Well the latheman did a fantastic job on the swing arm pivot set up.Not sure exactly what he did but it works great.
I fitted it as soon as I got home and forgot to take pictures.Ill pull it out next weekend and post some pictures.
Anyway,it allowed me to get the back wheel in and line everything up to see how things stand.Lots of measuements,lots of string and lots of head scratching
and I got the back wheel centered nicely
Now I get a better idea of how the chain will run.
The dotted line is the center of the original front sproket,the yellow area the width of the chain.
The string is the line from the edge of the back tyre,
If I want to keep the 180 wheel Im going to have to scallop the frame. Or I go with a 160 wheel which ,fingers crossed, will fit without messing with the frame.
I found a zxr400 wheel (with sproket,disc and axle) for a good price,so ive ordered that and should get it in a few days.
Well see what happens with that.
No the chain line isnt good.Its going to hit the frame downtubes.
This is the best way I can describe it.
If I fit an offset front sprocket to get the chain running true,as it should,then I will need to get the frame scalloped.
(A part cut out of the tubes and rewelded so the frame dosnt lose any structural integrity.)
I talked to latheman A.K.A.weldman, today and he reckons he can do it.Its going to be a bit of a job though,so,Im going to try a 160 wheel first and see how that looks.
In theory,it,ll move the whole chain line in by 10mm, which should be just enough to clear the frame.I,ll still need an offset front sprocket of course but one with a smaller offset (which should also be betterfor the gearbox).
I was looking at how much I could take off the sprocket carrier and there is 15mm twixt the inside of the sprocket to the plane of the tyre.The sprocket is 10mm wide and the chain itself is 26mm wide which means from the inside of the chain to the plane of the tyre would be 7mm. Not much to play with really. Ill think on it though. Lots of thinking before I start hacking bits off.
I got the ZXR400 wheel today and ran straight over to my very helpful local bike shop for an old 160 tyre.
got it home and fitted it.
Nice and centered
and the chainline is looking good
The sprocket carrier on this has a lot of space to work with,I measured around 30mm twixt the inside of the sprocket and the plane of the tyre.Though the ZXR sprocket looks like it came off a bicycle.Here you see it beside the original CSR front sprocket
So,I reckon this wheel would work without too much farting around.
The problem is that I really like the 180!!!!
They dont look much different. Im going with the 160 ! I cant be arsed with the extra messing around and the extra costs to get the frame scalloped for the 180 wheel.
160 it is then.
So, back to the chainline. I measure anout 34mm (1.338inch) space between the tyre and the frame.Thats it,thats what Ive got to work with. (keeping the wheel on the centerline)
The original chain is 26mm thick (1.02inch). That leaves 4mm either side of the chain,to clear the frame and the tyre. Not very much and I have no idea if a motorcycle chain has any side to side movement to account for.
I did talk with my local bike shop and he reckons that I could put a lighter chain/sproket set on it with no problems.
Bikes these days wear thinner chain/sprokets than those in the 80,s. So,that should give me a couple more mms.
The other thing is the sproket carrier. Its a lot smaller diameter than the original or that on the gixer, again though,as he pointed out,modern bikes tend to have smaller hubs/sproket carriers ,so that should be ok.
The thing that is unsure is how much I can safely take off the sproket carrier.From the measurements Ive taken so far,it looks like about 10mm,which is quite a whack off such a skinny bit of metal.
So at the minute thats what is keeping my head busy.
This is how I got it.The P.O. imported it from America,I dont know if he changed the wheels or if he got it like this.
When the build is finished theyll be going up on the 'classifieds' along with a load of other leftovers from the original bike,if youre interested.