CB750 rear wheel on 73 Commando ?

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Note that it's a rare Kenny Dreer box-section swingarm, so I was able to slightly open the axle slots. Not sure how a standard swingarm slot would fit a Honda axle.

It won't fit as the standard axle is 17mm. Opening the axle slots by maching off 1.5mm top/btm flats is certainly possible but this is an irreversible action of course .

-Knut
 
Bluto, I took a quick look at 71 cb450 pictures and the hub looks like you'll have similar modifications to mine to make it work, plus whatever else you have to do to mate the hub up to a rim. It looks like a workable choice to me.

-making a brake cable to go to the timing side of the swingarm
-moving the brake cable anchor fixture to the timing side of the swingarm
-welding a tab on the timing side of the swingarm to mount the drum brake torque arm
-slotting the swingarm to whatever the diameter of the Honda axle is. (my yamaha was 17mm)
-cutting spacers to center the new hub
-cutting,(or shimming) the face of the sprocket carrier after the hub is centered to align the rear sprocket to the front sprocket.

I used a guy on ebay to buy aluminum spacers. He was located in Georgia I think. They were pretty cheap
I used sprocket specialists in utah for my sprocket. I think it cost me $75. for a 40 tooth for my hub to duplicate the ratio I had previously 21/40. At some point I may go to a 39 as a half step taller rather than go for a 22 up front. It's nice to have a much simpler way to adjust the final drive ratio than taking apart the primary.
 
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Bluto, I took a quick look at 71 cb450 pictures and the hub looks like you'll have similar modifications to mine to make it work, plus whatever else you have to do to mate the hub up to a rim. It looks like a workable choice to me.

-making a brake cable to go to the timing side of the swingarm
-moving the brake cable anchor fixture to the timing side of the swingarm
-welding a tab on the timing side of the swingarm to mount the drum brake torque arm
-slotting the swingarm to whatever the diameter of the Honda axle is. (my yamaha was 17mm)
-cutting spacers to center the new hub
-cutting,(or shimming) the face of the sprocket carrier after the hub is centered to align the rear sprocket to the front sprocket.

I used a guy on ebay to buy aluminum spacers. He was located in Georgia I think. They were pretty cheap
I used sprocket specialists in utah for my sprocket. I think it cost me $75. for a 40 tooth for my hub to duplicate the ratio I had previously 21/40. At some point I may go to a 39 as a half step taller rather than go for a 22 up front. It's nice to have a much simpler way to adjust the final drive ratio than taking apart the primary.
Thanks, that is very helpful info. BTW JT has detailed info on their sprockets, looks like I can make one work by opening up the center hole by 4mm.
http://www.jtsprockets.com/catalogue/
CB750 rear wheel on 73 Commando ?
 
i'm all ears?
There are plenty of good choice wheels out there ,
I have aprillia pegaso wheels/Bmw funduro on mine, mainly because of the light weight and I like spoked wheels,and it has a really good cush drive
If you have a lathe then most hubs can be made to fit it's the rim width/chain offset that can be difficult
But you can modify the cush drive by Tig welding up the inside of the cush and bore the bearing housing deeper and moving the sprocket in a little etc if necessary
I recently bought a pair of stock commando wire wheels for another project and I was a bit shocked how bloody heavy they are!!!
 
i'm all ears?

here's a pair of cast aluminum wheels that are the same sizes as mine, but a different casting pattern for $40. per wheel...

Removed broken link

There are numerous ones that are even better, but you have to search and be patient. A few months ago there was a pair of wheels in portland craigslist that were WM3 x 19 front with a single disc and WM4 x18 rear. (not sure what the brake was) The guy wanted $150. for them both.

My method was to type into my local craigslist, "Wheels" and go through what is locally available, then cross reference what I find with a website that has all the specs of every bike so I can see what their sizes are. Mostly there's an era between the mid 70's and mid 80's were the tire sizes and wheel widths are workable for the swap. You just have to do your homework...
 
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I have an SR500 and I always thought that the wheels were a lot heavier than wire wheels on my long gone RD350s.

That said, I may have been wrong because according to Dain Gingerelli in an article in a recent magazine (Classic Bike, IIRC), the similar RD400 cast wheels were not much heavier that the RD350's wire wheels. There were both drum and disc brake Yamaha rear cast wheels, both on right side, of course. The TX500s and TX750s had wire wheels with faux Borannis/Akronts. I have one of those on the front of my SR500 - definitely lighter than the cast "wagon wheel" that the bike came with.

As for ditching that Commando drum, running a brake cable over to the right side wouldn't bother me much. Back in the 70's when my original 1971 Commando's cush hub's prongs worked loose, I replaced the whole wheel with some kind of Kawasaki wheel that was almost a bolt in; had to change wheel bearings and fabricate a brake stay and cable for it. That wheel wasn't light but it worked fine.

These days, I wonder what years/brands/models offer a light drum brake/cush hub that is most easily adaptable?

If the sprocket to wheel centerline and axle size are the same, then easy peasy.

As for OEM 19" wheels, I don't recall any other '70's -90's bikes that came with a 19" rear wheel but I'm happy with the 18" diameter of the Atlas wheel that's now on my Commando, so 18" is OK by me. Seems like there are some relatively light 18" dirt bike drum brake wire wheels with small axle diameters that came on MXs and enduros from that era. Wheel bearings could be changed to match our axles.
 
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according to wiki, the rd400 was the 1st factory bike that offered 1 piece cast wheels
 
One thing which has always attracted me to those seven spoke Yamaha XS / RD / SR style wheels was the similarity between them and Peter Williams "Wagon Wheels". I'm sure I've seen pictures somewhere of a JPN (road) fitted with them, and it looked pretty good.
 
The sprocket carrier face was machined down .25" to align the sprocket, the size of which is easily changable. In fact you can buy "saw cut" sprockets and change out to different rear sprockets sizes without removing the wheel.


details for these saw cut sprockets pls?
 
Took some preliminary measurements and looks like the CB450 wheel will work as both it and my Commando wheel measure about 84 mm from the center between the spoke flanges and the outside edge of the sprocket, may not need to move the sprocket at all. Axle diameter is 20mm, same as a CB750. 20mm axle spacers are uncommon but figure I could bore a 3/4" (about 19mm) to fit, those are easy to come by as they are used on older Harleys.
The CB450 wheel is heavy though, about 36 lbs. complete w/ axle, brake, and a tire. Also FWIW can probably get a JTR247 41t sprocket to work if I want to go to 520 chain by having the center machined to 74mm.

CB750 rear wheel on 73 Commando ?
 
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There are several reputable sprocket manufacturers that sell dished sprockets than can be modified. I can't quote one off the top, but a bit of research has already been suggested...
 
details for these saw cut sprockets pls?

go here; http://sprocketspecialists.com/

plug in the donor bike's wheel and see what options they have for that bike. When you chose a certain bike's wheel that gives them the drilling pattern for the sprocket. In my case, I entered the yamaha seca 550 and the sprocket I got from them bolted right up. They have regular sprockets, hard annodized, a saw cut sprocket and a saw cut with locklinks. I supose the locking link might be necessary for higher HP bikes or just safety's sake. You could call them and ask. They were really informative in the phone with me.
 
How heavy are the SR500 wheels?

Glen

I don't know, but I have an extra yamaha seca 550 wheel with a disc and a new avon tire on it, but I don't have an accurate scale to weigh it on. I really wanted to weigh it when Ken was doing his "what wheels weigh" thread since he launched it right when I was seeking info in my cast wheel conversion thread. I just was busy as hell, had no scale, and never got around to it. Maybe if I get a day off this week I take the wheel into the post office and get my friend who works their to weigh it. I'd like to know how much lighter than stock it is. It's certainly more torsionally more rigid than spokes. I'm pretty sure it's lighter too.
 
I don't know, but I have an extra yamaha seca 550 wheel with a disc and a new avon tire on it, but I don't have an accurate scale to weigh it on. I really wanted to weigh it when Ken was doing his "what wheels weigh" thread since he launched it right when I was seeking info in my cast wheel conversion thread. I just was busy as hell, had no scale, and never got around to it. Maybe if I get a day off this week I take the wheel into the post office and get my friend who works their to weigh it. I'd like to know how much lighter than stock it is. It's certainly more torsionally more rigid than spokes. I'm pretty sure it's lighter too.
Don't forget if you weigh your disc wheel to include the calliper/mounting plate/torque arm brake line with oil in etc
If you are comparing it to a drum brake wheel
Cheers
 
Thanks much for all the links, had already seen a few (but reread those), LOTS of good info and plenty to consider.
A couple of things I came across: a few posts state that the CB350K and CB450K both use 17mm axles, this is not correct, the CB450 is 20 mm (as is the CB750)
A few others said that widening the swingarm slots to accommodate a 20 mm axle would weaken it excessively, but OTOH there have been several references here to CB750 wheels being used successfully so I'm not sure what to think on this...it LOOKS to me like taking 3mm off the top and bottom would be OK but of course that means very little.
I'll have to decide whether to proceed with my CB450 wheel or find something else w/ a 17mm axle...in its favor the CB450 wheel appears to have the sprocket in the right position relative to the rim center and that is a BIG plus.
 
Thanks much for all the links, had already seen a few (but reread those), LOTS of good info and plenty to consider.
A couple of things I came across: a few posts state that the CB350K and CB450K both use 17mm axles, this is not correct, the CB450 is 20 mm (as is the CB750)
A few others said that widening the swingarm slots to accommodate a 20 mm axle would weaken it excessively, but OTOH there have been several references here to CB750 wheels being used successfully so I'm not sure what to think on this...it LOOKS to me like taking 3mm off the top and bottom would be OK but of course that means very little.
I'll have to decide whether to proceed with my CB450 wheel or find something else w/ a 17mm axle...in its favor the CB450 wheel appears to have the sprocket in the right position relative to the rim center and that is a BIG plus.
If you have a lathe you can usually re make the bearing spacers down to whatever size you like
I have done this many times,also using bearings with the same od but smaller Id
 
I have aprillia wheels on my commando, I opened the swing arm up to 17mm with no problems mainly because I wanted a larger diameter spindle
 
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