Is using a 26" mountain bike wheel a bad idea on the front of a minibike?

[700 efi guy]

I'm thinking about building a mini and I want a big front tire. I was thinking about using a mountain bike tire up front. My friend says that if I use it it wont handle the corners and will eventually "fold over". I am going to be using a 6.5 hp clone to push it. Has anyone done it? Will putting a rake on the front forks help prevent this?

 

[BAMBY]

I used a bicycle tire from a MUCH smaller bicycle, and it held up great! no probs with the bearings either... had it up to 45 and took turns like normal...

 

[newrider3]

You don't need to worry about the rim folding, you need to worry about a lack of traction, ie the front end sliding out when you go to make a turn. Not fun.

 

[BAMBY]

newrider3, that never happened to me, nor did it ever feel like it would, and i rode that minibike in the rain multiple times.
but think about it, its no different than riding a bicycle in the rain, except you dont pedal, you have a throttle... front tire doesnt normally slide out on a bicycle...
not saying it CANT happen, but, im saying I personally wouldnt worry bout it.

 

[devino246]

Just be sure that you have around 50/50 weight distribution and you should get plenty of traction in the front. A 20" bike wheel would suffice. I road at least 35mph on my BMX bike a while ago riding on some country roads in the central VA area. Nice 1/4 mile or longer hills.

 

[Blazkowiez]

I've ridden 2 customer bikes where they have constructed a mini-bike similar to what you are mentioning, one was well done the other however was absolutely frightening where I refused to rude the bike over 15mph, my main concern was handling, anytime I was taking a turn at a decent speed it had huge concerns regarding control and stability. I would advise against this if you have the money to do so.

 

[newrider3]

http://www.diygokarts.com/vb/showpost.php?p=37499&postcount=1

 

[devino246]

http://www.diygokarts.com/vb/showpost.php?p=37499&postcount=1

Totally forgot about that post. His tire looked close to bald. You can get a fatter tire with better treads for fairly cheap. (I like danscomp for bike parts.) That should help with grip.

 

[BAMBY]

notice the way the bike was built in the way newrider3's link shows.

Reasons that made it easier to have that front tire slide out:
*Extreme rake and excessive trail, which makes for weird(technically speaking) steering geometry
*Really long wheelbase
*All weight in the rear
*AND he has a front brake- you never know if he was using it while he entered the turn, that is a BIG NO-NO for motorcycles, especially when conditions are wet. you should always do the braking before you enter the turn, and the accelerate thru the turn, or just maintain speed thru the turn.

Just imagine taking a turn in that- compared to taking a turn on an "average" style minibike...
Not trying to bash the minibike, I actually like it, but its not the most practical design.

 

[700 efi guy]

well mine's really long, and raked, and the weight will be closer to the rear... maybe I'll just get a cheap tire from princess auto or something.

 

[devino246]

well mine's really long, and raked, and the weight will be closer to the rear... maybe I'll just get a cheap tire from princess auto or something.

Got any pics? I think a major contributor to that accident was front wheel braking. Bald tire+front brakes+slick road=lockup & road rash.

 

[700 efi guy]

I'll have to take a couple, it's far from complete, and my welds are fugly, I plan on doing a bit of grinding and some more welding too... I'll go take a pic.

 

[700 efi guy]

here's what I have so far. I want suspension so I'm still not to sure what I'm going to do for forks. I'm making a 3 point system in the rear. I am going to mount the drag links so the pivot point is centered on the output shaft so I don't have to worry about the chain loosing tension. I still haven't decided what I'm doing for brakes. I measured it and it'll be 8 feel long, I'm probably going to be 5-7 inches off the ground. I want it long and low. I still haven't decided what to do for shocks either. I was thinking the rear ones from a down hill mountain bike. that or see what I can find on kijiji for cheap. I picked up a 6.5 clone for 120 bucks at princess auto. any input?

 

[700 efi guy]

well I got some suspension forks cheap off kijiji, they came with a pocket bike. now I have a twist throttle, brakes and more! I'm still torn between big and little for the front tire. I've streached out the front forks but they're going to need to be reinforced.

 

[devino246]

That there is what some call a "nut buster". Just be sure you dont slam on brakes

 

[700 efi guy]

yeah no kidding, maybe i'll put some pipe insulation on it :s

 

[700 efi guy]

I think i will go with the mountain bike tire, I don't think that the long forks will take it

 

[devino246]

yeah no kidding, maybe i'll put some pipe insulation on it :s

Unless you get some thick *** insulation on there, its still gonna be.

 

[700 efi guy]

it almost sounds like you're talking from experience...

 

[devino246]

it almost sounds like you're talking from experience...

No experience. I have however worked with pipe insulation and theres very little padding. One solution would be tilting the seat back slightly. My kart has a kart racing bucket seat, so theres not much chance of sliding foward.