I thought a good inaugural post would be to share a bit about the bike R and I ride. The title of this post may seem a bit like gibberish if you’ve never looked into e-assists (electric assists) for bikes, so let me explain. The Stokemonkey is a particular kind of electric motor, powered by a battery and hooked into the bike drivetrain, meant to help power the bike when heavily loaded or handling steep hills. It’s on demand, with a small throttle located, at least on my bike, on the left handlebar. It’s been a great addition to the bike.
G&O Family Cyclery here in Seattle installs a lot of these systems on the bikes they sell. They specialize in Xtracycles and sell high quality set-ups and gear. They are, from what we hear from many family bikers, one of the best places in town for e-assists and all things family biking, so naturally we took our Yuba Mundo there for the conversion.
The conversion on our Yuba was a bit of a challenge, so I thought I would share what we learned during the process. First, about the brakes. We wanted disc brakes on both wheels for extra stopping power. Tyler, at G&O, discovered some problems with the mounts that made that difficult. They had been welded on slightly crooked, so he called Yuba and they promptly sent a replacement set of forks since it was obviously a problem from the factory. The replacements were even worse. He ended up facing (grinding slightly) the slightly better mounts on the original fork to flatten them out and allow the disc brakes to be installed. Unfortunately the rear mounts were worse. As they are much less accessible than the front mounts it is very difficult to face them. It requires a special jig, and essentially the mechanic has to also be a skilled machinist to face them correctly. So, we ended up with calipers on our rear brakes. This really hasn’t been a problem and many people rocking the Mundo have the same setup. I found I can stop completely using my rear brakes, albeit in less time than adding the front brakes in, so I’m not concerned about this compromise. So, be aware, your Mundo may not be perfect from the factory and your mechanic may have to use some creative problem solving to correct for it.
The second big thing to note is that the default mount for the Stokemonkey is problematic on a Mundo. It often begins to work out of place, messing up the chain tension and causing problems. One answer is to tighten it slightly over spec, however you run the risk of damaging the seat tube. The answer to this on our bike is an aftermarket mount designed for the Mundo. It is not readily available and a local machine shop created it for us. Time will tell, but it seems to have solved the problem. So, if you can’t find that sweet spot of tension on the mount, consider having it modified to fit the seat tube better.
All in all the process took longer than either we or G&O expected it to. Although a little frustrating for all parties involved, it was their first Yuba conversion and it did result in some good learning. My wife and I are very pleased with the results and in a couple more weeks we’ll be swinging by the shop for a one-month checkup to make sure everything is still in spec and fine tune anything that has changed during the break-in period. If you live in a hilly town I highly recommend the e-bike conversion for your cargo bike, especially if, like us, you live near the top of one of the steeper hills in town.
My Yuba Mundo with a Stokemonkey e-assist.