Mini ATV front Suspension

waynev · 11-11-2009, 08:15 PM

Well i finally got some time to get to the shop today with my spare set of mini atv shocks that i won on the auction.
First step was to see if i could lighten up the spring rate a bit as the springs are very stiff on the front end of these little machines.
It was a bit tricky to compress the springs to get to that nut but the arbour press came in handy.......

Well that made it much easier, i used a big washer that i had cut out of 1/8" aluminum and then cut a slot up to the center, i then used a screwdriver to pry the spring back and inset that disc then the arbour press made easy work of compressing the spring so i could get my 17mm wrench on the nut and then used a 19mm to turn the end off.

I found these springs to have way too much preload on them and yeah don't worry about these shocks becuase they aren't, it is a shaft inside a tube and that's it, they work on spring only.

I ended up cutting 3/4" off the end ( the one with the tighter spring spacing ) and reassembling the shocks. Before i cut off the springs there was no way in hell i could move these shocks with my two hands pushing against each other, now after removing the 3/4" i can now compress the shocks with my hands 5/8" and my bathroom scale spring rate tester comfirmed this.
Before cutting, the stock shock took 95lbs to move 1/2" and 190lbs to move 1", after cutting the rate dropped to 60lb for the 1/2" mark and 120lbs for the 1" mark.

So far these results look promising and i'm hoping to get them installed this weekend.

I also reversed the direction of where the tight coils were from the way the shocks came, here a pic of the finished shocks and the washer i used to disassemble.

I'll keep you posted on my results after mounting on the quad.

TurboT · 11-11-2009, 08:28 PM

Dude since I don't have a press like that in my back yard any tips? :P

waynev · 11-11-2009, 08:31 PM

Yep, a bigger washer than i used, a small tin can or something the fits nicely on the other end of the shock and 2 clamps to compress the spring.

Weldangrind · 11-11-2009, 08:47 PM

Or your friend's hydraulic press.

waynev · 11-11-2009, 08:48 PM

Quote:

Originally Posted by Weldangrind

Or your friend's hydraulic press.

Yep, that will work too, a pint per press right?

TurboT · 11-11-2009, 10:13 PM

Quote:

Originally Posted by Weldangrind

Or your friend's hydraulic press.

You got one of those in stock too?? :P

Weldangrind · 11-11-2009, 10:47 PM

In stock, ready to press. 8)

TurboT · 11-11-2009, 10:51 PM

Quote:

Originally Posted by Weldangrind

In stock, ready to press. 8)

I find it amazing you have this type of thing, but also since I've seen your garage, more amazed you have somewhere to PUT it.

Need to do something with my Mini Beast front end. I pushed down on the bush gaurd today and the shocks don't move, the axle's and control arm bolt points do. Terrible. The front end on that thing has to be taking a BRUTAL beating on the smallest of bumps at speed.

Weldangrind · 11-11-2009, 11:49 PM

Bring the shocks over, and we'll see what kind of magic we can work.

TurboT · 11-12-2009, 12:22 AM

Quote:

Originally Posted by Weldangrind

Bring the shocks over, and we'll see what kind of magic we can work.

I'll bring the whole thing over one day, when we get through the madness of other projects. I have a feeling it's not just the shocks, it's where they put them. They are too close to the middle of the quad, and not extended out enough towards the wheel, so the bumps get soaked into the weakest points before it gets to the shock.

Just my thoughts.. it's not a pressing issue I don't think this thing will be doing any heavy riding till next Spring: Other than perhaps me doing 'snow trials' in the street if we get any this year.

PCD · 11-12-2009, 12:27 AM

Nice waynev.

I have a spare set on the way as well and thats exactly what I'll be doing to them.

Pretty intersting about the "fake" shock, but it fits with the machine I suppose. For what it is, I guess springs are alright.

Weldangrind · 11-12-2009, 01:38 AM

Quote:

Originally Posted by waynev

I ended up cutting 3/4" off the end ( the one with the tighter spring spacing ) and reassembling the shocks. Before i cut off the springs there was no way in hell i could move these shocks with my two hands pushing against each other, now after removing the 3/4" i can now compress the shocks with my hands 5/8" and my bathroom scale spring rate tester comfirmed this.
Before cutting, the stock shock took 95lbs to move 1/2" and 190lbs to move 1", after cutting the rate dropped to 60lb for the 1/2" mark and 120lbs for the 1" mark.

Do you attribute the lower required force to cutting coils or flipping the springs? The flipped springs look to have transferred the tighter coils to the static end (if there is such a thing).

PCD · 11-12-2009, 02:15 AM

A progressive spring will still compress the "lighter" coils first (as intended) whether it is upside down or not.

Where mounting position matters is in high strung applications and thats mainly due to unsprung weight issues, however minor (thicker coil end is heavier than the thinner coil end) but this is meaningless for our application.

I'm not going to stress over this one too much since the shock is fake anyway, plus no matter how waynev measured the force required, he did a before and after using the same method and the results showed a milder spring rate.

Weldangrind · 11-12-2009, 02:38 AM

Quote:

Originally Posted by PCD

I'm not going to stress over this one too much since the shock is fake anyway, plus no matter how waynev measured the force required, he did a before and after using the same method and the results showed a milder spring rate.

Agreed. It was just an observation that the 'before' measurement had the coil in the conventional position, so I wondered if that was a factor.

What would be the point of flipping the coils then?

Waynev, did you place the scale on the press base to take measurements?

PCD · 11-12-2009, 02:42 AM

Quote:

Originally Posted by Weldangrind

Quote:

Originally Posted by PCD

I'm not going to stress over this one too much since the shock is fake anyway, plus no matter how waynev measured the force required, he did a before and after using the same method and the results showed a milder spring rate.

What would be the point of flipping the coils then?

I dunno, except if it were me I would always think it was "upside down" if the thicker coils were at the top. It would bug me

11-11-2009, 08:15 PM	#1
waynev Join Date: Aug 2009 Location: London, Ontario Posts: 1,097	Mini ATV front Suspension Well i finally got some time to get to the shop today with my spare set of mini atv shocks that i won on the auction. First step was to see if i could lighten up the spring rate a bit as the springs are very stiff on the front end of these little machines. It was a bit tricky to compress the springs to get to that nut but the arbour press came in handy....... Well that made it much easier, i used a big washer that i had cut out of 1/8" aluminum and then cut a slot up to the center, i then used a screwdriver to pry the spring back and inset that disc then the arbour press made easy work of compressing the spring so i could get my 17mm wrench on the nut and then used a 19mm to turn the end off. I found these springs to have way too much preload on them and yeah don't worry about these shocks becuase they aren't, it is a shaft inside a tube and that's it, they work on spring only. I ended up cutting 3/4" off the end ( the one with the tighter spring spacing ) and reassembling the shocks. Before i cut off the springs there was no way in hell i could move these shocks with my two hands pushing against each other, now after removing the 3/4" i can now compress the shocks with my hands 5/8" and my bathroom scale spring rate tester comfirmed this. Before cutting, the stock shock took 95lbs to move 1/2" and 190lbs to move 1", after cutting the rate dropped to 60lb for the 1/2" mark and 120lbs for the 1" mark. So far these results look promising and i'm hoping to get them installed this weekend. I also reversed the direction of where the tight coils were from the way the shocks came, here a pic of the finished shocks and the washer i used to disassemble. I'll keep you posted on my results after mounting on the quad.
	0

11-11-2009, 08:47 PM	#4
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	Or your friend's hydraulic press. __________________ 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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11-11-2009, 10:47 PM	#7
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	In stock, ready to press. 8) __________________ 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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11-11-2009, 11:49 PM	#9
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	Bring the shocks over, and we'll see what kind of magic we can work. __________________ 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
	0

11-12-2009, 12:27 AM	#11
PCD Join Date: Oct 2009 Location: Newmarket On Canada Posts: 382	Nice waynev. I have a spare set on the way as well and thats exactly what I'll be doing to them. Pretty intersting about the "fake" shock, but it fits with the machine I suppose. For what it is, I guess springs are alright. __________________ Good, Fast, or Cheap....Pick Two.
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11-11-2009, 08:28 PM	#2
TurboT Join Date: Sep 2008 Location: Surrey, B.C., Canada Posts: 2,185	Dude since I don't have a press like that in my back yard any tips? :P
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11-11-2009, 08:31 PM	#3
waynev Join Date: Aug 2009 Location: London, Ontario Posts: 1,097	Yep, a bigger washer than i used, a small tin can or something the fits nicely on the other end of the shock and 2 clamps to compress the spring.
	0

11-12-2009, 02:15 AM	#13
PCD Join Date: Oct 2009 Location: Newmarket On Canada Posts: 382	A progressive spring will still compress the "lighter" coils first (as intended) whether it is upside down or not. Where mounting position matters is in high strung applications and thats mainly due to unsprung weight issues, however minor (thicker coil end is heavier than the thinner coil end) but this is meaningless for our application. I'm not going to stress over this one too much since the shock is fake anyway, plus no matter how waynev measured the force required, he did a before and after using the same method and the results showed a milder spring rate. __________________ Good, Fast, or Cheap....Pick Two.
	0