CB360 - Monoshock Brat

[neevo]

Ah yeah that's much tighter than the 400F

Maybe need to look at a few options to make it work. Careful putting the lower shock mount closer to the swingarm. The closer it is to the swingarm pivot point the more the swingarm will travel before the shock travel is used up. Also it would completely bugger up the spring rate.

Is there an even shorter non linkage shock you can use?

 

[crazypj]

I would weld plate in from underneath and have bolt siting a little lower, just above frame tube

 

[neevo]

I would weld plate in from underneath and have bolt siting a little lower, just above frame tube

PJ how about notching the plate out where the shock mounts to get a little clearance and weld from underneath as you suggested?

 

[compoundcycles]

cool, yeah that was sort of my plan. To mount the plate on the middle or bottom side of the tubes in the picture and only have the mount above the frame just enough to pull to bolt out.

I'll mind the lower shock position in relation to the swingarm. I need to cut the swing arm brace down to size to fit still so I should still have a little room to tweak the shock angle vs the swingarm.

Neevo how did you determine your angle?

 

[compoundcycles]

Thanks for the suggestions.

 

[crazypj]

Yep, I would clearance the plate and also add 'extensions' to brace in against semi-circular seat/top 'tube;

 

[neevo]

I tried to copy the RD frame and angles as much as possible from pics off the intermet:

 

[compoundcycles]

So I settled on a new position for the top shock mount, but I forgot to take a photo with the shock in there. I'll do some more work tonight. I should only have to notch out a bit from the gas tank tab that is supposed to sit on the rubber pad for it to sit on top of the mount. The last photo is the bottom side.

It does get surprisingly close to the photo of the RD frame Neevo posted.

 

[trek97]

Pull that engine out. By now you have some serious crap down in the crankshaft bearings to clean out. Not to mention the valves, cylinders and rings.

 

[compoundcycles]

The motor was covered with a demin jacket before tack welding and fully removed from the frame before laying a bead. It was only exposed for the photos.

 

[MJPriceisright]

Lol love the denim jacket cover up! Why would you remove the engine while determining where your upper shock mount is going to be? Wouldn't that affect the ride height with the decrease in weight without it in?

 

[trek97]

It just seems w the engine opened up like it is in the pics. Welding BBs and such could get down in there.
But since you did have it covered, its all good. thanks...just a being concerned citizen, that all.
BTW, I dont know a damn thing about Monos...But, it really looks great.
You are free to continue...

 

[crazypj]

Have you checked the brace doesn't interfere with chain line?
Rocan had to cut a section out of his swing arm brace, it probably needs to be asymetric?

 

[compoundcycles]

MJPriceisright - you're right, I do need that weight in there. I had the engine in when fitting the upper shock mount, then pulled it out to flip the frame over so I could weld the bottom side.

trek97 - Good looking out man! Thanks, I'm probably always doing something I shouldn't be therefor I appreciate the concerned citizenship.

crazypj - I actually haven't checked if the chain clears the swingarm brace. Offhand I'm fairly sure it does...I really really hope it does. I'll be thinking about that one all day now

 

[compoundcycles]

Made some good progress last night. I'm still missing supports for the swingarm brace so I can't sit on it yet...but soon.

The shock angle may be a bit too steep but I'm gonna roll with it. I'm super stoked about the shock being visible from the top of the bike. If the seat starts just behind where the shock comes up through the frame I think it'll be a unique feature. Although there is a part of me that can't help but be nervous about that spring sitting so close to my crotch.

 

[neevo]

I'm really interested to see how far it compresses when it sits under its own weight (including the engine), and then with a person on there too.

Quite a steep angle on the swingarm but means nothing until someone's on the bike.

 

[compoundcycles]

Are you thinking it might compress too much? That the angle of the swingarm brace to shock should be more acute?

I was thinking worst case I lower (flatten out) the swingarm a bit which would also put the shock at a little less vertical angle.

 

[compoundcycles]

Here's another photo sans tank that is a little bit more level. Makes the shock look slightly less vertical.

 

[Finnigan]

Is there going to be a bar or connection between the shock mount arm and swingarm?

 

[crazypj]

I'm pretty sure you'll find you have too much angle on swing arm and shock will be way too stiff.
I would weld new plates on top of the lower mount, moving shock higher and further back (and reducing angle of swing arm)
In fact, I had to on the 400f I did ;D