New XS1100SH Build

[BillyRok]

Or you could start over with a frame that is complete. According to boats.net the '81SH and '81LH used the same frame...here's one if that's an avenue you want to pursue --

http://www.ebay.com/itm/1981-81-Yamaha-XS1100-XS-1100-Midnight-Special-main-Frame-/131290566118?pt=Motorcycles_Parts_Accessories&hash=item1e91870de6&vxp=mtr

[Cobia]

A close look at your pics shows that you have the tail section of the frame that got hacked off. What's keeping you from sleeving it internally and welding it back on? You may even have the section that goes from the tank to the tail section, the same applies to that. If not, I don't think it would be that hard to weld on sections to join the rear section to the front part.
I'm not a frame specialist by any stretch of the imagination so I don't know what is involved in getting the frame straight and true, but since you have all the parts to weld back together I would give that a try first before buying a frame and having mismatch numbers you have to justify.

[Arthur_of_Hex]

The past few months I've spent a fair amount of time researching monoshock builds. One specifically caught my eye on a streetfighter site with an xs11.

http://www.customfighters.com/forums/showthread.php?t=55957

The big question is this. If you are to monoshock, will it be a direct push design or a cantilever design? Direct push is just that, shock directly connects the swingarm to the frame. Cantilever arms use a specifically shaped hinged mount for the shock that moves inderectly with the swingarm in a predetermined ratio. I.E. the swingarm moves 8 inches and the shock compresses 3.5 inches. Manufacturers and engineers design the entire shape, movement and overall geometry of the swingarm to work specifically with the shock/spring preload, spring rates etc. Dirtbikes have the easiest cantilever systems to observe and get ideas from due to their open viewable design. The streetfighter xs was a direct push design, although it appeared that a cantilever coil over was used. In my research I remember specifically that the xvs650 Vstar uses a direct push coil over, partially horizontal fitment, and holds a fair amount of weight, given the geometry of a low heavy cruiser. At first glance, the OEM position of the 650's suspension and mount are in the general ball park of an xs11 monoshock build. If I were to continue my path down monoshock lane, I would start with a well planned strengthening brace on the stock arm, followed by detailed testing of mounting positions using an xvs650 shock. It may very well end up being too small for the 11, but it seemed like a good place to start for me.

[cgross220]

Sorry everyone, I've been pretty busy with midterms and work. I have 12 hours left in a 48 hour shift now and test tomorrow so hopefully you can understand haha. The only work I've been able to get done on the bike so far is cleaning all the corrosion out of the petcocks and putting all new gaskets on, as well as cleaning small things like the kickstand/centerstand.

Or you could start over with a frame that is complete. According to boats.net the '81SH and '81LH used the same frame...here's one if that's an avenue you want to pursue --
http://www.ebay.com/itm/1981-81-Yama...870de6&vxp=mtr

A close look at your pics shows that you have the tail section of the frame that got hacked off. What's keeping you from sleeving it internally and welding it back on? You may even have the section that goes from the tank to the tail section, the same applies to that. If not, I don't think it would be that hard to weld on sections to join the rear section to the front part.
I'm not a frame specialist by any stretch of the imagination so I don't know what is involved in getting the frame straight and true, but since you have all the parts to weld back together I would give that a try first before buying a frame and having mismatch numbers you have to justify.

I do have the rear tail section, and would weld it back on as I'm sure it wouldn't be too complicated, but I've now kinda become set on the monoshock design. I feel like not only could it help performance but it would also give even more of a "custom" look, something I very much want in this build.

The past few months I've spent a fair amount of time researching monoshock builds. One specifically caught my eye on a streetfighter site with an xs11.

http://www.customfighters.com/forums/showthread.php?t=55957

The big question is this. If you are to monoshock, will it be a direct push design or a cantilever design? Direct push is just that, shock directly connects the swingarm to the frame. Cantilever arms use a specifically shaped hinged mount for the shock that moves inderectly with the swingarm in a predetermined ratio. I.E. the swingarm moves 8 inches and the shock compresses 3.5 inches. Manufacturers and engineers design the entire shape, movement and overall geometry of the swingarm to work specifically with the shock/spring preload, spring rates etc. Dirtbikes have the easiest cantilever systems to observe and get ideas from due to their open viewable design. The streetfighter xs was a direct push design, although it appeared that a cantilever coil over was used. In my research I remember specifically that the xvs650 Vstar uses a direct push coil over, partially horizontal fitment, and holds a fair amount of weight, given the geometry of a low heavy cruiser. At first glance, the OEM position of the 650's suspension and mount are in the general ball park of an xs11 monoshock build. If I were to continue my path down monoshock lane, I would start with a well planned strengthening brace on the stock arm, followed by detailed testing of mounting positions using an xvs650 shock. It may very well end up being too small for the 11, but it seemed like a good place to start for me.

Thanks! All that is very helpful...I've been trying to figure out what shock to use and even had begun looking at ATV shocks but this seems like it would be much better.

[cgross220]

So I don't know if anyone's still reading this thread, shoot I hardly still am but I figured I'd post on here before I make a whole new thread.

I was debating between doing a front end swap or keeping my same forks and decided on keeping the same forks to try and prevent bottoming out...however, one of the bolts on my lower tree (part 28 and the matching bolt, #32 on any parts diagram) has broken off inside of the tree. It shouldn't be too crazy tough to get it out but i can't find the part on ANY parts website I've looked at...I was wondering if anyone has the parts lying around, or any alternatives?? Maybe even just the specs on the nut/bolt so I can go find something close enough to work. I guess my last option is to take out the one from the other side and bring it to a machine shop to get another made but if thats even do-able it sounds...expensive.

[jetmechmarty]

The stock forks will never be a match for large diameter modern forks. As you upgrade these components, you just expose the next weakness. After all, this is a +35 year old machine.

The stock forks can be improved. If they're bottoming out, the fluid level is likely too low. Air compresses. Too much air space and the forks bottom. To little air space and you blow out the fork seal. I believe I have 130 mm air space in mine, measured from the top of the fork to the top of the fluid. The springs were too soft when new, now add 33 years. Many like new Progressive springs. I opted for straight rate springs and emulators. It's no longer the same motorcycle.

[TopCatGr58]

I guess my last option is to take out the one from the other side and bring it to a machine shop to get another made but if thats even do-able it sounds...expensive.

Hey Gross,

Take the other bolt to a Fastenal or Hardware store, metric bolts, and match it up that way. I know metric uses a different standard marking than USA Standard...but a grade 5 equivalent should be sufficient vs. a grade 8.

As to getting the other one out....apply generous amounts of PB Blaster, and then some cycles of heat from heat gun. Are just the threads section broken off/stuck, or did the hex head break off and so the unthreaded shaft is also still attached?

IF it's just the threads, then it can screw thru out the other side of the clamp, so a regular right hand drill bit may be enough to grab it while you're drilling thru it to get it to rotate on thru/out?? IF the hex head is broken off, then you will want to see about getting some reverse twist drills to try drilling into the shaft in a CCW direction, and again the action of drilling alone may be enough to grab and twist the bolt out!?

T.C.

[BigOates]

Let me know if you don't have any luck at Fastenal. I've got a parts frame/bike in the back yard and may be able to take a look this weekend and see what the specs are on the bolt for you if needed.