Comstar wheels on 400/4

[vivvov]

Hello All

New here. So not that clever at navigating.
Been in the background reading though.
Intro'd myself the other day to the world and his dog..loads of folk from the US, SA, Aus...everywhere.

Then was googling comstar and 400/4.  Came across a dim distant thread..Cafe Racer Project in Oct 2010..rigwit provided some info.. thought message him......blank page and the site says new topic..so tracking back on the co.uk angle...

Situationis :

I've two 400/4s.  Between them I should have enough chrome to stretch to a half respectable stock.
The other..well I've started already. 

Totally dismantled one bike.
Just cut an inch and half off the seat to lower the profile and minimise the back end bump.  Got my eye on a leather chair on ebay for a re upholster.
Plus saw a cafe racer that had comstar wheels (some will hate this I know. Take heart I will keep all necessary bits in a boxes..even the foam I've chopped off..just in case it goes wrong).
This cafe racer had comstar wheels and I've already tracked down a pair off of a 250n, plus forks, back brake (and rear shocks) off of a 400n.

Question is this.  This cafe racer with comstar had only one front disc and I couldn't  clearly see if the caliper was 400/4 or 400n. 
Does anyone know if, by shear luck, 400/4 front calipers/disc  set up marry up to 400n comstar wheel disc bolt holes?
That way I could keep the 400/4 forks and caliper, single front disc set up and not have to start locating400N front calipers, pipes, brake fluid reservoir etc (even though twin discs would be good).

(The racer seemed to be using a 400n brake fluid reservoir so I'm not getting my hopes up).

Hope this makes sense.

Vivvov

[matthewmosse]

I have limited 400/4 knowledge, but do know having done a dry run build that the 250n front end will drop into a 550/4 headstock. That means a complete front end swap over yokes and all will probably work. from my messing around fitting comstars to my cb550k3 I know comstars will go over to that bike using the 650 wheels on the 550. So chances are the comstars should fit easily enough with possibly a bit of messing with spacers. the disk lining up with the caliper mount of a 400 4 might be an issue. 400 4 yokes are unlikely to fit 400 forks. I have a few of the required bits to measure up some of the differences but not all. I do quite like the look of comstars on a cafe bike, I know they looked good to me on my 550k3 which was a bit of a mongrel and they make a good and cheap alternative to spoked wheels which can get expensive.

[ka-ja]

Hi,
     I fitted comstars in the mid 80,s to my 400/4, I did it because it was the easiest way to increase front braking to twin discs. It is easily done front end wise by fitting cb400n superdream front forks,wheels, discs and calipers into the original 400/4 yokes, the back wheel needs a little work on spacers, but fits quite easily using original rear suspension, the font staunchions were set 15mm above the top yoke to correct for the 19 inch comstar.
       I am now rebuilding and have converted the comstars to spoked wheels to get the front end back to 18 inch, but converting the comstar hubs means the basic fitting work done in the1980's still applies. Any further info please ask!----Ken
Ps  avatar is the set up from 1985