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How to raise rear ride height, 86 750???

4K views 13 replies 7 participants last post by  gRegm 
#1 ·
Help would be very much appreciated!!!

I'm aware of the 1100 linkage-knuckle approach... but its less desirable due to various issues.
Finding one to start with... to say nothing of the ratio change...

Also aware of the rod-ends/turnbuckle approach...... but would at least like to know the specifics....
This would sorta be a last ditch approach.... it "has issues" too, so it would seem.

Please chime in!
Lets make this thread worthy of a sticky! :grin2:

Thanks in advance,
 
#2 ·
The best way is to fit a shock of a longer length, or has adjustable shock length - it changes geometry of the chassis, but obviously the original rising rate is unchanged. If you change other things you need to calculate what's happened as a result.
The rear end will benefit a lot with a nice shock installed and it would quicken the steering a bit - the front end should be uprated to maximise the better rear-end and altered stance.
 
#3 ·
Actually, the bike has a Fox shock (and spring, uprated)... and progressive springs up front...
Trouble is... and its just my luck....... its one of the Fox's that came without the adjuster.
No doubt thats the better way to go..
Recently, I searched and searched all around, in an effort to find parts for Fox, in order to upgrade it with the adjuster.
Parts for them are all but gone... a couple of places have a few things.... but only one guy thinks he MIGHT have it.. Jamie Daugherty jamie@daughertymotorsports.com... but he quoted over $300 to install it (IF he indeed has it) including a rebuild.... which it doesn't really need.. Just fresh fluid..
Throw in some seals while at it.
I might go that route eventually, when cashflow permits.... IF he still has the part..

Meanwhile.... I'm sure an adapter could be made, for above the shock... a mount which simply fits in where the top shock bolt goes, then wider below, with provision for top shock mount and bolt holes..
I just haven't any idea who might be able to make one!

In case anyone else DOES... it would be mighty appreciated!!!

Thanks,
 
#4 ·
The problem with the 1st generation 750 is that the swingarm will top out physically at a height only a little taller than the factory shock. This is why people go the 1100 linkage-knuckle approach. It's the only way you'll get more height out of the rear of a 1st gen bike without fitting a different swing arm and linkage. I've got an Ohlins in mine. It's got an adjustable lower link length so you can make it longer, shorter, etc... I've got it completely topped out and it's not much higher than it would have been with a new regular length shock.

And yes... It's a pretty small market of people interested in buying hi-end suspension parts for a 30 year old bike. My Ohlins listed for $1,200 USD. I was lucky that a member here bought it for his 1100 and didn't realize it wan't interchangeable so I got it for half price. $600. The OEM shocks are absolute garbage and they were garbage 30 years ago so a used Fox, WP or new Ohlins is a huge improvement.
 
#5 ·
Understand! Thanks for the info!!!

So... Anyone got an 1000 linkage knuckle to spare??? :D

I'll send the shock to Jamie, and hope for the best.... at least get a little some some more out of it..

What about the adapter-top-mount approach?
Wouldn't that nullify the swingarm issue?
I recall that the Yoshimura race chassis had a screw in/out clevis custom added, as a top shock mount...

Anyway, thanks much again!!
 
#6 ·
awason nailed it. the first gens rear linkage design prevent the installation of longer shocks, because the linkage will physically hit the frame, hence, preventing rear ride increase. weird. its' one of those things that you have to see to fully understand. i can dig up some of my fotos, if you like.

in the past, i installed a first gen 1100 fox shock on a first gen 750, and gained about an inch, with the stock 750 linkage. good results, but the bike got stolen. the 1100 linkage increases by about 30-45mm!

all of my first gens have the 1100 linkage, and the link will require modifications to make them work. ohlins and fox shocks are absolutely required with these first gens. the stock shock is absolute garbage.

daugherty motorsports does good work. totally worth sending your fox shock, and i even had them powder coat the spring.

pay the money. it's a great investments on these first gens.
 
#7 ·
First off... YES the stock 750 shock is complete garbage.... I chucked it a month after buying the bike new, and got the Fox.

For my second bike, I have an 1100 shock I got back in 86/87 from a parted out bike.
Thanks to your description, I'm now beginning to recall why it wouldn't fit.
Figured I could MAKE it fit.... but that didn't seem like the best idea... not without the knowledge others now have accumulated.
I kept the 1100 shock in hopes of using it, but pre-internet, couldn't figure out how to, and whether it'd be a good idea. I'll rebuild and use it in that bike now.
I saved the 750 spring.
I guess the approach is: install it partially compressed
(just a thread or 2 engaged on preload collar) with the 750 spring
(or aftermarket spring intended for a 750)
Then remove material from one of the mounts?
The sides?

The other bike... My LTD.... is what the Fox is for/on/from....
So its decided.... I'll send the Fox to Jamie regardless, but either way
(whether he has the ride height adjuster parts or not) I'll get an 1100 linkage-knuckle and get the mod done.

Ok, so who can do the linkage mod?
These parts are getting rare, and I don't want to risk screwing it up!

Also.... any negative effects from using the 1100 linkage?

86gixxx... pix are ALWAYS good! :D :grin2:

Thanks for all the info!!!
 
#11 ·
I'm going down the 1100 linkage path.

When searching I came across a couple of them here in Australia, if you need a contact who has one then let me know - there was one 20 minutes from me here in WA.

Regarding the ratio change, I got in touch with an engineer at Nitron. The valving between their 750 and 1100 shocks is almost identical, the spring rate for the 1100 was significantly softer.

The nice thing about dealing with Nitron is that they're happy to swap over the spring, should the one I've chosen not be the right one. I'm going to be one spring rate off at most.

I'll tell you how it works out in six months or so.
 
#14 ·
Hmm...
That makes me wonder if it wouldn't be easier to just bore out the 750 knuckle to fit the 1100 eccentric..
One would already have the 750 part, need only the eccentric/guts and bore job..
Seems at least as easy as cutting on the 1100 knuckle.

Its hard to tell from the photo what if any difference there is in the mount points.
Any chance you could somehow put one on top of the other and take another pic to compare?

In any case....
Ironic coincidence.. I've procured an 1100 knuckle, and it arrived JUST TODAY!!!

So now, I can see exactly what's what with it, and am ready to proceed.

Though it doesn't look all that difficult.... I have so many projects going, and time isn't on my side.
Anyone happen to know someone who could/would preform the mod to the 1100 knuckle??

Thanks!
 
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