21/16 combo will run fine without lowering (look at any stock bike that has that combo)

18" rear would have to be made or vee rubber makes one.

Have you thought about an 18x4.25 rear? That's what I run

18 rear will look more custom than a 16 and shows off the wheel more

 

As others said, the 120/70/21 is the proper size to use with the 21.

The overall dimensions of a 16 and 18 are nearly the same. The 18 will show more spokes and when you lower the bike will give a bigger impact by tucking the rim into the fender. And will give a more custom appearance as Kozy said.

IMHO if going with a 21" front the 18x21 is the right match and worth the few extra coins.

 

Oh and btw, the extra for the DB WW is definitely worth it and will not only look a hell of lot better than a Vee, but will last at least twice as long. The WW is a matter of preference, however, the WW is what really made my setup work. So it just depends on what kind of statement you want to make just as whether or not you'll want a 16 or 18 rear.

 

I know Kozy has recently done his wheels. How much "approximately" would just the tires probably set me back (white walls--prolly end up getting from DB)? Just looking for ballpark based on others experience.

 

21, 16 for me. If you ride alot of miles and go thru rear tires like I do the 16 is the way to go. I also think the 21, 16 combo has a more old school look and makes the 21 stand out more. Thats just me. What ever you do it will look and work fine for you. Good luck and get some pics out when its complete. Later brotha.

Stone

 

I agree with Stone. 21 front 16 rear. Just in case you should get a flat on the road the 16 www is pretty much readily available. 21 front 126 rear without lowering? No problem. The prices for all tires increased this year in February regardless of the manufacturer as I assume the price of rubber increased.

If you run a 16 in the rear as opposed to the 18 the rear of the bike will sit a little bit lower than with the 18, but not very much. The goal of the lowering is to even out front and rear heights so the bike is more level. Figure a Diamond Back WWW is $75 per side plus the price of the tire. The tires at dealer cost are between $160 and $200 so you do the math on that plus the availability issues.

Whatever you choose we wish you well.

 

You can always throw some lowering bolts in there 'till you can go Shotguns...

 

Agree with Stone, whichever you go with will look great. It's all a matter of personal prefrence, neither is right or wrong. Using the same flat tire analogy I'd have to guess a 21" probably won't be much easier to find.

 

Thanks for the info guys. I am leaning towards the 21/16 combo. I just emailed KC Int and choppershop1 to see who can give the better price quote. Thanks again.