Will this be worth it?

12348910

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Your calculations look about right. I didn't run them out, but 25 mph is about right for a stock kart with the governor still in place. What is the distance of your drag race? If the tires on your Barbie car are hard plastic like most, then traction is going to be a problem. You need to get some rubber on the road. Your running weight should be on the light side. Every vehicle has a driver, and every engine, predator, honda, briggs, ect in the 200 cc range weighs about
40 lbs. I would imagine that you will get rid of the battery and electric motor, so you should be able to get the bare vehicle weight lower than that of a go kart.
That could help with the gearing. You might be able to get away with 4.8 to 1.
If your opponent is running electric, he might be faster off the line but run out of
steam shortly after. That's why I asked how long the race is. The longer, the higher you can gear your kart. Chances are you won't get it perfect on the first try. Argue for more time while you wait for a bigger or smaller sprocket to arrive.
What are your opinions on removing the governor Should i do it or not? I believe it will be about 850ft long. We are racing on a very non busy road that is slightly down hill (only about 5 or less cars go past per day)
 

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Rat

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Im thinking your estimated total weight is a bit high.
My bike build sits somewhere in the neighborhood of 120lbs, so there's 320lbs to be move geared at 6.22:1 (9/56) behind a modded out and ungoverned 208cc with a 30 series.

It will pull to 35mph at around 5k rpm before the Tav2 pulls the rpm back down to 3800-4k while still gaining speed.

I'm am sure I've got some belt slip since the belt is stretched but either way it should give you some ideas.

I can turn as high of a ratio as 4:1 (9/36) just fine but it is hell for the belt, acceleration takes a hit and top speed is never met because the tav2 just wont shift; I'm going to strongly advise you keep your gearing in the range of 5:1-6:1 if you want the full performance range and especially for the acceleration to not suffer

Keep in mind that speed calculators only look at the mechanical aspects; they DO NOT account for wildcard variables like drag coefficient, rolling resistance of tires, or parasitic drag from other sources such as wind.
 

12348910

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Im thinking your estimated total weight is a bit high.
My bike build sits somewhere in the neighborhood of 120lbs, so there's 320lbs to be move geared at 6.22:1 (9/56) behind a modded out and ungoverned 208cc with a 30 series.

It will pull to 35mph at around 5k rpm before the Tav2 pulls the rpm back down to 3800-4k while still gaining speed.

I'm am sure I've got some belt slip since the belt is stretched but either way it should give you some ideas.

I can turn as high of a ratio as 4:1 (9/36) just fine but it is hell for the belt, acceleration takes a hit and top speed is never met because the tav2 just wont shift; I'm going to strongly advise you keep your gearing in the range of 5:1-6:1 if you want the full performance range and especially for the acceleration to not suffer

Keep in mind that speed calculators only look at the mechanical aspects; they DO NOT account for wildcard variables like drag coefficient, rolling resistance of tires, or parasitic drag from other sources such as wind.
I am going to just straight chain it and I will probably use a 5:1 gear ratio But I can let you know how it is when I start
 

Hellion

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Yeah I’m going to use a clutch but I thought I heard someone else say its called straight chain or something.

It was me. I didn't mean it literally, I meant it as a chain, two sprockets and a clutch (the clutch contains one of the two sprockets). In other words it's what some of us call the alternative to that whirling, belt-driven contraption know as a TAV/TC. It's slang words, bro.

There are racing karts that have a straight chain setup which does mean no clutch, so when the engine is running so are the wheels, with no possibility of free-wheeling that a centrifugal clutch provides.
 
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Rat

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Yeah I’m going to use a clutch but I thought I heard someone else say its called straight chain or something.
You can only go "straight chain" with a centrifugal mounted to a Jackshaft OR if you have a hard to find really expensive dry plate fully manual clutch pack looped in somewhere.

Aside from @Denny 's warning about tire size limitations, a typical Max Tourque (Hilliard style centrifugal) is still only good for WOT burns.

Okay, sure it's cheap... you plan to drag race...
Then what? Win or loose you have a useless clutch on a useless project, with an engine put to much better uses.... get the CVT now instead of regretting it later

Just my $0.02 any you'll notice I'll get no argument from anyone here with any amount of experience.
 

Hellion

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You could straight chain it, wouldn't that be fun?

You'd have to start it with the wheels off the ground. Right before the green light flashes, gas it hard and when you see the light, have someone kick the Powerwheels off the block of wood holding it up and the car will hit the ground running ...or whatever speed those glorious plastic wheels will allow. You will be burning some plastic!

:wai:

Those manual, cable operated clutches are good too, like RLS said.
 

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I would like to use these wheels but the bearing is what’s stoping me. First, it’s too big and second it spins freely so I need to use a pipe or something. I also need to think of a way to stop the wheel from going side to side because the axle is one straight piece. Could I weld a washer onto the axle so it don't slide? I don't need it to be reliable yet I just need to last less than half a mile at top speed then I can possibly change things to last longer.IMG_0830.jpeg
 
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12348910

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It was me. I didn't mean it literally, I meant it as a chain, two sprockets and a clutch (the clutch contains one of the two sprockets). In other words it's what some of us call the alternative to that whirling, belt-driven contraption know as a TAV/TC. It's slang words, bro.

There are racing karts that have a straight chain setup which does mean no clutch, so when the engine is running so are the wheels, with no possibility of free-wheeling that a centrifugal clutch provides.
I didnt mean to rude just in case you might have thought that. I was just using what I remembered someone say since I don’t know the correct terms. but thanks for re-explaining that I really appreciate your help so far.
 

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I hope to finally start to build next week. I know I say that and plans might change, but I have the motor at school I just need to find time for my parents to take the power wheels to school. This is bothering me more than anyone can think of since I’m not building yet. time is flying and the deadline is getting close so I’m hoping I can put everything I have and have learned together quick. But I really do appreciate all the help so far
 

Hellion

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I would like to use these wheels but the bearing is what’s stoping me. First, it’s too big and second it spins freely so I need to use a pipe or something. I also need to think of a way to stop the wheel from going side to side because the axle is one straight piece. Could I weld a washer onto the axle so it don't slide? I don't need it to be reliable yet I just need to last less than half a mile at top speed then I can possibly change things to last longer.

I forgot you are going with normal rubber, pneumatic tires and steel wheels. That's cheating you know, lol. At this point it is becoming a regular go kart with just a plastic Powerwheels body on it. Where's the challenge in that?

Yes, use a piece of pipe or tubing of whichever diameter that fits snugly over your axle and also takes up the gap in in the wheel's hub. You can weld a washer on the end, or both ends to keep the wheel where you want it. You might be able to drive out the bearings (with a hammer and drift punch) so you do not have to deal with them anymore. It would mean your tube section/pipe can be thicker to take up the gap. Then weld it all together.
 

12348910

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I forgot you are going with normal rubber, pneumatic tires and steel wheels. That's cheating you know, lol. At this point it is becoming a regular go kart with just a plastic Powerwheels body on it. Where's the challenge in that?

Yes, use a piece of pipe or tubing of whichever diameter that fits snugly over your axle and also takes up the gap in in the wheel's hub. You can weld a washer on the end, or both ends to keep the wheel where you want it. You might be able to drive out the bearings (with a hammer and drift punch) so you do not have to deal with them anymore. It would mean your tube section/pipe can be thicker to take up the gap. Then weld it all together.
I already removed the bearings. I just need to measure and find the right size pipe. I also didn't know if a washer would be strong enough but I guess I won't know if I don't try
 

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I already removed the bearings. I just need to measure and find the right size pipe. I also didn't know if a washer would be strong enough but I guess I won't know if I don't try
I can tell you from the pic you showed those are 5/8" ID flanged hub bearings, typically those are 1" OD.

Using a thick fender washer, or even 2 tack welded together is an old reliable trick. As long as your welds are solid it will hold indefinitely. It doesn't even need to be fully welded around, just 3-4 nice well penatrated beads making sure to check it and tap it square as it cools after each bead is laid.

The trick to tacking the washers together without creating a problem is just drill a couple 1/4" holes in one of each ends pair and use the hole to burn them together.

Considering the nature of the build and its temporary function, you could skip the washers and just weld the wheels directly to whatever pipe you use as an axle. Definitely not the right way to do something that meant to last and have repairs made though.
 

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Here is what I plan for brakes. They came off of a kids razor electric four wheeler But need pads. By the way the atv only went 3-4 mph so the brakes won’t affect anything since the pads have been junk for over a year And me/my brother have been able to stop in time. IMG_0846.jpegIMG_0847.jpeg
 

12348910

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Here is what I plan for brakes. They came off of a kids razor electric four wheeler But need pads. By the way the atv only went 3-4 mph so the brakes won’t affect anything since the pads have been junk for over a year And me/my brother have been able to stop in time. View attachment 143804View attachment 143805
This is what they came off of 20231129_170620.jpg20231129_170611.jpg
 

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