Hi all! Long time forum stalker, thought I’d finally post something about a little (big) project I’m currently working on.
The basic idea is similar to the Frances Cycles Mixte Haul or ginkgo cargo bike but taller for extra cargo space and weird factor. Using a 240mm dropper should allow the rider to still touch the ground at red lights, but elevate themselves above the masses when riding.
As of now, the front cargo bay is fully welded and I’m working on the rear. The idea is to build the two parts separately and then stitch them together at the end.
Love the badge! I assume the upper BB is where the cranks will sit, with a sync chain to the lower BB as well? I’m not generally a big fan of tall bikes, but this is tall for a purpose and is actually very clever.
Been riding this thing around for a few days, its an absolute blast. Very stable and controllable, and the dropper makes starting and stopping a breeze. It’s a perfect blend of fun and weird, but practical enough for commuting and grocery runs. Haven’t had the chance to weigh it yet, but it’s not overly heavy, especially for a cargo bike.
Unfortunately in the interest of time I had to forego the custom kickstand and fork. Ended up buying an omnium kickstand and an off the shelf bmx fork on which I welded an extended steerer. It’s going to remain raw for a bit while I ride it and look out for any potential issues cropping up.
“The chain line is pretty funky, almost like a high pivot but flipped.”
Thank you for sharing, I enjoy following this build very much. Why do you need the lower BB, wouldn’t it work to rotate the rear frame ends relative to the upper BB?
The main reason for the lower bottom bracket is to allow the chain to clear the chainstays. Going straight from the upper bottom bracket to the derailleur would result in a collision in more than a few gears. There’s definitely other ways to get around this. A raised drive side chain stay could have worked, but I didn’t like the look. I thought about doing a funky bend on the chainstay to clear a direct chain, but it’s very difficult to predict the surface spanned by the chain in all gears.
Basically, just having a regular bottom bracket and sprocket on the bottom guaranteed that I wouldn’t see any major collision or shifting issues since it transforms it into a more standard drivetrain.
Also machined a little kickstand mount for the omnium kickstand. This keeps it from rotating and scraping the chainstays, which I found to be the biggest flaw with single bolt mounting style.
Basically I just needed an idler, and the cheapest/easiest way to do that was to get a $10 set of square taper cranks and cut them off. I thought about cleaning them up a little better, but people tend to find the stub pretty funny.
I built this bike in the Cal Poly SLO MechE machine shop, which has a bike builders club.
Tall bikes are just fun, that’s pretty much all there is to it!
I suppose stilts are fun too but if we go down the ‘tall is fun’ path too far, we can’t make fun of people driving jacked up trucks so, it’s a slippery slope.
anyway, was just wondering if there was a purpose to that stub on the non-drive side.
Super cool cargo bike.
I had the same problem with the kickstand. I brazed a strip on the plate with falls in the groove of the kickstand. Wanted to do two, but was afraid things move while I braze and it wouldn’t align. One works fine.
Not as pretty as your solution though
Neat! Bear in mind those grooves are for housing to run through. Keeps things cleaner. But it looks like you’re using a SS mounted brake caliper so potentially running the gear cable down the seat stay too!?
On Omnium frames the front and rear edges of the kickstand plate are turned down a few mm to capture it. Show below. Should be a pretty easy detail to replicate.
I always wondered what the actual omnium frames did for the kickstand mount. Cool to see that their solution is pretty much the same as what I made, just that theirs is built into the frame.
I did know that, but never thought about it yesterday. I did it on another cargo frame. I used than the groove going the other direction.
Thanks for heads up
