Let's discuss forks

[Derrick Adams]

So Brandon and I have been talking about fork mods and still working on the inverted fork swap.

So, looking at newer CR80/KX80 etc forks it seems they are about right in length. What we're talking about is whether they can be modified to accept the extra weight.

From what i've gathered, it seems any forks can be changed for weight and riding style by spring change/or preload and different amounts of oil. Is this correct? Does the diameter of the forks really have anything to do with their effectiveness or just strength to resist bending?

Would you agree, it's fair to say that these "80" forks are set up for around a 100lb rider, yet designed to absorb much higher and larger jumps than a trike would put them through? Would it really be soo hard to dial these forks in for the extra 100lb you would add between rider weight and trike weight?

Are there upgrade springs available for these forks, or are they even needed?

What do you guys think?

[grundlegrabber]

What bike are you thinking about putting them on?

[3leggeddog]

86 250r.it is my new project.well derrick wants the swap as well on his 85 tri-z.it looks sweet,we are just unsure of the details,and forks sell for a hunded bux.figured we better find out the details before buying stuff we can't use

[Billy Golightly]

I bid on some CR80 forks this evening and didn't get them (Wasn't one of you guys was it?). I'm wanting to put some on my Z as well. The 80 forks are the way to go in my opinon, and then send them off to a suspension place like Race Tech and have them set them up for the trike and rider weight/style. You might even be able to use the OEM tripple clamps with a few mods instead of having to totally make new ones.

[Derrick Adams]

I was just thinking that we can set them up ourselves. I've been digging around for spring choices, but haven't found any yet. I really believe they're alot closer than you would think. Have you ever ridden an 80? Those things take a pounding! I'm thinking we could just do the cheap mods to them and dial 'em in.

Go for it Brandon, lets do it! (We have to start on the Honda, because we have more triples for those!)

[3leggeddog]

the ones sold for 112.00,i'm watching another set but it's not priority on this project,so i have to watch what i spend my money on.in the near furture we will explore this swap though.maybe we should go to a-1 in crestline to see what they have in forks?

[tecatecrazy]

this is the kind of thread I like to see! I've been looking for forks to do this upgrade to my tecate, but they are had to find cheap. I've been looking at kx100 forks assuming they are smaller than kx125\250 forks but I am not for sure and I dont want to waste a bunch of money on something that will not work.

Another issue that I have encountered is that the front brake mount is set up for a much larger rotor (as compared to the tecate) and fabricating a mount to match the smaller rotor may not even be possible. also there is the issue of the axle...something will have to fabricated there.

I already have the aluminum stock purchase (been sitting in the garage for a month now), just waiting to make a decision on a set of forks. i was kinda hoping to be the first to do this to a 84\85 tecate but, I am kind of a procrastinator when it comes to these things so that probably wont happen lol.

If I decide to start this project I be sure to keep you all updated.

:TrikesOwn

[Derrick Adams]

As seen by the many who have already done this type of mod, this is one that you have to plan on spending money on, plan on fabricating parts, and plan on making changes as you go.

The biggest issue is fork selection. When I do it, i'll run the dirtbike brake assembly as well and adapt the rotor to my hub. The brakes are bound to be better anyhow.

[TimSr]

From what i've gathered, it seems any forks can be changed for weight and riding style by spring change/or preload and different amounts of oil. Is this correct? Does the diameter of the forks really have anything to do with their effectiveness or just strength to resist bending?

Would you agree, it's fair to say that these "80" forks are set up for around a 100lb rider, yet designed to absorb much higher and larger jumps than a trike would put them through? Would it really be soo hard to dial these forks in for the extra 100lb you would add between rider weight and trike weight?


Diameter of the forks affects strength, but not much else. For that matter I dont understand what you hope to gain by inverted forks other than more strength in the stress area of the forks.

I would agree that 80 forks are setup for a 100lb or probably less rider, but I would not agree its setup to absorb bigger jumps. What its setup for is to absorb a lot less weight from a minicycyle pushing down on it when it lands. You can spring it heavier, like a trike, and put it on a trike but then what do you gain? Bikes can land from high jumps because they weight 100-200 lbs less than an ATV, and because they can be setup with a lot more suspension travel. New bikes, can handle it a lot better than old bikes because of the increase in travel length. With more travel you can use softer supension and handle the same jumps. One advantage to aftermarket shocks is more travel.

The only practical way an inverted fork setup will help you in performance is if they have more travel, and if you are comparing 80 forks Id check that carefully. (The dampening setup is better but Im talking practical application.) Ive never measured them, but coming from a mini they could very well have less travel. The TriZ has a great fork setup, even on the 85, which, with a simple spring change is more than adequate for me, so for me personally, I cant comprehend redesigning something that already works great. Ive spent my engineering time working on that cooling system!

[Derrick Adams]

[QUOTE=TimSr]Diameter of the forks affects strength, but not much else. For that matter I dont understand what you hope to gain by inverted forks other than more strength in the stress area of the forks.

QUOTE]


It's simple Tim, THEY LOOK COOL! :w00t:

I guess that's pretty much it, no other reason. If I knew that I could convert them and I wouldn't gain anything, but I wouldn't loose anything, I'd still do it. Just because I think it looks cool. I would like a little better front fork though, for some reason when you add an extra 100lb of mud to the bike, it doesn't take much to bottom them out!

Plus, I really enjoy fabricating stuff, to me it's the challenge. Not so much the benefits. I like to be different.

Now how many people do you know that would admit that?