Author Topic: fork springs  (Read 712 times)

Offline Marc B

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fork springs
« on: July 24, 2020, 06:30:20 AM »
Just a thought
would the front fork springs from a heavier bike fit in the front fork tubes?

Offline Sporty

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Re: fork springs
« Reply #1 on: August 12, 2020, 06:11:51 AM »
I've been searching for info on this myself. Springs aren't that expensive,  but I've already bought a bunch of parts... have to stop at some point.

I went to this site that list forks by diameter
http://organ-donor.org/motorcycle-data/fork-tube-diameter-list/#tube37

I compared bikes listed to the GS500

Then looked at the Progressive specs for size and rate of their recommended replacement springs for the bikes.

Specs here https://www.progressivesuspension.com/assets/files/7100-105-Specs-And-Tech-Info.pdf

Progressive list the 11-1128 .54/.80 (35/50) for the GS500.

A lot of the bikes from the organ donor 37mm list take the same 11-1128 spring as the GS500, so I figure those other bikes stock springs are just as weak.

I was looking for something that uses a stronger replacement spring. The Honda CBR600 (1988 or so)
Is a candidate as it take the progressive 11-1129 spring a .63/.89 spring.

Another option might be used stock 39mm Sportster springs (1984-2003).  The standard progressive  replacement is a .63/.89 spring
The used stock Sportster springs are mushy for a 500 lb bike, but might be an option for the 375 lb GS500.  I looked at those because I think I have a used set out of a Sportster. The length and diameter look ok if going by the Progressive spring chart.

Of course my logic may be highly flawed here, but if I can find those Sportster springs, I'll try them.
« Last Edit: August 12, 2020, 06:16:48 AM by Sporty »
Used Suzuki GS500 = motorcycle adventure without leaving the shop.

Current motorcycles: 1993 GS500E, 1996 XL1200, 1999 ST1100

Offline Marc B

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Re: fork springs
« Reply #2 on: August 16, 2020, 04:53:39 AM »
Good luck looking and let me know. :woohoo:

 

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