rear shock aftermarket spring rates? hagon 2810's

[Chuck78]

I've got to double check the diameter of that GS750 coil, as I was playing around on the Wallace Racing/Pontiac Power spring calculator and noticed a big difference in spring rate when going from 25.1 up to 25.4 diameter. with all other specs the same, 25.4 would be 46.5 lbs/in and 25.1 wold be the 48.56 lbs/in. I checked it on the top end as the spring came out, because the bottom end of the coil actually tapered inwards to a much smaller coil diameter for the bottom 2.5" approximately, making that section much stiffer. I'll try and double check the rest of the spring in the middle to make sure the 25.1mm diameter that I measured at the top is consistent down to the bottom tapered section.

When installing emulators with these springs in the dual disc forks,I suspect I may have to flip the decreasing diameter end up to the top to fit the emulator bodies inside of the coils as designed.

I tried sanding down my 3/4" PVC shims to fit into the forks, but that was not very productive... so I cut some 7/8"o.d. ("3/4 inch") CPVC water line pipe to length and wrapped some electrical tape around the ends in a barbell-like confguration to keep them centered in the fork for now. When I swap on the GS650G dual disc forks, I'll have some aluminum bicycle seatpost pieces to use with these springs in those forks. Just trying them out for now on the single disc setup.

[Chuck78]

I re-measured the springs today and they are 25.4mm, but just at the very top they measured a little slimmer. The bottom 3 coils taper inwards to a smaller diameter as I said, so I would estimate about 46.75lbs-in (.835kg/mm) to run just on the 14" thicker spring and ditching the 6" skinnier progressive spring.

My third good ride of the year today, my wife and my buddy got their GS550 and KZ1000 out of storage and we hit up Riverside Drive at sunset for the best in-town riding on the way to get dinner. I have to say this is a HUGE improvement, brake dive is almost non-existent, the cornering is way better especially with the geometry being able to stay where it should without the front end diving, and in no way did it feel like a harsh ride.

I shoulda listened to Salty, I think 1" pre-load for my lower body weight was too much, maybe 3/8" would be my estimate, if not what Salty said. The rear shocks I had to preload all the way to try and get them matched up a little better, but I still had about 1.375" of sag on the rear shocks on the stiffest setting. I need to check my spare GS1100E shocks to see if they have any stiffer springs. The ride height is a bit higher as well now, and the bike leans over a good bit more on the side stand. Putting in the first spring/spacer was a bit tough to get the top cap past the o-ring and threading in. I though the one on the side stand lean side was going to be at least as tough, but the upgraded side held the bike up almost all the way by itself alone! 1.0kg/mm front springs I think would have been too much, but who knows. There was no ride harshness whatsoever.

EVERYONE, I HIGHLY RECOMMEND THIS SETUP, IF NOT SONIC/PROGRESSIVE SUSPENSION SPRINGS... Well worth the research of calculating available travel, sprint rates, and # of coils to cut

[salty_monk]

I think I've used conduit to make us spacers for a 35mm form before... The galv stuff.

If using alu pipe I'd be concerned about wall thickness.
Make sure you put a metal washer of correct dia at each end. Good practice anyway...

[Chuck78]

The way the top caps are, I didn't see it necessary to put a metal washer in for a PVC spacer, but for conduit or metal tubing, DEFINITELY A standard 3/8" flat washer is 1" o.d and fits perfect for 35mm forks, but I am using the OEM washer that was in between the two springs from the factory. The CPVC spacer sits on it nicely.

The bicycle seatposts are suffient wall thickness for sure, they have to resist side loads as they are at a 72 degree angle with rider's body weight bashing down onto them often. The vertical crush strength is MUCH more stout even. I snagged two yesterday at the bicycle co-op that we volunteer at in trade for some electrical work I'm doing to the building