Tandem 24" Electric Bicycle Conversion

I have now converted my tandem bicycle to an electric tandem bicycle using a new 8Fun 24V 250W motor installed to the front wheel. The new hub motor model # is SWXK24V250W205R and has no engraving on the drive/right side. My 5-year old SWXK24V250W190R has engraving that says 'ZL200320123400.9 The brushles motor for e-bike'.

24" 6-speed Adventurer folding tandem bike manufactured by Intersource Enterprises and sold by Camping World for 269 USD. Converted to an electric bicycle by replacing the front wheel hub and spokes with an SWXK 8Fun motor hub from LEED and 203mm 12g Sapim spokes from Holmes bike. The cable and 30K Samsung battery pack are from LEED. 

The original tandem looks like this

The original handlebar has been replaced with a 620mm 6 degree mountain bike handlebar. A pannier rack and rear mud guard have been added as well.

The original lacing of the front wheel is 3 cross using 36 Sapim 12g spokes and nipples as can be seen here

The original aluminum rim, interior tube, and tires were used and only the 12g Sapim spokes and hub were replaced. I initially used spokes supplied by Clean Republic (203mm 13g spokes of an unknown brand). The 8Fun motor is from LEED although the same can be purchased from Clean Republic for the same price. LEED provides free shipping though. (Update: I just got a word from LEED that they also sell spokes although you will not see this anywhere in their website e-bikerig.com, instead you have to order it by email.)

The 8Fun motor hub is bigger so the only way to re-lace the wheel is by using a 2 cross pattern.

I road tested the re-laced wheel for 6 kilometers to see if the truing will hold and to set the spoke tension to its permanent position. The trail consists of at least three 4% grade climbs and one long 6% grade climb. The total road testing weight of two riders is 250 lbs and the original bike (with the 12g spoked front wheel) has a maximum capacity of 400 lbs. I tested the new 13g spoked wheel in longer rougher rides more than 6 kilometers and steeper grade climbs. Update: the 13g spokes made rattling sounds because they are too small for the wheel and the weight. I had to replace them with higher gauged spokes.

12g Sapim spokes from Holmes Bikes 

I custom ordered a set of 12g Sapim spokes from Holmes Bikes which I used to replace the 13g spokes I initially installed. After doing so, the wheel spokes no longer make rattling sounds like before. They are all tight and strong and the wheel feels smooth to roll.

Lacing the front wheel using 2 cross pattern

Lacing the wheel is a bit different from the DIY instructions that can be found on the Internet. Most of the stuff available are 3 cross instructions. One has no choice but to use this or this. What is not clear in the instructions is where to place the key spoke relative to the air valve hole such that the result will give access to the hole. The usual instruction is to place the key spoke on the top hole to the left of the air valve hole. I did that blindly at first and ended up with the air valve hole without access. Then  I discovered that one has to start on the left/non-drive side with the key spoke placed to the top hole to the left of the air valve hole. Otherwise, if the key spoke is placed on the right/drive side then it has to be placed one rim hole to the right away from the air valve hole and follow the sequence described here since the rim has right hole on the bottom and you can only put the key spoke on the rim top hole.

NOTE: More posts on e-bike conversion projects are available here.