R1 Single Shock Mod

[Texas Rookie]

Loved the idea of the R1 shock mod but wanted to make sure there were no wiggles in the chassis when I was done so a friend and I fabbed up some reinforcement for the SA out of 1/8 carbon steel. First made an A-Frame attached to the pivot tube as a base then boxed the a-frame and the SA for rigidity. My buddy did a great job on the metal work then I powdercoated it charcol for longevity.

Making a bracket to hold the top of the shock that adds approx an inch (so the shock length is stock) and allows me to use the existing frame shock mount (with the old XS bushing pressed into the bracket (additional pics of the bracket to follow)). Pressed one of the bushings out of the old XS shock and they fit into the lower shock mount of the R1 shock with a little persuasion. Will mount this to the 750 final drive housing using the stock mounting pin.




















Let me know what you think. Texas Rookie

[81xsproject]

Looks good! Keep the pics coming w/ the rest of the install.

[DiverRay]

It looks nice, but what does it weigh now? The swingarm is "unsprung" weight, and adding too much steel may cause problems on bumpy roads. I KNOW the rear wheel assembly weighs about 45 pounds, so just one or two extra is nothing. If you added five pounds, that is ten percent, and may be noticed if riding "quickly" on bumpy, windy roads.

[Texas Rookie]

Good point Ray, checked it and the gussets and powder added 4 pounds to the assembly. Hopefully, since most of the added weight is near the pivot point, it won't affect handling too much. I was more concerned with the twisting moment than weight (didn't think about it at all to be honest) and didn't think I could go much lighter than 1/8 plate and make a difference in the torsional rigidity. Next time, I might be able to shorten and a-frame a bit, taper the side plates a little more and was thinking about putting big staggered holes in the side gussets (but didn't have the appropriate drill bits).

Hopefully the advances in the shock technology will help compensate for the added weight.

All suggestions appreciated. TR

[DGXSER]

Ground Clearance?? Does this effect it any??

As far as lightening, Look at the points of attachment. Draw Diagonal lines between the corners/attachment points and then I would probably use a minimum of say 1/2" or so to each side of the lines. The area in between could be cut out to lighten the weight. This is how brackets are designed to hold up aircraft engine hardware and components.

[xschop]

Thumbs up

Good job. The R1 monoshock is 3 way adjustable even for rebound damping, just click it a few notches up and you won't notice a thing....chop

[50gary]

I love the fact that you're innovating, keeps it fun and the brain in gear. As far as the weight you've added it's 4# of "productive " weight because it has a purpose of making the S/A stiffer. But you've subtracted the weight of one of the standard shocks, about 4 to 5# so that's a fair trade. The R1 shock weighs 5# 3oz (just weighed mine). Linkage type shocks usually have about a two to one ratio that is for every inch the rear wheel moves the shock moves one half inch. The linkage multiplies the movement. My thought is will a linkage shock (R1) have enough travel when mounted in a conventional position? the other item working in your favor is the twin shocks are mounted out towards the end of the S/A over the axle for more unsprung weight disadvantage.
To improve braking, lower the center of gravity and lower the unsprung weight you may consider this mod as well. opps,Sorry I don't know how to insert an image. Regardless, I removed my OEM rear brake and made a bracket and brake anchor rod. Then used low mounted sportbike dual piston caliper, more power and less weight by two pounds it's win/win. Texas Rookie keep up the good (and interesting) work.
Cheers, 50gary

[xschop]

double up

I see a simple way to increase the strength of the bracing method you used. Since you installed the R1 shock on the FD side. You can ad a rib brace that runs from the front lower area to the Swingarm/FD mating area. This is a critical spot because this area will want to rotate counterclockwise (looking from back of bike) as the suspension dampens/compresses......If you did the rib to both sides, you would be Nuke-Proof.....

[T99Ford]

Hey chop:
When you did the R1 shock on yours, back in the day, did you even notice much swing arm flex? Yours was on the RH side, as mine is. I have ridden mine pretty hard since I installed it, and I have not noticed any flex or "hinge" problems at all. I have noticed that the R1 shock is much stiffer, especially that far out on the swing arm. I re-bushed the R1 schock and installed it in the "lazy" way, though I turned the reservoir on the shock inward so the clickers were easier to get to. It looked like the tire could potentially rub if the shock ever bottomed out, so I modified the reservoir housing and shimmed the shock out a little to prevent that. I had to back the spring off to the lightest setting also. But I have not noticed the need to re-inforce any portion of the swingarm. I have been running the corners at 90+, and haven't seen any rear problems, just front problems. I seem to remember that was your exp. too.

[xschop]

When I built the top bracket, It put the shock lower and gave it more travel. It is a nice shock and putting it on the FD side or the FD side doesnt matter, I wouldn't think. I liked the look of it on the right side. It made it look like a single sided swingarm on the FD side. It was hard to tell if there was any flex in the corners because my bike at the time was about 60-70lbs lighter from all the mods. I literaaly jumped the tracks by my house and the shock is super smooth. I had the Daytona front brace on with all new springs and oil at the time. Get some USD forks and your in Busines....