mini bike or kart?

[r97]

ok, as some of you may know i have a go kart that i want to turn into a racing style kart. now that would be great for the street, but i have some trails that i think would be more fun than the street, that said, i think it may be too expensive to convert the kart to run off road.

soooo.... i was thinking maybe i could make an off road mini bike, and a street kart. i would like to use the TC from my kart on the mini (since its off road). but since i probably can't afford a second TC, that would leave me with a cent clutch.

my question is, i know most race karts use cent clutches, but would i be really disappointed with the cent clutch? could i go up a decent hill and still hit 30mph? would i have to modify my engine (robin EX17)?

i'm thinking i can, but your opinion is appreciated, .

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i want to make a mini something like this, 5-7hp, TC, riding on hard packed ATV trails, with a few pretty steep hills (not that steep, i can ride my peal bike up em' with ease).

go kart like this, 5.7hp unmodified engine, cent clutch, needs to go up a maybe 10 degree slope thats maybe... 400ft long?

 

[anderkart]

So is this your go kart?

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go kart to either be modified a good bit, or have a new frame built for it (looks awesome, but handling is scary, its also very unstable...),

You probably would be better off with a T/C for climbing a 400ft/10-degree slope and still have it
geared to hit 30mph with your Robin Subaru engine powered kart.

Although if you had a 10 to 16hp engine with a high quality centrifugal clutch, removed the
governor for a 5000 max rpm, and the rider wasn't too heavy it'd probably work out just fine.

How much do you weigh?
(if your under 100lbs, it might just climb fine with your stock robin EX17 with a high quality centrifugal...)


Is your slope really this steep?

 

[bighead]

R97 have you considered moding a atc three wheeler to a fat cat conversion? You got a welder now and the conversion is really easy. You can pick up old three wheelers pretty cheap. May not fit in your budget but just saying. I will be building 3 of these soon.

http://www.youtube.com/watch?v=7Z5PFY1ocHM&feature=related

http://www.youtube.com/watch?v=bS-ZPduG4rg

 

[anderkart]

Yeah cool bighead, I love those 'fat-cat' conversions. I'd like to build one someday too!

 

[r97]

So is this your go kart?





You probably would be better off with a T/C for climbing a 400ft/10-degree slope and still have it
geared to hit 30mph with your Robin Subaru engine powered kart.

Although if you had a 10 to 16hp engine with a high quality centrifugal clutch, removed the
governor for a 5000 max rpm, and the rider wasn't too heavy it'd probably work out just fine.

How much do you weigh?
(if your under 100lbs, it might just climb fine with your stock robin EX17 with a high quality centrifugal...)


Is your slope really this steep?

yes thats my kart, but i'm going to make a new frame for it so its like a race kart. my kart as it is now has a TC but i was thinking i might be better to put the tc on the mini.

the measurements i gave were estimates. just measured i was off a good bit . 5 degree incline, 500ft length. i weigh 135lbs+.

R97 have you considered moding a atc three wheeler to a fat cat conversion? You got a welder now and the conversion is really easy. You can pick up old three wheelers pretty cheap. May not fit in your budget but just saying. I will be building 3 of these soon.

http://www.youtube.com/watch?v=7Z5PFY1ocHM&feature=related

http://www.youtube.com/watch?v=bS-ZPduG4rg

those things are pretty cool, they would definitely be fun to have! i think there is a 110cc ATC on cl for $400 right now. only problem with making one of those is the fact that it doesn't look like that big of a project.

 

[bighead]

Yah I hear you. Although the atc110 are much more work. They have that weird stamped frames. The 185 and up have the traditional frames.

 

[r97]

huh... thats odd, its a shame too because the larger ATCs are $700+, so i guess i'll throw it into the idea bin. not a huge bummer though, i think something like that rupp roadster i posted above with a 30 series and a 7hp would be pretty sweet on the trails around my house! it would also be compact so i could throw it in the car and go to my friends house.

 

[anderkart]

yes thats my kart, but i'm going to make a new frame for it so its like a race kart. my kart as it is now has a TC but i was thinking i might be better to put the tc on the mini.

the measurements i gave were estimates. just measured i was off a good bit . 5 degree incline, 500ft length. i weigh 135lbs+.

Cool, less than a 10 degree incline, plus both you and your kart will be lightweight. That's good news!
In that case you might as well use your T/C for your off-road minibike, and then just at least give your go kart a try with a centrifugal. (At least to me, It sure sounds like your minibike would need the T/C more than the kart anyway...)

 

[r97]

yeah thats what i was thinking, thanks man. now i "just" gotta:

-get the mini-minibike going
-make welding cart
-make welding table
-make bench grinder stand
-make a racing go kart chassis, buy axle, rim, hub, tire, and a cent clutch.
-make a mini bike providing i have enough $ to buy wheels, tires, sprockets, used engine, forks, and shocks.

that should be enough projects to have me covered for the summer, . hopefully i can get enough moey from lawn mowing and dog walking to buy all that metal! luckily i can make most of the parts from raw materials instead of buying them.

 

[gokart14]

yeah thats what i was thinking, thanks man. now i "just" gotta:

-get the mini-minibike going
-make welding cart
-make welding table
-make bench grinder stand
-make a racing go kart chassis, buy axle, rim, hub, tire, and a cent clutch.
-make a mini bike providing i have enough $ to buy wheels, tires, sprockets, used engine, forks, and shocks.

that should be enough projects to have me covered for the summer, . hopefully i can get enough moey from lawn mowing and dog walking to buy all that metal! luckily i can make most of the parts from raw materials instead of buying them.

YA I WISH i lived in town so i could mow peoples lawn!!! it sounds like u can make some good money. dog walking????? an idea when i was running out of metal i would weld to scraps together and grind the weld down!! (perfect length) i only did this on the roll cage.

 

[anderkart]

How about just replace the tail section of your old kart with a conventional live axle using racekart components? The front half of your old kart looks pretty dam cool and should work just fine if you've designed proper KPI into it.

We could probably find you a high quality/super-exspencive, complete 1-1/4" axle assembly with racekart style bearings, hubs, sprocket, rotor and all, in good used condition for somewhere between like $50 and $100...

Lots of good info here you should study/follow :--> http://www.racemates.nl/PKinfoTech_kart chassis setup_2.html#_Toc529198884
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These dimensions from mine should come in handy for ya too. This Beisse B3 model hooks up like you wouldnt believe. It makes turns at high speeds so freakin well it'll make yer guts hurt from all the G-force, I chit you not!

My chrome-molly frame rails measure 33mm. with a 3mm. wall thickness.

 

[r97]

YA I WISH i lived in town so i could mow peoples lawn!!! it sounds like u can make some good money. dog walking????? an idea when i was running out of metal i would weld to scraps together and grind the weld down!! (perfect length) i only did this on the roll cage.

HAHAHA, yea them scrap pieces come in handy sometimes! i am happy that i can make some money, but i only have one lawn to mow once a week, and one dog to walk twice a week because the owner is at work, but its enough money to fuel projects at a slow rate.

How about just replace the tail section of your old kart with a conventional live axle using racekart components? The front half of your old kart looks pretty dam cool and should work just fine if you've designed proper KPI into it :--> http://www.racemates.nl/PKinfoTech_kart chassis setup_2.html#_Toc529198884

We could probably find you a high quality/super-exspencive, complete 1-1/4" axle assembly with racekart style bearings, hubs, sprocket, rotor and all, in good used condition for somewhere between like $50 and $100...


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But If you wanna build yer own racekart, these dimensions from mine should get ya started:

My frame rails measure 33mm. with a 3mm. wall thickness.

when i made that kart i used the "scorpion" plans from spidercarts.com, i followed them, making sure i did all the steering to the plans. after driving it and having learned more, it has completely no Ackerman, KPI, camber, or Castor, in fact in the plans the tie rods were in a very weird orientation severely limiting the turning radius. the kart is also pretty heavy, and seems like it has a high center of gravity. and after seeing the videos of race karts flying around at like 25mph and just sliding sideways, i knew thats what i wanted, besides race carts look cool, and maybe i can even sneak it into a track day, .

anyway, i think i'm going to start over and make a race kart chassis from scratch. thanks for the picture, i found that a while ago and found it very helpful! later i may also ask you for some angles and dimensions of the steering components.

i plan to make the chassis out of 1 1/4", somewhere between .083" and .125" wall sq tube. then make a race style seat out of aluminum. i will also make one of those shiny bumpers out of aluminum .

an axle wold be cool! right now i have one 8" Maxxis HT3 tire on a 6" Douglas rim with a hub in the back. i also have an MCP hydraulic disk brake, and 1" bearings. i was thinking i could just get a 44", 1" live axle from BMI for $25, then the cheapest 6" rim and 8" wide tire i can find. of course i'll need a sprocket and cent clutch too. do you think around a 54t rear and 12t clutch would still have enough power for uphill?