2013 Front springs replacement

[900gc]

Great write up with interesting discoveries.

Since the damping is accomplished by the oil passing through valve orifices, changing the oil wt. can sometimes be enough to suit ones needs even without changing springs. With stock valving though, you can't stray too far from stock oil wt. or the adjustments won't be able to compensate enough to maintain a suitable ride.

I read a fork oil comparison someplace where they found the same wt. of oil of different brands varied quite a bit from each other. So even the brand of oil throws in some more variables now.

The idea of a progressive spring seems to make sense (more compliant over small road irregularities) but the theory doesn't often seem to work in all applications.

 

[Fred W]

Great write up with interesting discoveries.

Since the damping is accomplished by the oil passing through valve orifices, changing the oil wt. can sometimes be enough to suit ones needs even without changing springs. With stock valving though, you can't stray too far from stock oil wt. or the adjustments won't be able to compensate enough to maintain a suitable ride.

Yes and no. I agree from a bump compliance standpoint, but unless you have the correct weight springs for the bike's load, you'll never get the sag distances right. Even the slow speed damping eventually relaxes the suspension to the point of spring/weight equilibrium. The importance of the sag is to maintain the suspension at the correct point in its stroke with and without an impulse input. This maintains correct steering geometry and ensures that there is enough room in the stroke to take a big hit without bottoming out, both of which are pretty important.

I read a fork oil comparison someplace where they found the same wt. of oil of different brands varied quite a bit from each other. So even the brand of oil throws in some more variables now.

I have a copy of a pdf file that shows the viscosity of most brands of suspension fluids hosted at my web account.

Click the nerd icon in my sig line below.

 

[escapefjrtist]

I read a fork oil comparison someplace where they found the same wt. of oil of different brands varied quite a bit from each other. So even the brand of oil throws in some more variables now.

I have a copy of a pdf file that shows the viscosity of most brands of suspension fluids hosted at my web account.

Click the nerd icon in my sig line below.

Another great reference site for oil viscosity is Peter Verdone Designs. Once you know what you need there are generally many options to choose from

--G