CB750 Cafe w/ Suzuki 4LS Brake?
- Thread starter mrosso
- Start date
Cost of the wheel aside, you should be able to make it work. If the axle sizes are different, you could replace the bearings with some that have the same O.D. as the hub needs and the same I.D. as the CB750 axle. Then it's just spacers to centre the wheel, the brake stays to the fender mounts of the CB750 forks and a brake cable/lever/light switch swap.
Well, the speedo would be driven by the new hub. If you're lucky, the stock GT750 speedo cable would thread onto a CB750 speedo and the ratio would be the same.
That being highly unlikely, you'd either need to run GT750 gauges, or, an Acewell gauge which uses a magnetic sensor like a bicycle speedo to determine speed, and ties into your coils to determine RPM. Speedo/tach/idiot lights all in one gauge.
I may end up with an Acewell myself. Of course you only need a speedo for the safety inspection
That being highly unlikely, you'd either need to run GT750 gauges, or, an Acewell gauge which uses a magnetic sensor like a bicycle speedo to determine speed, and ties into your coils to determine RPM. Speedo/tach/idiot lights all in one gauge.
I may end up with an Acewell myself. Of course you only need a speedo for the safety inspection
TonUpSoldier
bad assed, super fast and fully gassed
FYI to everyone...UJM Speedo ratios are ALL the same...2240:60 Now the cable screw fitting is a different matter, however it wouldnt be difficult to fix that.
TonUpSoldier
bad assed, super fast and fully gassed
It is handy that they are all the same ratio.. The tachs can be a bit different...for instance on the GS's its a 4:1 ratio. dunno bout Hondas or Yammies. I myself have a nice set of OEM gauges that i just recently procurred. But the more i look at those Acewells, the more i think it wouldnt look to bad. I was trying to stay away from any tech on the bike, but i've broken down and just traded some stuff for a 7 inch HID headlight rig, (for safety of course..heheheh) and i dont think it would look too bad to have an Acewell on there. Plus i like the fact that its a single gauge. I really really wanted to find some Honda gauges, the seperate cup ones, but they are kinda hard to find and damn expensive when you find em in decent shape.
cafe75-550
New Member
I believe that the GT750's have 36 spoke wheels? The 750 has 40, so you'll need a 36 spoke rim if you don't have one already.
zedd
1968 CB350 Cafe Racer.
I used a GT750 4LS on a CB350 with CB500 tree, CB750 35mm legs and 18 inch alloy rim.
When fitted to the Suzuki, one end of the axle is plain (and the right size for the Honda end cap) and the other end is threaded. The plain end is locked with a pinch bolt and the other screws into the leg. If you measure the backing plates, one is slightly deeper than the other. The deeper one has the speedo drive and goes on the screw side of the forks.
I used the Suzuki axle, made a threaded sleeve for the threaded end of the axle so it would fit into the end cap and lock the brake plates together. Straight up the wheel fitted in place with my setup BUT it is off-center by the extra depth on the 1 backing plate. I shaved a little off the inside of the leg and spaced the other side to center it up. I did it this way as legs are far cheaper and easier to find than 4LS drums. The drum is worth more unmodified.
For the anchor arms, I made arms to go from the backing plate up to the 2 mudguard bolts - the anchor is attached to both bolts on each side. The mudguard bolts are only 10mm head / 6mm threaded shaft so they are fairly small. I would recommend retapping the legs and taking the bolts up to 8mm shafts. The Suzuki speedo cable mated to a Yamaha speedo without any problems (it looked better than the plastic Honda item)
When fitted to the Suzuki, one end of the axle is plain (and the right size for the Honda end cap) and the other end is threaded. The plain end is locked with a pinch bolt and the other screws into the leg. If you measure the backing plates, one is slightly deeper than the other. The deeper one has the speedo drive and goes on the screw side of the forks.
I used the Suzuki axle, made a threaded sleeve for the threaded end of the axle so it would fit into the end cap and lock the brake plates together. Straight up the wheel fitted in place with my setup BUT it is off-center by the extra depth on the 1 backing plate. I shaved a little off the inside of the leg and spaced the other side to center it up. I did it this way as legs are far cheaper and easier to find than 4LS drums. The drum is worth more unmodified.
For the anchor arms, I made arms to go from the backing plate up to the 2 mudguard bolts - the anchor is attached to both bolts on each side. The mudguard bolts are only 10mm head / 6mm threaded shaft so they are fairly small. I would recommend retapping the legs and taking the bolts up to 8mm shafts. The Suzuki speedo cable mated to a Yamaha speedo without any problems (it looked better than the plastic Honda item)
zedd
1968 CB350 Cafe Racer.
This is the side that is shaved back where the backing plate sits on the leg:
Standard Suzuki axle end and spacers to center the wheel:
Left side and backing plate anchor:
Right side and backing plate anchor:
Threaded sleeve to match the existing Suzuki end and fit the Honda end cap:
Finished:
And a little later - same bike with a TZ 10" 4LS:
Standard Suzuki axle end and spacers to center the wheel:
Left side and backing plate anchor:
Right side and backing plate anchor:
Threaded sleeve to match the existing Suzuki end and fit the Honda end cap:
Finished:
And a little later - same bike with a TZ 10" 4LS:
zedd
1968 CB350 Cafe Racer.
The sleeve is the easy part - look at the fixed end on the Suzuki axle and make the same thing to screw on the threaded end. I got a machine shop to make the sleeve - even has 2 flats so you can use a spanner to lock the assembly. What has to be done to center the wheel will depend on which trees you use (and how far the legs are apart). If the are slightly further apart than mine, you may only have to add the spacers.mrosso said:
As to how much to trim off the fork leg - set the wheel up and measure how far off center it is. On mine I had to trim off about 5mm and then add a spacer on the other side the same thickness. I trimmed of some metal and then hand filed the rest to make sure I didn't go too far and have to put spacers on both sides. Keep test fitting and measuring as you go.
The anchor stays were roughed out with a plasma cutter and then filed to shape to tidy them up. I drilled the backing plate hole and 1 of the top bolt holes, bolted them together and shaped from there so they are both the same shape. I then used the mudguard bolt holes for a pattern to get the location of the second top bolt hole.
You can see the 2 large diameter washers I used as spacers and the flat machined on the plain end - you could just cross drill the sleeve and use a bar to lock up brake plates and axle.
TonUpSoldier
bad assed, super fast and fully gassed
Try BikeBandit.com or Babbittsonline.com ...if its still made or even available, they'll both prolly have it.