I disagree. With the stock springs, at 15,000 miles I switched to the heavier Screamin Eagle fork oil, and noticed a significant stiffening of the front suspension. I have since switched to progressive shocks and standard weight fork oil, but the heavier weight oil made a big improvement.

 

mine are doing the same thing i changed fork oil to screaming eagle heavy duty didnt make a bit of differnce

 

Get some new fork springs. Fork oil is only going to help increase the dampening of the shock, it won't change the ride height, and nose-dives. Stronger fork springs, combined with proper preload will set your ride height, and overall stiffen the forks a little. Did my springs with progressive springs a couple months ago, and what a world of difference, and stuck with stock weight oil with the new springs.

 

+1 - The stock Sporty (all models) suspension, at both ends, just plain $ucks. The Progressive fork springs are not that expensive, about $80.00, just do it right the first time instead of spending the next year screwing around with oil weights.

 

The OP asked if his bike could be low on fork oil. If it was low on oil would you not notice a leak? I don't know, just askin...........BTW. I have progressive on mine.

 

If you own a 883 Iron like myself no one can tell you what size the stock springs are, which is annoying as I don't want to lower or raise the front at all! Just want to stop them bottoming out!

 

I agree with the above and will add that increasing oil HEIGHT will reduce bottoming, but at some point you will risk seal failure.

I have searched but cannot find the STOCK fork oil weight. Does anyone know the spec for STOCK fork oil weight, and STOCK for oil height. I found where someone said 12.3 OZ per leg, but does anyone know the height setting (from the top of the tube)?

FWIW - ATF= 7.5wt. I have lowered the forks on my wifes '05 883L (4900 miles), so I will need to add heavier oil, raise the height (probably 5mm or so), and drop a washer, or two, or three, or four, in for some preload.

Thanks Guys!

Also, any CD manuals out there for cheap or on line down loads? $60 for a Service manual is criminal!

 

i believe u need exactly 12.3 quarts of oil in ur forks. i had mine replaced with heavy duty fork oil at the 5000 mile check up. the tech said that it didn't have enough oil in the forks, that this was causing the consistent bottoming out. afterwards on the way back from the shop, i hit plenty of bumps (lots of road construction in northern illinois right now) and none of them bottomed out my forks.

so check ur fork oil level, if that doesnt work switch to heavy duty fork oil