Topic: CB500/4 fuel tank question

[E]

Hi, question for those who own a Honda CB500/4. Can someone please confirm the width of the tank tunnel? I know there are a couple CB500 and CB550 fuel tanks that have very narrow tunnels and only suit the single backbone.

There’s a CB500/4 fuel tank I want to buy and checking to see if it will clear my new project bike. It’s a 1981 Suzuki GS650E and they have a 3 backbone frame similar to a CB750. I tried the tank from my other bike (CB550F) but they have narrow tunnels.

The seller states the CB500/4 tank tunnel is wider and approx 200mm In width

Thanks

[Little_Phil]

500 and 550 tank mounting is the same AFAIK, so unlikely to fit and certainly not 200mm. It's actually 110mm at the front mount and narrows to 90mm at the rear.

[Bankerdanny]

Since all 500's and 550's have the single backbone frame (basically the same frame with some minor differences for side cover tabs, and rear passenger peg mounts, and ignition switches), I don't see why any year would have a wider frame tunnel.

[E]

Oh ok I think you’re right that all cb500/cb550 have narrow tank tunnels. I believe it may be a cb450 fuel tank reason for the 200mm tunnel width.

Anyone have success fitting a much smaller fuel tank on a bigger frame bike with 3 backbone without modifying the fuel tank?