The Xt400 side car (winter project)

Thanks for the info Erskine. I think the subframe will be strong and keep things simple. I am going to pull of the tank and see I can ad some plates with a mount that extends out to where I can attach to it. Everything on this bike is tight and hidden. I had no inkling of putting a hack on this bike when I built it. That is making things very difficult. I wish I had made a few small changes before I painted it. That would have made my life soooo much easier. Oh well, it will work out I just need to get creative. Thanks again for the pictures as well!


Erskine said:
Hey, I've emailed you more stuff, I think your subframe solution is the top banana. This is what both Beachcomber and myself are having to address on our respective K100 projects. Getting good and solid up by the steering head is the next priority............. is there the opportunity to hide some additional bracing under the tank from the steering head to the main tube?
 
MILLENNIUM FALCON said:
I wish I was that smart! :D The holes we already on the piece of steel. I like your ides for the rear mount the only thing is I am trying to do everything without welding to the frame.

Yep, that'd be me too ....what's lying around, and then the lightbulb moment. Guess it comes from 50 + years of designing odball cars / bikes.

Here's an idea if you don't want to weld to your frame.

On the long rear triangle [ with alloy plate ] - make up TWO 1/8" / 3/16" steel plates that line up with the centre lines of the frame tubes to create a sandwich which you can bolt through. You'll need spacers inside, AND some sort of locater peg / bracket to stop them "wandering". The top chair diagonal mount can then be attached / welded to the outer plate. Add some judicious ligntening holes and then replace the alloy plate. Won't be ultimately as strong as the welded piece, but not far short. You can then attach a forward bracing tube from the same plate forward and to the left [ of the shocker ? ] down to the lower rear frame loop. That's spreading the load back to the strongest point of the frame. Again - the lower connection can be some sort of removeable clamp that goes around the frame tube so you don't have to weld.

At the front, the lower headstock area is the strongest. You could place a horizontal tube across the downtubes [ again clamping on ] and take the top front diagonal from that. This type of clamp on fitting was quite normal in the 50's and 60's for bikes that didn't already have a cast sidecar lug built in to that location. Not as strong as a welded fitting, but allows you to return the bike to solo without having all sorts of extraneous bracketery !
 
I went back and looked at your build thread pictures when you were doing the frame .....
Independantly I kinda came to a similar solution for the head as Beachcomber.

If you were to remake the cylinder head plates, but larger and sturdier, and pick up on one or two of the holes in the steering head gusseting, packing out and sleeving where necessary, I think you could project forward a substantial mount just in front of the down tube.
 
My thoughts exactly. I did some looking at my options and I think the front mount wont be too bad. I (like you guys suggested) can use the top motor mount and the hole in the neck brace to bolt up a thick plate that will protrude enough to get a mount on it. I like the idea about sandwiching the plates for the rear mount. That would work. I'm still brainstorming . Thanks again for all the helpful tips. Here are some pictures of what i am dealing with.
DSC_0275-1.jpg

DSC_0276-1.jpg

DSC_0277.jpg

DSC_0278-1.jpg
 
If I remember right, the rear sub-frame is pretty flimsy, pretty sure I straightened one out with 6ft long 4x4.
Even bracing one side to the other you may want to move the rear mounting as far forward as practical?
 
You will have to drop the front mudguard obvs to a trials style but that will be ok as you'll need a muther of a fork brace down there any way.
 
My bike doesn't have the stock sub frame. I made this one out of some really heavy wall stuff. I think it is a lot stronger than the flimsy stock sub frame. But keeping it as far forward as possible would definitely be a good idea.

crazypj said:
If I remember right, the rear sub-frame is pretty flimsy, pretty sure I straightened one out with 6ft long 4x4.
Even bracing one side to the other you may want to move the rear mounting as far forward as practical?
 
Dropping the fender and adding a brace may be difficult since these fork weren't designed to have anything bolted to the lowers. Unlike the forks on your Honda and many other bikes there are no threaded holes on the lowers. Maybe I could make some sort of clamp on setup.

Erskine said:
You will have to drop the front mudguard obvs to a trials style but that will be ok as you'll need a muther of a fork brace down there any way.
 
MILLENNIUM FALCON said:
Dropping the fender and adding a brace may be difficult since these fork weren't designed to have anything bolted to the lowers. Unlike the forks on your Honda and many other bikes there are no threaded holes on the lowers. Maybe I could make some sort of clamp on setup.

Yup I think a clamp will be the way forward. I promise you it will make a positive difference and avoid a lot of probs that are caused by the unequal load on each leg.
 
MILLENNIUM FALCON said:
My bike doesn't have the stock sub frame. I made this one out of some really heavy wall stuff. I think it is a lot stronger than the flimsy stock sub frame. But keeping it as far forward as possible would definitely be a good idea.

Try to keep it back enough though, so you can still stand on the pegs will the balls of your feet and move your body around the place ;)
 
MILLENNIUM FALCON said:
Dropping the fender and adding a brace may be difficult since these fork weren't designed to have anything bolted to the lowers. Unlike the forks on your Honda and many other bikes there are no threaded holes on the lowers. Maybe I could make some sort of clamp on setup.

You can probably find a Tarrozzi fork brace to fit.
Clamps to the area of seal housing
I've made fork braces but can't do them as cheap as ready made ones
This is part machined one I made
ForkbraceMkII1.jpg

and a different style that should be more rigid ?
CB360MkIbrace.jpg
 
crazypj said:
You can probably find a Tarrozzi fork brace to fit.
Clamps to the area of seal housing
I've made fork braces but can't do them as cheap as ready made ones
This is part machined one I made

The difference is that yours are freakin works of art!
 
Those look awesome! How do they work when your tire comes up above the top of the fork lowers about 2". My 21" front does just that. Thanks


crazypj said:
You can probably find a Tarrozzi fork brace to fit.
Clamps to the area of seal housing
I've made fork braces but can't do them as cheap as ready made ones
This is part machined one I made
ForkbraceMkII1.jpg

and a different style that should be more rigid ?
CB360MkIbrace.jpg
 
The top one was made from thicker material for tyre clearance, I have pics of it fitted somewhere but couldn't find them earlier.
The lower one is going to have spacers made to raise the cross piece (which STILL isn't finished as I'm now swapping to USD forks ala' Neevo's ::) )
 
Cool thanks for the info! What do you guys think about something like this with a strut mount welded to it for my rear mount (triangle)?
tube-clamp.jpg
 
Yes. will spread the load nicely, and if it is possible ( clearance etc) you could put one on the other side of the triangle with a bar/tube welded between them to transfer the load to both sides. Does that make sense?
 
MILLENNIUM FALCON said:
Cool thanks for the info! What do you guys think about something like this with a strut mount welded to it for my rear mount (triangle)?
tube-clamp.jpg

Depending on where it's situated maybe too much load on a concentrated area - those kind of diagonal loads need to be spread as much as possible - same deal but pretty much the length of the subframe tube and as close to a "triangular" connection ? Just my thoughts.

I've seen badly designed / made diagonal connectors shere and bend on roadgoing outfits. I know yours will be a lot lighter, but I guess you still intend to give it beans on the bends and sweeps ?
 
To add to both Erskine and Beachcomber, what about cutting some tube the same Diam as the clamp down its length and welding a clamp top and bottom to the tube both sides and clamping the whole piece down the length of the frame to spread the load but keep it easy to remove?
Kind of making a long clamp?

Love this project BTW, went from awsome to Awsome x100 with the hack idea.
 
I would never do such a thing.. haha. The only thing holding me up right now is material. There is no place around here to get metal. It is very frustrating. I'm looking everywhere. uggh :mad:
 
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