XS 650/750 rear wheel on XS 400 DOHC

Nuno

New Member
Hey DTTers,
does anybody know if the rear wheel from an XS 650 or 750 will fit an 1983 XS 400??
The original wheel is too thin, I'd like to have something wider but honestly...if I have to change too much stuff to fit a wider wheel I'd go directly for a 17'' 150/60 or a similiar 18''...so I'm looking for an almost perfect fit.

Thx!!
 
Swivel said:
I think a XS650 16" rear weighs a hell of a lot and would be a hassle to fit.They made a "Special" model DOHC 400 with a 16"rear wheel.Y'could fit a much bigger high profile 16" tire than fitted stock on the 16"with a bit of advice from a tire pro.The tire might not clear the chain line if Y'try to go real big and fat.The Special 16" rear wheel should bolt straight in and be cheap to find on Ebay.

for what I know the XS650 has a 18'' wheel at the rear end....
In Italy we are not allowed to change the size of the wheels so I'd like to stay on the 18'' ... if that is really not possible then I'd surely go on a 17'' that would allow me to use any modern tyre on the market with less pain and hassle when I have to change tyres.
16'' would not really solve the problem

I'm wondering what's the biggest size that can fit on a 4.10'' x 18'' wheel

EDIT: I just found this but I'm very skeptic about it
http://www.dropbears.com/u/utilities/tyrerim.htm
this table states that a 150/70/18 can fit a 4.10'' rim, it means I have no problems at all and can keep my wheel .... I have my doubts. Does anybody has experience with this?
 
No, different axle size.
You could probably get slots in swing arm machined out for larger axle
I put XS400 wheel into XS650 as I wanted cast wheel with drum brake.
Used a Suzuki swing arm, it was same diameter axle a 400
SR500 is 18"
BTW, that's the 2nd gen XS400
dohc motor is pretty good base, hell of a lot quicker than the sohc 400
done a big bore on one, have some pics of block and crankcase boring (I think it was 6mm oversize 8) )

XS750 is shaft drive
 
crazypj said:
No, different axle size.

as expected but that's usually something that can be solved changing the bearings and adjusting the height of the spacers...no?
talking about overboring....that's something that I have planned but I'll leave for another rebuild... what pistons did u use?
 
That dropbears chart is correct. You are mixing up the "wheel" width with the tire width.
 
Nuno said:
as expected but that's usually something that can be solved changing the bearings and adjusting the height of the spacers...no?
talking about overboring....that's something that I have planned but I'll leave for another rebuild... what pistons did u use?

I don't think bearings were available with correct diameters to do a swap, needed thin tubular spacer made
As for overbore, I forget, either 74mm or 75mm, (492cc?)
I was doing a LOT of conversions a 5~6 years ago, using them as 'training aid' and allowing students to do their own engines with close supervision
 
@Big Rich : yes, I was looking at the table from the wrong point of view.....so the problem still remains!
@CrazyPJ : I was considering doing it with the XS650 pistons. 75mm, +6mm ---> 470cc, not a huge improvement but will surely add a lot of juice to the already fast (too fast for the standard XS, not my case :D) 400cc
 
447 pistons from an XS 650 wont work.
The top is too far away from the pin bore, plus, the pin is 20mm and you need 16mm
Neither is insurmountable problem but does require a lot of extra work

Thanks for working out the capacity, I may have used 78mm Suzuki GSX pistons or maybe Kawasaki 450/500 twin?

71cc would actually make a big difference, my CB360's only get 22cc and it's noticeable improvement
 
crazypj said:
447 pistons from an XS 650 wont work.
The top is too far away from the pin bore, plus, the pin is 20mm and you need 16mm
Neither is insurmountable problem but does require a lot of extra work

Thanks for working out the capacity, I may have used 78mm Suzuki GSX pistons or maybe Kawasaki 450/500 twin?

71cc would actually make a big difference, my CB360's only get 22cc and it's noticeable improvement

I found an old post where we already discussed it! I didn't even remeber it...
Seems like the pistons from a CB 450 would have the right size but I can't find the wristpin size anywhere on the net.
Do you remember how much can be bored from those cylinders?
 
I fitted new liners.
You can't generally bore more than 2mm (which would give you 71mm max bore)
 
crazypj said:
I fitted new liners.
You can't generally bore more than 2mm (which would give you 71mm max bore)

Yep, I meant...what's the biggest liner I can fit before I go too close to the fins or the camchain?
I'm filling you with questions but I don't have the engine with me now...I'm trying to have anything planned for when I'll be back home
 
Don't remember, I have a 'round' cylinder for XS400 here, pretty sure it has thicker wall than the DOHC motor with 'square' cylinder
Just remembered, I have a picture of the DOHC block with Suzuki GS500 liners fitted
These are 1mm OS (75mm)
XS400StockGS5001.jpg
 
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