Urbanus Magnus

My new Shimano-hubbed Sunrim Cr-18 wheelset arrived the other day, and to my chagrin - it's not drilled for Schrader valves, but presta valves (those tall, thin metal ones with threads). Nothing is wrong with presta valves - in fact they actually retain air better at high pressures - but the availability of tubes for wider tires is somewhat limited. So what does one do to remedy this problem, short of replacing the rims? Well, you drill the valve holes out, of course. Presta valves are 6mm wide, with a 6.4mm (1/4in) valve hole. In contrast, Schrader valves are 8mm wide, and have an 8.3mm (21/64in) valve hole. Luckily for me, the Cr-18 rims are wide enough to accommodate this wider hole; don't try drilling out thin rims, or those rims with a strongly arched profile, or you may end up weakening the rim significantly. Flat profile rims; its easily drillable.   Select a few dill bit sizes for stepped drilling - this will prevent th...

Quite a few years ago, Surly introduced the then-revolutionary Karate Monkey frameset (they claim it was one of the first commercially-produced 29er frames). Now, Surly has taken the concept behind their utility bike, the Troll, and bumped it up from 26in wheels to 29in: The new Surly Ogre.   Credit: Surly Bikes Surly says that their new frame has geometry similar to the Karate Monkey (which, by following their numbers, it does), but with all the function of the Troll. What does this mean? Well, it has: - Front and rear Canti/Linear brake mounts - Disk brake tabs - Double dropout eyelets, both front and back (so you can mount fenders and racks all round!) - Specifically design for fender clearance (yay!) - Fits up to 29 x 2.5" tires, more that one should ever reasonably need - Full-housing cable mounts  - Surly-compatible trailer mount The bike seems well-equipped to be an all-rounder, off-road (or road) tourer, or nice singletrack companion.  The only quibble I...

Without further delay, I present to you the Origin 8 CX700-framed-all-rounder: Origin 8's Cx700 frame allows me to run 29er tyres, yet doesn't look out of place running skinny rubber. The specs: - Origin 8 CX700 Cyclocross/Touring/All-Rounder frame, 56 cm * - CST Critter 29 x 2.1" tyres * - Mountain Equipment Co-Op Alloy Seatpost (rebranded Kalloy Uno) - 27.0 mm * - Brooks B17 Standard, Honey - Nitto B-115 - 40cm/25.4 mm clamp - RSX 3x8 Brifters - Avenir adjustable threadless stem w/ Origin 8 Spacers* - FSA "The Hammer" 1 1/8 in Headset * - Shimano BB-UN26 Sq. Tpr. * - Alivio 22-32-42 Crank - Victor VP-196 Pedals w/toe clips (VP-565 Platforms shown in pictures) - SRAM 12-32 7-Speed Casette - Alivio F. Der, 31.8mm clamp  * - Alivio R. Der - KMC Z-Chain * - Wheels: Alivio hubs laced to 36h Araya PX-35 rims - Jagwire "Basics" Cables + Housings * - Tektro 720 Cantis         A "*" means bought new. All other parts are scav...