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Discussion Starter · #1 ·
I'm 165 pounds and trying to set my marathon s up. The oil level is correct and both stock springs are installed. I set the sag up to be 25% of the 120mm of travel (30mm), with me in a downhill attack position. In order to achieve the 25% sag, I can't have any air preload. So, with that amount of sag and no air preload, the fork is super soft, too soft in fact. From what I've read here, the stock springs for the marathon s are for a 185-200 pound person, and most people my weight are taking the non-eta side spring out and just running air because the fork is too stiff. Am I missing something? I can't see how this fork is too stiff for a person my weight.
 

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If you are getting proper sag & using most of your travel (maybe 90-95%) on a rough ride, then there's nothing wrong with your setup. You have to remember that setup is affected a lot by personal preference, so there is no single setup that is correct. I weight the same as you, and I wasn't happy with the single-spring/air preload setup, and I returned to my dual spring setup.

You're doing it right, so don't sweat it and go ride:)
 

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Discussion Starter · #3 ·
bikerx40 said:
If you are getting proper sag & using most of your travel (maybe 90-95%) on a rough ride, then there's nothing wrong with your setup. You have to remember that setup is affected a lot by personal preference, so there is no single setup that is correct. I weight the same as you, and I wasn't happy with the single-spring/air preload setup, and I returned to my dual spring setup.

You're doing it right, so don't sweat it and go ride:)
Ok, good. Do you notice quite a bit of brake dive with this fork when your sag is set at 25%? Maybe I should put a couple more mm's of oil in to experiment. I've spent alot of time tuning my motocross suspension, and from what I've learned in that world is that there is a big difference between "soft" and "plush". I want this marathon to be plush and at the moment it's just soft. It gets progressive at the very very end of the travel, but I'd like that progressiveness to begin sooner through the midstroke. I know that's a fine line between midstroke harshness, but it seems like the midrange of this fork is missing..it's just super soft on top through mid, then pretty good progressively at the bottom.
 

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Yes, it brake dives a bit, but oil height probably isn't the best way to tune around that. I think that you'll have better luck tuning out brake dive with either higher spring-rate, heavier oil, or simply adjusting to the difference by moving your body weight further back on the bike.

Of course, higher spring rate or heavier oil will have disadvantages in other ride characteristics. Heavier oil will affect the entire stoke on compression and rebound and the slower rebound will cause the fork to pack up under multiple bumps.

I would try a touch less sag (higher spring-rate) and see what you think. Maybe adding a few psi air preload will get your sag around 20-25mm and the natural spring rate curve of the air will add some subtle progressivness. Oil height will have some effect on progressivness, but mainly during the final 20% of travel (approx.) as the stroke approaches bottom-out.
 

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Discussion Starter · #5 ·
bikerx40 said:
Yes, it brake dives a bit, but oil height probably isn't the best way to tune around that. I think that you'll have better luck tuning out brake dive with either higher spring-rate, heavier oil, or simply adjusting to the difference by moving your body weight further back on the bike.

Of course, higher spring rate or heavier oil will have disadvantages in other ride characteristics. Heavier oil will affect the entire stoke on compression and rebound and the slower rebound will cause the fork to pack up under multiple bumps.

I would try a touch less sag (higher spring-rate) and see what you think. Maybe adding a few psi air preload will get your sag around 20-25mm and the natural spring rate curve of the air will add some subtle progressivness. Oil height will have some effect on progressivness, but mainly during the final 20% of travel (approx.) as the stroke approaches bottom-out.
thanks alot. i've added a couple pumps to the air preload, reducing sag to closer to 20%, and it feels better. once it dries out here in Boise, I'll go give her the test off the rock on Bobs and see what happens....
 

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Pothole said:
thanks alot. i've added a couple pumps to the air preload, reducing sag to closer to 20%, and it feels better. once it dries out here in Boise, I'll go give her the test off the rock on Bobs and see what happens....
Good luck and I hope to see you in the foothills!
 
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