E-bike forks?

As I understand it, Pierre will use this for an e-bike with some cargo carrying capability. Hence a fork built BEEFY (those fork blades? Steerer tubes...) with dual disc rotor capability and 110x20 axle.

Pierre might have set the record for most expensive custom fork on this one, too, once the custom-color ordering gets done to match it to his frame.

Double trouble.

Winter in the mountains is hard on the outside of your house.

Ken, 148x12, the future, Keanu Reeves

As promised, here's part 1 of my thoughts, musings, ramblings... incoherent gibberish about new axle standards.

I'm not even going into the new 110x15 fork standard right now, we'll concentrate on 148x12.

First, remember: if you are buying a hardtail, a through axle has no actual benefit over a QR unless you weigh 400 pounds or are constantly forgetting to tighten your skewer. Your pathetic excuses for legs won't get any more power to the ground than they did before - the rear end of a hardtail really doesn't flex much, so adding a big fat axle make zero difference in how the bike rides. Of course, I build them all the time, and if/when I get around to building myself a new bike, that's what I'll do. Why? Because time marches on, and it's harder and harder to get nice QR parts - just like it's hard to find a really nice set of v-brakes these days. C'est la vie. Take the red pill. Or maybe the blue one? I can't remember, the sequels have caused me to block all Matrix-related knowledge from my brain to avoid the pain.

142x12 came out about 3 years ago and quickly took the world by storm. Why? It promised a bit stiffer rear ends on FS bikes, compatibility via adapter for most existing hubs as the cassette and disc rotor stayed in exactly the same place, and something new to sell to the bike-buying public. Which I would roundly condemn, except that I'm one of the purveyors of said new stuff.

27.5+? My doing.

As a giant world of diverse wheel/tire and drivetrain options has opened up in the post-29er glasnost, lots of manufacturers realized that cramming 3x29/27.5" tires into frames built around 73mm BB shells and 50mm chainlines (just a quick pause for a definition here: "chainline" here means the distance from the center of the frame to the center of the middle chainring, though these days that mostly means the *only* chainring. Here's Sheldon Brown's definition) would cause some terrible problems fitting everything where it needed to go. The chainstay, tire, and chainring all fight for space on a typical mountain bike frame (FS or hardtail) and if you have to give too much to the tire - you've either gotta lengthen the chainstays or do *something* to move the chainring out of the way. As more and more gears get crammed onto cassettes, the flanges of the hub have also gotten closer together (this has been going on for 20 years, really) which is generally bad, as the spoke tension between driveside/non driveside gets out of whack and the wheel gets less laterally stiff and weaker. Bigger rims (ie 27.5, 29) exaggerate these problems. Something had to give (well, ok, maybe "had" is too strong a word). Something is giving, anyway.

Enter "Boost" (why didn't 142x12 get a cool name?) 148x12 rear ends. The idea here is that you move both the cassette and disc rotor outboard 3mm, and move the flanges out to match. Result, you can move the *chainring* out a bit to make more room for the tire, keep a decent chainline, and end up with a bit stronger rear wheel to boot.

Now, there's another solution out there that I've been doing for over a decade along with a few other weirdos. It's to stick with 135x10 (or now142x12) spacing, but move the *entire* rear end (meaning, the hub/dropouts/stays) about 5-10mm to the driveside (the exact amount depending on application). This gives you a great chainline for single ring bikes and loads of room for short chainstays and big tires. It's also a near-dishless/even tension rear wheel. Great stuff, IMO. Cannondale ripped me off this year with their "AI system" (here's C'dale's explanation of the setup). Stupidmobile (you know, the 29er with 40cm chainstays?) was built this way. So are many bikes I build for customers, because it gives you a ton of benefits and really only has a few drawbacks. You can also do fun stuff like an 83mm low-q-factor fatbike by using various amounts of rear end offset (Felix's runs a 135x10 rear hub offset 10mm).

Whew. Did that all make sense? No? That's what I run into a lot. Many people don't like the idea of asymmetry, so the whole idea is off the table. I think that's a big part of the 148x12 idea - easier to explain, inherently less weird and threatening...but we don't do normal and unthreatening around here!

Ken wanted it *all*. 148x12, lots of tire clearance (in his case 27.5x2.8-3 or so) and short, short chainstays (well, not totally insane - we did 41.5cm). So we went nuts and did an *offset 148x12* setup. In this case, it's just 2mm of offset to get the chainline we wanted, but it still felt weird to take a brand new Anvil dummy axle and chuck it up on the lathe!

So long story short, Ken's bike is weird but should be awesome. Your bike can be awesome too if you think outside the box a bit and let me get creative - it's custom, folks. The world is your oyster.

Or we can just do 148x12, because what the heck, I already paid for the dummy axle, and the writing is on the wall...

Aaaand... we're out.

And just in time. Ugh. It's supposed to be 114 in St. George this weekend!

For those who are curious, this week was devoted to fulfilling my promise of a wedding tandem to Redcoat and Smoyle, who got married a little over a year ago. Logistics (they live in Switzerland) and inertia kept it from happening until now, but I'm finally (almost) done. Yes, it's coupled to fit in an S&S case.

Bungee cords are crucial when figuring out where to put the couplers to fit into a case...

Note that I will only sell tandems to WW frame owners (ie repeat customers) and UT locals. I am FAR from a tandem expert and in many cases talking to Santana or Davinci is a better plan but I am pretty happy with how this one came out and I'd be comfortable selling you one if you're interested. Cost for a frame will be around $3000 but will depend on details so please call or email for a quote.

I'll try to get one more photo tonight of the finished frame.

We'll be back from VT on the 8th of July, don't expect quick (or any) replies to email/phone until then.

Quick pic - 140mm postmount

As I guessed earlier, pulley bosses are awesome for making post mount setups. Also, fillet brazing the bosses in does not save any time if you suck at fillet brazing as much as I do, especially once you account for cleaning the flux off the fixture. Doh.

Gold star to whoever figures out what the derailleur cable sticking out of the fork is there for.

Totally Unbiased Review: Stupidmobile

First off, just to make sure we're clear - the manufacturer of this bicycle made me do something like 10 hours of work, for no pay, just so I could ride it. The company made me pay for all the parts as well as powdercoating the frame and didn't even give me an employee discount. Apparently if I break it, I have to fix it myself.

Bastards.

Sorry about all the shadows. 

So I decided to name it "Stupidmobile". Why? Well, mostly because this bike has the most ridiculously short chainstays you've ever heard of (40 cm, or 394cm if measured horizontally). A 2.1" 29er tire only has 15mm of clearance to the BB shell itself. There's not much way to go a whole lot shorter and for someone who has a 36" inseam, the whole idea of chainstays this short is... well, stupid. Right?

Well, not so fast. My first ride (around the block, in the rain) had me pretty worried - so much so that I pulled out the angle finder to check things over, because it seemed MUCH too twitchy for a bike with a 69 degree head tube angle. After confirming things were right, a little cogitation solved the mystery: I had been riding exclusively on the cargo bike (7' wheelbase!) all winter. Any "normal" single bike was going to feel weird.

Nevertheless, I was still nervous last week when the trails dried out enough to get some real rides in. I set out to find out just how stupid Stupidmobile actually was by riding a number of variations on our local (literally a 10 minute ride from the door) trail system. The Shoreline trail is mostly bench cut singletrack on steep, semi-rocky (limestone) soil. It occasionally wanders up a drainage (the Dry Creek section is a classic) or a mountain (Mt. Van Cott is a fun way to cough up a lung) and it features what might be the most fun section of singletrack in Utah - the Bobsled (yes, it's really berms the whole way, yes, those guys are jerks for riding it when it's muddy). Long story short, it's got most of your types of XC terrain to test frame geometry.

I have to admit that at first, I wasn't riding the bike very well. I was oversteering everything due to the super short wheelbase - the bike steers much quicker than you'd expect from something with a 69 degree head tube angle and coming from an FS bike (my main ride in 2012) with almost an extra 1.5" of wheelbase, it was a bit of a shock. If you leave your butt in the saddle over any kind of rough terrain the tucked-under rear wheel will let you know in a hurry by attempting to eject you. I managed to not crash up the Dry Creek climb and figured I'd take it easy on the Bobsled. Unfortunately, I was with my buddy Paz Ortiz who is not only the only non-douche realtor I know in SLC but also a really badass descender and enduro/SuperD racer. He and I always duke it out on the descents so I ended up riding way faster than I should have.

Man, that rear tire is close to that bottom bracket. 

The results were stunningly awesome. Stupidmobile's short wheelbase let me rip through the berms and the slack front end made things manageable on the rougher and straighter stuff (though to be fair I think a longer bike would be better on the rough/fast/straight sections). I've got experience with this type of geometry and in fact I've been riding similar bikes for years - but I figured there would be diminishing returns under 42cm or so of chainstay length and 42" wheelbase (at least for me). I was wrong. The bike is probably not *faster* on most terrain but it's not slower than a longer bike either and it's super, duper fun for trails where jumping, flying, and general silliness are your goal. Would you be faster in a race? Probably not - the bike is pretty unforgiving of mistakes and a poorly executed bunnyhop that comes up short over a log or rock is going to result in an ass-over-teakettle disaster. I don't even want to imagine how hard it would be to keep things under control after a few hard climbing efforts with your whole body exhausted and your brain on autopilot. It would be bad.

But for rides under 2 hours, or short races, or anything where the goal is fun and not playing chicken with your lactate threshold? Awesome. I love it, I don't regret a thing. I'd recommend it to customers, even, with a few caveats (see the bullet points below).

Awesome stuff:

-Very "intuitive" and hip/lean steering action. If body english is your preferred steering method, this is the kind of bike for you. If you like to jump over/wheelie over/roll up the berm to the side of obstacles, this geometry will help you do it.

-Great climbing traction whether standing or sitting. Man, there's a lot of weight on that rear wheel.

-It's very easy to unweight the front wheel (shocking, I know) for getting up over obstacles whether you're going uphill or down.

-Just plain fun. But then again, it's a mountain bike. Pretty much all mountain bikes are fun unless you're a seriously grouchy individual.

Not much creativity from the Waltworks photography div. on display here.

Not so awesome:

-Mistakes will be punished severely. If you come up short on that jump over the little rocky section your dentist will be getting another mistress and/or boat, probably. Kidding aside, this is a terrible geometry for riding where you'll be trying to go fast when you're not fresh and alert. You need to be on the gas and be paying attention to your lines because the bike won't bail you out of a lot of mistakes that a longer one would.

-Unless your technique is very good or you run a very low bar position, it's hard to keep the front wheel down on some steep climbs. The lack of weight on the front wheel and general high trail number mean that this bike does want to wander on slow technical climbing - those who really enjoy that type of stuff may want an adjustable travel fork or a bit different geometry. It's not unmanageable but it's also far from a perfect climbing bike.

-This frame requires a zero-dish (hub offset to the driveside by 5mm) rear wheel and you can *only* run an outboard position (~56mm chainline) ring. That means no crank mounted bashguard (ISCG can be done, though) and no front derailleur. XX1 cranks are a no-go. A Rohloff hub could work reasonably well as they use a 54mm chainline if you are a planetary gears kind of person.
EDIT: Actually, with a 28t MRP bling ring running at 51mm chainline, XX1 will work. In theory you could avoid the offset rear end here.

-Even with the whole rear end moved outboard to line up with the ring the chainline is not especially good in the highest or lowest gear. The stays are so short that the angle just gets extreme. I've had good luck running 9 out of 10 cogs on a 10 speed cassette, which is plenty for me, but those who want a full range will not be happy with the drivetrain performance. Singlespeeders will have no problems. EDIT: With a 28t Bling Ring, chainline is much better and I get full use of all 10/11 gears.

-Tire clearance is somewhat limited - a 2.3 will fit fine but anything bigger is a tight squeeze. Adding 5mm to the chainstays or using an 83mm BB shell (which brings another set of issues that I won't go into now) would take care of this.

So bottom line: I love this bike. I like it even better than my previous short-stay setup from a few years ago and for the right rider (ie more interested in having fun on 2 hour rides than absolute speed or 24 hour solo sufferfests) I think this sort of geometry is a great fit.

I should also note that the new Paragon Polydrops (which Mark asked me to test prototypes of with this frame) are working great after probably 15 hours of riding and I'm happy to build with them (no extra charge) for anyone who is interested. They are probably not the ideal dropout for this bike due to their length (makes it hard to use the second bend on s-bend chainstays to get any heel clearance) but they offer some cool flexibility in terms of bike setup and I have had zero problems with them thus far. Most riders may prefer the low mount or classic DR2010 (or sliders for the singlespeed crowd) but that's a decision that's complex enough that I'm not going to go into it here.

Trying new things

I often run into the stereotype that all steel framebuilders (or all custom framebuilders period) are wool-shirt wearing, bearded grouches who only build lugged randoneur frames.

There is of course a smidge of truth to this, mostly because doing what you know is quick and easy. For example, I built a pretty conventional 29er SS frame for Mike C recently (it'll go to powder today or tomorrow) - I knew exactly what parts I would use, had them all in stock, and knew exactly how to do every operation needed to take the frame from a pile of tubes to a complete bike.

On the other hand, I (yesterday) built a fork for Ian that uses a 15mm quick-release through axle. This is something that I had never done before, but I felt it was appropriate for his use, not to mention the fact that these axles are becoming more and more common for XC bikes, and if I want to keep building forks for people, I'm going to have to figure them out eventually. Of course, the bearded grouch builder response would be "there's nothing wrong with a 9mm quick release"

Long story short, the fork (usually about 1/4 of the work of a frame, comparatively) took at least as long as Mike's whole frame.
-I had to make the dropouts. I *should* have ordered in some 3/4"x.120" 4130 and put it on the lathe, then tapped the other side to make the threaded dropout. Instead, I made the dropout in 2 pieces - one piece of 4130 turned out to 15mm (the slip fit) and one M14x1.5 nut which I turned down to match the OD on the lathe. Talk about a dumb way (from a time/effort perspective) to do things...
-I had to make adapters to attach things to my fixtures. The 15mm axle won't fit in my fork fixture, so I had to make a dummy axle, as well as an adapter to fit my disc tab fixture to *that*. And all of them had to be to pretty decent tolerances to make sure things lined up well, so I couldn't just slap things into the lathe and blaze away.
-After I welded in the dropouts, I realized that I needed to chase the threads - so off to the hardware store again for a ($28! Ouch!) M14x1.5 tap.

I'm fairly happy with the results, though, and the next time around, all the things I learned should make it go much quicker. There will be an upcharge ($75) for these setups, until someone starts making a plug/play dropout for them that I can just weld in (hear that, Mark?)