Steering angle? How much 30 degrees? Minibike build.

[PeterA]

My minibike drives a bit like a wobbly shopping trolley, so I need to make an adjustment to the steering angle.

I am aiming now for about 30 degrees????

Considering I have a large diameter wheel on the back and a smaller wheel at the front will 30 deg. be enough?

 

[Whitetrashrocker]

Put your axle in front of the forks and see how that works first. You've got it all backwards.

 

[mckutzy]

At least you have it easy to dismount the axle and flip the lower bracket to get the axle in the front...

 

[PeterA]

Yes the front forks just slide out and you can turn the wheel around. Interestingly though, we all agreed that it handled better this way round.

 

[TX7]

http://www.seegercycle.com/Rake-and-Trail.aspx

 

[Joe-405]

I personally would put a skinnier front tire on it and try it. And add a steering stabilizer.

 

[TX7]

I'm convinced that bike has some home made components, it looks like the fork tubes are backwards. Reverse them, and your rake and trail should be improved. The front axle should be in front of the forks.

 

[PeterA]

I have made the whole thing.

Drives better withe the wheel this way. But looks better with the wheel and axle forwsrd the other way.

Why do you suggest a skinnier front tyre?

 

[Whitetrashrocker]

Did you look at the link that TX7 posted?

Perhaps some better pics of the front end. From different angles maybe?

And a skinnier tire has a smaller contact patch and won't give as much feedback.

 

[Joe-405]

What he said. Front tires that are wide follow every road issue. I guarantee it will help if not fix it.

 

[PeterA]

Couple more pics.

 

[Bbqjoe]

As every body is saying, without just coming out and saying it, the whole front end needs a rework.

 

[PeterA]

Ok, i measured the rake angle and trail.

I have about 17.5 degree on the forks.
And trail is roughly 27mm.

So what rake angle should i adjust it too? It might look like the forks are a bit bent too, obviously because the angle is too steep.

If the forks were flipped so the axle was infront, looking at my sketch on the notepad here would probably give me 0 to even a negative trail. This agrees with the feel and way it drove too.

 

[TX7]

Triple tree offset can be a factor in steering. The handlebars and triple tree offset might not be compatible, ...just a theory. Bikes with factory and home made components tend to throw off handling values. I'm just throwing out possibilities at this point, just trying to help, your configuration doesn't look right to my eye, but only you would know how the bike handles. I hope you get this figured out, Peter.

 

[PeterA]

This is around 22 degrees.

 

[Bbqjoe]

The axle behind the fork makes me feel queezy.

 

[karl]

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[TX7]

Karl, where are you in Northeast Ohio? I'm in Macedonia, Northern Summit County.

 

[Scout]

Ok, i measured the rake angle and trail.

I have about 17.5 degree on the forks.
And trail is roughly 27mm.

So what rake angle should i adjust it too? It might look like the forks are a bit bent too, obviously because the angle is too steep.

If the forks were flipped so the axle was infront, looking at my sketch on the notepad here would probably give me 0 to even a negative trail. This agrees with the feel and way it drove too.

I would try to hit 30°, then you can bring the wheel back by putting the axle in front of the forks, or a new triple tree with more offset.

 

[Flyinhillbilly]

I'm with these guys, it needs more rake and trail. I built choppers for several years, and the rake and trail can make the difference between a tank slapping death trap and something that you can ride with no hands.