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Discussion Starter #1
Does anyone know or have experience with converting front forks on the 1800 to air with caps like some of the older bikes had. Is it possible to get an adjustable suspension or even worth the trouble ? Simple drill and tap and install air fittings on each cap, What do you think ?
 

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Max McAllister said:
All manufacturers quit using air as a mechanism for preload, because it is tragically flawed.

The more air pressure that exists inside the fork forces the seals to drag on the tube more, decreasing compliance.

But the biggest reason is that it blows the seals out. I spent the first three years of my career in the MC biz replacing blown fork seals on air forks. It cost the OEMs MILLIONS and MILLIONS of dollars.

A proper spring and spacer will generate the correct preload without any additional seal drag, or loss of reliability. For sure, 100%, an air preloaded fork is more prone to failure than one with the right springs.

The oil level in the fork is set to provide maximum wheel travel without bottoming. This is based on atmospheric pressure in the fork. That is why dirt bikes (which have the most advanced suspensions of all production motorcycles, even better than road racer production suspension), have a screw to let the air OUT before riding the bike. You want the EXTENDED fork to have atmospheric pressure in it.

Note that dramatic changes in altitude will actually affect your suspension's performance as well.

8)
 

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Discussion Starter #3
I just had to ask out of curiosity , I knew there had to be a reason for the change from air . You have presented a very clear explanation as to the problems it presented . Thanks
 

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i just drilled and tapped my caps. i also went with progressive springs. i use amsoil fork oil and it makes a big improvement. i will post how the air works when i get to ride it. i did the same to my yamaha xs1000 and i had 23 years on the same seals. it also keeps the water out. i did a fork oil change around 10000 miles and i found water in the fork. i now have 32000 miles.
 

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I don't know. If you need improvement check out Traxxion suspension, you can go with just the springs and a new front fork fluid which may be the ticket for you.
 

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they worked great but i am going to add a line to balance them. it is too hard to get them even.
 
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