Hi folks, I thought I would share my experience on building an Xtracycle cargo bike using the Free Radical and a host bike. Perhaps it will be of use to those considering doing the same. I was considering responding to some posts but thought I would just put it out there in one place. Warning: Opinion lies ahead!


Host bike selection (or donor bike to think of it that way):

First of all I'm sure the dedicated Xtracycle frames like the Big Dummy and especially Xtracycle's own new frame the Edgerunner would be the best selection, but are costly. I'm only addressing the host bike for the Free Radical and folks with a little DIY in them.

Xtracycle says almost any bike will work, and I'm sure that's true, but I think it's worth putting some thought into the matter, and not just using that old bike collecting dust in your garage just because it's there. Maybe it does fit the bill, but if not, go down to your local used /recycled bike emporium, Goodwill, or get on Craigslist and find someone else's dust collector for like $50 or less. Exchange your dust collector while you're at it. My opinion: 26" wheel mountain bike with a rigid fork. 700c mixte frames may be tempting and I know of one converted to 650 that looks nice, but you want sturdy and beefy and lower to the ground, so an overbuilt mountain bike frame just makes sense and are easy to find. Rear suspension will absolutely not mate with a Free Radical and would be pointless anyways. Front suspension is also pointless. If your bike or the one you find has a front shock, no problem, just replace it with a rigid steel one. You can find those cheap at the used places, or online from Surly and others. Let me be clear, a front shock on an Xtracycle is at best useless extra weight, and it also will likely degrade the handling of your bike. A Free Radicalized Xtracycle, b/c of the length and design is plenty noodley and springy all on it's own and with the decently wide tires you should run on it, you don't need a shock pogoing around as well. It's not like you are going to be hucking dirt drops on it down a mountainside.

I found mine with the Free Radical already attached off of Craigslist. It's an old (reeally old) school mountain bike from mid-80s. It has worked fine with the mods below (which should be considered with any Mtn bike) but I'm considering swapping it out for what I think would be best option: an overbuilt aluminum frame mountain bike with a sloping top tube. Think of a late 90s Trek, Specialized, etc. I saw a frame only last week that would have been perfect except the size was too small for drumroll... $25.
I'm a fan of the old ways, including lugged steel, but a stiff, oversized Alu tubed frame I think would work well in a Free Radical set-up which tends to be a little too springy. The more modern style of mountain bike frame geometry with the steep sloping top tube would be nice because of the step over factor. It's hard to swing your leg around the seat to mount an Xtracycle, especially if you have kids back there, so having a lower top tube makes sense.

Remember you'll need a frame with a chainstay bridge to mount the Free Radical. Those are the majority so it shouldn't be a problem. I think Xtracycle has a way around that, but why bother since you can easily find a bike with a chainstay bridge and your build will be more secure with one.


Get that weight low:

In my case I'm using the bike to haul around 90+ lbs of children (in two units) and/or their crap, kids bikes, a family grocery load, etc. You want to get that weight as low as possible for stability and control. Especially important with kids since you can't stuff them down low in the cargo bags, they have to sit on top What I ended up doing was building up a 24" rear wheel. This lowers the rear end and has several other benefits as well, here's the list:

1. Lowered the rear end by about an inch (from the standard 26" mountain bike wheel)
2. Allowed me to cut down the Xtracycle cargo racks by 0.75 of an inch, thus lowering the load even further. Yep, used a hacksaw, no turning back now!
3. Corrected the bicycle geometry. In my case anyways, the Free Radical resulted in the host bike frame being tipped forward from normal (I could easily tell, b/c the parallel top tube was no longer parallel), so lowering the rear end helped correct that. I suspect the 24" wheel would help, or at least not hurt, the geometry and handling with many mountain bike Free Radical set-ups.
4. Slightly lowers the gearing. Running a smaller rear wheel will lower your entire drivetrain's gearing, not a bad thing on a cargo bike.

I note that Xtracycle stole my idea as their new custom frame has a 20" rear with a 26" front. OK so one potential downside is that you can no longer use rim brakes on the rear b/c the brake mount posts are now too high to allow you to mount cantis or v-brakes to engage a 24" rim. I didn't consider this a problem because:


A disc brake, on the rear at least, makes a lot of sense.

I've never had disc brakes before, and I don't run them on my other non-cargo bikes. I don't have a problem with the stopping power and utility of rim brakes. However I pretty much had to go to a disc brake when I went to a smaller wheel, and in use it makes a lot of sense. If you are going to go to a 24" wheel, which I highly recommend, then you may as well use a disc-compatible hub in the build. Being a modern thing, the Free Radical frame has a tab on it to mount a disc caliper. In my case, it allowed me to make other improvements as well. My host bike rear wheel was so old that it had a 120mm OLN (hub width) with a 5-speed freewheel. The Free Radical is designed around the modern standard of 135mm OLN. My axle was mounted with a whole pile of cludgy washers to get it out to 135mm. Since I was building a new wheel I naturally used a 135mm freehub and put a wide range 8-speed cassette on it. I could have used a 9-speed too of course, but didn't see the need. So building a 24" rear wheel not only lowers the load, but gives you an opportunity to add a disc brake and to modernize or improve your rear wheel gearing. Here are the advantages of having a rear disc brake:

1. Mainly, you get a very effective drag brake. Heavy bikes, like tandems for example, have been set-up with special drag brakes on the rear wheel for years to help control speed on descents. Living in a hilly place like Seattle, I find this to be a critical feature of a heavy, long and somewhat awkward xtracycle. Many times I have riden down hills with my kids on the back, feathering that rear brake most of the way to safely control my descent. The disc brake works well for this b/c it modulates really well and doesn't overheat and fade like a rim brake would. I feel much more confident on these descents knowing I've got that disc brake back there.
2. Due to cable routing and hanging issues you really shouldn't use cantis on the rear (I know, my bike came this way). V-brakes won't have these cable problems. However access to the rear brake to make adjustments is a minor PITA with the Xtracycle racks and bags in the way. The disc caliper is a little easier to get at, and it's true, once set up they need very little adjustment.
3. If you're a retrogrouch like me, don't worry, the entire mechanism is hidden behind the cargo bags, no one will know!

Note, I still run a cantilever on the front wheel and that works just fine. If you have or want a disc brake on the front, I'm sure that would work great, but I haven't had problem stopping the bike with the cantilever. Of course a V-brake would work as well. It may seem a little odd to have a set-up with the more powerful brake on the rear end, but in the Xtracycle case it works well. Note that if you do want a front disc brake, then your host bike will need to be modern enough to have a 1.125" threadless headset, since disc rotor tabbed rigid forks are only available in that configuration - trust me I've looked. In the mountain bike world that puts you in the mid to late 90s or later, so still a good range of years.


Center kickstand:

I consider this to be an essential, non-optional Xtracycle component. Mine came with a only a side kickstand and loading the bike was awkward, frustrating and in the case of children as cargo, downright dangerous. Without one the bike will fall over on you sooner or later. A cargo bike needs a center kickstand to be stable and loadable by one person. Xtracycle's model works well and I just had to bite the bullet and buy it ($150). I'm going to fabricate leg extensions for it by cutting down a kid's handlebar to make it even more stable - there's a youtube video about how to do that. Xtracycle also sells extensions.


So I have other opinions about the handlebars and shifters, etc. but that's getting more into personal preference and whatever works for you. Photos of my Xtracycle are attached. They are fun build, fun to ride, and good for you and the planet - go for it!

Hmmm cost. I didn't keep track and it would vary depending upon your scrounging and DIY abilities as well what you need in the final product in terms of the rack and accessories, but I think you could build a center stand equipped bike with basic racks for around $600-700.