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moonbeam1719

Airpro fork bottoming kit

11 posts in this topic

Airprofork.com

I posted this in the specialty forum with no luck...it's for snowbikes.

Anyone try this yet? A lot cheaper and less hassle to get it back on the dirt. Curious to whether it does what's claimed and if there's any chance of damaging my forks.

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It's just an air chamber.

 

It allows you to tune in the feel of the forks by have a larger air capacity to compress, or, to add air to simulate stiffer springs.

 

It will not hurt your forks.

 

You can blow out a fork seal easier because of the extra air, but it is not a signifigant increase of that happening.

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OK thanks a lot. .never heard of it before and there's no reviews on it anywhere that I can find...the snow bike set up definitely needs stiffer forks and if this works it will save a lot of time and $.

My bike is a 2016 yammy 450f with spring forks not air forks...I forgot to specify that.

Edited by moonbeam1719

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Snake oil.

 

The air volume in the fork is a part of how it's tuned to run, for one thing, and for another, allowing hyper atmospheric pressures to escape on their own seems completely impossible without allowing air to escape with each compression stroke, creating a vacuum in the fork that will either cause a negative preloading or suck dirt in past the seals.  That's why you don't bleed the fork except at full extension.

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The link went directly to their automatic fork bleeders.  I just went looking for their bottoming kit.  As said, it isn't any more than an old school sub tank that lets you add air to the top of the fork.  Kind of flies in the face of the idea that bleeding the forks is important if they're doing the exact opposite.  The exact same thing can be done by adding oil to the outer chamber (reduces the air volume in the fork, thus increasing the "rate" of the internal "air spring" effect). Way less expensive that way, although not as simple to adjust.

 

The problem with either pressurizing the fork or adding oil to achieve that effect is that it makes the fork overall more harsh in compression.  Another solution to bottoming in most twin chamber forks is to use a heavier weight oil in the outer side.  Most twin chambers use oil lock collars and cones for bottoming control, and as these are fixed size oil "brakes", heavier oil flows through them more slowly and resists bottoming more.  The downside is that it can mix into the inner chamber over time, so it can lead to needing more frequent fork oil changes. 

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OK thanks gray racer. ..for snowbike use, the forks need to resist the initial compression to keep the front end from diving so much..especially on the trail....there is a lot more pressure on the forks almost all the time in a snowbike application so this just may work.

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OK thanks gray racer. ..for snowbike use, the forks need to resist the initial compression to keep the front end from diving so much..especially on the trail....there is a lot more pressure on the forks almost all the time in a snowbike application so this just may work.

Putting in stiffer springs or adding spring preload will do just that. Adding air pressure to a spring fork will create harshness and have more effect down the stroke than in the initial part.

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Putting in stiffer springs or adding spring preload will do just that. Adding air pressure to a spring fork will create harshness and have more effect down the stroke than in the initial part.

 

This

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Thanks airpro. ..so if I understand correctly the added air pressure is there to resist bottoming at the end of the fork stroke?..do you have any reviews /comparisons vs spring and valving changes?..feedback from actual customers would be greatly appreciated. If this product is the real deal then I'm sure you'll sell a lot as this is a big deal in the snowbike world..I'm only 150 lbs and I'm running .60 springs which helped some but not enough to justify the cost and hassle of seasonal change outs..And yes I've done valving as well with minimal results.

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