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Discussion Starter · #1 ·
I am looking to put a front fork on my Kona Unit and there are so many out there. I would like to get some feedback from some of you guys who have forks. I like the Fox line, but it may be out of my price range. Rockshox have a allot to choose from but it is confusing. I haven't really looked a Marzocchi. I am mostly a single track guy, nothing to radical. Anyway, hope to hear from you guys.
Thanks:confused:
 

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Discussion Starter · #4 ·
I looked at the Manitou. The line seemed to have changed. The two that I would have to look at would be the Tower. I am leaning toward the Pro. But I do not know the difference between the springs? Is there someone who could explian the difference between the Mars and the Act?

Thanks guys.
 

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wipple370 said:
I looked at the Manitou. The line seemed to have changed. The two that I would have to look at would be the Tower. I am leaning toward the Pro. But I do not know the difference between the springs? Is there someone who could explian the difference between the Mars and the Act?

Thanks guys.
Act air is a coil spring inside an air chamber. Most the work is done by the coil, but you can add air to fine tune the forks sag. The forks with Act say 0-50psi can be added on them, but in the manual it says 0-100. either way, its very tunable and a good design that works well.

Mars air is also a coil/air spring. But with Mars, The coil is much smaller and the two springs work in series. Unlike Act where most the work is done with the coil, with Mars, I believe most the work is done with a high volume air chamber with the small coil being the assist. Mars is a much lighter then Act since the coil is much smaller. It also works very well, but is a much more complicated design.
 

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Discussion Starter · #6 ·
Thank you. That cleared it up. So there is no real advantage to the Mars system that I see. I have one other question. What is the advantages of the 20mm to 15qr to the standard qr. Thanks again.
 

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wipple370 said:
Thank you. That cleared it up. So there is no real advantage to the Mars system that I see. I have one other question. What is the advantages of the 20mm to 15qr to the standard qr. Thanks again.
The advantages of Mars over Act is weight(about half a pound lighter) and Mars is a little more adjustable without changing the coil springs. If you weigh in between 150-200 lbs, The stock coil in the Act system will fit you perfectly.

20mm and 15mm axles will give you more stiffness in the fork. This helps give you precise steering in rocky sections. With standard QR, you might feel the wheel deflect off of the rocks or roots more. If you weigh over 180lbs or ride at high speeds in rocky or rooty(is that a word?) terrain, Getting a 15mm or 20mm axle is probably a good idea. If you a light weight, and ride on mostly smooth trails, You probably wont notice much of a difference.

If you are are replacing your current fork, You will need to go with the axle type your current fork has, Or buy a new hub or wheel that has the axle type on the fork.
 

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What is your budget, and do you have a hub that can accept a 15 or 20mm hub?

15qr, according to Fox, offers a torsional stiffness improvement of 15%, and transverse shear improvment of 25%. This results in more precise steering control. Well to some: not all can feel it. It follows 20mm will be even stiffer, but I have no figures for that.
 

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supersonic said:
What is your budget, and do you have a hub that can accept a 15 or 20mm hub?

15qr, according to Fox, offers a torsional stiffness improvement of 15%, and transverse shear improvment of 25%. This results in more precise steering control. Well to some: not all can feel it. It follows 20mm will be even stiffer, but I have no figures for that.
20mm would be slightly stronger, But doesnt give a noticeable amount more stiffness the 15mm
 

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mullen119 said:
20mm would be slightly stronger, But doesnt give a noticeable amount more stiffness the 15mm
I remember seeing a thread here about tests showing that the 15mm was closer in stiffness to a 9mm qr than 20mm TA.
 

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Discussion Starter · #13 ·
Supersonic - my budget is under 400. I have the traditional QR, what ever that is.

Mullen - I am 6'4" 265lb rider would that make a difference when choosing between a Mars or ACT? My riding style is not all that crazy. I ride on Long Island, and for the most part it is all flat with allot of roots.

I am leaning more towards the new tower expert because of price, but if the extra cash makes sense, then I will pull the trigger. I feel as though I am almost there, I am stoked. All these question are starting to make sense to me now.

Thanks again.
 

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Im surprised about the 20mm being that much stiffer then 15mm. I have no data other then when I go from 9mm to 15mm, I can feel a big difference in stiffness. And when I go from 15mm to 20mm, they feel about the same stiffness wise.

Either Mars or Act will need an extra firm coil with your weight. You would have to order it through a shop since Manitou wont sell directly to the public.

Extra firm ride kit part number for Mars is:
141-26744-K003 (for 120mm)
141-26743-K003 (100mm)
141-25690-K005(80mm)
Act only comes in firm and is:
141-23998-K008(for 120mm)
141-23998-K007(80-100mm)
 
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