There are a few important specifications in the bicycle world that range in ease to find. Shimano Hyperglide spline, Hayes 6-bolt rotor, e*thirteen ISCG05, etc. Some of these have clear and openly defined specifications. Others don’t. One of them that has become crucial for many in the past few years is the Cannondale BB30 crank … Read more
We got a chance to visit BC Design Co. in the Bunche neighborhood of West Oakland yesterday. It took a while to arrange this. Student schedules are a nightmare to work around. Ben Chaloupka is a professional fabricator of architectural metal work in the SF Bay Area. Obviously, he’s doing work at the very high … Read more
This post is dedicated to Ronen Sarig. May he call me out on my bullshit forever. Slopcore! Using computers has been present in my life for a long time. I’m no expert programmer. I call myself a ‘user’, I’ve seen some things. I’ve tried to get things done. My father bought an Apple IIe back … Read more
Long range planning is underway for a extra fast hardtail mountain bike (MTB-LT32/29) that should be completed in the spring. Similar to the Corsair, it will have a 686mm BCD tire on the front rim. Suspension forks for such a bike are expected to reach the consumer market around then. One of those forks, a … Read more
Making things in the workshop has changed significantly in the past decade. We are using tools and methods that didn’t exist or were cost-prohibitive during most of my career in metal work. I’m currently building a motorcycle chassis. There are some tricky things that go into making this. I try to adopt these new methods … Read more
Back for 2026, the MADE bike show in Portland Oregon! [2023], [2024] It’s always fun to go to the show. People! Things! Ideas! We are lucky and privileged to do such things in our lives. Where else do I go and so many people that I’ve never met know my name. I was really flattered … Read more
I’m on my way up to the MADE bicycle trade show in Portland Oregon later this week. It’s a quick 10 hour drive from the bay. On site Thursday evening to Sunday morning. I figured that I’d have this post at the top of my feed to help folks navigate to detail on the bike … Read more
In my last post about the kinematics that I worked out for the new motorcycle, I referred to something in the choice of ‘countershaft’ sprocket location that was interesting. Now we are going to look at the anti-squat and countershaft position. This is something that I discussed years ago regarding idiocy in the bicycle world … Read more
I’m doing a bit of R&D for an eCruiser project. I’m an old man now so sportbikes aren’t my goal and dirt bikes will have to wait until I move from the bay area. This post focuses on the rear end kinematics. The last bike I was riding, a 2014 Honda CTX700, was an awesome … Read more
I’ve been wanting to clean up the brakes on my Gulfstream commuting bike for a while. The cockpit of the bike looked like a mess in the last post that showed it. Enough to motivate me to step up. I put a bit of time on this bike so I’d like it to present as … Read more
It was about two weeks ago that my university sent another graduating class out into the cold cruel world. Unprepared and ill-advised, they are entering the most challenging job market since 2008. It might be be worse than that as we are only in early stages and the real situation is far from clear. I … Read more
My friend Philip handed down to me a Bafang MM G320.1000 mid-drive conversion motor. That’s a very nice thing he did. This made more of my R&D possible for very little cost. That’s my favorite. Look and see. I’m not interested in this type of system as it’s sold. I’m looking for something else but … Read more
I want to do an update on the 2024 PVD Gulfstream RD+. A couple of years of riding and this gem is still shining. Good design lasts and has many uses. After a short time using the bike for road riding and testing for fit in that element, the drop handlebars were swapped for a … Read more
I’m doing some R&D for some ideas that have been circulating in my mind. Electric motors and batteries are creeping into everything. For this case, I’m looking at approximately a 40:1 gear reduction in a motor drive line. There would be a primary (??:??) and final reduction (15:40). That means 15:1 for the primary and … Read more
I like to think about thinking. The process of how an idea gets from A to B is one of the most magical things I can imagine. I try to get better at it but that has always been difficult. Why? Because I want to predict the future. I have a problem. Often in discussions … Read more
Here we are again. The end of the Spring 2026 semester at San Francisco State University (SFSU). Students will be receiving grades and graduating. Sadly, it’s a fraud. At the end of last semester (Fall 2025), when grading was about to happen, our provost posted a dispatch for our faculty to reflect on. She didn’t … Read more
I did a round of development on the skate truck this week. I’m making a push for the G7 truck production. I’m looking into lots of details. I’d like to get these to the point where I can move to a machined aluminum short run version. I ordered some cheap 70mm 82A wheels from Amazon … Read more
The arrival of the 32″ wheel has given the bicycle marketing people from around the world a chance to demonstrate (in real time) how little they understand about fundamental bicycle geometry and design. I’m actually embarrassed for the media companies, frame builders and marketing companies that are so heavily publicizing their incompetence. Wow! Drawing a … Read more
An idea came to me while riding around Tamarancho the other day. It’s regarding the steerer profile for the 32″ forks that we should be seeing soon. I’m looking for a shorter tapered section so that I can use head tube options below 85mm. I sent an email regarding this to a fork manufacturer. To … Read more
It was time to test the state of tariffs and overseas machining. I had some parts that I wanted to improve the Samantha fixture so I’d use them to see how things are going. If this went well, I could resume some bigger projects. The changes improve many functional things about the fixture but also … Read more
This is something that I’d been doing in my head for years. I was always guessing. An educate guess, but still a guess. Now, I have it solved. Designing dirt going bicycles is difficult. There are many crucial details that need to be figured out and understood to produce a design. If a few hundred … Read more
Cable management is important on a well designed bike. There is an art to placing them in precisely the right location. It’s even better if that can be done with a tidy and clean appearance. One solution to this that many arrive at is to get the cables inside the bike as soon as possible … Read more
Yesterday was an interesting day. It started very early for me. An hour and a half drive to an 8am tour of the huge Tesla factory in Fremont, CA. We spent the morning looking at state of the art automation and the first steps toward humanoid robots in the workplace. In the shell of an … Read more
A bit over a year ago, I sat down with my friend Ronen Sarig to discuss what made him tick. I had been looking forward to this. We share a bond that spans many levels. Riding bikes, engineering, philosophy, etc. I knew we’d have fun with this…and we did. The problem was me. I felt … Read more
This was a fun little project. Something to discover new things. I was interested in working with a crossed roller bearing in a future design. I ordered one and found a project that would introduce me to working with the element and add some value in the shop. It’s a simple rotisserie but it mounts … Read more
Let’s talk about the front of the bike. This has been the part of the bike getting renewed attention in the past few years. New stem products and 32″ wheels have gained some traction in the mountain bike marketplace. As these encroach on what I’ve been doing for so long and do the most advanced … Read more
Back in mid-2023 I produced a run of FM160/30.5 to PM180/60 adapters. These turned out pretty awesome and are still the coolest thing to this day. This was a bittersweet thing to do. I was impressed with how well they worked out but the fact that I had to was insane. Wildly, to this day, … Read more
I’ve been discussing disc brake fitment for at least a decade. Past blog posts are evidence of this. I’ve also been designing parts for myself and other companies that interface with disc brake systems since designing the Independent Fabrications IS dropout back in 1998(?). I’ve even been wildcatting the specifications since my beginning. Over that … Read more
I’ve been working to develop new tools in my shop that expand my capacity in novel ways. As I look at my goals and future projects, hydraulic power is an area of the shop that hasn’t been exploited well but should be. I believe that most would say the same. If you don’t work in … Read more
I’ve long acknowledged a problem with my method of geometry development. I wasn’t prepared to deal with or thought that I could run the clock. The day has come to get it resolved. Looking back in time, being forced to build my special handlebar systems in 2018, and even before that when I started working … Read more