HandleBar Angle/Control

TurboT · 08-24-2009, 04:53 PM

Just recently I had my 50cc Mini ATV out with my daughter and she was having a really hard time keeping the things straight anytime she hit any bumps. Now I know she is quite young, but before she was riding on fairly flat grass or dirt and she was a little wobbly, but nothing serious.

This weekend she rode into a small ditch, into long grass (off the path) quite a few times, and just generally seemed to have no control of her ride on uneven surfaces.

When I assembled the quad, I puposely 'tipped' the handbars more towards the rider, instead of a more traditional 'upright' position. I did this so they would be closer to her for perhaps better reach of the brake lever.

I am wondering if this angle of the bars would contribute to more difficult steering??

waynev · 08-24-2009, 05:15 PM

Most of the problem is probably becuase the shocks are so stiff on these mini quads and little bumps don't get absorbed and will bounce the quad around making it harder to keep it striaght.

TurboT · 08-24-2009, 08:13 PM

Quote:

Originally Posted by waynev

Most of the problem is probably becuase the shocks are so stiff on these mini quads and little bumps don't get absorbed and will bounce the quad around making it harder to keep it striaght.

Yes I would agree that is an issue.

I'm wondering if the handlebar angle accentuates that problem or if it wouldn't matter.

waynev · 08-24-2009, 08:23 PM

I don't really think the handlebar angle has much to do with it, you did do your toe adjustment when new right?, i know my 50cc was off and needed adjustment to get the front wheels tracking straight and also to make sure the wheels were straight when the bars were straight.

TurboT · 08-24-2009, 08:30 PM

Quote:

Originally Posted by waynev

I don't really think the handlebar angle has much to do with it, you did do your toe adjustment when new right?, i know my 50cc was off and needed adjustment to get the front wheels tracking straight and also to make sure the wheels were straight when the bars were straight.

It was quite good when I put it together but it is something I can check again to see if something went haywire there. Woudn't surprise me if it's thrown itself off.

waynev · 08-24-2009, 08:56 PM

On our microsprint's we usually shoot for 1/8" toe out but on my son's 50cc quad i just used a long straight edge to line up the rear tires to the front since the suspension won't move much with the kids aboard, i also made sure the handlebars were perfectly straight when the tires were lined up.

Weldangrind · 08-24-2009, 10:11 PM

Some toe out is recommended, even with a mini quad. In our experience, handlebar angle does affect handling; too high or too low, and you're swinging the bars through an arc, rather than rotating with the forks. Try to maintain an angle that is similar to the forks, and then adjust to meet rider comfort.

Stiff shocks definitely accentuate handling difficulties, as does bumpsteer. If the shocks can compress enough to allow bumpsteer to occur, the quad will dart out from the intended steering angle.

One other area to check is the steering. On both of our machines, there is a clamshell plastic bearing at the top and a short metal tube at the bottom. Aside from these two points, the steering shaft is exposed, unlike a traditional motorcycle or bicycle steering neck. On both of ours, the o-rings in the clamshell were cut (presumably to speed up installation), and the shaft was loose as a result. The fix was to remove the handlebars, stretch new o-rings over the handlebar mount, and roll them down the steering shaft. Lots of grease was applied to the o-rings and steering shaft, and the slop was gone. At the bottom mount, the cotter pin hole was too far below the castle nut, so I stacked washers until the nut lined up. It's much better.

So, I'd check both steering mounts, tie-rod ends for damage and proper 1/8" toe, looseness in the ball joints and handlebar angle.

Cheers!

frostbite · 08-25-2009, 08:22 AM

What are you running for tire pressure? Too much can cause a lot of excessive bounce, especially on a small machine with a stiff suspension.

TurboT · 08-25-2009, 05:36 PM

Hey guys.. thanks for all the input. I've left the machine out at my Sis and Bro - in Laws so hard for me to check all this.

I would say the tire pressure is a factor I thought of, and I will reduce it some to see if that helps. They are pretty firm, and kept them that way only because when the atv's were new, they had a hard time getting going with the gov screw all the way in to limit the top speed. Now that they seem to roll easier, I can adjust the tire pressure to make them softer.

W&G I don't think the springs compress at all with my little girl on them. They are very hard. I think they are the biggest problem here, that when she hits a bump the wheel just kicks the bar over, and because she's not very strong it throws the bar to the side and she can't correct it fast enough. I was watching her on her peddle bike last night, and she's whipping the handlebars around on that as well. Part of that is balance related on two wheels but might need to work with her on bar control.

I noticed my 110cc the other day has some minor movement in the steering column. It is very subtle but when I grab it I can make it 'click' back and forth. Plus I can't keep the kingpins tight on it either, however my oldest who rides that doesn't have control issues at all it seems. I will be going over these machines once again when I get them back home.

Cal25 · 08-25-2009, 06:42 PM

Air preasure might make alot of differense.

Does it react the same with other riders? Could it be that she has gotten more comfortable and is "relaxing" a bit, allowing the front end to be steered away from the intended course?

TurboT · 08-25-2009, 06:48 PM

Quote:

Originally Posted by Cal25

Air preasure might make alot of differense.

Does it react the same with other riders? Could it be that she has gotten more comfortable and is "relaxing" a bit, allowing the front end to be steered away from the intended course?

Anyone else riding it has other issues mainly due to it's size... by other issues I mean handlebars kicking into their knees.

My youngest is quite aloof, and is probably just not hanging on tight enough, or hasn't the strength in her upper body to deal with the aggressive feedback in the steering. I'm hoping to find some ways to alleviate that to make it a bit easier for her. As mentioned she is okay on flat surfaces with lots of room, but put her on a set path with bumps and she can't seem to stay on it.

I did happen along the Gio site today, and ran across this article/blog merely by accident, but I thought it relative to this discussion, so I've pasted the link.

http://www.giobikes.com/Blogs/techni...nt-guide-tips/

waynev · 08-25-2009, 08:04 PM

Just for reference i set my son's pressures at 8 psi, but i think i could still go a bit lower.

Weldangrind · 08-26-2009, 01:41 AM

Quote:

Originally Posted by TurboT

Plus I can't keep the kingpins tight on it either, however my oldest who rides that doesn't have control issues at all it seems.

Kingpins? Doesn't it have ball joints?

TurboT · 08-26-2009, 04:54 AM

Quote:

Originally Posted by Weldangrind

Quote:

Originally Posted by TurboT

Plus I can't keep the kingpins tight on it either, however my oldest who rides that doesn't have control issues at all it seems.

Kingpins? Doesn't it have ball joints?

Hey D,

My dad called them 'kingpins' so I am assuming that is the correct term, maybe he's mistaken in his old age.

If you see in this photo, the "A" arms are connected to the wheel spindle at the top and bottom. There is a vertical tube running between the two connection points. This is what I mean when I say "kingpin"

I'm assuming there is a bushing or something inside that tube. There is a bolt on the top, and a nut on the bottom. They loosen all the time, as do the bolts that attach the spindle/axl to the 'a' arms. I've used RED loctite and they still loosen. The result is a really wobbly front tire.

I thought I had it corrected as I tightened everything and it seemed better, but this weekend I was on it, and the rough terrain seemed to loosen it up.

I don't much like the design, as the points where it attaches to the "A" Arms tends to act more like the shock than the actual shocks.. if that makes sense... by the time the force reaches the shock it has already been taken up by those fasteners.

This is obviously not the unit I'm having trouble keeping straight though.. but it is another 'keep me up at night' issue with them.

frostbite · 08-26-2009, 08:50 AM

The hard suspension's seem to be a recurring issue on Chinese bikes. I know my Lifan is really stiff.

Is there anything that can be done to 'soften' a spring (heat with a torch, etc...)?

08-24-2009, 04:53 PM	#1
TurboT Join Date: Sep 2008 Location: Surrey, B.C., Canada Posts: 2,185	HandleBar Angle/Control Just recently I had my 50cc Mini ATV out with my daughter and she was having a really hard time keeping the things straight anytime she hit any bumps. Now I know she is quite young, but before she was riding on fairly flat grass or dirt and she was a little wobbly, but nothing serious. This weekend she rode into a small ditch, into long grass (off the path) quite a few times, and just generally seemed to have no control of her ride on uneven surfaces. When I assembled the quad, I puposely 'tipped' the handbars more towards the rider, instead of a more traditional 'upright' position. I did this so they would be closer to her for perhaps better reach of the brake lever. I am wondering if this angle of the bars would contribute to more difficult steering??
	0

08-24-2009, 10:11 PM	#7
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	Some toe out is recommended, even with a mini quad. In our experience, handlebar angle does affect handling; too high or too low, and you're swinging the bars through an arc, rather than rotating with the forks. Try to maintain an angle that is similar to the forks, and then adjust to meet rider comfort. Stiff shocks definitely accentuate handling difficulties, as does bumpsteer. If the shocks can compress enough to allow bumpsteer to occur, the quad will dart out from the intended steering angle. One other area to check is the steering. On both of our machines, there is a clamshell plastic bearing at the top and a short metal tube at the bottom. Aside from these two points, the steering shaft is exposed, unlike a traditional motorcycle or bicycle steering neck. On both of ours, the o-rings in the clamshell were cut (presumably to speed up installation), and the shaft was loose as a result. The fix was to remove the handlebars, stretch new o-rings over the handlebar mount, and roll them down the steering shaft. Lots of grease was applied to the o-rings and steering shaft, and the slop was gone. At the bottom mount, the cotter pin hole was too far below the castle nut, so I stacked washers until the nut lined up. It's much better. So, I'd check both steering mounts, tie-rod ends for damage and proper 1/8" toe, looseness in the ball joints and handlebar angle. Cheers! __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
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08-25-2009, 08:22 AM	#8
frostbite Join Date: May 2006 Location: Fredericton, NB, Canada Posts: 1,744	What are you running for tire pressure? Too much can cause a lot of excessive bounce, especially on a small machine with a stiff suspension. __________________ Frostbite "The beatings will continue until moral improves"
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08-26-2009, 08:50 AM	#15
frostbite Join Date: May 2006 Location: Fredericton, NB, Canada Posts: 1,744	The hard suspension's seem to be a recurring issue on Chinese bikes. I know my Lifan is really stiff. Is there anything that can be done to 'soften' a spring (heat with a torch, etc...)? __________________ Frostbite "The beatings will continue until moral improves"
	0

08-24-2009, 05:15 PM	#2
waynev Join Date: Aug 2009 Location: London, Ontario Posts: 1,097	Most of the problem is probably becuase the shocks are so stiff on these mini quads and little bumps don't get absorbed and will bounce the quad around making it harder to keep it striaght.
	0

08-24-2009, 08:23 PM	#4
waynev Join Date: Aug 2009 Location: London, Ontario Posts: 1,097	I don't really think the handlebar angle has much to do with it, you did do your toe adjustment when new right?, i know my 50cc was off and needed adjustment to get the front wheels tracking straight and also to make sure the wheels were straight when the bars were straight.
	0

08-24-2009, 08:56 PM	#6
waynev Join Date: Aug 2009 Location: London, Ontario Posts: 1,097	On our microsprint's we usually shoot for 1/8" toe out but on my son's 50cc quad i just used a long straight edge to line up the rear tires to the front since the suspension won't move much with the kids aboard, i also made sure the handlebars were perfectly straight when the tires were lined up.
	0

08-25-2009, 05:36 PM	#9
TurboT Join Date: Sep 2008 Location: Surrey, B.C., Canada Posts: 2,185	Hey guys.. thanks for all the input. I've left the machine out at my Sis and Bro - in Laws so hard for me to check all this. I would say the tire pressure is a factor I thought of, and I will reduce it some to see if that helps. They are pretty firm, and kept them that way only because when the atv's were new, they had a hard time getting going with the gov screw all the way in to limit the top speed. Now that they seem to roll easier, I can adjust the tire pressure to make them softer. W&G I don't think the springs compress at all with my little girl on them. They are very hard. I think they are the biggest problem here, that when she hits a bump the wheel just kicks the bar over, and because she's not very strong it throws the bar to the side and she can't correct it fast enough. I was watching her on her peddle bike last night, and she's whipping the handlebars around on that as well. Part of that is balance related on two wheels but might need to work with her on bar control. I noticed my 110cc the other day has some minor movement in the steering column. It is very subtle but when I grab it I can make it 'click' back and forth. Plus I can't keep the kingpins tight on it either, however my oldest who rides that doesn't have control issues at all it seems. I will be going over these machines once again when I get them back home.
	0

08-25-2009, 06:42 PM	#10
Cal25 Join Date: Feb 2008 Location: Terrell and Grapevine Tx. Posts: 1,585	Air preasure might make alot of differense. Does it react the same with other riders? Could it be that she has gotten more comfortable and is "relaxing" a bit, allowing the front end to be steered away from the intended course?
	0

08-25-2009, 08:04 PM	#12
waynev Join Date: Aug 2009 Location: London, Ontario Posts: 1,097	Just for reference i set my son's pressures at 8 psi, but i think i could still go a bit lower.
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