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Old Mar 20, 2004, 10:48 PM
STeve B in NC
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North Carolina, USA
Joined Sep 2003
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Partial USD fork pics

It was just me and the baby at the house today for a while. I was messing around on the computer and I started a pic of my partial USD fork mod. I did this mod on one bike about a month ago, but had problems with the 4-40 bolts coming loose despite being threadlocked. Using the grub screws up in the fork legs seems to have corrected this, as the setup is now very solid. The 4-40 bolts really strengthen the forks and take the slop out of them. I'm quite pleased with the perfomance and rigidity now.
While cruising the miniature motorcycle section of the local Home Depot, I also came across a few other nylon and metal and rubber spacers and washers that could be used in place of the cheap plastic sliders in the kit forks, so I may experiment a bit with these to see what improvement I can get in performance and friction dampening.

Anyway, I thought I'd post the pic in case anyone else was interested. It's a simple mod to do, and well worth it IMO.

STeve B in NC
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Old Mar 21, 2004, 02:54 PM
STeve B in NC
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North Carolina, USA
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I made a mistake on the bolt size. It's not a 4-40 bolt but a 4mm bolt x about 12mm long.
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Old Mar 25, 2004, 04:35 PM
STeve B in NC
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North Carolina, USA
Joined Sep 2003
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Got it right I think

I've been fiddling with spacers and the plastic bushings for the forks. I think I finally got it right. I ended up putting a metal 4mm washer and then a slightly larger rubber washer on the far end of the plastic bushing, all held onto the bottom end of the fork slider by the 4mm bolt. The rubber washer gives some dampening, especially with a few drops of 40wt. oil in the forks. The 4mm bolt is long enough that when it's tightened down and threadlocked, the plastic bushing and washers are slightly loose on it. It actually kinda looks like a damper rod on a 1/1 bike. I've got a set of medium tension 1/10 on road car springs on the outside, which stiffens up the spring rate. The forks are rock solid and have really improved the handling.

The bike will now track steady through high speed turns that used to produce the dreaded wobble. The mod has also eliminated most of the headshake with acceleration and top end speeds. I've left the steering damper on, but it doesn't seem to need the rubber o-rings. The front end doesn't pogo up and down when pushed hard, and the bodywork can't scrape the ground when the forks bottom out. I think I may have solved, or at least improved a great deal, what I consider the weakest component of these bike's handling.

Just passing it along.


STeve B in NC
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Old Mar 25, 2004, 09:02 PM
Big thrills w/o hospital bills
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Brisbane, Australia
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Steve,.. you need to get some pics of the mod so we can see how it all went together,... i had my forks appart the other night and try'd it out to see how they felt, i think i had the delrin sliders locked down a bit too tight and they did'nt slide in the fork body very well, so i gave it a miss,...(i think you have it, keeping the sliders loose is a good idea),... but what i have noticed is, before you tighten up the bolts at the top of the triples, try spinning the fork leg inside the fork boot and at the same time feeling/compressing them to find the spot that has the least bit of binding in them, then lock it down in the position you want,.. then do the same with the other one!... I've found it to work really well, and that's without doing any sort of mod to them...!

Pics,pics,pics...!!! lol

shaun
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Old Mar 25, 2004, 10:22 PM
STeve B in NC
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North Carolina, USA
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Quote:
Originally posted by scaulfi
Steve,.. you need to get some pics of the mod so we can see how it all went together,... i had my forks appart the other night and try'd it out to see how they felt, i think i had the delrin sliders locked down a bit too tight and they did'nt slide in the fork body very well, so i gave it a miss,...(i think you have it, keeping the sliders loose is a good idea),... but what i have noticed is, before you tighten up the bolts at the top of the triples, try spinning the fork leg inside the fork boot and at the same time feeling/compressing them to find the spot that has the least bit of binding in them, then lock it down in the position you want,.. then do the same with the other one!... I've found it to work really well, and that's without doing any sort of mod to them...!

Pics,pics,pics...!!! lol

shaun
Ok shaun here's a pic. The tube on the right in the pic has a wrench holding up the fork cap, the fork on the left shows how the 1/10 spring fits perfectly (thanks Ron). You can see the metal and rubber washers on the end and the 4mm bolt head. The lower springs fit nicely over the bolt head. It really is an easy mod.
I know what you mean about the sliders and having to spin the fork tubes around to get a good fit. I think the forks get bent a bit after a few good crashes, so you have to tighten things down where they slide well. I sanded the kit sliders down a bit so they slid well in and out of the fork legs. The metal and rubber washers on the end is what now gives them a snug fit. So you don't have to spin the fork legs to get things moving well, they fit well regardless of how things are put together. I drilled out the hole in the sliders to allow the 4mm bolt to thread in, but the plastic slider is free to spin on the bolt as are the metal and rubber washers. I also had to drill out the hole in the top triple clamp to allow the 5mm threaded end of the fork tubes to go thru so the 5mm nut could be tightened down.
The main reason I wanted to do the mod was to get more rigidity to the forks, and the bolts do this nicely My stock forks would get loose and wobbly every few runs, and it got to be a pain. I thought a lot of the wobbling I had in the chassis was from the rear, but I now know it's up front. Just like John was talking about the loose plastic NF triple clamp affecting handling, my squiggly forks were really making things sloppy. The difference with the mod is really like night and day.
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Old Mar 25, 2004, 10:36 PM
STeve B in NC
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Here's another pic. Looks just like stock (except for the external springs) until you see how it handles!
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Old Mar 26, 2004, 03:00 AM
www.steliosh.net/rcmoto/
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Athens, Greece
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Steve, can you please give us a pic from the side, with the front forks on the bike stand, the bike fully dressed with fairing, so I can see how it *looks* from the side?!

I look at my bike on the shelf, and the front fender is *inside* the fairing... it just doesn't look right... it like it's too heavy at the front.

C'mon! You love taking pic's of your babies!
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Old Mar 26, 2004, 03:09 AM
www.steliosh.net/rcmoto/
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This is what I meant, above. See how it just doesn't look right: The rear is so high (no battery in the bike), and the front so low...
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Old Mar 26, 2004, 03:12 AM
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speaking of forks, and hoping I'm not too far off the topic: I installed NF's top triple clamp, and then I had the idea of the correct *parallel* steering linkage. Piece of cake, really! 5 minutes' worth of cutting gave me the correct steering. Mind you, the bike was steering ok, both sides with the old style, but it just didn't *look* right! Still have to test it however!

I still have to grind the holes in the lower NF triple clamp. The sliders won't fit into them...

And... speaking of who-loves-to-take-pics-of-their-bikes.... o well!
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Old Mar 26, 2004, 06:55 AM
STeve B in NC
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North Carolina, USA
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Quote:
Originally posted by steliosh
This is what I meant, above. See how it just doesn't look right: The rear is so high (no battery in the bike), and the front so low...
Steliosh,

Here's a side pic of mine, not on the side stand. The bottom of the body sits level with a battery in. Your forks are staying partly compressed if the fender is under the fairing. The extra springs alone will help with that.
I've always thought the little stock springs in the forks were kind of a joke. They are way too soft if you push the bike hard. The reason the bottom of the body work on my bikes is sanded away is that the forks spent so much time bottomed out. Try the extra springs first Steliosh, then you will want to do the mod to the spacers to get rid of the slop in the forks, I promise you. The difference is so pronounced, that I'm now not happy with the rear shocks performance, and am going to look into improving that.

STeve B in NC
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Old Mar 26, 2004, 11:01 AM
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Nice work.....I like it, but the only thing is (but that's my opinion...)the springs don't look very cool! But it works! Wright? So who bothers about it?!
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Old Mar 26, 2004, 11:39 AM
STeve B in NC
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North Carolina, USA
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Quote:
Originally posted by gertjan
Nice work.....I like it, but the only thing is (but that's my opinion...)the springs don't look very cool! But it works! Wright? So who bothers about it?!
You can't see the external springs with the bodywork on. Can't even tell they are on there.

STeve B in NC
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Old Mar 26, 2004, 12:04 PM
Big thrills w/o hospital bills
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Quote:
Originally posted by mollycbr123
Ok shaun here's a pic. The difference with the mod is really like night and day.
Cool!,... Thanks Steve... The outer springs look like the Ricky C mod,... when i was testing Pats USD forks, i found a hardware that sells all types and sizes of springs for general use, i found some for pats forks that worked out perfect, they had 2 - 3 different hardnesses of the same type of springs that i think i'll try out in the TT forks, ones that give a better return on dampening etc,... i'll have a look sometime this weekend...!

The difference is, it's the middle of the night here and it's the middle of the day there...!


Quote:
Originally posted by steliosh
C'mon! You love taking pic's of your babies!

lol,... So do I,...

Steliosh,... here's 3 of my babies for you to check out ride hight from also!... The blue one is the latest in the pit shed...!

I think your fairing is sagging a bit,... the rear end looks a bit high too,... i try to keep the ride hight so the bottom of the fairing and the swingarm look almost level to the ground...

shaun
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Old Mar 26, 2004, 12:15 PM
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Shaun - nice arsenal from down under!!!
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Old Mar 26, 2004, 12:26 PM
Big thrills w/o hospital bills
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Thanks grymg...

If only i had a ticket to vegas,... i'd bring them all with me!...

shaun
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