Systems and Systems of Systems

A while back, I wrote a piece on recognizing expertise in those around us. It’s pretty good, you should check it out. In that essay, I talk about how an expert can recognize systems around them and build those systems into other systems, better, that they can explain all this. I’ve been doing just that … Read more

What does a day of modeling look like?

“I would have written a shorter letter, but I did not have the time.” -Blaise Pascal COVID-19 is a bad thing but many of us keep trying to find and see the good things. One thing that I have enjoyed about the COVIDs is the time I can spend really savoring the design process. As … Read more

SRAM Master Pistons

SRAM Guide and Level brakes work pretty well. I use them. In general, they do what is needed. Not perfect, but nothing seems to be right now. For flat bar all-road conversions that have flat mount calipers, we use the Level levers, not the Guide. This keeps the leverages correct. Level levers can also be … Read more

Windy’s Bird of Prey

This is the time of the all-road bike. It’s been the bike to have for the past 3 months as COVID-19 has brought a whole new mode for my bike rides with my wife, Windy. Many mountain biking areas near us have been closed for a long while. At the same time, Bolinas/Fairfax Road and … Read more

The finish line.

Advice for the aspiring designer; Have lots of patience, keep working hard, don’t ever stop! I’m currently working on producing a new fixture for making my bicycle frames (a mandrel bender also but that is another story). I need a tool that will work better than what I have been using for modern geometries, mopeds … Read more

PVD/RAD Refined

Back in November 2019, I posted  a stream of consciousness, ending in an enlightening concept: PVD/RAD. It looked promising even in that primordial state. The problem with that post is that it was confusing and left folks with more questions about the process than the answers it could have. Six months later, I’m still excited … Read more


Today is my day to eat some crow. Attentive readers will know of my work on brake caliper mount locations and a tool for attaching flat mount caliper bosses in the correct location. I’ve been pretty proud of this work. It cleans up a big mess. Devin Bodony of Lichen Precision, a machinist bro that … Read more

Fork Testing with the Camera

After all the drama of the winter injury season has subsided and the lazy days of COVID-19 are here, I finally got back to the fork test video that I had intended to do on the day I broke my clavicle….and then big toe. Originally, I had intended to do this filming with a GoPro … Read more

Fiftyfifty tires.

2020-04-17 All-road tire test: Subject: Maxxis Velocita AR, 622-40,120TPI, 380g, tubeless. Setup: 50psi with Cushcore CX insert on both wheels, Orange Seal endurance. WTB KOM i25 rims. Tire width measures 42.25mm on the i25 rim. Bike: PVD T-47 Airspeeder All-Road. 40/10-50 gearing. Rider: PVD, 205 lbs, fat, out of shape, expert dirt. Conditions: Dry but … Read more

You can’t fix it in post.

In photography and filmmaking, the joke is often made that “it can be fixed in post” to justify doing very low quality work. It’s true that there are a several small issues that can be fixed after the image has been captured. Some colors can be shifted, a smudge removed, subtle white balance changes, the … Read more


This came up in a discussion the other day. I figured that I’d bring it up here as it is current in what I’ve done in a recent design. I’ve been working with my klunker platform enthusiastically and have just produced the Supermarine Spitfire which was building on the Sopwith Camel. It makes use of … Read more

Some bikes are more evil than others

Here we are, well into 2020. The bike industry has just two products to sell: ebikes and all-road bikes. Nothing else matters. Those are the money makers and all that folks are really paying attention to. Everybody is trying to stake a claim. On February 15th, I saw a few images on someone’s Instagram that … Read more

New carbon

Just touching base on what has been keeping me busy recently. After the Supermarine Spitfire crash, I took a deeper look at the materials that I use in my handlebars. A greater safety factor was needed at the cost of a little bit of flex. Some of these bars have been in service for next … Read more


Gambling is an art with a vicious side to it. We bet on black and by magic, we get black…over and over. We get cocky. We think we know what we are doing. Then, up comes red and we are busted again. The gambler always loses. Dunkirk. The first ride on the PVD Supermarine Spitfire … Read more

Special knarp for dropper posts

Here’s a problem some may have come across when setting up a high performance bike. It’s a little tricky. I needed to actuate a OneUp dropper post using an older style BikeYoke Triggy lever that used the 4.3mm (diameter) x 4.4mm (long) derailleur cable end at the lever. Typically, for this seatpost, we will clamp … Read more

The devil went down to Georgia

Supermarine Spitfire. Today is new bike day. I try to raise my bar when I build a new bike. Each has to be an improvement on the past. Better, faster, funner. Whatever it takes just push farther. Maximize, minimize, optimize. There’s so much room for development. This is another next level bike where few see … Read more

Frame reach isn’t a driving dimension

The current trend in bicycle marketing is to talk about frame reach, the horizontal distance from the bottom bracket axis to the center of the top of the headtube. The ‘long’ in long/low/slack is for “longer reach” or “longer top tube”. Although this is just flagging that they don’t understand much about what they are … Read more

I’m soooo RAD!

POST: 2020/02/15 – An attempt has been made to refine the content you see here in a newer post. This should help a bit as it is clearer and more straightforward. Last year, PinkBike published an article describing Lee McCormack’s concept of fitting bikes using his Rider Area Distance (LLB-RAD) method of bike fitting. McCormack … Read more

Punk isn’t dead.

It’s time for the Philadelphia Bike Expo! I wanted to be there this year but lots of important work got in the way. The design for this tool was done a couple of weeks ago. The tool was supposed to be finished before PBE and show to folks in real life but thanks to late … Read more

Move fast and break things

Generally, I like the motto “Move fast and break things.” It’s punk rock. It’s what tech needs to do. It pushes hard, fearlessly. It’s better to take the risk now than just pudder along doing the same old thing. Move the ball forward! This, except when things do get broke…and it took forever to do … Read more

BREXIT Brakeset

I got these new brakes from the UK just before a hard BREXIT hit on Halloween. What an insane situation for a trade company. Spooky AF. #thanksobama The moving target that is mountain bikes never fails to disappoint. Everything has changed and will again. We can’t rest. Generally, things keep getting better. I’ve been saying … Read more

SRAM Coaxial

At Eurobike a few weeks ago, SRAM made public their Universal derailleur hanger (UDH) concept. There was a bit of hype from the marketing shills. None of it made much sense. The problems that all of the marketing people were saying it solved really aren’t legitimate problems or serious consumer problems. I didn’t think much … Read more

Alloy Nipple Seats

I use alloy nipples when I build mountain bike wheels for myself. It’s a real weight savings right where light weight really counts. They’re really the only choice for performance use. But, they break and you fix them. Your wheels are light. Simple. Over the years, I’ve learned a few tricks… It’s the details that … Read more

I don’t care if it comes in violet

I had an issue a few weeks ago that I’m getting around to talk about just now. There’s a reason for that. It’s because I now have the part that I need for my all-road bike to work again….and this is bullshit. I had a pretty good crash a few weeks ago. Bad for my … Read more

OneUp 210

There’s a lot of change that’s been happening for the last 8 years or so in the world of mountain bikes. I discuss much of that on my blog here. I’m most associated with discussions on geometry and frame engineering but I do a bit in many other areas as well. Rarely do I talk … Read more


侘寂. Imperfection is sometimes a strange kind of perfection. We’ll see a hot rod, motorcycle, or bicycle and it is such a terrible thing in the details but in that, it’s fantastic. Producing something like that takes time, wisdom, and a little bit of luck. Knowing just what blemishes bring out the soul of something … Read more

American Irons

Every cyclist has to to fix a flat tire. For that, there’s IRON! Not all tire irons are the same. Most are terrible. I’ve been handling these things for a pretty long time. Every now and then you find some that just work well. In the bicycle world, tire levers (irons or spoons) are treated … Read more

Making an impact

I recently needed to remove a fussy T25 drive screw from a SRAM XX1 crank. Despite both the screw and tool looking in good shape, the tool kept camming out of play, rounding edges, and was turning into a terrible situation. I didn’t understand why this was happening but it was time for evasive action. … Read more