Max rear shock length for GL1100

[toomanybikes]

I'm looking to swap the standard air shocks for a traditionally sprung set. Stock length is 12.5" on my '81.

I'm 6'3" so raising the seat is always desirable. What is the longest shock I can mount before I start having problems with swingarm travel, drive train stress, side stand, and center stand viability? I'm sure 13" would work fine, but is 14" too much?

[dontwantapickle]

I have 14" shocks on my 81. They work fine.
The only thing I have found is that the rear tire still touches the ground when the bike is on the center stand.

[toomanybikes]

I have 14" shocks on my 81. They work fine.
The only thing I have found is that the rear tire still touches the ground when the bike is on the center stand.

That must make it tricky to oil the chain.

Thanks for the input.

[dontwantapickle]

I have 14" shocks on my 81. They work fine.
The only thing I have found is that the rear tire still touches the ground when the bike is on the center stand.

That must make it tricky to oil the chain.

Yes it does.

[redglbx]

[Sidecar Bob]

I don't recall seeing it discussed here but on the CX500forum people often turn the Custom model into "cafe" style bikes and want to use longer shocks to alter the bike's "stance" so it comes up frequently. This thread has good information (mostly from Murrayf) about how much u-joint angle is too much
https://www.cx500forum.com/threads/max- ... gle.73265/

[toomanybikes]

I don't recall seeing it discussed here but on the CX500forum people often turn the Custom model into "cafe" style bikes and want to use longer shocks to alter the bike's "stance" so it comes up frequently. This thread has good information (mostly from Murrayf) about how much u-joint angle is too much
https://www.cx500forum.com/threads/max- ... gle.73265/

Thanks Sidecar. I've done similar projects on CX/GL500's, including finding the max shock length for the GL, 315mm before you get interference with lower shock mount members.

I have a different user name over there. but you've helped me a few times.

[Sidecar Bob]

Um... The GL500/650 have Pro-Link rear ends. The bottom of the shock attaches to the rising rate linkage so I can't imagine how there could be "interference with lower shock mount members".

But anyway it isn't interference you need to worry about but the angle of the u-joint.

[toomanybikes]

Um... The GL500/650 have Pro-Link rear ends. The bottom of the shock attaches to the rising rate linkage so I can't imagine how there could be "interference with lower shock mount members".

But anyway it isn't interference you need to worry about but the angle of the u-joint.

The image below shows how there can be interference. If the shock is any longer, the mounting bolt hits the other pieces.

Also, the center stand still works at this length, but just barely. The rear wheel still skims the floor.

IMG_20201023_064743.jpg

[Sidecar Bob]

Oh, you mean interference between the bolt and the linkage (Honda calls that part the shock connecting rod).
What's the u-joint angle with that long a shock?

[toomanybikes]

Oh, you mean interference between the bolt and the linkage (Honda calls that part the shock connecting rod).
What's the u-joint angle with that long a shock?

I no longer have the bike, so I can't measure it. Here's the best pic I have for estimation.

swingarm.jpg

[Sidecar Bob]

That has to be pretty close to the max of 4.5 degrees that Murray recommended.

[Gowing]

I have 14" shocks on my 81. They work fine.
The only thing I have found is that the rear tire still touches the ground when the bike is on the center stand.

That must make it tricky to oil the chain.

Thanks for the input.

[redglbx]

The only inputs I’ll give on this is that as I recall the extended free length of the 75-79 gl is 13.75” ,, the factory shocks from 78/79 really aren’t all that bad in spite of the reputation the magazines gave them. I had a set of used Koni’s for years that I had rebuilt and was quite happy with those until they needed rebuilding again (25yrs) and the current Koni owner (Ikon) would not sell me parts to refresh them , only wanting to sell me new.

So if me riding becomes a real possibility again I’ll either stick with the currently installed 78’s or try to buy a set of Hagon’s that have been highly recommended here. I had bought a set of YSS’s a few years ago and granted they were not “high-end” shocks but quite frankly they were/are shite shocks loosing all dampening capability within the first 500mi and zero customer support. My .02

[redglbx]

Mods, please delete this duplicate post.

\The only inputs I’ll give on this is that as I recall the extended free length of the 75-79 gl is 13.75” ,, the factory shocks from 78/79 really aren’t all that bad in spite of the reputation the magazines gave them. I had a set of used Koni’s for years that I had rebuilt and was quite happy with those until they needed rebuilding again (25yrs) and the current Koni owner (Ikon) would not sell me parts to refresh them , only wanting to sell me new.

So if me riding becomes a real possibility again I’ll either stick with the currently installed 78’s or try to buy a set of Hagon’s that have been highly recommended here. I had bought a set of YSS’s a few years ago and granted they were not “high-end” shocks but quite frankly they were/are shite shocks loosing all dampening capability within the first 500mi and zero customer support. My .02