Need suspension help for a 78 750, rear shock suggestions

[tkent02]

Maybe you're barely a buck fifty like myself? Good thing is companies like Dave Quinn Motorcycles (preferred Hagon Dealer) have a free 1 time spring exchange if you don't feel good with the original spring selection. I remember TheCafeKid said the same thing about an $800-$900 group purchase buy on a set of lower end Ohlins, he got rid of them... The rebound dampening needs to be roughly tailored to the spring rate as well, so buying new from a reputable shop or the manufacturer (YSS-USA, Dave Quinn, etc) is a huge bonus.

After I'm dead and all the meat has rotted off my bones I may get down to 150. When I was rock climbing and skiing daily I was 180, not anymore. Dave Quinn is the one who sold me the Hagons, the spring rate is fine, the damping is just hard as a rock. Same with the new Progressives, the spring rate is good, the sag is correct, the damping is brutally hard.

 

[Ecklund]

I put these on front and back and haven't looked back. Some think they're a bit pricey, but worth every penny IMO.

I'd like to do a side by side of the Progressives with the high end stuff from YSS or Ohlin or even the high end Hagons.

My suspicion is that the high end stuff gives better ride quality over a wider range of road conditions but just not three times better as the price would suggest.

I have the Progressives too with the HD springs.

I was thinking about a set of YSS or Ohlins for the '75 GL1000. Maybe an inch or so taller than stock. It runs OK now as is and it will be used to pull a side car so maybe when I do the front suspension...

 

[Guest]

Question for those who tried.. In what way, if any, taller than stock rear shocks will affect the ride? I would like to lift up the rear by about an inch, when the time comes for new rear shocks.

 

[Steve]

Question for those who tried.. In what way, if any, taller than stock rear shocks will affect the ride? I would like to lift up the rear by about an inch, when the time comes for new rear shocks.

That will depend a bit on the bike. As usual, we are forced to ask ... WHAT BIKE ARE WE TALKING ABOUT???

Generally speaking, raising the rear of the bike will decrease the angle of the steering head a little bit. Some claim to be able to tell the difference in the steering, apparently I am not that sensitive. Besides the steering angle change, there will also be a small change to the 'trail', but I am not sure whether it will increase or decrease.

On a longer-wheelbase bike, the quicker steering might be a welcome thing, but on a shorter bike, it might make the bike downright 'twitchy'.

You are more likely to notice the difference when you park the bike. Longer shocks will make the bike lean over farther on the side stand. If you use the centerstand, there is a possibility that the rear wheel might still touch the ground.

The seat will obviously be farther from the ground, hope your legs are long enough.

If you have a shaft-driven bike, there will be a change in the angle of the u-joint. They usually like to run as straight as possible. The farther they are bent in constant use, the quicker they will wear out items that are 'downstream' of the u-joint, like the splines in the final drive and the rear hub.

Welcome to the nuthouse, now fill out your profile to show your general location and your bike.

.

 

[Guest]

My apologies - 1980 GS 1100e with shorter (bmw style) handle bars. Thanks for your input!

 

[Danb4563]

I got very lucky with my 1981/82 Fox Factory Shox once I got a misleading seller to give me a partial $100 refund on the "chrome on shafts is perfect" claim so I could spend $170 on two reproduction shafts...

Those rare vintage Fox's are a Piggyback design with a reservoir piston separating the Nitrogen from the oil. They were from a GS1000. Short spring ("medium") & long spring ("medium-light") combo. I was afraid it might be too soft. Nope. Tried preloaded at close to 6 or 7 steps out of 8& the thing was stiff as a board, could not compress on bench. Backed off to previous owner's 3rd setting, firm ride but good. Dampening was amazing. Might back off 1 more to test, but those things are amazing. No fade at all on rough roads, viscosity insensitive design also. Basically like a the $450 YSS but a much larger piston & steel main cylinder alloy head & res. Great setup.

Sorry to jump in here with an unrelated question, but I have to know Chuck, what are you running for a rear brake? Looks way different than any I have come across

 

[Chuck78]

It's a gold painted (stripped now) GS1150 caliper with the older 750/850/1000/1100 tubular brake stay shortened and the end narrowed to fit. Rotor is an 89-91 right front floating rotor off of an 1100 Katana I believe.had to redrill the bolt pattern a half a hole off because the Katana took 10mm bolts and the GS takes 8mm. Much lighter than stock. The gs650 caliper is slightly lighter than the big 750/1000/1100 rear caliper as well.

 

[Danb4563]

It's a gold painted (stripped now) GS1150 caliper with the older 750/850/1000/1100 tubular brake stay shortened and the end narrowed to fit. Rotor is an 89-91 right front floating rotor off of an 1100 Katana I believe.had to redrill the bolt pattern a half a hole off because the Katana took 10mm bolts and the GS takes 8mm. Much lighter than stock. The gs650 caliper is slightly lighter than the big 750/1000/1100 rear caliper as well.

Nice setup! Looks almost stock.

 

[one_civic]

I ended up buying the older Koni's however the seals are NLA from Ikon. I found a guy who still has the old style seals and he makes a conversion kit to use the newer seals.

The Koni's that I put on my bike were originally for a cb750 / 76P-1296 / They are 1/2" longer and I have noticed quicker turning.

Anyway's here are some pics of the Koni's that I rebuilt / restored as well as the old vs new style seals. The guy I bought the seals from still has plenty of stock for the older style seals.

His name is Robert Haag and he rebuild's old shocks on the side specializing in Koni's,

I was also able to get new bump stops and eye bushings from David Gardner who is the Ikon rep. for the states.

 

[one_civic]

old style seal

 

[one_civic]

old style

 

[one_civic]

new style

 

[one_civic]

Robert Haag machined a sleeve if you would like to use the newer style seal, I used his NOS seals, If anyone on this forum would like more info or to purchase rebuilt Koni's or parts for their older Koni's, send him an email,

Robert Haag / Konimon on ebay

or

rhaagusa@yahoo.com

I called him up and he gave me great advise and some tricks on rebuilding older Koni's

 

[Guest]

Great info, thanks for posting this all up.

 

[one_civic]

I have a bunch of detailed photos saved but can only post 1 per comment due to size so if anyone needs more info on rebuilding the older style "emulsion oil / air" Koni's send me a PM,

Cheers

 

[Chuck78]

Those are pretty good shocks after a rebuild. The valving is still sorta old school, not up to par with Ohlins, YSS, or fancy modern shocks, but a fairly huge improvement over stock, and a good match in dampening quality to cartridge emulators up front. They are a twin tube setup which is way better than a standard emulsion design, almost as consistent in dampening as a piggyback/IFP.
Beatnic (Doug from DEK Performance Suspension, GS750 fanatic on dotheton.com and here occasionally) told me the reason you see a lot of them that are locked up or have no dampening is because the top out bumpers deteriorate and chunks of them get jammed in the valving of the shock.
Otherwise, they are a great shock for the money if you find a rebuildable set with shafts with good chrome.

I have a set of 76F-1296's sitting here for a GS425 475cc 10.5:1 stripped down lightened racer build with Suzuki 43mm RF900R cartridge forks, Shindy Nissin 6 piston caliper, and CBR1100XX Blackbird 310mm rotor. 3.50x18 & 2.50x18 DID alloy rims, Pirelli Sport Demon 140/70-18 rear and 110/80-18 front. The 76F-1296 is a clevis bottom alloy body version with no externally adjustable dampening. I am curious what the 76P is in comparison to a 76F. Length difference?

 

[one_civic]

If I remember the 76P-1296 Koni's on my bike are roughly 13.5" clevis to eye

 

[Chuck78]

The 76F-1296 are 340mm or a but over 13-3/8 but less than 13-1/2"