I had posted about this 21" front in some other threads and tried to find them but this one came up and I think the thread title matched the subject better anyways...
I just wanted to give a report about my new 21" wheel after a trip to Death Valley let me try it out for the first time. I got these as an extra set of wheels so I'll put my Tourances back on my stock spoked wheels for street use. The specs on these (from Woody's Wheel Works):
Supersize Superlace & True
Seal Bike Wheel rear can go TUBELESS
Rim Excel 1.60x21 A60 with rimloks WITH ROTORS AND ABS RING INCLUDED
Rim Excel 3.50x17 Black
SS Spokes & Nipples
Superlite Hub Brake Adapter
Superlite Hub Front Dual Billet custom
Superlite Hub Rear billet..super tasty...
I was asked if I felt I was giving anything up on the street. I don't really ride the bike in the corners like a lot of others do so it's hard for me to say what I've given up. I still hit the corners at a good clip but wouldn't really get that aggressive. I still have the other set so I can put those back on for street use anytime I want.
As far as offroad performance goes, I've noticed a big difference. I was going through sand a LOT easier, as well as over rocks and larger obstacles.
These wheels are also a LOT stronger, so they'll take more abuse.
Even though the wheel still works with the fender, I took it off because I heard that because the clearance is so much less that even a small bit of mud can bring you to a standstill. I wish there was a better fender solution out there for the 21" front. Wunderlich has one but you have to buy this new $800 fork clamp set and that seemed like a total waste. Touratech has a "rally" front fender that is supposed to have more clearance but don't know if it's meant for the 21" wheel. I doubt that it is. There isn't a whole lot of mud out here in SoCal anyways, so it hasn't been an issue in the 13 months I've been riding this bike.
Without a fender, I have to deal with more crap hitting the headers and the engine, as well as water and mud splashing up through the forks and handlebars into my face. I even had a small rock fly up and hit me in the face shield. If you have an upgraded skid plate like the BDCW one, that should help a lot. I've seen the header guards out there too.
I am also now running a tube up front so that means I have to have my front wheel removal tool, extra tubes, tire irons, etc... in case I get a flat. With tubeless, all I needed was a plug kit. But so far no flat, so that's cool. I'm doing a Baja ride and will put a bit of slime in it just for good measure.
So in a nutshell I'm really pleased with the new wheel set. 21" does make a big difference and meant I could do more and enjoy what I did a lot more. I wish I had a fender and now have to hassle with tubes, but I'm largely happy with it.