Category Archives: tech zone

Build Your Own Custom Mundo!

So you want to build up your own Yuba Mundo Cargo Bike?  

Here’s a post to help you cover the basics.  

Sweet Custom Tangerine Yuba Mundo Cargo Bike

Sweet Custom Tangerine Yuba Mundo Cargo Bike. (With Monkey Bars, Bread Basket, Stand Alone, etc.)


The foundation of your dream ride!

A custom Yuba Mundo is a great way to show off your personal riding style, from the look to the ride.  Here are some basic components to consider when building your Mundo:

– Yuba Mundo Frameset 

 – Rear Wheel – The Mundo’s rear drop-outs are 14mm, not 3/8″ (10mm).  So, you’ve got some options here:

  • Purchase a Yuba Mundo Rear cargo bike wheel.  This is the easiest and likely the cheapest way to go unless you already have a rear wheel.
  • Purchase a set of Yuba Axle Adapters.  These fit over the round axle and space a 3/8″ wheel in a Mundo dropout.
  • Find/Build your own wheel based on a BMX-style 14mm axle.  (You’re on your own here.)

    14mm to 10mm Axle Adapters

    14mm to 10mm Axle Adapters

Yuba Seat post (it’s an unusual size at 31.8mm x 500mm, so its easiest to get it from us)

You can purchase a seatpost from Yuba. Our seatposts are 500mm.  This is needed if you are over 6-feet tall.  Otherwise, you can purchase a 31.8 x 350-400mm from most bike shops.

Wheelskirts (if you ever are going to have children ride on the back, they’re required.)

We also strongly recommend these accessories:

– Utility deck  — You can make your own, but in case you’d rather not…

– Stand-Alone Kickstand — Nobody makes a stand like the “Stand-Alone”.  This kickstand ROCKS!

– Deflopilator — Keeps the front wheel straight when the bike is on the Stand Alone

And one more thing:
Mundo Chain (156 links!)

(Of course, there’s always the full line of Add-ons to trick out your new custom Mundo, such as the Bread Basket and the Go-Getter Bag.)

Custom Mundo FAQs

Rear Hub Spacing: 135 mm

Maximum Tire Clearance: 2.15 in (with standard drive train).


When you’re done, we’d love to see a picture of your Custom Mundo, either by email, @YubaBicycles on Twitter and Instagram, or Facebook.

Transporting Multiple Bikes by Mundo

Periodically we repost a tutorial or other useful content from Yuba riders. This tutorial, from Gray Harrison of the Me and the Mundo blog has some great ideas about how to transport multiple bikes by Mundo. Enjoy!

There has been a lot of interest in the posting about carrying bikes on the back of my Mundo, so I’ve decided to put up some more details and a “how to” on the process.

The original inspiration for trying this out was that the Fort Collins Bike Library needed to move about 65 bikes from their storage location to the downtown library kiosk.  New Belgium Brewery was hosting a meeting of folks from around the country to plan this summers’ Tour de Fat festivities, and all the visitors needed bikes.  The plan was to ride the bikes from storage to the library, and then walk back to the storage to pick up another bike.  Repeat until done.  I volunteered to help move the bikes, but not being a fan of walking I figured there had to be a better method, and thus the Mundo Multiple Bike Loading System was born.

In front of the Bike Library
Carrying 2 bikes at a time.

The basic idea was pretty easy: get a couple of v-shaped bike trays, such as those made by ThuleYakimaRocky Mounts, mount them to the Mundo’s outriggers, and start moving bikes!  Sounds easy, and as it turned out, it really was.  A few technical details needed to be worked out, as I will show you, but it didn’t take long to figure out.

Here are the things you’ll need:
(2) full length bike trays
(4) 1″ hex-head stainless steel machine screws with the same diameter and thread pitch as the ones that come mounted in the Mundo’s outriggers.  (The stock screws might not be long enough to go through the bike tray into the fitting).
A drill
A measuring tape (to measure exactly where to drill the holes in the trays).
Some old carpet or other material to protect the frames where they contact the Mundo in transit.
(2) Yuba 3 meter Cargo Straps (or similar).
(1) hour of time to do the first installation. (Note: once everything is measured and drilled, the process of removing or installing the racks takes less than 5 minutes).

Detail 3
Here’s what the final installation looked like.  The trays are different styles only because they were the only 2 available at the time.

The most expensive part of this project were the 4 stainless steel machine screws, as the used bike trays were donated by the Fort Collins Bike Co-op.  Getting a tray or 2 for a project like this could be a bit of a stumbling block, but if you keep your eyes open you can probably find one on craigslist, your local community bike shop, or even at a metal recycling center.

Although the original inspiration for the project was a short-term job, my long-term objective was to have a way to easily carry one or more bikes with the Mundo.  I have tried towing bikes, and it is not an ideal way to transport more than one bike, or even one bike over longer distances.  This setup with the trays allows me to, for instance, carry my mountain bike to the trailhead (about 10 miles) using the Mundo instead of a car.  It’s a great way to get to and from the trails without having to ride my mountain bike on the street for a fairly long distance.  The Mundo’s electric assist makes it super-easy to get up to the foothills quickly where I can then enjoy the amazing Colorado singletrack.

In Action 1
carrying the mountain bike to the mountains.

Here are some more detailed pictures of the installation process for the trays, and for those of you who might need to transport 3 bikes, I think there is a way of mounting a 3rd, short tray on the top of the cargo rack.  You’d have to have the kind where you remove the front wheel, otherwise the bike would stick out too far and you might have a problem with too much weight hanging off the back of the rack.

Detail 5
The outrigger with one screw removed in the front and rear to allow the rack to be installed.
Detail 9
Detail showing the extra-long machine screw needed due to the extra thickness of the rack.


Detail 7
Lining up the hole drilled in the rack with the outriggers’ screw hole.  Note the slot in my wood deck for the Go-Getter bags’ strap to go through.
Detail 10
Here is the tray on the other side showing the holes drilled to match up with the existing screw holes in the outrigger.
Detail 11
A view from the top, the rear screw is in, the front has not been attached yet.  Also note the piece of old carpet around the top rack to protect the bike being carried from rubbing against the steel of the Mundo.
Detail 15
As long as the tray is mounted at the correct angle you should have plenty of room to pedal.  The exact placement of the tray, and where to drill the holes was the most critical measurement during the installation.
Detail 19
Here’s the mountain bike mounted on the Mundo for transport to the trailhead.
Detail 23
Here’s a closeup of how to strap the upper part of the bike to the rack of the Mundo.
Detail 21
Another view of the strap holding the bike up.
Detail 22
Using the wheel straps that come with the bike tray to hold the wheels in place.
In Action 2
And hey, I’m off to the mountains!

Thanks for taking a look, and feel free to contact me if you have any questions about carrying bikes on your Mundo.  Once the system is in place it’s easy to put on or take off as needed, and as you might expect, it gets a lot of comments as you ride through town.  And if you want to see a short video of the bike carrying a bike, go to my vine page.  If you need to carry even more bikes, you could always build a custom trailer such as this one I recently saw at the Bike Library, built to carry 5 bikes!


Car Bike Rack for an elMundo

People frequently write in to ask us what bike rack we recommend for the the car to transport an elMundo (or Mundo) long distances, say between a winter residence and a summer residence.

Over the years, we have recommended several products,  but each had their drawbacks. The roof racks designed for tandems or recumbents weren’t ideal for elMundos because it is difficult for many Yuba riders to lift 50-70 lbs over their heads. The “remove the front wheel” type of rack requires remembering to bring the tools to pull off the wheels, and then lining up those little suckers while lifting the bike up. Then there’s the racks that aren’t designed for bikes over 35 pounds, which we haven’t recommended but people have tried.


A elMundo and a Mundo NuVinci Lux, ready to go on an adventure!

We finally found a rack that’s easy to use, and can accommodate two (yes two!) elMundos. The Hollywood Racks Sport Rider for Electric Bikes (HR1450E) is an easy-to-use hitch mounted rack that fits standard 2″ trailer hitches. Loading the bikes is easy, because the rack is fairly close to the ground, so you can put the front wheel in the rack first, and then lift the rear wheel (and motor) into the rack.


We  were concerned that the sideloaders would rub and scratch the paint on the second bike. In our test, this did not happen, because the sideloaders rubbed up against the rubber of the tires on the second bike. If it was a major concern, a user could tape or zip tie some cardboard between the bikes to prevent any contact at all.


The rack conveniently folds up against the vehicle when not in use.

**Please remember to remove the electric batteries before putting your electric bike on a car rack, because the vibrations of the road can decrease battery life.

Gear Review: TiGr Lock

photo 1

The TiGr Lock, billed as “elegant bike security” delivers on its promise of strength combined with lightness. The locks are made out of titanium, so despite their length size and strength, they are lighter than the U-Locks we normally use to secure our bikes. Although, it was designed to fit around the top tube of a road bike, we found the lock easily fits in a Go-Getter. It’s relatively long length made it easy to secure multiple bikes to a Mundo and then to a bike rack, compared to the long shackle U-Locks we normally use. With other locks, the width of the Sideloaders can interfere with aligning more than one bike next to a Mundo for locking up.

The TiGr lock is a a great lock for people who have custom cargo bikes with high end components, or people who are responsible for locking up a pack of bikes at once regularly (lookin’ at you car-free parents!).

photo 2

Here’s the beauty shot of the lock in action.

Check your StandAlone for loose or missing bolts that can lead to ‘squishy’ feeling

The StandAlone kickstand can be a life saver when loading kids and cargo. The photo below shows a StandAlone doing the job on a fully loaded Mundo on a moving ferry with no guardrail! That’s a dependable center stand.

But the performance of this stand relies on 4 bolts being correctly tightened. Due to the forces involved when parking your Mundo with a heavy load, these bolts can loosen over time. If the bolts are loose and you continue to ride and use the kickstand, they will continue to loosen and one or more can even fall out. Once a kickstand bolts falls out, the stand continues to work, but you may feel that the kickstand is ‘mushy’ or ‘sloppy,’ or that it can barely keep the bike upright, especially on a slope. A telltale sign is that the bike may feel fine when loaded heavily on one side but not the other.

First off: Get down and look!

Look for two top bolts (and tighten them, while you’re at it with a 6mm allen key). These are less likely to loosen through daily use, but worth checking.

Now check the two pivot bolts on the sides. The image above shows the most obvious example, when a bolt has fallen out completely. If you don’t see an empty hole, you also need to look on the inside to make sure there’s a locknut on each bolt.

Here’s what it looks like if you have a missing locknut. See the bare threads on the pivot bolt. Bad!
If you have one or more missing bolts or nuts, here’s what to do:

Gather these tools:

  • Flat head screw driver
  • Phillips head screwdriver
  • 2 open end wrenches of appropriate size for the nuts (probably 12mm or 13mm, cone wrenches are fine)
  • Allen key wrenches of appropriate size for the bolt head (probably 5mm or 6mm)


You’ll also need the missing parts for your Center stand. You can get these from us for $0 from our online store:

You can also buy this hardware from a local hardware store. Each Stand Alone has two hinges, and each hinge needs the following parts:


  • 1x M8 by 25mm long bolt or socket head cap screw
  • 2x M8 nuts (using one normal, and one nylon-insert nut gives more resistance to loosening)
  • 2x washers

or if you don’t have access to metric hardware, British Imperial fasteners can be used instead:

  • 1x 5/16″ by 1″long bolt or socket head cap screw
  • 2x 5/16″ nuts
  • 2x washers

Step 1: Turn the bike upside-down.  If one hinge bolt is being replaced, leave the SA attached to the bike and skip ahead to Step 3.

If both hinge bolts are being replaced, FOR SAFETY, close the stand so it’s in “riding” position on the bike and then remove the two bolts that mount the SA to the bike.

Step 2: Remove the springs


To remove the springs, place a flat head screw driver into the coils of the spring, and pry up, releasing tension on the spring hook. Insert the philips head screw driver into the spring loop, and work it off the arch.  Repeat for second spring.



Step 3: Apply some bike grease to the inside and outside of the hinge plates


Step 4:  Insert the bolt(s)

If only one bolt is being replaced, and the springs are still attached,  use the legs to manipulate the hinge and align the hinge holes.

Insert a bolt with a washer from the outside.

Put on a washer, and a nut on the inside.  Turn the nut closest to the hinge down so it’s finger tight to the hinge and the right and left nuts are roughly equally threaded onto their bolts.  Thread on the second nut (the nylon insert nut if you have one), using the alen key and wrench as necessary to snug it up to the first nut.


Step 5: Locking the nuts –

Using two wrenches, turn the bolts against each other firmly (like a threaded headset).  The nylon insert nut should have it’s nylon engaged with the bolt threads – if it is not, loosen the two bolts, and turn them a closer to the hinge, then re-lock the nuts.


Step 6: Re-tension springs

Using a ball-end hex key as a lever, pry the spring hook over the arch, and re-seat the spring. Repeat for second spring.





Step 7: Reinstall stand on bike and open and close the SA to check that the motion is unrestricted and solid.


Yuba Safety Check

Keep Kids Safe with the Yuba Safety Check

You wouldn’t take your kid for a ride without a helmet, would you? Of course not. Did you know that there’s more you can do to ensure your child’s safety on the bike? Please take a minute to review the Yuba safety specifications, and ensure that your bike is compliant with the safe intended use.

If you’re riding with children under 40 lbs:

  • Children should ride in a Peanut Shell Child Seat, which should be attached firmly to the back rack.
  • Foot support should be installed and utilized.

mundo_wheelskirts_email If you’re riding with children under 18 years old (but over 40 lbs):

  • Wheel Guards are required for all passengers under 18 years old to keep shoelaces, hands and feet out of the spinning rear wheel. Purchase Wheel Guards from your local dealer or online here.
  • Educate your passengers about the dangers of spinning wheels.
  • boda_wheelskirts_emailUse foot supports for shorter passengers, and ensure that they are properly installed by checking the bolts regularly.
  • Give your passengers something to hang on to, make sure that the Hold on Bar or Rumble Strap is tight and adjusted properly for your passengers.

At Yuba Bicycles, we take the safety of our riders and their passengers very seriously. If you have any questions about best practices for safe riding with passengers, please contact your local bike dealer.

Plans to make Wheelskirts for V2 Mundos can be found here.

Understanding Weight and Power on a Cargo Bike

Occasionally, we pull an article from around the web-o-sphere because we feel that it is a particularly enlightening or interesting article for people interested in cargo bikes and expanding the conception of what is possible to do by bike. This article by punk astronomer Doug Reilly fits the bill. He uses science to help people understand why additional weight on a bike isn’t noticeable until encountering a steep uphill grade.

Doug’s project brings the wonders of the heavens to anyone who wants to see them at his regularly occurring “star parties” in Geneva, NY.

Understanding Weight and Power With Cargo Bicycles

by Doug Reilly

“Isn’t that thing heavy?” I’ve had a few people ask me that already. The Yuba Mundo specs out at 48 pounds, and that’s probably calculated with no cargo and few of the common accessories like running boards and a side-loader bag. Let alone that copper bell I added! Probably my daily running weight is about ~65 pounds. Certainly it’s far heavier than the 8-pound carbon fiber wonder Jim Hogan at GBC let me hold a while back. It was so light I almost threw the bloody thing through the roof of the store, just trying to pick it up. I expected it to have some weight. It appeared to almost need to be held down.

Does it matter how much your bike weighs? Certainly if you’re a professional athlete, or an uber-serious amateur, it can matter. That $11,ooo carbon fiber frame might shave a portion of a second off your time, and that might be enough. If you’re going to compete in a mega endurance race like the 3,000 mile Race Across America*, probably a big cargo bike isn’t your first choice as well. But for most people, should bicycle weight be a big concern? And should it shy people away from grocery shopping by bike?

I was a bit worried getting such a big, heavy bike as the Yuba Mundo. My specific worry was Washington Street. On the way to work, it’s all downhill, but on the way home, well, let’s just say I do wish it was reversed. It’s somehow not fair that I can get to my office in 3 minutes but it takes me 10 on the way home. I won’t show you a picture of Washington Street, because you would see how puny it is and therefore what a weakling I am. But it’s my hill, and I wondered before the Mundo arrived how it would do on that long gradual climb. Notice that I said how “it” would do. You know, because, it’s all about the bike. (Not my legs or cardiovascular strength.)

I needn’t have worried. The Yuba does its thing, amazingly. Those gear things really help! For the last seven years I’ve been riding a single speed, now I don’t know what to do with myself and my 21 shiny new gears. I actually get home faster than I did with my old single-speed hybrid, which weighs less than half what the Mundo does.

The other day I ran across these stats, posted on the blog of Portland, Oregon based Clever Cycles:

Speed of a 20-lb bicycle at 160 watts effort : 14.8 MPH
Speed of a 60-lb bicycle at the same effort, level ground : 14.6 MPH
Speed of a 20-lb bicycle at the same effort, 5% uphill : 7.2 MPH
Speed of a 60-lb bicycle at the same effort, 5% uphill : 6.1 MPH
Speed of a 20-lb bicycle at the same effort, 5% downhill : 23.9 MPH
Speed of a 60-lb bicycle at the same effort, 5% downhill : 25.5 MPH

These figures come from an online calculator, backed up with some fancy formulas, found here.

These figures also struck me as self-evidently true given how much easier and generally faster the cargo bike is to ride than the single speed. The Yuba weights 60 pounds. The single speed about 20. So if weight isn’t the biggest determinant of how much effort it takes to pedal a bike, then what is? I decided to ask a few experts, and I got an answer I didn’t really expect.

First, I went to the source, and emailed Todd at Clever Cycles and asked him why weight makes so little difference. Here’s his response:

Lighter *is* faster, but by a far, far smaller degree than widely supposed. Most of the work of pedaling a bike above speeds of about 12mph is overcoming wind resistance, not overcoming the inertia of the bike itself. Also, heavier bikes are notably slower to accelerate. It’s just that once they’re rolling, it’s not much more effort at all to keep them going.

It’s funny that I don’t perceive the Mundo as being slower, except when it’s loaded up with a lot of cargo and I’m heading up hill. Quite the opposite. I guess this is just perceptual, since my previous bike only had one gear, and apparently a pokey one at that.  The heavier Yuba Mundo is also slower to stop, and this jives with Newton’s laws of motion, too. I actually bought a louder bell (a nice brass Crane bell with a spring loaded clapper) on my bike last week because I was worried someone would walk out in front of me while the bike was loaded and I was zooming down a hill. It takes a good long while to stop, even with well adjusted disc brakes (which by the way, I would consider to be essential components of any cargo bike). Objects in motion like to stay in motion, indeed.

I asked the same question of my friend and once college roomate Phil, who is now one of the world’s top experts on the subject of athletic power. He confirmed and expanded upon Todd’s explanation, and reading his response it began to feel a bit as if we were talking more about airplanes than bikes:

1. Roughly 80% of the energy of pedaling a bike involves overcoming air resistance. Thus, under all conditions other than a strictly uphill climb, aerodynamic considerations vastly outweigh weight considerations.

2. The most important consideration with respect to how quick you will get up a hill is the power to weight ratio, i.e. how many watts can you generate versus how much mass you are moving up the hill. Very good riders (i.e. guys that contend for the Tour De France) generate maybe 5ish watts per kg body mass and can hold than for less than an hour. More pedestrian riders probably generate 2 watts per kg over a similar time frame. You make considerably more power than this in the metabolic sense, however, you are only about 20-25% efficient in terms of what actually gets delivered to the external environment. This is why you get hot when you exercise…the rest of the energy is liberated predominantly as heat.

3. The most important consideration with getting down a flat road is power versus frontal surface area. Hence the aerobars you see on time trial or triathlon bikes. You are trying to poke a smaller hole in the air.

The takeaway is that the extra mass matters, sure, but not as much as one would think. Which is another way of saying that carrying your groceries home on your bike instead of your SUV is not as crazy an idea as you might think.

Another conclusion I made form this inquiry is that I made a good decision in getting the Yuba Mundo. It’s extra length adds weight, sure, but doesn’t add anything (or not very much) to the aerodynamic cross section of the bike. Something like a bakfiets, with a wide honking cargo box on the front, is, to use Phil’s expression, punching a much bigger hole in the air.

It’s funny, but now that I’ve been riding the Yuba back and forth to work every day, getting groceries with it, and of course, lugging my telescope around on it, I can’t believe I sat in a car for long and let an engine, and way too much fossilized dinosaur poop, do the work for me. It’s not much work at all, and the cost per mile is stronger legs and lungs.

*The link is to an excellent RadioLab episode that features a story about the RAAM. RAAM’s official website is here.

Pimp my Ride, iCargo Bike! (Part Deux)

The fine folks at iCargoBike in San Clemente sent in a bunch of pictures of custom builds they have completed recently. They’re so sweet, that we thought we’d share them one by one. Today’s bike is their shop bike; for those of you who don’t work in the bike industry, that means the bike that every employee in the shop can use to run errands, or barrow when their ride is broken down. And what a sweet shop bike it is…..especially the surfboard rack (clearly just for work purposes, eh?)

Shop Yuba v3 with avid bb7 disc brakes and Swalbe Fat Frank tires, with 36 volt li-on amped front drive geared kit.




Two years at the beach and the spokes are rusty but amped motor and battery still working strong, nice iCargoBike custom surfboard rack.

Stay tuned! More of their awesome builds coming your way. If you see anything that sparks your interest, please contact the fine folks at iCargoBike.


Mundo Disc Brake Upgrade Option

Mundo 21 Speed with Disc Brakes

Since the release of the Mundo V3 (fall 2009), prescription upgrading to disc brakes has been available*.  Although the V-Brakes provided with the Mundo provide excellent stopping power, the Mundo comes with disc-ready hubs and disc-brake mounting tabs so that riders can install disc brakes as an option.

The following adapters and disc rotor sizes are required to upgrade the Mundo to disc brakes.

Front: 160mm rotor and 160mm front adapter** (standard)
Rear: 180mm rotor with 140mm rear adapter (Mundo specific configuration)

* valid for Mundos with serial #AD00100001-AD00100230 (under the kickstand plate)

**Installing rotors larger than 160mm not recommended and voids the Yuba warranty.

Shimano Mechanical

Yuba Bicycles recommends the following disc brake kits:

• Tektro Io Disc Brake kit. Our price: $130 (not pictured here, but available at the Yuba Web Store)

• We do offer the 160/140mm caliper adapter so you can purchase the disc brake kit of your choice (from a local IBD) and still make sure the pads are going to achieve 100% pad contact with the disc.

For further questions: email


New Product: Towing Tray

towing tray

Have you been looking for a way to take more bikes with you? Perhaps you’d rather bike to your cyclocross races to get warmed up? Or maybe you want to take your kid to the park with their bike to gain confidence before having to battle traffic?

Introducing the towing tray, exclusively from Yuba Bicycles. Fitting all v3 and v4 models, the towing tray makes it possible to bring along any bike from a 16″ up to a 29er, with a tire width up to a 2.25″. It is made out of the same material as our Utility decks – recycled milk jugs – and is durable and tough. A side bumper keeps the towed bike from scratching your Mundo. Towing tray kit includes running board with a slot for front tire, adjuster for 20″ or 16″ tires, and bumper.

After installation, to use the towing tray, adjust the support for the size of bike with a screwdriver. Then, use a cam strap to attach the towed bike to the Mundo frame, locking the front tire of the towed bike down to the frame of the Mundo, as shown at right.

Order a Towing Tray