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Determine if aftermarket springs are in forks?

Old Jan 16, 2009 | 01:51 PM
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Determine if aftermarket springs are in forks?

So YRUYUR and I were comparing our bikes the other day, and mine is noticeably taller. That is sitting there with the springs uncompressed and no one on the bike the forks are extended further than his bike..

Now I purchased the bike from a umm "larger" person and wonder now if he put some aftermarket springs in the forks, or something.

I don't want to fully disassemble the forks, but is there some way to determine if these forks have been worked? Or perhaps the preload is just cranked way up??
Old Jan 16, 2009 | 02:00 PM
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I've been wondering the same thing about mine. After comparing with Reaper's 'Hawk when he had stock springs, mine was much stiffer. We then adjusted my sag for me (220lbs naked) (not sure if you wanted that image ) and the adjusters are about a 1/4 of the way in. For a bike with a "soft" front end, most people complain about cranking the adjusters ALL the way in and it still being soft. Not the case with mine, no dive, just perfect.

I'm probably going to change the fluid in them if I don't do a conversion soon, but even then without stockers to visually compare, I don't know if aftermarket springs are marked with the brand name.

Without knowing I'll just keep pretending that I'm a 150lb MotoGP star when I ride it.
Old Jan 16, 2009 | 02:07 PM
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lots of ways to guess... only one way to know for sure.

tim

btw: aftermarket or not you need to set the sag properly - if you can't get it in spec you
need new springs.

Last edited by trinc; Jan 16, 2009 at 04:47 PM.
Old Jan 16, 2009 | 03:25 PM
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Next time there is a suspension workshop in town I will try to make it. (aztrackday.com does them periodically for $35 so I think I will attend the next one if I can)
Old Jan 17, 2009 | 08:50 PM
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Hi guys, just been down that track myself.
The only way I could achieve correct sag was with the preload screwed right down to 1 line showing.
Took the caps off as per the manual (leaving forks in place) and lo and behold non std springs! (linear rate springs, aluminium spacers that had been cut by a hack)
I had new racetech kit on hand and was able to compare the bits.
The result was I had to increase oil level from 165mm to 155mm and make new spacers so that I had some preload adjustment.
Moral of the story - just because the mods have been installed by the previous owner doesn't mean they were installed properly.
Next step will be a fork oil change to see what difference that makes and if necessary a strip down to see what other stuff has been done by the previous owner.
Old Jan 18, 2009 | 10:52 AM
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Yeah, it's tough to determine just by looking (unless you have an obvious clue like revhead's spacers). You mentioned that it's sitting high - what are your sag numbers? If you are having difficulty getting the correct sag then it's an indication that the springs are not suited to your weight - stock or otherwise.

When you say "noticeably taller", exactly what are we talking about? Even if your bike has higher rate springs it won't be more than 5mm or so, which is difficult to see by eyeballing it. Did you take any measurements? Where are the forks in relation to the triples on both bikes?
Old Jan 18, 2009 | 01:46 PM
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Originally Posted by JamieDaugherty
Yeah, it's tough to determine just by looking (unless you have an obvious clue like revhead's spacers). You mentioned that it's sitting high - what are your sag numbers? If you are having difficulty getting the correct sag then it's an indication that the springs are not suited to your weight - stock or otherwise.

When you say "noticeably taller", exactly what are we talking about? Even if your bike has higher rate springs it won't be more than 5mm or so, which is difficult to see by eyeballing it. Did you take any measurements? Where are the forks in relation to the triples on both bikes?
I mean just looking at it, the tank is like an inch higher, and there is at least that much more of the fork showing.
Old Jan 18, 2009 | 02:25 PM
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Start by comparing apples and apples... Check that both bikes have the forks at the same height in the triples

Then check the settings... count the twists to stop and you can always set them back to how they where...
Old Jan 19, 2009 | 04:32 AM
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Originally Posted by lazn
I mean just looking at it, the tank is like an inch higher, and there is at least that much more of the fork showing.

I really doubt this has anything to do with the springs, there must be some other difference between the two bikes. Aftermarket springs won't cause that big of change is static sag of the motorcycle only.

Are you sure his bike hasn't been lowered somehow? That seems to be really popular these days.
Old Jan 19, 2009 | 10:00 AM
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Well he has Heli bars on his, so the forks may sit different in the tripples to accommodate that.
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