How hard to use a dirt bike 21" rim on HD chopper?

[Unholyghost]

In the fashion of old school chopper building, I can't afford to buy the bike I want, so I'm building it! I'm a poor degenerate with a 77' Ironhead swingarm chopper build. I want a 21" front wheel to give me a little more lift and that proper chopper feel. Can't afford a proper 21" HD wheel.
I had a mechanic recommend that if I'm not too picky a cheap way to go would be a dirt bike front tire. I looked em up and the price difference is staggering!
I've since been searching for more information about this swap. Like, how does the axle size effect my decision? Do brakes factor in? Can I run a street tire on it?... etc. There's nearly no talk about this process at all, ANYWHERE.
It seems like this practice would be handed down from the grandpappys of choppers, yet no information on forums.
I don't want to abandon the front brake all together so I'm thinking a drum brake would be cool (cleaner bars, less mess, still have some front stopping influence.) I want a skinny front tire, too. This seems perfect, and cheap.
How can I run an old dirtbike wheel and make it work on my 77', 4+, 35mm, 3/4 axle?

[Rninet]

It will probably be a bit of work , dirt bike rims are usually 36 spoke and Harley's are 40. So lacing it to the hub is out .,I machined up all the bits to mount a KE 175 rim to a Norton front end for a buddy . It was a lot of pissing around to get it figured . If you were paying for the machining a new Harley rim would be cheaper. He never finished the build so I never found out how it worked.

[beanhead78]

by the time you do a bearing swap/ hub machined, etc... have patience and just get the proper wheel. eg, i had a 16" harley wheel laced to a bsa QD hub. i wanted an 18" because of primary clearance offset. saw one on ebay, couldnt afford it. put it in my watchlist, about two weeks later i got a notice. buy it now, complete runnable wheel and rubber sent to my front door for 30 bucks. sometimes the sun shines on a dogs ass.

[feelyx]

less than 100$ build your own....
http://www.ebay.com/itm/1974-77-Harl...BX-Vye&vxp=mtr

http://www.ebay.com/itm/2-15x21-Drop...5XlmHM&vxp=mtr

http://www.ebay.com/itm/40-UP-WG-CHR...FXs3EW&vxp=mtr

[Unholyghost]

Ya' know, this would be the most old school way to do it. I've never built a wheel before and the idea of it seems a little daunting. This is only my second build and the first looked very amateurish. I'd throw a chopper stopper on one of those and have the perfect front end for this bike. Is trueing and lacing a complicated science?

Edit: Looking at used narrow drum brakes looks like building it myself is pretty pricey too. I'd really like to get rid of my reservoir from the bars but keep a brake. It seems like I can't get the wheel I want for less than $500, after rubber.

[Unholyghost]

I've definitely got a lot of lines out on eBay with my fingers crossed for some price drops. Winter is coming and I've got time.

[feelyx]

http://sheldonbrown.com/wheelbuild.html

This is about building bicycle wheels, but same principals apply... it really isn't hard to build a wheel, give it a shot

[TurnerR]

Go to a swap meet man. You can find wheels from 25-50 all day long and usually have a tire on it. May be worn, but lets you get the ball rolling. You will spend waaaaay more trying to build a wheel than just buying a complete one.

[Unholyghost]

I'm up in Seattle, the swap meet culture around here is slim. People here seem to hoard the good stuff.

[nuklhd]

lacing and truing a rim is all shown in the manual. lacing is not hard, truing it up is just time and patience. not for nothing but that link for 12 dollar spokes is scary. are they plastic spokes? that's awful cheap.

[feelyx]

lacing and truing a rim is all shown in the manual. lacing is not hard, truing it up is just time and patience. not for nothing but that link for 12 dollar spokes is scary. are they plastic spokes? that's awful cheap.

Says closeout of new old stock.... ?? Roll the dice......??

[feelyx]

Is trueing and lacing a complicated science?

Not complicated at all, once you figure your first one out, its all down hill from there... I charge 70$ to lace and true a motorcycle wheel and 50$ for bicycle wheels... You would be surprised how many people break spokes.. especially the lightweight bicycles. Learn it and it can pay for your addition.

[panheadpete]

Front drums suck - try and keep the disc

[Unholyghost]

Front drums suck - try and keep the disc

It's true that they aren't as effective/safe. I honestly have a bigger problem with the mess on the handlebars and the look of the rotor. Ultimately, I want a bike that is fun and looks the way I like. If I wanted safe and reasonable I'd get a Volvo wagon.

[panheadpete]

There are numerous ways to clean up your bars and still run a disc - maybe consider "mess on your bars" vs the mess on the Volvo wagon when you hit it.

Maybe its because Im almost 50 and have run bikes with no front brakes, drum front brakes, OEM discs and A/M discs - But i LOVE good brakes and have had too many close calls to have anything else on my bikes that are regular riders. I'll take alive and well over hipster cool any day.

[beat]

feelyx- rite on w/ mr brown.

OP- lacing wheels can be frustrating, but its really not that hard.
the hard part is trueing 'em up. well, that aint that hard either if its a front wheel usually. it just takes time & patience.
on a rear wheel it does get tough if the wheel/sprocket needs some offset.

but yer asking about a front wheel. usually no offset. if you lace and snug the spokes right you shouldnt have to work out the "hop" up&down motion. you just need to dial in the side to side motion..patience.

way off subject, but no one ever told/tought me this and i never read it in any manual but i figured it out myself after building many bicycle & motorcycle wheels.
to true a wheel it must be a spoke count of a base 4. 36 like most japs. 40 like most american and brit bikes...some fancy shit w/ 80 or 144 spokes.
i could be wrong,but i dought it. to get the wheel in line it needs a spoke count w/ a multiple of 4.

OP- i have a mid 70s sporty 21" wheel single disk(w/o the disk) w/ a knobby tire on it i keep around for mock up.
if ya want it hit me up.
it wont be free, but damn close...and shipping from VA to WA may not work for ya.
who knows?