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Best Reasonable Fork Upgrade ?

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Time to resurrect this thread.

I'm switching to 1.0 kg/mm Race Tech springs out front & swapping oil. I've seen mixed opinions on using a 5w oil (including easy bottoming), but the general consensus is to use lighter than 10w.

I'm considering either the Motorex Racing 7.5w, Motorex Racing 5w, or the Maxima Racing 5w. Anybody care to weight in before I order?

Also, the service manual calls for 483 cc of oil. I'm assuming that's per leg. Should I order 1 liter & use something else for flushing, or order 2 liters & use the expensive stuff for flushing?

Prefer not to swap out seals unless a leak develops. Should I order a set & have them on hand just in case??

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You should replace the seals while you at it.... you don't want to do all this work only to have to take it all apart again anytime soon, do you ?

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My forks are filled with Maxima Fork Race Fluid 7w (120-150).It is the same fluid Traxxion Dynamics is using in their cartridge kits. http://www.motorcycle-superstore.com/2/9/1...Fork-Fluid.aspx

Anyway,I very happy with the results,as a matter of fact I don`t see any reason whatsoever to change valving for street riding.All high speed harshness is gone.

Just like I mentioned in other thread parts needs to be cleaned extremely well,simple draining is not enough,I always pump brake parts cleaner through cartridge till nothing but clean fluid comes up.

I would order 2 liters just in case,it can always be used later.I don`t use suspension fluid for flushing, just brake cleaner.

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If it's smart to swap the seals, I'll order them too.

I've just had a few people tell me to leave 'em alone if they're not leaking now.

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I guess the question is... how old are the seals in your forks right now ?

Yes if your just changing the springs and swapping out the oil, then the easiest and simplest job would be to not touch anything else. But, if you haven't done your seals in a while.... why not now ?

Just my $.02

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Oh I follow the logic, it's just that I'm just getting mixed info. I'll definitely order them & plan to replace them unless somebody has compelling reasons not to.

I am hearing OEM is the THE way to go when it comes to fork seals. If that's not the case, somebody steer me straight.

I wish I knew more about this stuff. Never had a set of forks apart before...

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My 2 cents? First thing is your weight. The springs might not be right for you, and changing those are relatively easy.

I moved up to stronger springs. I'll know this spring how much they help.

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According to Race Techs site, the 1.0s are what I should be getting & that's what I'll order.

Any other feedback on oil from those that have tried 7.5 or 5 wt?

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I was using 7.5 and wad happy with it. Stock valving.

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I went with 1kg straight rates and 7wt oil and it made a big difference. I left my seals alone and they are fine.

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Troy, you know my take on the seals... 95k miles on this XX, 57k on my fix, I do the forks at least once every year, and have never had to replace the seals.

The secret is to clean your fork tubes once in a while, and make sure you do it when you have them out.

We'll flush the insides and cartridges with lacquer thinner before we re-assemble. You'll be able to eat off of them.

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This was my answer to the blackbird front end.......................... may not come under the heading of reasonable though LOL

post-53763-1270151779.jpg

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This was my answer to the blackbird front end.......................... may not come under the heading of reasonable though LOL

Little different from the rest of us , but I use Hyperpro-Combi

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7.5wt with the stock valving & 1.0 kg/mm linear springs feels pretty good. Less harsh, damping feels smoother but not slow. No issues bottoming so far. Thanks again Hobi!!

On a side note, with the spacers & new springs cut to match length of the old spring/spacer combo, ride height in the front feels higher by around an inch with the forks positioned the same.

Can someone with stock springs & a shimmed rear measure distance from the bottom of the lower cowl to the ground at the farthest forward point?

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I have seen a lot of variation in my time doin the zxxx. We were doing it on the centerstand and got anywhere from 4.25 on mine and 4.75 on Eric's to 5.5 on Alan's zxxx. I think. Front angle of the forks is the critical point to problems. Mine got weavie above 100 at 23 degrees.

Off the top of my head and only a sip of coffee...

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Well, the search engine merely added to the confusion.

What's the best general upgrade for the rough ride over bumps, expansion joints, etc. I ride basically every day (to work year round in all temp's 10-100 degrees) and the ride has got to get better.

This is my 2nd bird and I believe a better ride is about due. ('98 w/40 K miles).

Suggestions?

thanks

I added two shots of 15w fork oil to each side in under 5 mins I was back on the road.

Also, decrease your tire pressure to 34f / 36r.

Works for me!

That's not a good idea.

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We were doing it on the centerstand and got anywhere from 4.25 on mine and 4.75 on Eric's to 5.5 on Alan's zxxx. I think. Front angle of the forks is the critical point to problems. Mine got weavie above 100 at 23 degrees.

Off the top of my head and only a sip of coffee...

Unfortunately, I no longer have a center stand (Arrow exhaust required it's removal). Can somebody post the distance with the bike upright, or even on the side stand?

With the increase that came from this spring swap, the higher front makes turn in feel very similar to how it did before the shock was shimmed. I'd like to get back to where I was in that department. Turn in was good & stability was still there.

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I have a shimmed 98 w/stock springs ...cowl to ground inches ?

I will have a reply Tues morning....I will measure the bird tonight....

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Thanks a bunch!!!

Yeah, cowl to ground in inches. Center of the cowl would be great.

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Mine was 6" at the front of the cowl to the ground....(Bike on the centerstand...)....Let me know if you need the measurement off the centerstand as well....

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And....5" at the front of the cowl (center point) off the stand...1" difference bet. on and off the stand for my bird....

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Thanks a ton!!

Just as reference for whomever does this next...

Cutting the new spacers so that the new spring + new spacer length = uncompressed length of the old spring + old spacer, yielded a half inch increase in clearance at the front edge of the lower cowl using 1.0 kg/mm springs with no change in fork tube position.

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For anyone that hasn't finished their fork set up yet. First thing to set is sag---then follow up with ride height. Here is a link to an article on setting sag or other suspension issues from a master of his trade---Dave Moss---here ya go--------happy trails, kel

http://www.feelthetrack.com/downloads/Suspension3.pdf

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Thanks a ton!!

Just as reference for whomever does this next...

Cutting the new spacers so that the new spring + new spacer length = uncompressed length of the old spring + old spacer, yielded a half inch increase in clearance at the front edge of the lower cowl using 1.0 kg/mm springs with no change in fork tube position.

Here's the thing, Troy:

The maximum the forks will extend has nothing to do with the length of the spacers and springs. What it DOES have something to do with is the amount of rider sag. Stronger springs = less compression when there's weight on it, therefore it sits higher.

We did not set your sag, but really should. Ideally, with the correction in the spring weight according to the Racetech web site, your sag should be close with the same length springs/spacers.

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