fork springs

[koolcat]

so Im thinking about doing the race tech spring upgrade in a 2007.. im doing fork seals anyway so while I have it apart I might as well.. my question is does it matter what size the springs are? the ones im looking at are .85 mm..
Im average size guy .. is it worth it to even do this upgrade?

 

[RJ2112]

so Im thinking about doing the race tech spring upgrade in a 2007.. im doing fork seals anyway so while I have it apart I might as well.. my question is does it matter what size the springs are? the ones im looking at are .85 mm..
Im average size guy .. is it worth it to even do this upgrade?

There's too many things to guess about in this post....

You would feel a difference in how the fork works, with appropriate springs in there. It won't move around so much, and be a lot more stable in it's action.

Not knowing what average size guy means, it's tough to say whether the springs you are looking at are the best choice. The .85 is more likely the spring rate expressed in Kg, to compress the spring 1 mm.(.85/mm).

That spring would be correct for someone who is about 190 lbs in street clothes, looking for a ride that is almost stiff enough for the track.

Handling is improved, when the chassis doesn't shift around a lot.

 

[DownrangeFuture]

I have the hyperpro springs in mine, and that annoying headshake when the wheel almost power wheelies but doesn't is gone. And the rear doesn't feel like it's going to wash out so easily. Even when you roll on too hard from the turn.

As far as spring rate, I can't comment. I bought my springs from someone on here. But if the feel is that much better with untuned lowering springs, I can only imagine how much better it'd be with spring rates specific to you.

 

[koolcat]

There's too many things to guess about in this post....

You would feel a difference in how the fork works, with appropriate springs in there. It won't move around so much, and be a lot more stable in it's action.

Not knowing what average size guy means, it's tough to say whether the springs you are looking at are the best choice. The .85 is more likely the spring rate expressed in Kg, to compress the spring 1 mm.(.85/mm).

That spring would be correct for someone who is about 190 lbs in street clothes, looking for a ride that is almost stiff enough for the track.

Handling is improved, when the chassis doesn't shift around a lot.

Im more like 165.. its written like this 0.85 mm/kg..not gonna do alot of track riding just in the street..touring..

 

[DownrangeFuture]

Then it sounds like the number should get bigger. I'm no expert though. I do recall spring calculators that should get you in the ballpark for what you're doing.

 

[oldfast007]

This may help, click on the calculate spring rates, and yes they make a big difference

RT - Digital Product Search

 

[chomorro]

arent you supposed to weigh yourself with all your gear on??

I gain 25lbs with all my gear and backpack with lunch :thumbup:

 

[RJ2112]

Im more like 165.. its written like this 0.85 mm/kg..not gonna do alot of track riding just in the street..touring..

I stated it backwards, then.... that's indicating the spring will compress 0.85mm for each kilogram of force applied. 100 kg will compress the spring 85 mm. which equals 3.4 inches.

Since the weight on the bike is split between the front suspension and the rear, the amount of weight you put on the fork is roughly half.... so you really only put about half the weight of the rider, gear, and bike on the front suspension when you are just rolling along.

The issue comes along when you land on the brakes hard. The reason MSF says that 85% of your braking comes from the front tire is due to the weight transfer when the chassis pitches forward under maximum braking.

If the fork is all the way compressed, when you are on the brakes as hard as you can be the tire may get bounced off the road by a bump. Tires in the air have no traction, no braking, and very little control. Better to have some fork travel left.

This is why I don't like the progressive OEM springs. To get a 'cushy' ride, the spring has a portion of it's length that is 'softer' than the last part. To have a smooth ride during non-emergency times, you use up a limited resource that cannot suddenly appear when you need it. I don't like that trade off.

If you want a softer ride, I'd suggest you try the .85 springs first, and drop in another set at a lower rating after you've tried them for a while. Spring swaps are easy.

 

[iSteve]

I stated it backwards, then.... that's indicating the spring will compress 0.85mm for each kilogram of force applied. 100 kg will compress the spring 85 mm. which equals 3.4 inches.

I'm pretty sure the .85 is the amount of weight (kg) it takes to compress a spring X amount of mm.

 

[koolcat]

This may help, click on the calculate spring rates, and yes they make a big difference

RT - Digital Product Search

Thanks for that link..I came out .85 which is exactly what the set of springs are that i was looking at..so if stock is .77 then I can expect a softer ride?
Everybody thanks for the input it really helps..first time taking forks apart .. I hope its easy

 

[CHEMIKER]

I put in the 0.85 Racetechs this weekend. They are stiffer than the stock springs, but in a good way. If your stock forks are like mine were, it's like riding with marshmallow suspension on roads made of pillows.

It's pretty easy to do, just make sure you have all the stuff you need. The biggest thing is a good way to measure and cut the spacer straight, like a hacksaw and a miter box. Will you be replacing the oil too?

 

[koolcat]

I put in the 0.85 Racetechs this weekend. They are stiffer than the stock springs, but in a good way. If your stock forks are like mine were, it's like riding with marshmallow suspension on roads made of pillows.

It's pretty easy to do, just make sure you have all the stuff you need. The biggest thing is a good way to measure and cut the spacer straight, like a hacksaw and a miter box. Will you be replacing the oil too?

yes Ill be replacing the oil..just curious how did you hold your bike up with the forks off? Cant put anything underneath because of the exhaust?

 

[CHEMIKER]

yes Ill be replacing the oil..just curious how did you hold your bike up with the forks off? Cant put anything underneath because of the exhaust?

I put like 50 lbs of weight on the passenger seat to lighten the front end. Then I placed a cinderblock covered with a towel under the exhaust. The headers are strong enough, and the weight on the back helps.

 

[CHEMIKER]

Here's my to-do list that I put together from other guys instructions. I also link to DefyInertia's spring change thread. Between the two, there should be almost everything you need in there.

http://www.600riders.com/forum/garage-mechanical-help/39676-front-suspension-shot.html#post428857

 

[koolcat]

well after I got them off the right front fork (the one that was leaking) looks ever so slightly bent..the bike had been layed over on that side when I got it,
but i never really looked that close at the forks.. now Im wondering if I should rebuild them anyway...or look for some new forks... very slight bend..

 

[CHEMIKER]

I don't have any experience with bent forks, but if you find you need to replace it, see if Ben H still has his forks: http://www.600riders.com/forum/garage-mechanical-help/39676-front-suspension-shot.html#post426500

 

[RJ2112]

well after I got them off the right front fork (the one that was leaking) looks ever so slightly bent..the bike had been layed over on that side when I got it,
but i never really looked that close at the forks.. now Im wondering if I should rebuild them anyway...or look for some new forks... very slight bend..

Most suspension shops will straighten bent fork tubes, if the bend is slight. If you can see a bend, either replace the fork leg, or get it straightened.