make forks stiffer?

[simon_C]

being a big guy on a relatively small bike, the front end tends to bottom out and dive pretty easily. is there any way i can stiffen up the front end easily? does that PVC spacer trick work for this?

[BassCliff]

Progressive fork springs

Hi Mr. simon_C,

Sure, you can put in bigger spacers, but then you run the risk of totally compressing your springs when you hit a big bump, not pleasant. If you have air forks, you can try putting in 15psi or so as preload. Most here will suggest installing a set of Progressive fork springs and perhaps moving up to a little thicker fork oil (15wt?).

You seem kind of new around here, judging by your post count. Have you seen the mega-welcome? Thanks for joining us.


Thank you for your indulgence,

BassCliff

[simon_C]

Hi Mr. simon_C,

Sure, you can put in bigger spacers, but then you run the risk of totally compressing your springs when you hit a big bump, not pleasant. If you have air forks, you can try putting in 15psi or so as preload. Most here will suggest installing a set of Progressive fork springs and perhaps moving up to a little thicker fork oil (15wt?).

You seem kind of new around here, judging by your post count. Have you seen the mega-welcome? Thanks for joining us.


Thank you for your indulgence,

BassCliff

actually, im not really new around here, my old account (same name) got deleted when i didnt come here for a few months. i had about 200 posts under my belt at that point.

[BassCliff]

Welcome back!

actually, im not really new around here, my old account (same name) got deleted when i didnt come here for a few months. i had about 200 posts under my belt at that point.

Well then, welcome back Mr. simon_C.

Do you have air pre-load on your forks? Progressive springs aren't too terribly expensive, maybe $60 or $70, depending on where you buy them.

Thank you for your indulgence,

BassCliff

[simon_C]

i honestly dont know, whatever came on the base model gs400 in '77

[Macmatic]

Go for the progressive springs, great upgrade for the money. I run progressives with 1.25in PVC spacers and no air and am pretty happy with the setup. I'm north of 250 and south of 300lbs on an '83 GS750

/\/\ac

Make sure to put a washer in between the spring and spacer if you use one!

[silverhorse47]

Simon I'm not sure if the progressives and heavy weight oil are for you. There are some threads on actually cutting some coils off the springs to increase stiffness (don't recoil now) and then using spacers to take up the slack, as it were.
If not on this site, then some other? Can't remember.
S.

[Nessism]

I've cut the springs on several different bikes with excellent results. Remove a couple of inches of coils and replace the lost height with PVC spacers. Cut a little more as necessary but I wouldn't go more than four inches or so.

The GS bikes that have air assist have soft springs so it's hard to get them firm enough by cutting out coils. If you have this kind of fork it's best to go straight to the Progressives.

[Houdini]

I recently cut down the springs in my GS450 from 20” to 14” !!! and made some PVC spacers at 6.5 inches (dont forget washers between the springs / spacers), added some old 10wt. Spectro fork oil to 5.5 inches. The OEM spring was a progressive so I cut off the soft side. My son & I came up with an ingenious idea, basically I knew I needed to be at a 45lb/” rate (by going to the Sonic Springs web site spring calculator). So we put a dowel through the spring and on a bathroom scale measured the travel from 10 to 60 lbs to determine the OEM was at 33. We kept lowering 2 thin wrenches until we got the desired point at which the rate became 45. A circular saw with a metal cutting blade, followed by clean-up filing,heat & final bending to get the end flattened. What a huge difference, preload was in the 1-1.25” range, & I did some hard stops & was able to get 4.5 out of 5” total travel. Having put 1000 miles on this config I think I want to change the fork oil to 15W at 6" from the top to see if it improves the ride.

As long as you have the spacing between coils to accomodate your fork travel (I could have cut 2 more inches), cutting the springs is the really poor mans method to increase spring force.