Topic: 71 cb 750 project 330 wheel

[631girl]

ive been posting in wrong section, sorry. here are some pics so far..

[fastbroshi]

  Wow you've got a lot going on there.  Thought it was a hardtail at first but it looks like you've got a shock in there.  So is that one gear just going to be an idler of sorts that just changes the angle of the chain?  Never seen one done like this.

[Frankenkit]

Are the pipes supposed to be touching the ground?   Where are the controls/foot pegs going to go?  what's up with the propane tanks out the sides?  Inquiring minds want to know!

[mystic_1]

Is that a hydraulic rear suspension?  Pneumatic?

mystic_1

[shag nasty]

very interesting

[KB02]

I will be keeping an eye on this.

I would say that extra gear is a tensioner.

Very nice work so far. Let's see what else you've got going on. What's the front end off from?

[vanillagorilla]

Vunderbar! The tensioner is actuated by the arm. when the bike lifts up it adjusts up as well. Very nice. Don't know how well it will work, but really cool design.

[Zaipai]

Will you chrome the swing arm or paint, or have you decided?

How hard was the front end to put on? Wonder if it would fit my 550 easy?

Looking good so far.. watching with great interest..

.: Scott :.

[dragracer]

Jackshaft set up looks interesting. That wide rim with the 300 series tire is coooooool. I thought about doing one with a 3" offset front sprocket and bearing support plate like my dragbike but the output shaft on the Honda is a bit small to support the side load. The jackshaft setup like the newer sportbike kits will really draw some attention.


Nice work. Keep us informed.

[dragracer]

I assume that pneumatic cylinder will be used as some sort of air ride control

[Industrial Cafe]

let's start over on this thread.

  Please try to post a video of the swing arm in action, it's driving me nuts!  use a floor jack if you have to.
we all know it's an unfinished mock up and it's going to have parts that need to be revised or added.

[Spikeybike]

let's start over on this thread.

  Please try to post a video of the swing arm in action, it's driving me nuts!  use a floor jack if you have to.
we all know it's an unfinished mock up and it's going to have parts that need to be revised or added.

pretty please ......with cherries on top

[Syscrush]

I don't understand the point of that idler/tensioner.

Does it provide some anti-squat behavior?  Because the tension on the chain between the jackshaft and the rear wheel won't change as the suspension moves through its travel.

[Industrial Cafe]

that's why I want a video.

[HavocTurbo]

As much as I am trying to keep my mouth shut, and straining to refrain from any negative comments:

I have several questions...

1:
Where on earth did you find a modified STOCK rear wheel? I have been looking for the better part of a year for a modified STOCK suzuki wheel with no luck. If you made it or had it made please direct me to pricing so I can send you a wheel and my specifications. I would also like to know how you did it as I have been trying to mod a STOCK suzuki wheel for some time now with poor results.

2:
I have read both posts and looked at as many pictures as I can stand while coming to this conclusion. It appears in these pictures that the jackshaft is actually the pivot point for the swingarm. Is this true?

If it is true can you prvide pics of the swingarm installed WITHOUT the tire and air cylinder? I am interested in your mounting.

3:
Assuming (notice I assume) that the jackshaft is the pivot point for the whole rear assembly, why need a seperate tensioner at all? Why not just cut off the stock CB750 adjuster ends from the stock swingarm and weld them in place of your axle holes? That would allow you the use of tensioners without a dramatic piece blocking the huge size of the rear wheel. It would also eliminate the need for all that extra fabrication of the "tensioner" arm. Which as it looks right now is unable to be determined as to whether it actually moves or not. I am interested in this as well.

4:
I would also like to see the top mounting for the air "shock". That looks like a crap load of weight it has to support and am interested in how you braced the rear of the frame to handle all of this weight.

5:
What process did you use for adapting the front fork "trees" to the CB750 neck? I have done several (about 20 now) and wanted to see another person's take on this process. Perhaps just press in and machine a sleeve for the bottom of the stem?

6:
I am also interested in your final gear ratio. Are you going to keep the 630 main chain and use the 530 final chain? Or convert it all to 530? I would think that with 5 (five) sprockets, there would be ample room to fiddle with the settings for rideability.

7:
Now I'm going to touch on cornering. I am interested on how a set of drag pipes would look. I think that if you made a set of drag pipes where the lower pipe molds into the upper (in effect a four in to two) that might give you plenty of clearance.

8:
Mid or forward controls? I'd be a sucker for mids with clip-ons. 

9:
Are there seperate fills for the propane "oil" tanks or just one? Perhaps some nice big AN fittings with braided stainless hoses? I be interested in how you get this to work as well.

That's about all I can think of for now. I am definitely interested in the fabrication it has taken to get to this point. I have done some crazy stuff but nothing as "different" as this.

[Industrial Cafe]

yeah hector, do something productive and post some info... besides this is the only forum you need to post in, you might pick up bad habits in other forums

[J.Webster Designs]

bam631, I will be at bike week for sure. I will be riding around on my 76 CB750F. I would like to check out your bike when you get down here.

[HavocTurbo]

The wheel was widen by kosman industries in ca.. But be prepaired to wait 6 months..  the bushings to adap the metric to standard bearings where not complete.

Why did you change the wheel bearings?
I would assume the stock wheel bearings would be enough if you used two sets spread out on your elongated axle.

The axle I bought 2 busa axles and adapted together with female ends.. Then welded a cupling nut inside..used 5/8 bolt to go through a mini hub inside the arm which you can't see in pics..

You kinda lost me here. Why not just make the Id of the mini hub the same size of the stock axle? And instead of two axles why not just fab up a single long axle to fit through everything you went through all the trouble to make? I'm not nitpicking... it just seems like a WHOLE lot of unnecessary trouble to me.

I used stock arm from cb and only used the mounting tube off it and added the tubing work..

After further review I do now see that the jack shaft is indeed separate from the swing arm mounting point. Looks in fact to be a single sided swing arm. And attached from the jack shaft and pivoting along yet another axis is the "tensioner". Have you moved the rear suspension it's full swing? I would hope that the "tensioner" wouldn't put so much pressure on the chain that it would snap from a slight pothole in the road.

as of the air ride I used 2 aircylenders with a mini compressor.. The front I added air fittings but not going to use.. Bc what if it leaks and  instead of goin straight the bike takes a turn..

You lost me here. We talking about the front or the rear? Because I only see ONE air cylinder... and if you lose air in one fork the bike wouldn't automatically turn... just break itself apart from lack of symmetry. There I would suggest a balance air line from one for to the other.

The forks are from a 04gsxr 600 and fit perfect @ bottom the top neede to convert into a bronze bushin. No bearing.

Um.... well that cannot be good. If you like.... send me your lower tree and your original CB750 stem along with the original GSXR stem and I'll make you a bearing compatible combination. Otherwise your frame is in for a rough ride.... modern suspension or not.

Oh the little sprocket is used 1. Bc I didn't want to use a bigger sprocket in fron or bac. Bc the chain was rubbn the arm and since the wheel it has no trave to adjust chain.

Hmmmm.... alright.


So you answered some of my questions. I'm enlightened for that. I actually called those guys at Kosman and they are sending me a full price list for my customers' ideas on wheels. So thank you for clearing that up. I apparently cannot weld EVERY form of aluminum as I had hoped I could with my welder. www.kosmanracing.com - For those of you interested.

I still have some questions that I posted above and hope that you can find time to answer those as well.

[HavocTurbo]

Well then.....

My question is still out on the tensioner travel. Does it move out far enough to put serious strain on the chain? Just asking as it looks like it would snap it at full compression.

And then there are these....

4:
I would also like to see the top mounting for the air "shock". That looks like a crap load of weight it has to support and am interested in how you braced the rear of the frame to handle all of this weight.

5:
What process did you use for adapting the front fork "trees" to the CB750 neck? I have done several (about 20 now) and wanted to see another person's take on this process. Perhaps just press in and machine a sleeve for the bottom of the stem?

7:
Now I'm going to touch on cornering. I am interested on how a set of drag pipes would look. I think that if you made a set of drag pipes where the lower pipe molds into the upper (in effect a four in to two) that might give you plenty of clearance.

8:
Mid or forward controls? I'd be a sucker for mids with clip-ons.  

9:
Are there seperate fills for the propane "oil" tanks or just one? Perhaps some nice big AN fittings with braided stainless hoses? I be interested in how you get this to work as well.

Again.... not trying to nitpick... just trying to see the whole picture.

[Industrial Cafe]

hey, you could have a much better time with your front end if you did this-
http://forums.sohc4.net/index.php?topic=63784.0

instead of having to use some out of the ordinary bushings, it uses the stock cb750 bearings.

[andy750]

220oC is about right. Anything from 185 -220 seems to be normal.

 

[Zaipai]

What I do is put a couple of box fans pointed at the motor, one on each side blowing tword he heads.. I would imagine that would be enough to keep it running cool.

Thanks for the reply, now that you have painted almost everything I can not wait to see it.. Hope it gets easier for you, sounds like the really hard parts are behind you.

.: Scott :.

[Frankenkit]

The more experienced folks will probably chime in here, but if it backfires of the 4th cylinder after you really rev it up, it could be that you're running kind of rich, build up some carbon and then it'll ignite wrong when you let off- but only on that cylinder.  I guess you could check that by looking at your spark plug and seeing if it's really black, but that's my only guess on that.  Lots of stuff can cause it to run a little rich on one, too, from a dirty pod on one side to that carb being set a little different from the others, etc etc.

[mkramer1121]

220oC is about right. Anything from 185 -220 seems to be normal.

 

what if it gets pass that.. what you i do to keep it under 220f

Its an air cooled engine, you ride it to cool it...   But the box fans will help too...

[HavocTurbo]

220oC is about right. Anything from 185 -220 seems to be normal.

 

what if it gets pass that.. what you i do to keep it under 220f

Its an air cooled engine, you ride it to cool it...   But the box fans will help too...

  or you could just spray it with the hose?? 

but seriously.... box fans work the best.