Forked Up. New to the XS1100 and the Forum

[johnnyboy]

Hey All,

A friend of mine and I dug an XS1100 out of a barn in our preferred state: not running and covered in an inch of dust and bird poo. It was listed as a parts bike and...well, has a few missing pieces. It's okay. Don't worry. It has even less pieces at the moment sitting there with a nearly naked frame. The idea is to turn it into a tasteful custom that retains its chunky muscle bike vibes and ability to eat miles. I'm still learning about this bike and it peculiarities but one thing rose to the top I could use some help with that may alter the course of this build.

From what I gather my bike looks like a fun hybrid between the Standard and the Special. Here are the components.

Special

• Frame, per the ID number starting with 3H3. Putting it as a 79' SF
• Top triple tree (from my looking on Ebay)
• Possibly lower triple.

Standard:

• Forks
• Tank
• Gauge Cluster

Can anyone confirm these components from the photos?

From what I've read, this situation doesn't sound uncommon. However, if the triples are from a Special and the forks from a Standard, this changes my suspension geometry. What am I looking at here? An offset that's made for longer forks, meaning I've shorted the forks and decreased the rake and trail. Does this sound right? Has anyone experienced the change in handling? I'm not opposed to altering dimensions slightly if it means having it be a touch more responsive, so long as it doesn't get too squirrely. I'm also not opposed to finding Standard triples if that's going to be safer in the long run. I just want to understand what I have right now and what I could have with the Standard triple.

Thanks for the help, guys. I'm looking forward to building this beast.

[Radioguylogs]

The forks and the tank are definitely from a standard.

I don't know about the triple tree, but I thought the diamater of the standard fork pipes was different than the special, such that you would need a standard triple tree with standard forks. Maybe I'm mistaken.

[DEEBS11]

And it's the air fork from a 1980. Standard is 37mm diameter. I think the Special is also but the fork seal outer dimensions are different than a Standard. The top clamp could be Standard but what throws you is the 2 XS11 Special handlebar clamps but I run that set-up on my Standard. It's a 78 frame but I will bet it was in a front end accident and they bolted 1980 forks to it. Nice fork brace.

[bikerphil]

The forks and triple trees are from a Standard. Your steering geometry is correct because the PO switched both. The Special forks have a leading axle so the triple trees are different to adjust for that. Both type forks have 37MM stanchions.

The way to identify the TT is the Standard lower has the 2 pinch bolts on the front and the Special has them on the side.

[johnnyboy]

Thanks everyone. That's very helpful and optimal for the build. The guy we bought the bike from mentioned that before he bought it, the bike was involved in a crash. We were wondering where the damage was. This makes a lot more sense. The number on the motor doesn't match the frame either but I don't have the specific numbers in front of me. We'll be on the lookout for any frame damage.

Was that fork brace standard on the 80 model standards? I've read a lot of folks suggesting them on the forum and saw there are a couple aftermarket options but I wasn't sure if it was standard equipment on any models.

Anything I need to know about the air forks?

Also, should I start a new thread for a build thread or just treat this as the build thread?

[Radioguylogs]

Fork brace was not original equipment.

I don't have any comment about the air forks. I just add the recommended air pressure and they are good for me.

It's fine to continue this thread for your build, but the choice is yours.

[JeffH]

Thanks everyone. That's very helpful and optimal for the build. The guy we bought the bike from mentioned that before he bought it, the bike was involved in a crash. We were wondering where the damage was. This makes a lot more sense. The number on the motor doesn't match the frame either but I don't have the specific numbers in front of me.

We'll be on the lookout for any frame damage.

Might be an optical illusion, but from your photo it appears that frame is really bent.
If it is as bent as it appears, that frame would have taken a hard hit.




Hope the frame checks out ok for you so you can plan your build.

Jeff

[johnnyboy]

JeffH Thanks for the spot. If it is...my title for this thread is pretty spot on.

I take it that section of the frame is not supposed to curve like and follow this line? I haven't noticed any crinkles or cracked welds or anything but I don't have a reference to compare this to. Any other tell tale signs I should be on the lookout for when I get into the shop next? I can also measure the wheelbase to see if the forks are pushed in.

Edit: Added second photo of a 79' frame I found. It appears to also have a bit of a curve?

[DiverRay]

There is a little bit of curve in that part of the frame. If you don't see any sign of something pushed, the forks probably took the major portion of the impact. I remember reading the measurements of the "new" frames someplace, but CRS has set in and I'm not sure if they are in the manual. Do look at the front lower tubes, and maybe measure distance from headstock to rear motor mounts on both sides to verify they are the same.

[DEEBS11]

Guys, I made up this contraption after a trip to the hardware store and it worked great on mine. I gave it to the guy when I sold the bike.