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 the bits from binding and ruining the rim. I chose 3 bits: a 7/64in bit, a 9/32in bit, and of course the 21/64in bit.
If there is already rim tape, peel it back with a tire lever and commence drilling. Once done, it should be noticeably larger:
File off the burrs in the metal to prevent punctures, and the job is done.
Then try fitting in a Schrader valve tip, just to check to see if it all fits in neatly. If you have trouble getting in the valve, try making sure the hole was drilled straight, or possibly go for the slightly larger 11/32in bit.
Now that I’ve drilled out these new rims, I’m all set to replace the old wheelset. The old Shimano/Araya combo has conducted me very “wheel” over the past 5000km and 5 years, and supported another 5000km or so for the 13years before that. 10 000kms and 18 years later, though, it is time to move, lest something *does* in fact break during our Italian trip.
Araya Wheelset: 1994-2012
$10 Craigslist sale, anybody?
Here are the new beauties: I’ve finally made the switch over to 8 speeds and double walls.
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 have with this frame is that there is no down tube cable stop, or place to bolt one on (as in the Origin 8 CX700). Be prepared to have to DIY a cable stop if you want to use drop bars. I like the offset seat tube, which will definitely aid in fender-izing your bike.
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 3×8 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 scavenged from my other bike.
FSA “The Hammer” Headset; dirt cheap, but so far, smooth and strong.
Misc Odds and Ends: -“Greenfield” seatstay/chainstay kickstand – Mountain Equipment racks (Blackburn Knock-offs) – MEC “Wedgy” Seat bag – Zefal water bottle cages – Planet Bike ATB Pump
I must say that I am *very* pleasantly surprised at how well this new bike handles, and with the overall quality of the budget-conscious build. As I ripped almost all the parts from my previous “main” bike, the total build cost came in at $428 CAD, all told. Thats actually $28 over what I wanted to spend, but oh well; I wasn’t about to reuse my a 17-year-old bottom bracket and grind the old front derailleur to 31.8 clamp dia.
The Frame The Origin 8 frame was a big surprise for me – it is a relatively new offering, not like the tried-and-true Surly Cross Check or LHT. But, without taking risks, I would have been missing out on something great. What makes this frame a better all-rounder base is the extra-wide clearance for up to 2.3″ 29er tyres, which is substantial considering the ~ 42mm tyre limit for the LHT. The specs for the Origin 8 clearly said “Fits 2.1″ tyres”, but they lied, because there is quite a bit more room to shove in a larger tyre. With my 2.1″s on, there seems to be just enough room to install a fender, albeit tightly.
2.1″ 29er tyre and still going strong; the Origin 8 CX700 frame probably can squeeze in a 2.3″, if you don’t need fenders.
The wheel can gain a few extra inches clearance if pulled back in the rear-facing track-style dropouts (track ends).
What I also like about this frame is the thoughtful lay-out of the rack mounting points. On the rear, they are placed high above the dropout, in the seatstay, which allows standard racks to be used with the over-sized 29er tyres by giving extra clearance. They also provide a helluva lotta heel room; about 3″ more to my pannier bags as compared to my old bike. Oh, and this layout also allows the unimpeded use of disk brakes on the rear. The only problem is that there is slightly less space to strap things to to top of the rack, as there is less room between my seat and the rack’s deck.
Rack and fender mounts are up and forward, in the seatstay.
As for the frame weight: For a $165 steel frame, its pretty good. The weight of the 56cm frame and fork(uncut) together totaled 3.1 kgs, or 6.8 lbs (measured on fairly accurate digital scale). However, these numbers mean nothing without a frame of reference, which I will provide: the equivalent Surly CC weights 7.07 lbs frame+fork, the LHT weights 7.3 lbs, and the only truly off-roadeable frame, the Karate Monkey, weighs in at a good 8.1 lbs. Salsa’s “Fargo” is also slightly heavier for the same size; 7 lbs 14 oz (~3.5 kg), according to their website. So, is my frame a “lightweight”? No. But it is a decent weight, and beats out some of the brand name frames and forks, for under half the price.
To have a 29er – im pretty pshyched. The CST Critter tyres are dirt cheap; I found a pair for under $25. They are pretty puncture resistant, as I’ve ridden over nails/ construction rubble and no problems have reared their ugly heads. The rolling resistance is definitely higher than I’m used to, what with my road tyres, but they off-road and mud/dirt traction is amazing (to me at least). No comparison can be made to any tyre under 45mm wide, if only for a 29er’s ability to “float” in the muddier bits, as opposed to getting bogged down (as with my skinnier tyres!). More testing to be done, but so far, thumbs up on traction in most regular conditions; seek a tyre with greater volume and more aggressive knobs for the very soft stuff, or mud, but otherwise a very good all-round 29er tyre. Schwalbe “Big Apples” or similar might be warranted for lighter off-road riding, or just light gravel use, as the rolling resistance of the Critters could be a “drag” for long distances.
MMmn…big tyres = traily fun and offroady goodness
The tyres do surprisingly well in light mud and on rock, like on this crushed-brick-and-mud-based road.
More gallery shots, for your viewing pleasure (click to enlarge):