SS50 wheel upgrade - 17 inch to 18 inch?

[bobbabits]

Hello all, as a project I'm currently turning an SS50 into a cafe racer style bike. However, I'm over 6ft so would like to fit larger wheels than the standard 17 inch ones. Does anybody know if I would have any issues fitting 18 inch wheels from a CG125? Thanks

[hairygit]

The things to watch for are clearances between tyre and mudguard, the front especially. Also the speedo will read lower than you are actually going (Imagine the embarrassment, a speeding ticket on a moped!) plus gearing will need dropping, say one tooth smaller front sprocket. Or you could go really crazy, join the C90 club forum, there are guys on there that have modified SS50 motors to 108cc without any visible changes to the external appearance of the engine!

[bobbabits]

The things to watch for are clearances between tyre and mudguard, the front especially. Also the speedo will read lower than you are actually going (Imagine the embarrassment, a speeding ticket on a moped!) plus gearing will need dropping, say one tooth smaller front sprocket. Or you could go really crazy, join the C90 club forum, there are guys on there that have modified SS50 motors to 108cc without any visible changes to the external appearance of the engine!

Thanks, no mudguard on the back and the front one will be replaced with a chopped version. I was more concerned about touching the frame.

[K2-K6]

It's not going to make that much difference in the height of the finished bike as it's only 12.7mm greater on wheel radius.

https://tiresize.com/comparison/

The above link maybe of use to help calculate the difference between the two.  Although it's directed towards car stuff it'll give you some accurate dimensions to assess clearance and what you gain/loose.  You'll need both tire specs to work but that shouldn't be a problem. 

[bobbabits]

It's not going to make that much difference in the height of the finished bike as it's only 12.7mm greater on wheel radius.

https://tiresize.com/comparison/

The above link maybe of use to help calculate the difference between the two.  Although it's directed towards car stuff it'll give you some accurate dimensions to assess clearance and what you gain/loose.  You'll need both tire specs to work but that shouldn't be a problem.

Thanks.

Does anyone know if the CG125 wheels will fit easily? They look like a good swap as already have the drum brake, etc.