Oh, what the heck... one more

Sarah's (not my Sarah) new 29x4" bike. Featuring BB wrench counterweight and no shock bushings yet! It's friday...

No decals either? Walt's not even trying...

Pretty normal modern XC geometry, dropper post compatibility, and remote lockouts and adjustable travel out the wazoo. Sooner or later I gotta modernize my own stuff, my own FS bike looks pretty darn obsolete these days.

This thing would fit me pretty well if the seat tube and head tube were both 2" longer

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...

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?)