Stokemonkey overview
Stokemonkey is Clever Cycles’ answer to the problem of steep hills and heavy loads. It’s an electric motor assist kit for cargo bikes like Xtracycles, Surly’s Big Dummy, and the Yuba Mundo. Longtails have amazing cargo capacity, and Stokemonkey gives you the power to haul it all over mountains or swiftly across town.
Most electric bike products are designed for people who don’t, won’t, or can’t ride regular bicycles, even without passengers or cargo. Stokemonkey is different, designed for everyday bikers who will continue to ride on their own power most of the time, but want a more capable car alternative some of the time. We don’t believe in replacing human power with electricity; we believe in replacing cars for work that even the strongest cyclists seldom if ever choose to handle without a car. Developed in a car-free household, Stokemonkey is for fellow riders who want to become more completely independent of cars in their daily lives.
- It’s for people who want to transport their spouses, children, and camping gear dozens of hilly miles offroad and back. It’s for picking up a friend with two checked bags at the airport. It’s for your knees. And if there are thousands of vertical feet between your farmers’ market and your family kitchen, now you can pedal those couple dozen melons home without qualifying for charitable sponsorship.
- It’s for people who commute twenty-five miles each way, can’t shower at the office, and never want to sit in traffic.
- It’s for people who understand that vehicles heavier than what they carry are inefficient almost by definition; that fiddling with their fuels comes at sustainability problems from the wrong end, and ignores the social and health problems of car dependence in built environments altogether.
How it works
When you want help, you turn a variable throttle on the handlebars to activate the motor. The motor drives the pedals, just like the stoker of a tandem bicycle helps the captain. You cannot use the motor without pedaling, but you can pedal normally without any motor resistance, and coast whenever you let go of the throttle. As you shift gears to maintain normal pedal speeds, you keep the motor operating between its most powerful and efficient speeds, for several times the torque, higher top speeds, and much better range than typical electric bike products lacking variable motor gearing.
A backlit handlebar-mounted display provides system status, including power usage, battery state, efficiency, and typical cyclocomputer functions, in addition to programmable parameters like maximum power and motor speed.
Stokemonkey uses a brushless motor with no internal moving parts other than sealed bearings, for maintenance-free, cool running, virtually silent operation. All drivetrain parts subject to wear are standard bicycle components for decades of service. Stokemonkey is powered by non-proprietary 36-volt rechargeable batteries you carry like any other cargo.
In development since 2003, Stokemonkey is protected by US patent 7,261,175.
Performance
Stokemonkey’s exceptional torque moves heavy loads off the line quickly, helps you walk your grocery-laden bike up stairs, and enables you to haul adult passengers up the very steepest streets. We’ve managed 480 pounds gross up the steepest block in San Francisco (31.5% grade). This extreme torque capability distinguishes Stokemonkey from electric bike products not designed for cargo applications. Stokemonkey can sustain about 500 watts of assistance, which is comparable to the maximum sustained effort of a world-class bike racer. But Stokemonkey weighs a fraction of what the racer does, your power comes on top, and this full combined power can be applied even at walking speeds: think tugboat or tractor more than scooter.
Powered range is limited only by the amount of battery packs you carry. Experience suggests that your working range will be similar to what it is riding a light, unassisted bike, but that you will carry more, and arrive sooner with much less fatigue. Top assisted speed is limited electronically to 20 MPH to conform to US federal Consumer Product Safety Commission rules, but this speed can be maintained even up modest hills.
Stokemonkey adds 21 pounds to your bike before batteries, which start at about 10 additional pounds. Gross vehicular weights can start well below 70 pounds, not unlike many loaded touring bikes.
Cost
Stokemonkey costs about $1300 without a battery and charger. Generally, we don’t sell kit components separately, but you may omit parts for which acceptable substitutes exist. See the Order form for more complete information.
Stokemonkey usually pays for itself every few months when used to replace a typical car. More importantly, you get to ride a bike more often, even when you need to haul your family, groceries, or just your unbearably smug self further or faster than you would on a regular bike.
Guarantee & warranty
Stokemonkey comes with a six-week money-back guarantee, and a two-year warranty against defects in materials and workmanship. We advise you to become accustomed to your cargo bike before ordering, so you will have the full guarantee period to install and evaluate Stokemonkey.
July 18th, 2010 at 08:51
[...] type of cargo bike that has an extra long frame. And “stoked” means that my bike has a Stokemonkey electric motor that helps me out on the hills.) In general this summer I’ve been biking 10 to [...]
July 27th, 2010 at 17:43
[...] to a longtail bike like the Surly Big Dummy setup with an electric kit like the Bionx system or the Stoke Monkey. This would also have the normalizing effect in that I would always have plenty of capacity for [...]
August 16th, 2010 at 02:42
I am impressed by this solution. I am also convinced that hubmotors are a bad choice for gradients and loads, the motor must be kept at optimum rpm’s.
But there is one question I have: When I want to use the motor and have a respite from pedalling, I don’t like the thought that I have to keep moving my legs…. Would it not make sense to have a freewheeling mechanism for the front chainwheel, so I can either pedal, or use the motor, or do both?
eLation in Australia even point out on their website that a driver could be catapulted off his bike accidentally without such a freewheeling mechanism.
I am very interested in your system but appreciate your comment on this issue.
Thank you.
Bodo LInnhoff
August 20th, 2010 at 08:51
Hi Bodo – I believe I address your questions about freewheeling pedals in the FAQ, here: http://clevercycles.com/products/stokemonkey/faq/#waycow . In short I don’t consider this a problem whose solutions don’t introduce new, more troublesome problems. There’s more discussion here: http://www.flickr.com/photos/cleverchimp/3390730515/in/set-72157615918793181/
September 2nd, 2010 at 09:54
[...] interesting option is the StokeMonkey kit, which uses a motor that drives a second chainring on the cranks, much in the same way that a [...]
September 27th, 2010 at 23:56
When one of my business partners, Jenn, began riding my personal ride (a Stoked Xtracycle-enhanced Bianchi Milano) as one of our company’s delivery bicycles, she fell in love with it and asked me to sell it to the business. I did. It has now served ably in full-time commercial operations. And now, I long for another Stokemonkey setup and will likely and imminently purchase another for my longhaul commuter. I’m strongly leaning toward the Surly Cross Check + Xtracycle Freeradical + Stokemonkey. Hold me back.
This is what I tell almost anyone who asks me, “What’s that red thing?”: Stokemonkey is a beautiful system.
The Stokemonkey kit is highly functional (i.e. it just works, doesn’t fail, hauls A$$, hauls weight, hauls long distances), is simple, bullet proof and nearly maintenance-free (the shop replaced the freewheel on the motor when it started making noise — under $30). Its riding virtues I like the most are: efficient, through-the-drivetrain operation resulting in low energy consumption, smooth to operate, wonderfully quiet. And while some don’t care and others may want a two way freewheel, I love that Stokemonkey is an electric assist system — meaning there is no free ride. It is a bike after all.
October 22nd, 2010 at 00:21
Stokemonkey is, by far, the best product we have tested and shipped for our cargo bikes.
See what it has done for one of our clients in Vermont – One Revolution
http://www.flickr.com/photos/31530356@N08/5104424154/
June 12th, 2011 at 10:21
Update: Last October, Clever Cycles built for me a Surly Long Haul Trucker with Stokemonkey with 10Ah LiFePo battery from E-BikeKit. We switched out the stock front fork with one that would accommodate disk brakes. I just passed the 2,000 mile mark on my super-commuter last week. I typically commute twice each week to work, 21 miles each way. I have a shower to use at work, so I make a sprint of it. While I can make the trip easily on a single charge, I typically charge the battery while I’m at work. My average speed is about 18 MPH (I track everything in a log book, but haven’t tallied it all up). Stokemonkey makes this rather longish commute with 20-30 lbs of gear a practical trip. There are several sustained moderate to steep hills and this is where Stokemonkey makes a huge difference. I can even make it up my super steep hill at the end (so steep, I used to walk it when I commuted a shorter distance on my mountain bike). With the weights I’m carrying, mine is best described as a speed-commute. However, having the extra capacity is great and there have been times when I’ve brought home much more than my laptop, clothes and lunch containers (The NRS Access Duffel is an excellent, huge all weather bag for placement atop the Xtracycle deck). I have also completely eliminated the half-way lightrail ride, which saves me additional time and a little more money.
My love for this system continues to grow. :)
August 17th, 2011 at 14:47
I’ve used a Big Dummy/Stokemonkey since the Spring of 2010 for commuting between several offices in Metropolitan Washington D.C. I started commuting with the Big Dummy as a test – to see to what extent a cargo bike could replace my car. My mileage is at my personal limit for bicycle commuting, ranging from 50 to 100 miles per day, about 300 miles per week. I use the cargo capacity of the Big Dummy to do what a road bike can’t do; I take about 40 lbs of luggage over-and-above the weight of batteries.
My Big Dummy build includes a Rohloff hub and ‘battery bank’ arrangement that provides 1.0 to 1.7 KWH, configured each day to fit the need. Dinotte LED lights are fitted front and rear, powered through a step-down converter.
The bike has traveled more than 10,000 miles since last year and my initial question – Can the Big Dummy/Stokemonkey substitute for a car? – was answered many miles ago. I don’t know how many tens-of-thousands of miles the major components will last but, clearly, the Big Dummy/Stokemonkey is a viable choice for transportation.
Richard Cress
September 2nd, 2011 at 11:22
Anyone know if having a Nuvinci hub on my bike makes it a no-go to stoke? I have the Breezer Infinity and want to xtracycle it but I’m thinking that the hub might make it difficult to add electric assist. Thoughts?
September 2nd, 2011 at 11:31
It works well; in fact this is one of the better drivetrains to stoke. The Xtracycle conversion is more labor-intensive than most, but entirely do-able. We cut the chaincases short.
December 20th, 2011 at 04:46
I’ve been using the Stokemonkey/Nuvinci N360 combo for about 3 and a half months now with like 1200 miles under its belt thus far. I also tried it with my old 3×9 derailleur setup for a time and…it’s like night and day, really.
I really wasn’t crazy about the Nuvinci before electrifying my big dummy for some reason. I sorta longed for derailleurs actually! Upon pairing it with the Stokemonkey though I feel like the 2 are made for one and other. It’s just smoother. It’s got synergy. Haha, I dunno how else to describe it.
Fallbrook tech now makes a new IGH called the Nuvinci harmony or something, that automatically shifts and is supposed to pair well with e-assist bikes or something but I’ll never know if it’s worth the leap because the N360 works so well. So far so good!
In spite of the hub motor taking a dirt nap once early on (you guys replaced it suuuuuper quick. Thanks Jeremy Scholz!) I still think every other day or 3 that I’m glad you guys made such an excellent product available. Hope the supply chain issues clear up and more peeps out there can get stoked. I’m constantly getting grilled by random peoples on what the red spinny thing on my big weird gaijin bike is and it’s totally convinced at least a few people I’ve met over here in Japan to take a sip of the cargo bike koolaid.
January 6th, 2012 at 14:06
Bummer! I’ve been lusting after a StokeMonkey since I bought my Big Dummy in 2007. I hope the supply chain issues are resolved soon as I’m selling my second car this week and really don’t want to use a hub based motor.
January 7th, 2012 at 14:35
Micro-update: we’ve successfully tested a replacement candidate motor that’s a little lighter and more efficient, and better sealed. We’re at the beginning of a negotiation phase with the supplier to see if we can have the necessary modifications made at a reasonable cost without needing to order thousands. So it’s coming along, but not likely to be shipping again for many more months.