Hi
Love the forum, and 1st time poster, 1st time builder here.
I'd like to build a 2 speed hub for my Dahon S1.
Here's the parts I've researched... (much to the thanks of Sheldon Brown's incredible pages)

Sturmey-Archer B2C Kick-Shift Hub Kit 36h 116mm Black with Coaster Brake
Sun CR-18 20" 36h Rim Black
Stolen Parts 30mm 20" PVC Rim Strip
Wheelsmith 2.0 x 12mm Black Brass Nipples, Bag of 50
Wheelsmith 14g Spokes 2.0x184

Can anyone help me with choosing a rim?
Thanks!
Chapito

it might be better if you ask the mechanics forum.

spoke length is calculated from measurements of the rim and hub, so without the measurements from the two, it's impossible to calculate the proper spoke length..

Sun CR-18 is a sturdy rim.

you should go for 1.8mm/15g spokes which are easier to lace up on small wheels, especially with 36 spokes to work with.

thanks AEO
I simply picked the 14g from the SA website specs, but thanks for the headsup!
I'll post to the Mech forum too

Check out spocalc.xls by Damon Rinard. I have used it for years and it works well. If the hub and rim are in the database it is very easy, otherwise you just need to take some measurements on the hub and rim, add them to the database and you are good-to-go.

Harris Cycles has a version, otherwise do a web search....
https://www.sheldonbrown.com/rinard/spocalc.htm

HI Pine Cone,
I tried using Roger Musson's link https://www.wheelpro.co.uk/spokecalc/ via Harris page.
Being a newbee, I just got a little confused with the terminology. I dont have the parts in hand yet to make measurements, I've been trying to pull the correct rim and hub specs off of their web pages. I'll give Rinard's a try.

Any suggestion for a rim? I'd like to find a candidate that is a good match to the Mu Duo's rims.

Thanks!

::UPDATE::
Thanks again Pine cone, The spocalc was the ticket! And a big thanks to all who share their vast knowledge with the rest of us
Cheers

You will often have difficulty finding lots of choices in quality 20" rims and spokes. You need to make sure you know which 20" rim you want, the ETRTRO 406 (most likely) or 451. If you get a 36 hole hub it is best to get a 36 hole rim, but lots of places might only have 32 hole rims.

I would try to talk to someone in a store that really knows about small wheeled bikes, ask their advice, and then buy the parts from them even if they aren't the cheapest source in the world. Good advice is worth paying for.

I worked in bike shops for about 6 years and it always annoyed us when people would ask us for advice and then buy from our competition because they were a little cheaper. I'd try Harris Cyclery or Gaerlan, or see if ThorUSA can help you. Thor posts here on a regular basis and is a Dahon dealer so he would be my first choice. I have bought from him before and he is knowledgeable and has good prices and service.

I have small-wheeled bikes (folders and a recumbent) with Sun and Alex rims. A lot depends on what sort of tire width you plan on using, what you weigh, and what sort of use the bike will get. I like double-walled/box-style rims and I like eyelets in the spoke holes.

You should also match the spoke diameter to the hole diameter in the hub. Putting a small diameter spoke in a hub with a larger diameter hole with result in a wheel that tends to break spokes. I would go for a 2 or 3 cross pattern, and the availability of spokes in a given length might influence that choice. Looks like you probably want spokes somewhere between 172 and 185mm which is too large a range to just guess. The right shop should be able to tell you what length spokes you need for a given hub/rim combination.

Good luck! It's fun to build wheels... Won't save you any money for the first few, but after that it is cheaper and you can get exactly the wheel you want.

I agree with the above. Good advice is also highly correlated with good service, IME.

Velocity rims tend to be more expensive. But my experience with them is very good.

Dan's Comp -- a BMX online store -- has very good prices on spokes. Short spokes are hard to find in LBSs.

Do you have a source for that kickback hub? I've been wanting to track one down, but I didn't think they were out yet.

I found it on the Harriscyclery special order catalog. It didn't show up through a google search I had to go to the site directly.

Thanks for the heads up on the 2 speed hub.

I Usually have short length spokes in stock .. different types ...
Interesting with short spokes is that you need polyax nipples from Sapim as they will turn in the direction of the spoke and dont bend the threaded part straight ....

Also if really tecnical you want a little more bend in the Curve.... that makes the seat nicer and faster and doesnt put stress in the neck of the spoke... :-)

Thor

Hi Thor
Thanks for the info. I'm new to this so the experienced point of view is great—an education to be exact.
I want to built this wheel so that in the future when I upgrade to something like the Dahon Mu Uno, I can swap out the stock rim for my 2spd. I selected the parts by trying to match a build up from Dahon specs.

Are the polyax nipples user friendly (or at least beginner DYI friendly)?
Would I have to use a special spoke or just the same Wheelsmith/DT type ss straight spoke?

you prolly wouldnt even recognise the difference
and yes they will work with DT spokes or wheelsmith .... but of course the Sapim spokes are better than them to start out with
and not more expensive either

thor

straight spoke you mean NON butted ..versus STRAIGHT PULL ( no bend at the head ) carefull with terminology or we make UPS rich sending stuff back and forth ..lol

LOL yes! non-butted
It's like learning a new language and grammar—I'll get it!

Thor–
I checked out the Sapim nipples online—I see what your saying—they are rounded to tilt as needed. Aren't the DT nipples similar? they also look rounded. I'm curious, is that a feature exclusive to Sapim?