Honda Twins banner

Mini-Cafe XL100/SL125-based

16959 Views 27 Replies 7 Participants Last post by  kirkn
Here's the inspiration:

My build bike is based on a hybrid bastard I built 17 years ago - an early Honda 125 motor installed in a mid-80s Honda XL100 chassis. I was 25 when I built it. It traded hands a number of times, including friends and relatives and wound up back in my hands, much worse for wear, a few years ago.

I decided to build a mini-cafe out of this bike. I probably could've / should've started with a better foundation, but, it was what I had on-hand. Plus, that history... :)

So far, I've gathered most of the parts I'll use. I got a NOS 150cc big-bore kit from ebay to install:

I also decided to use a later model 2-piece head, because they have larger ports & valves, and a better cam and valve spring selection:

I need to finish the port cleanup on the newer head and do some clearance checks between the new piston and the larger valves, then reassemble the motor. Motor cosmetics are in hand, too:

Got a larger 26mm carb from an XL175 and it's good to go.

Also working on a side-project to rewind the 6-volt stator to a 12-volt system to allow a better selection of lighting. That may come later on, though.

Got a nice 19" twin-leading shoe front wheel to go on the project. Naturally, it needs refurbishing, too.

Got a nice speedo/tach set, too.

Got a super-nice CB200 tank for the project. It's got a long-ish cafe look for this chassis and I like the rubber mohawk on those tanks.

Now, I need to source a cafe seat (or build my own) and fit it to the bike, then get going on the actual build.

So, the bike still has a long way to go, and it shares places on the 'project' list with lots of other things - life, etc. :)

But, at least the project isn't yet going BACKWARDS! :D
See less See more
1 - 20 of 28 Posts
But, I could use some advise / opinions:

Here's the chassis as it stands now:

The way it is, the rider is positioned just above the upper shock mounts - either slightly ahead of , or slightly behind them, depending on how he slid fore or aft.

My plans, though, will require cutting off and repositioning that rear frame loop 'kick-up'. Moving it reaward and laying it flat. My concern is that this will position the rider too far aft of the rear shock mounts. I'm mainly concerned with frame strength. Do you think positioning the rider at or behind the shock mounts will cause a cantilever effect that will be a problem? How would I go about gusseting it, if I wanted to? About all I could think of was to weld a 3/16" thick x 1" tall or so vertical stiffening rib along the frame rails, either above them or below.

In mock-up testing, the 'natural' seating position will be right about where the frame loop angles upward right now.


Any thoughts?

See less See more
Ideally, you want to be "on" and forward of the shocks for turning ease and stability......Plus, those shocks have too much travel and "softness" for a cafe' or RR type seating..... I'd reweld and re-gusset the top shock mounts back to the "corner" (right where the loop bends up) and use slightly shorter, stiffer shocks in that more vertical positioning (Right at the rear-most hole on the horizontal part of the frame top rails ....a bit rusty looking in your pic) leave the existing loop (tabs removed), and add another level one to complete the "tail"........ Could you post a pic of the frame with the 200 tank on it?....Trying to visualize the "front" end of your seating area.... Steve

Yep, that's the ticket. Those lay-down shocks were always a weak point in the look of this chassis, but as mentioned, it's what I had...

The tank will sit about 1/2" further forward than this picture and the rear end of the tank will be a bit lower - it's just sitting on a piece of wood for this picture.

I've marked up the picture with the rearward mounted shocks. Some new gussets and it'll work like a champ.

What's there now is flimsy and only on one side of the bike - that existing hole is where the original muffler attached. The more forward hole is where the original seat attached.

This should put me right above the shock mounts, which will do fine.

Thanks for the input!

BTW, the ignition coil will go up under the rear of the tank instead of hanging out in the breeze - there's lots of room under there, and the battery will go under whatever hump in the tail section I come up with.

See less See more
Whoa! Lots of thought and some sound advice going in on that build.
Kinda interested to see AND hear more! Lead on. :cool: ;)
And, at my usual snail's pace, I've managed some more disassembly and to get the frame rails cut. Also, marked up a bunch of tabs, brackets etc. for removal. $15 worth of 3/4" tubing and 1/8" plate from the local Ace Hardware store laying on the floor too.

The upper shock mounts will get relocated to just behind where the tubes are cut now. That should put 'em just about perfect.

And, as a possible lucky break, this shock repositioning MAY allow use of a CL100 exhaust. I kinda like the CL's upswept system and the early 'tucked in' heat shield they have and I still need an idea for an exhaust system anyway. The original shock location interfered with the CL pipe I have. Hmm.... maybe some mockup fitting may be in order.

Not sure which would look best on the project - a traditional street type megaphone exhaust or the CL system. I'm sure the stock CL system would be more restrictive. Hmm.... need to give it a bit of thought.

See less See more
Kirk, If you "gut" just the "stinger" portion of the CL pipe, it will perform admirably.....Sound wonderful,..... and be just barely quiet enough not to adversely arouse the local constabulary....... I suggest you MOUNT the pipe, and use IT as a guide for positioning the shocks...... You can always saw off the muffler and change to a short reverse-cone meg later....LOL.... Steve
Woo Hoo! The shock repositioning is going to work for allowing the use of a CL exhaust. I'll build 'er this way and decide later if I want to change to a traditional 'down' pipe.

See less See more
Gorgeous little engine - fine work, Kirk !!
Lots of decent details going into this one alright! :cool: ;) I'm looking
forward to more. ;)
Kirk... My first rule is use what you have/ modify it to work/ or trade it for something that will...LOL

Seriously, I thought that might be the case when I suggested mounting the pipe up before fabbing the mounts.... Too Cool!.... Your project is showing great promise...

On a similar project, I "narrowed" some clubman bars (took 2&1/2" out in-between the riser clamps) and I now find that I probably won't be using them... (they somehow "look" wrong on the '63 Honda 90 lower-link/pressed metal forks)...If you'd like to use them on your project, (they look better/fine mounted on tubular forks), drop me a PM..... I guess I'll run "low-rise ,Euro" style bars..... What do you think?...(I can edit in a front view Pic as well if you'd like.....)

Keep on buildin'... Steve
See less See more
Kirk.... Any further progress?.....Steve
This is going to be a hot build. Keep up the good work.
Yeah, rippin' right along...

I took the chain off.

I sat on a stool and looked at it.

I figured out a rough mental plan of how I'm going to fab up new footpeg mounts. The existing mounts bolt to the underside of the engine itself.

That's about all, so far.

:D :D

Speaking of handlebars, mine are just a pair of low-rise bars flipped upside down. I'm not crazy about the clubman bars, generally. Gotta do something with the cobbled-together bar mount, too. One of the previous owners snapped off a bar clamp bolt, then snapped off an easy-out in the bolt. Sigh. Got a bid in on ebay for a complete upper triple clamp, so we'll see.

Next will be unbolting the old engine, wheels and fork, then grind/burn off excess tabs & brackets, then weld up the new shock mounts, then, then, then....... :D

Plus, we're going camping this weekend, so my time has been spent prepping everything for that. Be back Monday evening.

But, as long as the project doesn't actually move BACKWARDS...
See less See more
LMAO!...I know THAT feeling!.....Steve
Kirk, I would be real surprised if your project ended up going backwards, you've got some real progress in that bike and sure is looking good too, I might add. :cool: ;) But, like Steve, I too know the feeling! :D

Later on, Bill ;)
Baby steps today, baby steps!

Got the chassis fully stripped (except for the steering stem). Frame (what's left of it) weighs about 3 lbs, or so it seems... :) Sure is a tiny little thing.

Also, got out the torch and burned off all the little excess tabs, brackets, etc. Not much left there. I'll grind off all the rest of the warts and it'll be ready to weld on the 'stand-up' shock mounts and rear frame extensions & loop. Not much more and it'll be all "reassemble" from there.

And, for the light-hearted, here's all the bits torched off... :)

And, in case you were wondering why I go so slow, in the background of the first photo, you can see the frame of my resurrection / restoration of a 1977 Hodaka 250SL I'm working on in parallel with this little project. It's already 'over the hump' and in the go-back-together stage, but everything about THAT project needs / needed refurbishing.

Anyway, there you have the latest.

See less See more
Kirk, I trust that you will use some sort of internal "pins" or "sleeves" to reinforce the tubing joints during the re-weld......... Other than that, I, like everyone else, just can't wait to see the results.... :D Steve
I saw somewhere the amount spring rate decreases with inclined shocks so if you mount them upright you automatically get a spring rate increase (did Bill post it?)
Cool little bike , should be good for 90+ (with a downhill or long straight)
First-class, high-dollar all the way, baby... Here's how they do sand-blasting in the big leagues! :lol:

See less See more
1 - 20 of 28 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.