[paduck2003]

Why is the front rim bigger than the rear rim on motorcycles? Mine is a 19 in the front and a 15 in the rear


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[Mark-B]

Could be that a smaller diameter rim - tire? will deliver more power to the road. I'm not sure to be honest.. But sounds like it could be an excuse.

 

[JDLowEnd]

I think on the Honda bikes the rear is almost always the same, among the same line of bikes. I think this is probably for production reasons, easy to push out mass amounts of the same thing. The front wheel is based on style and design of the bike aero/ace vs. spirit/phantom. Although I can not tell you why they did not make a 15'' front wheel. Maybe to be different from Harley?

 

[MikeB]

It's an interesting question. I'm sure there are many theories but the one that is probably most valid is the old "it's always been done that way so it would look funny otherwise."

There are many things about motorcycles that ignore technological progress or practicality in the name of tradition. Harley-Davidson has made it a sucessful corporate strategy.

 

[gat803]

It has to do with a lot of things.

The motorcycles particular intended purpose, frame geometry, front end rake/trail, all play a part. Add to that gyroscopic stability, weight, and greater/lesser rolling resistance....and appearance/style comes in a distant last.

Machines that travel off road will usually wear something close to 21" up front. This lets the tire roll over bumps and ruts more easily. It also allows the front to "lead" the rear better (so to speak) Smaller front wheels have a tendency to push (understeer) in low traction turns. If you want a bike to handle well when power sliding, you'll put a larger diameter wheel up front. (the current drift fad, not withstanding. lol)

Sport bikes often have the same size rims, front/rear. Again, has to do with stability in the intended environment. Cruisers are low performance machines, so style and appearance will usually overcome good handling manners. This is why we're starting to see these ridiculous big (23" and larger) rims up front.

There is more to it than the above, but this gives a basic description without writing a book...

 

[Mark-B]

Gat, you are ..like ..The Wikipedia of Bikes! I often read your stuff - just as a gauge - to tell exactly how ignorant and full of crap I am :mrgreen:

Balloonot and John Hopkins (amongst others) too.. On the technical side those dudes are like ..?? I don't know.. The Bike Whisperers, or something..

 

[2500hdon37s]

It has to do with a lot of things.

The motorcycles particular intended purpose, frame geometry, front end rake/trail, all play a part. Add to that gyroscopic stability, weight, and greater/lesser rolling resistance....and appearance/style comes in a distant last.

Machines that travel off road will usually wear something close to 21" up front. This lets the tire roll over bumps and ruts more easily. It also allows the front to "lead" the rear better (so to speak) Smaller front wheels have a tendency to push (understeer) in low traction turns. If you want a bike to handle well when power sliding, you'll put a larger diameter wheel up front. (the current drift fad, not withstanding. lol)

Sport bikes often have the same size rims, front/rear. Again, has to do with stability in the intended environment. Cruisers are low performance machines, so style and appearance will usually overcome good handling manners. This is why we're starting to see these ridiculous big (23" and larger) rims up front.

There is more to it than the above, but this gives a basic description without writing a book...

very true of what said above, but starting to see 23in+ wheels.... they're HERE, 30+ in wheels are here! Pointless if you ask me. Just a fad like the "donk" cars and "cen-cal" lifted trucks that run big wheels and rubber band tires, hopefully it'll die out soon. But its hard to stop a fad that says "look at me, I spent THOUSANDS PER wheel!"

I personally LOVE the 17/19 set up on my bike. front isnt too big looking and it still handles great.