My Karate Monkey
Purchased October 2003

Below are reports posted to mtbr.com after the initial build, after making changes and riding it at Fall 2003 Barbie Camp, and again after converting it to use a 3-speed hub for commuting in December 2004.

The current setup changes seasonally and is substantially different than any of these, with different handlebars, accessories and drivetrain. As of 2007 the winter setup still uses the 3-speed hub with big semislick tires and a very powerful homebrew light system with running lights. The summer setup uses a 1x5 derailer drivetrain with road slicks. Of course it's the workhorse bike that sees over 2000 miles a year which I never get around to taking pictures and writing about!

Initial build: October 15, 2003

Just finished putting together my Monkey and took it out for a ride around the block. Very tentative impressions:

  • Feels a little sluggish taking off. No doubt due to the big wheels and 3 extra pounds over my old bike.
  • Moves fast once it gets going. I looked down at the speedo, and observed that the numeric speed was higher than I had perceived by "feel". Then I realized I hadn't recalibrated the 'puter for the 29" wheelsize yet, so it was still reading about 10% low! Wow.
  • Doesn't seem any harder to bunnyhop than the 26"er, other than what you'd expect due to the extra weight of the bike.
  • Rolls over curbs noticeably better than the 26"er. Will be good on technical terrain.
  • Doesn't ride any smoother than my 26"er. Probably because I'm accustomed to giant volume tires at 20/30 psi, and now I'm running the noticeably skinnier Nanos at 30/35. Will try airing them down a bit. We need fatties!
  • Seemed to hobby-horse a bit on dirt? Will need more saddle time to confirm this. If it continues to be true, I may add a link and slide the rear wheel back 1/2". (Currently have it almost all the way forward in the dropouts for my 36:20 and 34:22 gears).
  • Turns on a dime. Actually a bit better than my 26"er. Should be great on switchbacks and tight singletrack.
  • Bike does not at all seem "too big", nor do the wheels. I'm only 5'7", so it just g?es to show you 29"ers aren't just for tall guys!
  • No toe overlap problem, although it's close.

    Remember, these impressions are based on only about 1/2 mile of riding around my neighborhood. Tomorrow I should have a much better idea of what I think. Too bad I have to go to work first!

    Also, I measured the BB height at 11.75" with Nanoraptors mounted on 22mm rims. Exactly the same as my 26" bike with "normal" (2.0-ish) tires on it. Given that fact and a wheelbase within 1/2" of the old bike, I do not expect to have problems with pedal strikes.

    Now I have to wait a few days more before I get my disc-compatible wheels from MeanTodd (running V-brakes for now) and my Jones and Klaw from Speedgoat. Can't wait to get the discs running, and some wet-compatible tires mounted up. It's raining.

    November 2, 2003

    Built this up a couple weeks ago. Here's the build:
  • King headset, cheapo stem, Bontrager 25" bars, two sets of bar ends (inner ones are for cruising the flats)
  • Thudbuster seatpost (cut 3 inches to fit the bent seat tube!), Spec Telluride Saddle
  • UN-52 BB, 1992 DX cranks, PC7X chain, Deore levers, Avid 185mm discs
  • Salsa Delgado rims laced to XT disc hubs (MeanTodd-built), Klaw rear, Jones ACX front
    Weight as built is 27.5-28 lb:


    Being -- well, me -- I've set it up with one my usual unusual drivetrains. Two chainrings, two cogs, two ratios available. Pursuant to redhaze's suggestion, the cogs are Sturmey-Archers meant for internal gear hub use, with the splines ground slightly to fit a standard freehub, which I then filled out with the usual stack of spacers.

    Available gear ratios are 34:22 (equivalent to 34:20 on a 26" bike) and 37:19 (a hair higher than 2:1 would be on a 26" bike). Both gears require same the effective chainstay length, so I can switch gears without readjusting the rear disc. I bought a star ?ockwasher at Home Depot to clamp in between the QR nut and the disc side of the (horizontal) dropouts. So far I have had no problems with axle slippage even under fairly heavy use. Here's a closeup of the drivetrain:


    Last weekend, for Sunday's ride at Barbie Camp I decided to try an experiment. The bike industry hasn't yet seen fit to make any 29" tires in widths greater than about 2.0, so I had to take an alternate route to test out this bike with a front fatty. Redhaze had a 26x3.0 Nokian Gazzaloddi mounted up on a 26" wheel with a 185mm rotor. Overall diameter of this is right around 28", so this didn't really drop the front end very much:


    Looks a little funny, but it worked great. Great grip, steamrolls over everything in its path, no adverse effects on handling. There were lots of pine cones on this ride. Other people's bikes would spit them out the side when they hit them, but mine simply crushed them. If there aren't any 29" fatties out by Spring, I'm getting a Gazzi. Oh yeah, plenty of tire clearance in the KM fork:


    3-speed hub conversion: December 9, 2004

    I have converted my KM into the ultimate winter commute bike. The last few years I've been commuting on my singlespeed 'crosser, but my current route includes over 800' of climbing on the way home, with a long, steep, fast descent. That means the ideal commuter bike would have:
    • Gears. But after singlespeeding for so long, I really don't like the idea of running a derailer (squeek-squeek-squeek!) through a rainy Portland winter. I've been perfectly happy with 4 speeds since last summer, and for winter conditions 3 speeds will do just fine. The obvious solution is ... an internal gear hub!
    • Disc brakes. I got along OK with V-brakes and sticky Ritchey pads on my crosser when my commute was flat, but I now have a 3-mile continuous descent at speeds of 25-30 mph. When I need to brake I need maximum braking power instantly, regardless of how hard it's raining. Gotta have discs.
    • Fat tires. To utilize that braking power, I want more grip (i.e., fatter tires) than I can fit on my 'crosser. At least 700x42, and I may even experiment with the Schwalbe Big Apple.


    Since the KM is already a disc-ready, horizontal-dropout frame with enough tire clearance, this project was very easy to do. I acquired a SRAM DualDrive Disc 3x9 hub. This is a 3-speed internally geared hub with disc mounts on the left, and a conventional freehub shell on the right. It's designed to be used with a cassette and derailer, for a complete 27-speed drivetrain at the back of the bike with a single chainring, and is commonly spec'ed on recumbents. I'm not using a cassette, just 1 cog (well, actually 2, so I can experiment with this thing off-road too) and a bunch of spacers, single-speed style with no derailer or tensioner. At about 900g, this hub is about a pound heavier than an XT disc hub. In other words, the total drivetrain weight would be about the same as a 1x9 using a conventional cassette and derailer.

    I had the hub laced up to a Salsa Delgado Cross rim, to match my other 29" wheels. The complete build on this wheel (including hub) was well north of $300 by the time it was all said and done, but since I bike to work 2-3x per week I decided I could justify it. Compared with the venerable Rohloff, this hub is half the weight and 1/4 of the price. If you really need 14 gears, well then get the Rohloff. But if you can get along with 3 gears, get this one.

    Tire-wise, I'm running a 700x42 IRC Mythos XC Slick in back. Actually I'm disappointed with this tire's grip on wet pavement, and I plan to swap it out for a Maxxis WormDrive in the same size. Front tire is a studded Nokian Hakkapeliitta 700x45. In western Oregon we're too close to the ocean to get both cold and wet weather at the same time. It's either/or: usually either wet and above freezing (30s/40s F), or dry and (in the morning) just below freezing. A few years ago I fell on frosty pavement (fortunately at low speed), and I've run a studded front tire all winter ever since. Heavy as hell (~1000g), but worth every penny and every gram.

    OK, here's a photo bike, fully outfitted for commuting:


    Note to self: hold the camera steady next time (duh). Sorry.

    Here's a picture taken with flash, and headlights blazing, in the exact same light conditions.


    That's what a motorist is going to see at night: 25 watts of halogen light, multiple LEDs (not all visible here) including spinning TireFlys, and a couple square feet of DOT-grade reflective tape. Not only is this bike impervious to all weather, it's visible in all weather. I don't care too much that it's ugly, although I do have a very cool project planned to beautify this bike and maximize visibility at the same time.

    Drivetrain closeup:


    This hub is shifted via a pin in the center of the axle. The black "clickbox" ($20, about 50 grams) mounted on the end of the axle converts shift cable travel to action on the shift pin. I'm still experimenting with the gearing. I tried 38x18 initially, but after the first ride I lowered it to 36x18 so I could take advantage of the high gear more of the time. Ideally I'd like slightly tighter spacing, especially between the middle and high gear, but it's acceptable. With internal ratios of 0.70, 1.00 and 1.35, I have gear choices of 38, 55 and 74 gear inches, respectively. I'll also be experimenting with this thing off-road this winter using 34x20 gearing (34, 49 and 65" gears).

    Here's the rather busy cockpit:


    I've grown fond of having a second set of (stubby) bar ends mounted inboard of the grips to get an additional comfy/aero hand position for cruising the flats. I mounted the shifter (old DX front friction thumbie) on one of these, for quick installation and removal so I can yank off the drivetrain and go singlespeed mtb'ing at a moment's notice. That makes the cable routing kinda funny, but it works. Also notice the trail bell, Air Zound horn (don't use it often, love having it when I do), integrated mirror/bar ends and TurboCat S25 headlights.

    Note to self: uh, I guess this bike is not a full-time singlespeed anymore. Gotta replace the "Singlespeed / One Is All You Need" top cap with the "29er / Bigger is Better" top cap.

    Note to self: geez, clean the deck already!

    So I've ridden this bike to work the last 2 days (7 miles am, 12 miles pm) and it has worked great. It's been pretty rainy, including a torrential downpour on part of yesterday morning's ride, so it's been a good test. Love having the discs -- when it's wet they make a lot more noise than rim brakes, but they sure stop better too. In the dark and rain I do not notice any efficiency loss with this hub, and I'm not sure it's very noticeable in better conditions either. In any event it's certainly much more efficient than a derailer drivetrain with a chain that's gotten all crusty and cruddy from riding in the rain. I'll post another report after I've ridden it for a few weeks, but so far the verdict is a big thumbs-up.

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