Rear shock extending mount

[91_gsx600F katana]

The 08 R6 shock lowered my rear about 3/4" i beleive and I always wanted the rear to be higher! So I embarked on figuring out how to raise the rear, cut the dog bones, cut the rear subframe, or mess with the mounting point of the shock!

I decided on the latter for safety reasons, and heres just a few pics of what Ive done so far.

The mount entends the overall length of the rear shock 1" which the R6 is 290mm center to center length, stock pre rear shock is 300mm. Given the extra inch I put my total length of the R6 shock at about 320mm roughly. This should give me roughly 1.5" of raise over my R6 shock (remember its been lowered .75" already roughly) so really its only about .75" raising over stock (new and not sagging old lol).

The pics show the bracket which is made out of 3/16" steel plate, it bolts through 2 of the stock holes (rear bolt is 1/2" thick! and the front is stock 10mm). I used another 10mm for both shock mounts and all hardware is grade 8 or 10.9. I made it bolt on so it can be removed. I originally wanted multiple mounting holes so i can change ride height but the design of the shock mounting wont allow it.

My clearance to my swing arm is good (about stock) and you can see the clearance from my dog bones to the shock reservoir is rather close. All pics are showing the bike on jack stands and the rear swingarm is just hanging (no weight on the swing arm). The shock spring just barely touches the pivot at the bottom and I cant seem to compress the spring at all to check for clearances through full range of travel. If my mind is comprehending this correctly the spring should move up and away from the pivot, the dog bone should help this and the reservoir should move farther away from the dog bones correct?

I need to get a tool to remove the spring and to adjust preload but for now I just have to think it out lol.

What do you guys think? Am i correct in my assumptions of how the shock/spring will travel once the spring compresses with the weight of the bike on it?

[Kreylyn]

Yes, the shock will move away from the cushion when the suspension is compressed. You have recreated the issue with the stock 2nd gen B-12 shock. It does the exact same thing.

I'll be interested in hearing how everything fits back together and how it works for ya. It's a new approach I've not seen yet, so... very interesting to me.

Krey

[91_gsx600F katana]

What exactly have I recreated? The spring barely contacting the cushion or how close the reservoir is to the big bones? The B12 shock u can't even mount on the bike bc the spring contacts the pivot cushion too much and u can't get the bolt through?

I really want to drop the bike down and see how it looks! I'm just afraid of things touching or binding and breaking parts.

[Kreylyn]

What exactly have I recreated? The spring barely contacting the cushion or how close the reservoir is to the big bones? The B12 shock u can't even mount on the bike bc the spring contacts the pivot cushion too much and u can't get the bolt through?

I really want to drop the bike down and see how it looks! I'm just afraid of things touching or binding and breaking parts.

The B12 doesnt' have the resevoir.

The comment was specific to the spring touching the cushion... that's what the 2nd Gen B12 shock does and the reason it's recomended to shim the travel length (effectively shortening it's over all length a tad) to prevent that.

It's certainly possible to mount the b12 shock with out modding it... you just have to slightly compress it a touch to get things to line up. It's not that hard to do actually, but... it's much better to modify it and make it right.

My concern for your setup currently is... if the spring is hitting the cushion at this point, then you would now have the concern of the repetative contacts bending/denting something and even damaging things. It's only a mild concern, but... It doesn't take hard hits only to do that. A lot of repetative small contacts will work the metals pretty good too.

Every time the suspension fully extends, that would be an "impact" to be concerned about. If there is something that can be adjusted now to reduce that even if only slightly, then I just thought you should be aware.

Krey

[91_gsx600F katana]

I understand krey. I took another look at it today and the spring doesnt actually touch the pivot, its like 1/32" away but that is with the rear tire in the air and the suspension just hanging (which it should never experience! :P ) I put the bike down on the ground for the first time in about month and man does it look great! Originally My rear light was about 36 3/8" from the top of the rear swing arm. After the R6 raising mod it climbed to 38" which means it went up about 1 5/8" which is pretty darn close to what I calculated at a 1.5% ratio of shock length to rear tail height.

Now comes the fun parts....ugh. I knew the dog bones would get closer to the reservoir as the bike compressed but I wasn't sure how much! Just sitting with no weight on the bike its about 1/2" roughly distance, Then I sit on it (190lbs naked) and it goes down to about 1/4-1/8" (more around 1/8"). In the pic my dad is sitting on the bike but he weighs more than me at about 215lbs so the pic is alittle closer than with me on it.

I needed to make sure it didnt contact during compression so I had him jump down on the bike seat a few times and only once did it barely and I MEAN BARELY touch the dog bone (casting ridge). So Then I decided that I will grind down the casting ridge on the dog bone to give me about 1/16" extra clearance. I think I'm in the clear but to be sure Im going to get the spring adjuster and increase the rear spring preload alittle to help with bottoming it out on very large bumps/holes.

Pics of the finished ride height, shock clearance at rest (no rider) and full compression (rider). This was before I ground down the dog bone alittle.

[Kreylyn]

I understand krey. I took another look at it today and the spring doesnt actually touch the pivot, its like 1/32" away but that is with the rear tire in the air and the suspension just hanging (which it should never experience! :P ) I put the bike down on the ground for the first time in about month and man does it look great! Originally My rear light was about 36 3/8" from the top of the rear swing arm. After the R6 raising mod it climbed to 38" which means it went up about 1 5/8" which is pretty darn close to what I calculated at a 1.5% ratio of shock length to rear tail height.

Now comes the fun parts....ugh. I knew the dog bones would get closer to the reservoir as the bike compressed but I wasn't sure how much! Just sitting with no weight on the bike its about 1/2" roughly distance, Then I sit on it (190lbs naked) and it goes down to about 1/4-1/8" (more around 1/8"). In the pic my dad is sitting on the bike but he weighs more than me at about 215lbs so the pic is alittle closer than with me on it.

I needed to make sure it didnt contact during compression so I had him jump down on the bike seat a few times and only once did it barely and I MEAN BARELY touch the dog bone (casting ridge). So Then I decided that I will grind down the casting ridge on the dog bone to give me about 1/16" extra clearance. I think I'm in the clear but to be sure Im going to get the spring adjuster and increase the rear spring preload alittle to help with bottoming it out on very large bumps/holes.

Pics of the finished ride height, shock clearance at rest (no rider) and full compression (rider). This was before I ground down the dog bone alittle.

This is where removing the spring, and putting the shock in mounted up comes in handy. You can then actuate the shock for the entire pivot arc to check for actual clearances, as it WILL definately compress the shock all the way out on the road in use.

If the shock does not stop the swingarm with the end of it's compressed stroke before the swingarm hits the resevoir, or other hard parts hit something, your going to beat the heck out of both (swingarm and resevoir or what ever is allowed to hit).

Krey

[91_gsx600F katana]

Well you worried me enough to modify the upper shock mount today. This will be the last time I can work on it until at least 2 weeks.

I shortened the upper mount, originally I thought I made the mount 1" lower than the original hole, but apparently it was 1 1/8" on center. I shortened the holes up to 7/8" now. I filled the hole in with weld and re drilled for 7/8" on center distance. This brought up more install issues compared to the old design but i got it back in. THe rear height has dropped about 1/2". I would like to say now I have 5/8" clearance from the reservoir to the dog bone but dont have any measurements of the compressed distance, me jumping on the bike did nothing and I didnt hear/feel any contact.

I think my only other option if I dont like this or still dont have enough clearance is to modify the dog bones. I mean does the rear shock actually go through the full length of travel and hit the bump stop on the bottom? seems like alot of weight would be needed for that to happen.

Im looking at getting the spring adjuster to increase preload. Im not sure if the same tool unscrews the spring or tension enough on the R6 shock to take it apart? I have no idea and didnt really look at how to dissasemble it when it was out i guess.

[Jimmie]

I've been toying with the idea of changing the upper mount, for the purpose I bought a R6 top mount. My idea was to box the frame tube where the OE mount is situated and thus be able to change both ride height and angle of the shock. With my current setup the clearance with the lower shock mount is a little less than I desire but so far no evidence of impact.
Though I must admit that I haven't got very far in the process so this is very interesting to follow.

[Kreylyn]

Well you worried me enough to modify the upper shock mount today. This will be the last time I can work on it until at least 2 weeks.

I shortened the upper mount, originally I thought I made the mount 1" lower than the original hole, but apparently it was 1 1/8" on center. I shortened the holes up to 7/8" now. I filled the hole in with weld and re drilled for 7/8" on center distance. This brought up more install issues compared to the old design but i got it back in. THe rear height has dropped about 1/2". I would like to say now I have 5/8" clearance from the reservoir to the dog bone but dont have any measurements of the compressed distance, me jumping on the bike did nothing and I didnt hear/feel any contact.

I think my only other option if I dont like this or still dont have enough clearance is to modify the dog bones. I mean does the rear shock actually go through the full length of travel and hit the bump stop on the bottom? seems like alot of weight would be needed for that to happen.

Im looking at getting the spring adjuster to increase preload. Im not sure if the same tool unscrews the spring or tension enough on the R6 shock to take it apart? I have no idea and didnt really look at how to dissasemble it when it was out i guess.

Actually, to take the spring out you compress the spring alone with a compression tool, and then the plate it seats on just slides right out. If you have the right tool, it's really easy to do. If you don't, it's really hard and very dangerous to try and "fudge" a way to get it off. Jus sayn.

Tool like this for example...

http://www.sears.com/shc/s/p_10153_12605_00929898000P?vName=Tools&cName=Mechanics&AutoTools&sName=Automotive%20Specialty%20Toolsmv=rr

There are lots of brands and such. I'm sure with a bit more time spent searching you could probably find a less expensive option even. I have a set I'm thinking was less than $20 shipped, but I didn't buy them so don't remember the source off hand.

Krey

[91_gsx600F katana]

I've been toying with the idea of changing the upper mount, for the purpose I bought a R6 top mount. My idea was to box the frame tube where the OE mount is situated and thus be able to change both ride height and angle of the shock. With my current setup the clearance with the lower shock mount is a little less than I desire but so far no evidence of impact.
Though I must admit that I haven't got very far in the process so this is very interesting to follow.

Do you have any pics? How far have you lowered the shock to raise the rear or to lower the rear?

Actually, to take the spring out you compress the spring alone with a compression tool, and then the plate it seats on just slides right out. If you have the right tool, it's really easy to do. If you don't, it's really hard and very dangerous to try and "fudge" a way to get it off. Jus sayn.

Tool like this for example...

http://www.sears.com/shc/s/p_10153_12605_00929898000P?vName=Tools&cName=Mechanics&AutoTools&sName=Automotive%20Specialty%20Toolsmv=rr

There are lots of brands and such. I'm sure with a bit more time spent searching you could probably find a less expensive option even. I have a set I'm thinking was less than $20 shipped, but I didn't buy them so don't remember the source off hand.

Krey

Ahh. Gotcha! I have large ones for car springs I believe. I'm alittle worried about clearance during the compression and how much the spring actually compresses. I guess only way is to see how it performs and to check with the spring removed.

[Badfaerie]

This is the spring compressor that Kreylyn has

http://pitposse.com/pospcoset.html