Quick preamble. Daughter is 5 1/2 and enjoys riding on the 7 speed version of the trail-a-bike. Since a lot of the riding will be with her I'd like to make the tow as enjoyable for me as possible. We tested her capacities on a ride that ended up taking us over 45km on 10-15° ascents and descents (we had planned for a 35km flat course!). She loved it so lets find a solution that doesn't weigh 40 pounds + excluding the rider in tow. She'll use it with us for a least two more years if not more, so transforming it is worth it. My real first option would of been be a tandem with an adjustable crank apparatus or a Co-Motion periscope but shelling out $5k for a tandem that the girlfriend may never accept when the little one grows up isn't a viable option.
The rear fender is off and the stock pedals have been replaced by a pair of XT platforms I had lying around.
I believe the part that would have the biggest impact is the wheel, the current one weighs a ton. I haven't had much luck in locating a 20" mounted wheel but I did find interesting rims on recumbent sites. Since a new wheel is in order, I'm taking this opportunity to think about gearing. I toyed with the idea of using a Capreo or a Nexus/Alfine hub, but since higher gears aren't the goal here I believe sticking with a classic 8-10 speed compatible hub is the best choice. I own many 9 speed cassettes so that's an easy choice. Any wheel recommendation?
9 speed means the problematic grip shift (no way a 5 year old can use one) is out the door and a replacement will be installed. I'm looking at three options: bar end shifter installed on carbon drop bars (another available item in the shed), 9 speed down tube shifter installed on the main tube or Tiagra R440 Flat Bar Road Shifter. Opinions?
Another drivetrain issue is the crank. The current one is crooked and the BB isn't worth much. I thought locating a single chaining crank with 135mm arms would be simple. I'm most likely not looking in the right direction because I can't find anything let alone expensive custom models. Anyone?
I'm not going to touch the seat post since it's a vital part or the folding frame and the seat can't weigh that much. This leaves frame modifications and I'm tempted to grind off the crank protection tube. I'm no engineer but I can't see how this extension provides any vital role in the frame strength.
Anyone else riding 50k+ with a 5-8 year old?