- Introduction: The Mongoose Envoy Project
- Chapter 1: The Raised Rear Deck
- Chapter 2: Better Brakes
- Chapter 3: What Kind of Motor?
- Chapter 4: Motor Choice
- Chapter 5: Motor Installation
- Chapter 6: Motor Settings
- Chapter 7: Misc Upgrades and Notes
- Chapter 8: The Build Sheet
- Chapter 9: Low Cost Builds (You Are Here)
So in Chapter 8, I put up a Build Sheet. If you do all the math, you will find my $750 bike turned into a $3600 bike (some bits, like the battery, I already owned and just plugged in). Given how expensive quality cargo bikes are, and the level of quality I have now, I am very happy with that cost vs. benefit. I have a really solid frame and top quality components, and a bike that is probably the best all-around transportation/auto replacement bike I have ever owned.
But what of all of this was actually necessary? I build bikes as projects. Generally, I am more concerned with making the bike the best it can be. I don’t pay as much attention to final cost as most people would. Especially since I oftentimes upgrade in bits and pieces, which is less of a shock to the budget.
Based on my experience with the stock Mongoose bike – seeing first hand what worked, what didn’t and what I changed because I had more money than brains – I can see a different way to go that might be of a lot more interest to people who just want a good bike that doesn’t break the bank. For the record, I’m of the opinion that the Mongoose Envoy represents a significant break from current cargo bike offerings in that it can be built into a first class solution for a lot less, thanks to its bargain basement starting price.
So… lets build a few different configurations using my kitchen-sink, spaghetti-against-the-wall build. In the end, I replaced everything but the frame, headset and fork.
All prices are in US Dollars. The last two builds are non-electrified.
Build #1: Just The Very Basics+Assist ($1,807.48)
This is a low-cost build that changes only the things that I think must be replaced.
Right off the bat, you can see I left on the Magura 4-piston MT5 brakes, and the great big (but relatively inexpensive) thick rotors. These brakes work so smoothly and so well when I have had this bike fully loaded. I think you’d be insane not to take any and all uncertainty completely out of your braking equation. These brakes are not overly powerful when you consider the duty cycle they will have to put up with. Safety first, but this choice also guarantees trouble-free ease of use.
This build uses the BBS02 because it is lower-cost and still does a spot-on job. You can see from my motor choice post that if I did not already have other BBSHD bikes in my stable, I would have chosen the ’02 for this build as it is ideally suited for the cargo bike job. The cost below does upgrade to the mini color display; adding $40. Knowing the different displays as I do, this is well worth that minor upcharge.
Note I changed the shifter… that has to happen thanks to the change in brakes. The stock brake levers are combined with shifters (cheaper that way, I bet) and if one goes, so must the other.
Mongoose Envoy Bike Amazon 731.49 Magura MT5 disk brake set bike-discount.de 137.00 ISH-203 203mm rear disk adapter bike-discount.de 6.86 QM5 203mm front disk adapter bike-discount.de 6.86 Tektro 203-17 downhill rotors (2) ebay (hi-powercyles) 42.40 MicroSHIFT TS70-9 shifter Amazon 22.88 BBSO2 motor kit Luna Cycle 490.00 68-73mm standard motor mounting hardware wiring harness speed sensor basic crankarms Luna 500C mini color display Universal thumb throttle Battery Solution 52v 12.5ah battery pack, basic Bicycle Motorworks 369.99 pack construction, 50a BMS and Samsung 25R cells
Build #2: Change Out The Drivetrain ($1,933.00)
Includes everything above, plus the following, which adds $144.61 to the build price.
Everything From Build #1 plus... KMC X9.93 chain (7 feet/more links) Luna Cycle 57.75 Shimano HG400-9 12-36T cluster Amazon 25.99 Shimano RD-M591 9spd derailleur Amazon 41.78
This takes out the frankly bottom-end Shimano drivetrain and in its place substitutes a smooth-as-glass 9-speed click-shift setup. Yes the chain is expensive but if you want to do a mid drive right, you have to pay attention to the chain and the rear cluster, which in this case is a durable, steel, welded-together unit that will give longevity and will not tear into your cassette body.
You can get a strong steel cluster with an 11T small rear cog, and I suggest you resist the temptation. 11T cogs are always problematic on mid drives in the first place. On a cargo bike the problem is worse. The speed you can achieve dropping that one tooth is likely unattainable anyway. Especially when you factor in the weight and the motor-bogging that will occur under load. Don’t do it. Get the 12T.
Worth noting: The stock Mongoose 8-speed cluster is also a welded steel unit so its just as survivable. Also the Mongoose chain is an 8-speed KMC, so its likely just as durable. The weak links – no pun intended – are the rear derailleur and shifters. Mine worked poorly although I intended to replace it with a 9-speed from the get-go, so I didn’t try to adjust it into compliance.
At this point, we have a really first class electrified cargo bike that stops easily, shifts smoothly, will survive over the long term thanks to the components we plugged into the drivetrain… and we’re still under 2 grand.
Build #3: Add a Front Rack ($1,988.48)
Yikes we’re still under 2 grand here!
Everything From Build #2 plus... Front Rack Axiom Streamliner Front Rack Amazon 46.99 Delta AxelRodz skewers Amazon 8.49
Adding the front rack greatly increases your versatility. For mine, I use waterproof RockBros 27L panniers similar to Ortlieb rolltops: They are big, carry a lot and mount about 2″ low on the rack.
Note my discussion of the installation of this rack in the Odds and Ends post. You’ll need to spring for about 20 stainless 5/32″ fender washers to fit the rear AxelRodz skewer onto your front axle. This sounds crazy but really, it works very well.
Build #4: Beef Up The Drivetrain ($2,187.43)
We’re adding almost $200 with just these next two parts.
At this point, since we are building with a BBS02, we’ll want to address its weak links a little differently than I did with my BBSHD.
The Lekkie chainring gives you some offset to bring your chain line back into alignment, provides a tooth profile that eliminates any chain drops and lasts, essentially, forever provided you do your part as described in the mid-drive section of the motor musings chapter.
Everything From Build #3 plus... Lekkie Buzz Bars (crankarms) California-ebike 99.00 Lekkie BBS02 46T chainring California-ebike 99.95
As for the crankarms, those are self-extracting, quality bits of forged alloy, versus the low-end Chinesium alloy used on the stock arms. Those square-taper arms are often replaced, and the fact they only cost about $15 each makes said replacement relatively painless… but never having to replace them in the first place is an idea that has some merit.
You can consider the crankarms an optional option and see if you pedal hard eough to make them fail, which you might not, in which case you’ll save yourself a hundred bucks.
Build #5: No E-Assist, Proper Parts ($1,081.69)
What about just treating the Envoy as a ‘donor’ to make an analog bike? Take advantage of the great frame and replace the iffy components to make yourself something really good for really cheap?
I did not throw on the hand built uber-wheels, or change the tires. Both of those components work well on the stock bike. Sure I think custom wheels and upgraded tires are a good idea, but they are icing on a cake and, particularly with the wheels, spike the build price up considerably.
I focused on turning the bike into a silky-smooth-running, safely-stopping hauler.
- The drivetrain – excepting the front crankset – was replaced with a great Shimano 9-speed long cage derailleur
- The chain may seem expensive, but you’ll have to buy two 9-speed chains to make one long enough to fit this bike, or just buy the super-strong one I did that is in one piece already with no potential mid-chain weak spots where the two chains would otherwise be attached together.
Mongoose Envoy Bike Amazon 731.49 Magura MT5 disk brake set bike-discount.de 137.00 ISH-203 203mm rear disk adapter bike-discount.de 6.86 QM5 203mm front disk adapter bike-discount.de 6.86 Tektro 203-17 downhill rotors (2) ebay 42.40 MicroSHIFT TS70-9 shifter Amazon 22.88 Shimano HG400-9 12-36T cluster Amazon 25.99 Shimano RD-M591 9spd derailleur Amazon 41.78 Shimano FD-M591 derailleur (front) Amazon 29.95 KMC X9.93 (two of them) Amazon 36.48
Build #6: No Electrics, Fully Loaded ($1,566.41)
This one has almost everything but the kitchen sink thrown in for max comfort and quality. Here again though, I left off the hand built wheels.
- The Thudbuster LT is pricey but its such a big change to the comfort of the bike, a top build has to have it.
- $90 for a kickstand is hard to choke down, but if the bike falls over once at the store with 100 lbs of groceries in the bags… it doesn’t seem quite so expensive.
- Those Jones bars are just too comfortable. Nothing wrong with the stock bars… but if we are throwing on stuff to feel good, these have to be on the list.
- I use the RockBros panniers with my own front Axiom rack and decided to include them here. They are big, waterproof and inexpensive. While you do not want to overload your front rack, these can carry jumbo bags o’ tortilla chips without squishing any. So as usual, size does matter.
Everything from Build #5 plus... Thudbuster LT 27.2 XL Amazon 119.99 Ursus Jumbo Superduty kickstand Amazon 79.99 Jones H-Bar SG Loop Handlebars Jones Bikes 79.00 Jones 205mm Kraton Soft Grips Jones Bikes 20.00 Front Rack Axiom Streamliner Front Rack Amazon 46.99 Delta AxelRodz skewers Amazon 8.49 RockBros 27L Panniers Amazon 108.99
Wrapping it all up…
The first four builds above address all of the functional weaknesses of the $730 Mongoose Envoy. Do these things and you have
- upgraded an analog bike into a solid electric performer
- addressed every functional weakness in the original bike
The last two builds take a look at the same thing, but go in the direction of making the bike the best it can be without a motor.
One functional item I am leaving off here is a heavy duty wheel build. While I have one in progress, and its on the build sheet, the fact is I have not yet killed the stock wheels. Nor have I ding’d them. They are still nicely true, and my desire for a 30mm internal, survive-the-apocalypse set of wheels can be argued as me overdoing it… again.
There are a lot of other line items on my personal build sheet that are not discussed on the electric builds. Stuff like the Thudbuster seatpost, or the Jones bars. These address personal comfort issues that don’t need to be there. Those are items you can spring for individually over time… or not. You know how the bike upgrade thing goes…
So have at it!