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Spring Identification

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I'm sure this information is here somewhere but I can't find it. Have a used 2013 Beta 300RR with Marzocchi 48mm forks. There is a sticker on the front forks stating setup as follows.

Fork   Spring = .48kg

            Oil level = 350ml

            Oil height = 12

            Spec = XC-M241

            REB = 14

           COMP = 15

Shock  Spring = 5.8kg

           COMP HI = 2 T OUT

           COMP LOW = 14

           REB = 10

Was to stiff so I set clickers to stock settings and ride was much better. I weigh around 200 pounds and 215 fully geared. Front seems a bit stiff and rear seems a bit soft. I ride hare scrambles.

How can I tell what springs are in the forks and the shock? Since being used who knows if the sticker information is correct or not at this time. Is there part numbers, ratings, info on the springs????

 

Have a great day,

Bob

 

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I'm pretty sure that if the springs aren't marked the only way to confirm rates is to have them tested.  I'm no suspension guru but from your description, it's my understanding that your issue is more likely to be resolved with valving than springs.

Because they're compressible, springs are more weight sensitive than speed sensitive.  Their primary purpose is to hold the bike up at the optimum height to best utilize the available range of suspension travel, and not to control the speed of compression or rebound through that travel.  Thus the emphasis on setting rider sag to set the bike at 2/3 or so of travel, then measuring free sag to determine if your springs are a bit stiff or soft for your net riding weight.

Valves on the other hand control flow of hydraulic fluid, which unlike the springs is not compressible.  Thus the ability to consistently control and fine-tune the rate of compression and rebound damping.  Generally speaking, valving is speed sensitive and not weight sensitive, so the opposite of springs.  This is why both are so important in a properly tuned suspension.

That's how I understand it anyway.  I'm open to Much Enlightenment from others who know more about these things.

FWIW I'm really happy with .46 springs in the Marzocchi 48mm CC forks I'm running on my 2016 Xtrainer.  I'm 210 lbs in my birthday suit and around 240 lbs with full gear, pack, tools, and 2L water for backcountry solo riding.  I also carry about 15 lbs. of chainsaw and mount over my forks. I'm running 320cc of 5 wt fork fluid.  My forks have been shortened 30mm to fit my smaller bike (not sure if that matters.)

20180912.jpg

Edited by wwguy

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That chain saw looks scary!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

  • Haha 1

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IMO anything above 0.46 fork springs in a 2 stroke will feel very stiff. 

Another thing that is suspect is the fork oil height. You just can't measure that on a CC fork. 

Regarding spring rates, the best way is to have them measured on a spring dyno but until you find one you can also use this: https://www.acxesspring.com/spring-calculator.html

There's also an application to use on your smart(ish) phone. 

Be very careful measuring the wire diameter as it is very critical on the fork springs. On the shock spring subtract 0.1-0.2 mm to compensate for the paint. 

Use also 'Music Wire' on the material selection. 

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I'm 200 with no gear and use same springs you listed. I like the ride as feels more plush, as it doesn't get down into the lower part of the valving until needed. Play with the clickers a bit more, couple clicks at a time, only adjust one thing at a time. I think you'll find the sweet spot.

Get race sag set- most like close to 100mm race, I'm just a touch over. There's a ton of threads a to how to set that up so do some research here and you will learn a lot.

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