Topic: New Project / Max. Rear Wheel Sizes?

[Brookesy]

Hi everyone,
I'm planning to launch into a new project and i need to check a couple of things.
If anyone can point me in the right direction i would appreciate it.

Here's the plan... ground up build. K2 frame (think i've found one) F2 engine (looking for one)
I want to put a 180 / 15 rear tyre on it and rear disc brake

Does anyone know what's involved or has anyone done it?
Is there a rear swingarm that fits into the frame and will accept the 180 wheel?
What about getting the sprocket out far enough?

Any ideas would be great

Brookesy.

[Sam Green Racing]

Hi Brookesy,

Not realy into Modern sizes but Dennis Dragman836 runs a 7 ins slick on his drag bike.
His swing arm is longer, but I don't know if he made it any wider.
You may be able to step the chain out a bit at the front by reversing the way it goes on.
That way if you can do it should give you the width of the sprocket plus the width of the lock plate.
It would the be a case then of packing the rear sprocket out the same amount.
Good luck.

Sam Green.

[Brookesy]

Sam,
Thanks for that.
180 (mm) is ... wait for it ... 7 inches.
I might be on a winner (would be nice)

Only time will tell.

[Sam Green Racing]

Did you find out if the 180 will go in ?

[Brookesy]

I haven't had any more luck.
I'm going to talk to the 750/4 club in Brisbane about it next time there's a club run on.
I'm about 2 hours out of Bris. so contact is limited.
Although i did catch up with them on the weekend at the Bris. bike show.

Looks like i've got onto the frame i want. (K2)
and i have people chasing a set of F2 cases to start on the engine - which they tell me will be easy enough

It's not going to be a short-term project so it's lucky i have my other ride...
but unless i can finish up with the bike that's in my head - it won't happen

maybe i can push the sporcket out further and fit a 200... given enough effort maybe anything is possible

[Sam Green Racing]

Just had a thought, the front sprocket on the F2 mounts differently to the early K models, so you would not be able to do it how I said.

[Lumbee]

hey, just a thought, I've heard a Yamaha R6 wheel lines up perfectly with the front sproket of the CB750.  I think the R6 wheel will take a 160/180 rear tire.  You may want to look into it.  I'm building a chop have did a little research into it.  Still have to worry about axle, spacers, and mounting the rear brake caliper.

[Leino]

hey, just a thought, I've heard a Yamaha R6 wheel lines up perfectly with the front sproket of the CB750.  I think the R6 wheel will take a 160/180 rear tire.  You may want to look into it.  I'm building a chop have did a little research into it.  Still have to worry about axle, spacers, and mounting the rear brake caliper.

Now you got my attention RaDigga  Do you know what year R6?

[Lumbee]

Lieno...I emailed the dude that has that application...I'll let ya know what he says...

[Chris Liston]

hey, just a thought, I've heard a Yamaha R6 wheel lines up perfectly with the front sproket of the CB750.  I think the R6 wheel will take a 160/180 rear tire.  You may want to look into it.  I'm building a chop have did a little research into it.  Still have to worry about axle, spacers, and mounting the rear brake caliper.

The R6 is a 180.  I used to own one and miss it alot.

[Lumbee]

Lieno...the guy emailed me back...he says he used a 98-2002 rear wheel (17'' X 6'') from an R6...and keep in mind this was on a chopper...not sure what problems u might run into using a stock frame.

[carsholduptraffic]

brookesy, how's the action in brisvegas??
the stock swingarm will only take a 150 on a 16, but going smaller may allow you to go wider. a close call though. and it will push wide out of corners a heap unless you do something about the front too. the only 180 i've seen on a honda4 was on a rigid chop back in my murwillumbah days.........and it was almost ridculous!!!!!
you could go a suzi gs swingarm etc, if you like to play with spacers and such.
good luck with the project.
nick in canberra

[CB750R]

I just put an FZR rear wheel, its tire is a 150mm X18inches, and the first thing to rub is your brake arm, the second, is I have maybe a 1/4 inch between the chain and the tire, with the correct chain line, so I dunno how you'd run a much bigger rear than than with out messing the chain line up.  Plus a 180mm rear tire is going to slow down your steering, and reduce your performance.  180mm tires are needed for the 110-140 horsepower motors to give them enough contact patch to allow them to accelerate with out melting down the smaller tires. last time I checked a fully decked out over bored CB motor might get you 80hp reliably, sorta seems like a little over kill.  As per which rim might fit, I've done some rough measurements, and I might end up putting a YZF600, (not R6's) rim on the rear, it uses a 20mm axle, and from my best on bike measurements looks like it'll slide right in an F2's swingarm.

[Lumbee]

...hey Grant...so that FZR sproket lines up with the the CB750 front sproket?  What year wheel did u use?

[CB750R]

its roughly a 90 I'm not too sure, there're all pretty similar, and this was off a friends bike, that wasn't an FZR either, so no way to tell except that it was barney purple, so I guess you could colour date it!!

I had to make some special spacers for this wheel to work the axle is 17mm instead of 20, and the hub is 20mm narrower than the comstar. So, I made two ten mill wide spacers, that step down to fit into the swingarm and take up the difference in the axle to swingarm size!! the spacers look like top hats sorta, if that helps. If someone really wants to make this set up work, I'll pull the rear out and take some pictures of the spacers and such.

  my friend has a YZF rim that I was talking about, I'm going to try and see how it fits this winter. 

[Brookesy]

Sorry Guys, I've been away and it's also hard to get computer time - 4 teenagers in the house.

Thanks for the input, some interesting stuff there.
It's all go up here - Nick, it's just as cold here as it is in Can-o-berries.
Bris-Vegas is a bit warmer but i'm up in the hills mate. We've had -3 to -5 this week and South-Westerly winds.

I've picked up a nice K1 and i have put a bit more thought into the whole thing.
Power to the ground isn't the problem - i just like the look of fat rear tyres.
My 750DC Shadow has a 160 on the back and i love it - Mr. Honda found a way to make it handle.
Throwing it through the twisty stuff is a delight.

So, now i'm now wondering will the F2 swingarm fit into the K1 frame
Looks like i can fit a 150x18 in if it will fit - more feedback would be good.

Has anyone tried non-stock swingarms?
Also, what is involved in putting a rear disc brake on?
Non-Stock front ends? CBR900??

Lots of questions, i know, but i'm in the planning stages and i want to get this right.

Brookesy

[Quail "Owner of the comfortable k8"]

I plan to relace my rear wheel due to rusted spokes, does any one know the widest rim I can put under my k8?  What diam would you use use and why?

[Egil]

Last owner  put  disc brakes at rear at my CB750K7 ,he take it from a CB900Bol`dor have disc and wheels from thise bike!


Egil

[Brookesy]

Any other comments?

[Quail "Owner of the comfortable k8"]

Any other comments?

Why do you have some profound statement your about to make now that we are all quiet?

[kghost]

I just put a 77 Supersport swing arm on a 77 K frame for the cafe project. (750)

I also run a 120 tire on the back instead of the 110. No problems there.

[Brookesy]

Well Kids... while you're all quiet and listening...

Nah, nothing goin' on here mate.
I just wanted to know if anyone else had something to add.

Has anyone done a monoshock rear end on a K?
Just a thought - it's beyond my skills.

I keep gonig out into the shed - measuring stuff and thinking.
Eventually it will all click - i hope.

[Egil]

                      Monoshock CB750
Back in the "Motorcycle Mechanics  no 176 june 2002 "

On page 58 Show us yours readers bikes

One reader have Honda  CB750 F2 whit Kawasaki zzr running gear

If your are reel   intrested ??

The Bike look reel nice .

Egil

[Brookesy]

Hi Egil,
I PM'd you

if you can scan the magazine article and post it i'm sure we would all be interested.

Brookesy

[dusterdude]

just for info.i put a 5.10-16 on my k1 750.i had to cut the inside of the chain guard and move the brake anchor arm over about a 1/4 inch.