Building super monkeys
Posted 13 August 2006 | Filed under Bicycling, Gear, Longtails, StokemonkeyFrequently I get asked what’s the best kind of Xtracycle to build, with or without Stokemonkey. I hesitate, because there are many right answers, and I don’t want to suggest that my personal preferences have such universal validity. Least of all do I want to suggest that you need to spend a lot of money chasing down some ideal uninformed by your own experience. Nevertheless, I’ve put between 100 and 10,000 miles each on a total of nine different Xtracycles over the last five years, and I can’t help but have developed some strong opinions.
I’ll edit this post later to tell you why I think this Surly Karate Monkey with ISO 559 wheels, Xtracycle, Stokemonkey is the best I’ve built yet. Meanwhile, enjoy the pictures.


August 14th, 2006 at 01:37
Todd, from the pic gallery, it looks like you have too much d-housing. The point of the Rollamajig is to allow a straight cable run from the last stop to the derailleur, decreasing friction and keeping the cable out from under the FreeLoader. Or no?
August 14th, 2006 at 02:10
Two stems for adjusting between two riders?
August 14th, 2006 at 07:41
Thanks tricky — I was missing the little pierced ball component of the Rollamajig when I assembled (hastily as usual) so couldn’t let it do a sharp bend. Will remedy.
Miketually, I want the bike to fit medium-to-big people, as a tester, so yeah that’s the double stem idea.
August 15th, 2006 at 07:06
Why is the Karate Monkey the best Todd? Why? Tell us!
Meanwhile, here’s my new and improved Xtra:
http://sconnyboy.blogspot.com/2006/08/new-kid-on-block.html
August 15th, 2006 at 07:20
Todd, have you gotten around to expanding your blog entry yet?
August 15th, 2006 at 15:55
Too bad it’s not………blue!
http://cellarrat.blogspot.com/2006/05/lexxas-ride.html#comments
August 15th, 2006 at 17:13
I’m very curious as to why a 29er with 26″ (or in this case, more like 27″) wheels would be an improvement over a 29er with 29″ wheels. I mean, other than the Xtracycle will swallow 26″ wheels but not the big’uns.
I have a Redline Monocog 29er (with 29.75″ tires on it) that I would love to “stoke up”. I haven’t done so because I know I’d probably overtax a Free Radical (at 450 to 500 lbs. before adding any cargo) and because I’d have to give up my humongous rear wheel.
August 15th, 2006 at 17:54
It wasn’t fair of me to tease like that. Still, I’m a bit overwhelmed at the task of explaining completely why this is a good setup. I keep wanting to make animations, or at least movies with lots of handwavey gesticulations, to show the kinds of geometrical issues involved. It could take a while. So here’s the ultra-condensed cheater version of why better than either a niner frame with niner wheels, or a typical MTB conversion:
August 17th, 2006 at 06:48
Having ridden the Super Monkey, I can attest to it’s awesomeness! In fact, we’re in the process of building that up on Bike Hugger. I posted photos to our SUB gallery and will continue to add to it as the project progresses – we’re blogging the whole thing as a Bike Hugger project bike.
This set up, as Todd describes above, addresses my biggest concern which is foot-down when weighted. Imagine coming up a hill in Seattle, stopping at a light fully loaded, and shifting all the weight with your back to one toe. Much easier to just foot down. Additionally it’s like riding a “working” bike, an industrial cruiser with a very nice motor assist.
August 20th, 2006 at 22:34
Awesomeness! I sold 10 Free Radicals in the last 2 month’s. Just oredered 6 more.
I think we have passed the 100th monkey!
August 20th, 2006 at 23:20
Todd is right on. The Super Monkey is just about perfect. The main features I like are the Schwalbe Big Apple
tires (26 × 2.35″ I assume), the disc brakes (8″ rotors are best) and the Albatross handlebars. As for
steering geometry, I think it would be good to publish the exact data here.
From the Surly website and the Schwalbe website I was able to determine that the trail of this bike is
67mm (http://kogswell.com/trail.php?h1=685&i1=72&j1=44&e4.x=11&e4.y=6). I am assuming here that the
head tube is still 72 degrees. What size is the frame and can you give me an exact wheel/tire diameter
and head tube angle measurement? Most road bikes are around 60mm. The new Kogswell bikes are going to have
much lower trail. This is all very interesting to me. Low trail seems to be desireable.
August 21st, 2006 at 12:39
Aaron, good to hear from you and that’s great on sales. One of those sales is to a commuter that lives up the street from us.
August 21st, 2006 at 13:18
Aaron, the actual measured wheel diameter of the 2.35″ 559s is 666mm, not the 685 you’ve indicated, so the trail would be ~63mm. I say “would be” because I know the head angle is shallower than 72 degrees, because the FreeRadical tips the frame back somewhat. The FreeRad was made to keep the angles the same with 26″ wheel bikes that have less drop than a 700c/29′er. More drop means that the FreeRad jacks the rear axle up above the original axle line, resulting in the frame tipping back, slacker angles etc. I haven’t quantified it. I suck at trig and don’t have an inclinometer.
I know the Porteur with the highest-rake fork gives only 30mm trail! 60-something trail is more than plenty for my taste, but reasonable. What you’d end up with with actual 29″ wheels and a freerad would be… way, way high trail, flop/cruiser/chopper city i think.
September 6th, 2006 at 11:56
[...] A bit over three years ago, as I was designing Stokemonkey, I corresponded with Surly’s Dave Gray about various ideas, as he’s a crafty person with some experience of electric propulsion. Months ago I sent Surly a kit, in hopes that they’d bang on it and tell me what they thought. Surly designs and sells, by my guess, more quality steel bicycle frames than anybody else in North America, and they tend to build into particularly fine, heavy-duty Xtracycles, attractive platforms for Stokemonkey. [...]
September 8th, 2006 at 09:16
[...] The Bike Hugger people have sagely cloned our own Super Monkey and named her Bettie. At this moment, there are already ten blog entries at Bike Hugger about Bettie, lots of pictures, video clips. (There is no Bettie-specific t-shirt yet). [...]
September 27th, 2006 at 14:06
[...] One of the handling fine points is steering geometry. As I’ve at least begun to explain elsewhere, I’ve found that bikes with poofy tires and a weighted front wheel (the rider’s weight in the longtail case) benefit from uncommonly low geometric trail. Surly’s Big Dummy has a steeper head angle than the 71 degrees more typical of bikes with 26″ wheels. They’re also testing unusually high fork rakes. Together, these should bring the trail down lower than you could finagle it going the conversion route. [Note: Big Dummy design is subject to change before it comes out.] A lot of these ideas about steering geometry are presented lucidly by Jan Heine in his study of old French tandem and porteur bikes, both of which I think bear on longtail designs, too. The Kogswell Porteur is an explicit embodiment of Heine’s work. [...]
November 27th, 2006 at 18:43
Is the Stokemonkey compatiable with the small – 16 inch, or medium – 18 inch Karate Monkey?
Like your Supermonkey, I would like it to be useable riders of differing size – my 5′ 11″ self and 5′ 2″ wife,
or so the fantasy goes…..
Any thoughts
November 28th, 2006 at 17:07
adam, the good people at surly indicate that the 16″ karate monkey frame should accommodate a stokemonkey, just barely.
November 30th, 2006 at 01:21
…and the last question of this … the 700c or 26inch version of the Xtracycle? Of course
the answer will be obvious, but well, it could be both – 700c/29er frame but 26 inch wheel.
Regards, Adam.
November 30th, 2006 at 09:20
adam, if you’ve got disc brakes it doesn’t matter, because the rim brake stud position is the only diff between 26″ and 700c kits. (though some 700c kits have come also with “elevator shoe” inserts to raise the level of the V-racks)
January 21st, 2007 at 21:38
Hi Todd,
You should get a commission from Surly. I’ve built a Karate Monkey with very similar specs (xtracycle, Velocity Cliffhanger 26″ rims, Schwable Big Apple 2.00″, etc) after reading your blog. I also dumped my very rarely used security blanket — I mean car. I used the BB bracket and cranks I had on another bike (Deore LX – 175mm). I’ve experience a few pedal strikes when leaning in turns. What length do you use on your crank arms?
Thanks for being such an inspiration!
O in Seattle.
January 21st, 2007 at 23:07
Olivier, I use 170s with quite wide pedals. Not sure of the Q-factor on my cranks (Sugino Mighty) but I suspect it’s lower than recent Deore LX. I think the 2.35″ rather than 2.0″ Big Apples are significant. You might be able to raise the BB by modifying how you’ve got the FreeRadical attached. Other than that it’s a matter of knowing what kind of a lean you can afford to pedal through. Congratulations on ditching the car.
January 22nd, 2007 at 10:01
Pedaling thru turns?
The cargo bike we are designing has a low BB height on purpose. Not being able to pedal and lean through turns is a small price to pay for being able to have a low COG and ability to put a foot down. A 69 or lower (we use 67 on our cargo bike http://www.rideyourbike.com/cargobike.html) seat angle is also preferable. Something you won’t find on any American made bike except the Flatfoot designs started by the likes of Electra (I have a female customer that has a nice ladies blue one she wants to Xtracyclerize). I have found that at low speeds and heavy loads, I really do not lean the Xtracycle much. I keep the bike upright much more than a regular bike would. A long front center helps, especially with fenders, so my foot doesn’t hit the wheel/fender.
Xtracycle/longtail desireable features: shallow seat angle, low BB height, steep head angle/low trail, long front center, fat tires, wide bars.
January 29th, 2007 at 13:47
[...] I’m in a hurry to build it up. I’m likely to migrate over all the parts from the original “Super Monkey” I blogged last August. That is, unless you lived nearby and wanted to swoop in and make an offer to take it in the next few days. I don’t have room for more bikes. Life is so hard. [...]
September 2nd, 2007 at 23:06
Hey Todd,
Since you’ve built so many xtras and logged so many miles I wonder if you could help me some words of advice about what might be the best way to go for my needs. I’m looking to build a bike that will allow me to commute, pick up groceries, haul my 2-year old around without having to tow a trailer….and be the bike that I can use to tour across the country in a couple years. My first instinct was to go with a 700c bike, maybe a cross bike or a touring bike because I like the handling of those bikes better. But I heard that the handling of 700c xtracycles is compromised because the FR was designed for 26″ bikes. Is that true?
Also, what do you think of the Kogswell P/R as an suitable frame to convert? I like the idea that if I ever decided to go back (or go with a more standard MTB) I’d have a cool frame to build up into light commuter/town bike.
Thanks for any and all advice.
September 3rd, 2007 at 10:57
James, a lot of people are very happy with their 700c Xtracycle conversions. It is true that the X was designed around 26″ wheels, but to conclude that this “compromises” the handling of 700c conversions implies that handling is more of an exact science, or realm of qualitative absolutes, than is the case. The handling of any conversion will be different than before the conversion. Whether it is better or worse is subjective. It’s been my experience that the handling of 700c conversions tends to be more different than 26″ conversions. Specifically, the head and seat angles become more relaxed. I personally dislike the “chopper” steering feel this can impart. Others dig it. Also, I tend to see Xtracycles as more dedicated hauling bikes than as all-rounders. (I like purpose-specific bikes; keeps the stable rich and interesting.) Thus I favor features that are harder to get in 700c conversions, like bombproof wheels and especially high-volume tires. Since your application is more all-rounderish, you might be fine with the 700c conversion results.
I don’t have more than a passing familiarity with the P/R (couple blocks each on 2 fork flavors). It’s kind of neat. I think you might get struck by lightning, though, if you messed with the agonizingly-deliberated, front-rack-optimized geometry by slapping an X on the back, and especially if you had to ditch the match-painted rear fender. Very punk-rock, as a chunk-dclxvi friend would say. 650B and V-brake pad position… o, I’d pass.
September 3rd, 2007 at 18:20
Thanks Todd. It’s interesting to hear you describe the handling of more-relaxed 700C conversions as “chopper”-ish. I think I’d dislike that as well, given that what I like about the handling of 700C bikes is their more precise feel. So I think the 26″ route would be the way to go, especially if I can pick up an older Bridgestone or Ritchy/Bontrager hardtail since their handling was more what I liked in MTBs. And I do like the flexibility that MTB frames offer in terms of running bigger tires. The Monkey with the Big Apple tires certainly seems ideal for everyday applications, but how do you think it would work as a long-haul touring bike, mostly on roads but occasionally on fire trails and other rougher surfaces?
September 4th, 2007 at 12:06
If I may jump in, regarding handling and Big Apple tires… I was a long-time skeptic of 26″ wheels and the super wide tires in particular. While I wasn’t some lycra-nut that thought 23c was the widest one should ride outside of single-track, it did feel like the 700c wheeled bikes I rode were invariably peppier and more precise feeling.
When I had my long-tail built, I used 26″ wheels because I had a very nice spare set and using them would save me a few hundred dollars. I also went with the Big Apples in 50c. I have to say the bike and those wheels are wonderful feeling. I am amazed that big, fat tires can feel so good. They gobble up gravel, cracks, pot holes for lunch and steel grates for dessert. That much is a given. However, they do not feel the least bit sluggish or imprecise. I’ve not taken it on a long-haul, but I intend to and have no doubts it would perform just fine.
In short, I’d not spend too much time worrying about wheel size. If you have a preference then certainly go with your preference. But don’t let it become the prime criterium.
November 2nd, 2007 at 13:54
You have a great bike there, Todd. I think I’ve figured out that with the KM fork, disc brakes and big apples, there is no way to run a front fender. Am I right? Also, does this also apply for the same set up on your Big Dummy test bike?
November 2nd, 2007 at 13:59
there’s no problem running fenders on this or the big dummy built with 24″ wheels. i use a bent spoke as a strut to support the fender close to the tire from the steer tube.
February 13th, 2008 at 14:05
I’d been thinking about this for quite awhile, in light of some of the great xtracycle builds out there, and had a thought.
There are cases where a both/and instead of an either or can exist. So clearly one of the oft cited benefits of a KM xtracycled is the lower standover allowing you to more reasonably put a foot down at a stop while still in your saddle.
Meanwhile, there exists the incredibly beefy instigator frame made for 26″ wheels with higher bottom bracket. Well my wife and I go to the mountains regularly so consequently like having the higher bb for the 4×4 roads that lead to some of the better, lesser traveled trails, but also see the benefit of the foot down ability of the KM. Then it occured to me that both could in fact be possible.
I’m currently building an instigator up with an xtracycle kit and now have plans to add a gravity dropper seat post. The idea being that the seat post has a remote lever so you can drop your saddle using a remote lever as you approach a light or come to a stop, then after the first crank rotation away from a stop, flip the lever and unweight the saddle and your back up to full height, all while enjoying the benefits of the higher bottom bracket.
I’ll let you all know how it works in practice.
February 15th, 2008 at 11:36
With the Big Dummy just about here I’m just wondering about ‘best’ option for an Xtracycle. My impression from reading info so far is that BD would be stiffer with a load and KM X with 26″ wheels would be less stiff with load, but have the benefit of less ground clearance, ie easier to manage at low speed and stops. (Accepting that the BD additional ground clearance would be an advantage off rosd).
Have I got that about right?
February 15th, 2008 at 11:51
that’s right, andy. but build the BD with 24″ wheels and you get low and stiff together. you need to run fat tires (big apples!), but that’s good too.