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Fork spring help

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Old 11-25-2009 | 09:21 AM
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Fork spring help

I need to change my fork springs. How do I tell what weight to get? I weigh 250 lbs. May want to take the wife for a ride every now and then (135ish).
Old 11-25-2009 | 09:32 AM
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Race Tech has a calculator to answer your question...
http://old.racetech.com/evalving/Spr...pringType=Fork
Old 11-25-2009 | 09:34 AM
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One source of information about spring rates is www.race-tech.com.
Old 11-25-2009 | 10:45 AM
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Try Sonicspring,better calculator.More accurate.
Old 11-25-2009 | 02:20 PM
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great links guys thanks
Old 11-25-2009 | 03:49 PM
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Greg always asks what your weight is while wearing full gear - what ever you have. The suspension on the bike is very sensitive and at its very best when it's properly tuned. 15 pounds DOES make a difference. A good adjustable shock is an important part of this package and absolutely required for two-up riding.
Old 11-25-2009 | 06:03 PM
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I suggest 1.0kg/mm springs for your weight. I hope that helps!
Old 11-26-2009 | 08:24 AM
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FWIW - Here is a little chart showing rider weight vs. fork spring rate. Please note that the weights shown are without gear i.e. in street clothes:

VTR1000F Fork Spring Rate Chart
115-150lb = 0.80kg/mm
150-180lb = 0.85kg/mm
180-215lb = 0.90kg/mm
215-250lb = 0.95kg/mm
250-300lb = 1.0kg/mm


As you can see, mhaisten is on the bubble between 0.95 and 1.0. For these cases I round up.

Last edited by JamieDaugherty; 11-26-2009 at 08:27 AM.
Old 11-27-2009 | 09:21 PM
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Don't forget to account for weight lost from the bike from aftermarket stuff. Hell, you can lose 15# just from slip-ons, of course that's mostly in the rear though.

Spring rate also depends how you ride. If you're doing a lot of track days and braking hard then you'll want to go up in rate .05 to .10 kg/mm. For just street the table Jamie posted is perfect.
Old 11-28-2009 | 08:30 AM
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Originally Posted by Hawkrider
Don't forget to account for weight lost from the bike from aftermarket stuff. Hell, you can lose 15# just from slip-ons, of course that's mostly in the rear though.

Spring rate also depends how you ride. If you're doing a lot of track days and braking hard then you'll want to go up in rate .05 to .10 kg/mm. For just street the table Jamie posted is perfect.

That's a good point. I should have put the caveat on that table that the rates are for street riders. These are reasons why it helps to get with a suspension tuner who can help sort out these kinds of variables for you.
Old 09-07-2015 | 06:04 PM
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Hi everyone. New to forum today.
Got 8,000 miles on VTR I purchased one year ago. Immediately (within 500 miles), largely based on this thread, I chose "180-215lb = 0.90kg/mm" springs to replace the stock jokes. (( I weight 178 lbs without gear )). As soon as I let the VTR down off the jack I knew immediately the springs were too soft. They are definitely preloaded correctly as I was precise with the required cuts ( also I can only tolerate the preload adjuster about halfway in. After that the tire gives too much rumble feeback on the road. a good indicator that preload is correct). So, last week, after 7,500 miles I went with the next spring "215-250lb = 0.95kg/mm". The feel of this spring (also a racetech) is a huge improvement. Bike actually has a smoother ride too cause I run a bit less preload. Its much less prone to that dive/knife when doing a quick flip into a turn. Its also less prone to wallow and wag a bit when encountering minor asphalt rolls in high G banked turns. I'm actually kind of elderly (just a few months shy of 65) but have quite a bit of motocross and supermotard experience but I really don't think that matters that much. The .90 KG is just a bad choice for a 178 lb VTR rider who occasionally scrapes the pegs on the street. Just some feedback for future fork spring swappers. Oh, and it has stock fork valving. Later...
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