ehhhhh

>>1078556
>Going from a 16" to 18" rear, same profile tyre.
>Will it affect gear ratios.
Yes, you've increase the size of the wheel by 12.5%, making the gearing taller overall.
>Will it be fine?
Probably, so long as the wheel fits and doesn't rub on anything. I guess make sure the wheel is the same width as the old one.
>Will it be sluggish, lose top end?
Taller gearing means that your theoretical top speed increases. Your 18" wheel has a bigger perimeter to rotate around than the 16" wheel, so for the same RPM the larger wheel will go a further distance. But by the same token, your engine now has a larger lever that it has to push on, so you'll lose acceleration.

>>1078703
This is why you can swap sprockets.

His info is correct, just adding.

>>1078705
Forgot about the sprocket. I was thinking along the lines of changing car wheels.

While your putting your larger wheel, increase the size of the rear sprocket as well. That will get your gearing back into factory spec.

>>1078705
>>1078712
thanks lot that makes sense, yes will check the wheel clearance to avoid any rubbing

>>1078556
>i have a shitty motorbike with a 16inch rear wheel

First thing to learn is post the YEAR, MAKE AND MODEL. Chantards think all bikes are identical. What the FUCK is wrong with you people that you refuse to post what you are working on? I've never read so many bikeposts where that's a secret.

The reason is someone, somewhere has already solved your problem.

Keeping it real, the diameter won't mean much but what does matter are the rear sprocket offset which must match your engine sprocket, the tire centerline which really should be same as front wheel but a little bit off say up to an inch isn't critical for fucking around, tire clearance of course, and the rear brake design and layout.

Buchanan's make custom spoke kits for anything so lacing on an 18" rear is an option, but if your bike is an expendable turd or you are thrifty you should consider throwing a 16" Shinko or other old style tire on it instead because that gets you the look without the hassle.

http://motorcycleparts2u.com/shinko-sr241-series-87-4441-wp

If you have a vintage Triumph like pic related you can easily find complete wheels online or at swap meets, or check chopper forums since chopper guys like 16" rears and may trade.

Custom sprockets for anything are easily available.

If you post a build thread on Chop Cult you may find someone doing similar mods to the same mysterious "shitty motorbike" or a model close enough to copy.

Wheel swaps to different wheels usually mean making axle spacers. If drum brake may need a custom torque arm. If disc you should get the complete wheel with caliper and all the hardware you can manage but not just any random wheel will fit.

Is the picture your motorbike or à random scrambler you finded on Google ?

>>1078841

I'd rather see my sister in a whore house than my father with a shinko.

Get a tyre that might actually stick to the ground.