]

If your speedo is calibrated correctly, it's still possible, the governor is a mechanical device that isn't capable of reading rpms, it just operates off of centrifugal force, based on how it's adjusted, could possibly be anywhere from 3200 to 4000 rpms. I agree about the brakes, you definitely need some better ones.

 

[Kenny_McCormic]

I believe you want the "wheel diameter" to be set as rim size, a 24" mountain bike tire is not 24" the rim is.

 

[t0x1k]

Well, I need to replace the axle, and get new brakes. I managed to get the cart to 40mph, so it's calibrated correctly. I stopped the kart doing 40, it grabbed for maybe 15 feet and it started losing grip, it burned it up, smoked for a good 5 minutes and after that the brake hasn't stopped the same.

I'm thinking of hydraulics from a motor cycle and the old sprocket as a rotor, providing I can grind all the welds and get it off.

 

[lemegacool]

go take a look at ebay for used calipers... i got that for like 70$ more or less i dont remember...

 

[t0x1k]

Junkyard has them for less, I can get an entire setup for $30.

 

[lemegacool]

i dont have junkyards here or else i would go swim in them all day !LOL

 

[t0x1k]

Yeah, this new one I discovered has a better selection than one I've always gone too. better motorcycles, master cylinders are rare though; and it's organized, oh and cheaper.