Big dummy

Dummy axles and how they are held are a crucial part of a frame building program. We have to accurately place where the wheel axles will be, just as we do with the various tubes. The frame should hold the hubs so that the tires, gears, derailleur, and rotor are in plane, centered among the … Read more

Second Principles

When we work in engineering and design, we refer as much as possible to ‘first principles’, those datums or facts on which the entire project rests. “A basic assumption that cannot be deduced any further”. Everything comes back to these. They are both our lighthouse and safe harbor. In bicycle design, there are many of … Read more

The New Head Tube

Construction of Windy’s new mountain bike is underway. Among the details that needed working out was the head tube. In optimizing the geometry, space got a bit tricky at the head of the bike. I wanted to free up some rider space for her and that means keeping the top tube low. That meant using … Read more

PVD Fixture Updates

It’s been a while since discussing the SKYNET and WOPR frame fixtures. They are some of my most important work and I review them from time to time. I’m not going to go into too much about the fixtures as little has changed, aside from one important detail. Early in the designing of the Cyberdyne … Read more

Industrial Craftsmanship

I design and produce quite a few things as a hobby. Bicycles, motorcycles, & skateboards and the details that surround them. I do other projects but the short list is probably the most elegant way to describe it. I could get even more discrete when I say ’tilt steer vehicles’, but that requires more explanation … Read more

Caliper Mounting Systemization Equations For CAD

For those familiar with my work, it’s known that I try to push my models hard in the design of my bikes and the parts that go onto them. Because of that, equation driven construction geometry for entire bikes and groupings of parts turn into hundreds of parameters and equations for any given configuration and … Read more

The correct location for hub markings

I had to build a wheel for Windy’s bike the other day. When we put her new full suspension bike together, I had to ‘borrow’ a rear wheel from another bike to stoke the setup out. The rear hub had to be an Onyx and that got her going. It just left my klunker disheveled … Read more

Push it Until it Breaks

This post is about durable solid modeling. Durable models are those that are difficult to break after minor changes when marking-up in the virtual model space. Very often, I see others using methods that produce very fragile and delicate models that explode any time the smallest of change is made. There are methods to prevent … Read more

Sabertooth!

It was so long ago that I can hardly remember. Maybe a dozen years. New ways of looking at bikes was driving new choices in parts. I had to start getting more and more creative with setups. More than any other part, the stem became a crucial part. Not just any stem, the RIGHT stem. … Read more

PBE2022

It was looking to be a lively year for the Philly Bike Expo. Well on the backside of the pandemic, things would be closer to ‘normal’ than in the past few years. Also, with the collapse of the North American Handmade Bike Show, PBE was, without question, The Show for North America in 2022. Over … Read more

Flashdance

The other day, I got to go visit the Firefly Bicycles studio in Boston. I’ve got some history in the world surrounding this. I talked with Tyler Evans during the tour and after about what this is all about. Not many know that Tyler’s personal story was made into a movie, Flashdance, although Hollywood took … Read more

OnePointEight

I finally had a chance to work with some of the new OnePointEight head parts. These are being rolled out for heavier eBikes. Matt has a Transition Repeater 29″. He was ‘upgrading’ from a RS ZEB R 160mm to a Fox 38 Grip 2 Factory 180mm. The ZEB that the bike came with has a … Read more

Bike Design with Crayons

We just learned about the 2023 Marin Gestalt X10. A $1,549.00 bike that is almost worth riding. I try to rep Marin County with my bike work. It’s an incredible place to ride, especially if you want mixed terrain. We have hundreds of miles of gorgeous fire roads and a ton of singletrack from mild … Read more

Microscope Holding Upgrade

I just recently got the chance, again, to post microscope images of some failed handlebars. While I’m not into having failures, it’s nice to use my neat setup microscope. Images like the ones that I took are extremely difficult to obtain. Holding a handlebar (or portion of a handlebar) the long way, rigidly, under the … Read more

My first weld failure.

In response to whether he should give up a project, Thomas Edison once said, “I have not failed 10,000 times—I’ve successfully found 10,000 ways that will not work.” I’ve been welding my own bike frames, forks, and handlebars together since 2006. That’s about 16 years. Before that, I had a good amount of experience preparing … Read more

Suckered by Junk

This was supposed to be a nice little post about a setup tweak to Windy’s Stumpjumper and a different look at front end setup. Instead, we are also going to look at what makes a terrible commercial handlebar and what makes one good. When setting up Windy’s new bike, we were trying to push the … Read more

The Downhill Hardtail

This Sunday, I’m getting to close out the season at Northstar. I love riding downhill although I don’t do it much these days. I’ve had a nice summer in this regard. I was able to ride a day at Northstar early in the season and another two days of riding at Trestle in Colorado. Not … Read more

Welding Table Support Clamp

I tell people all the time that I’m not a very good welder. I know good welders. I am not one. Still, I need to get metal connected and I can use all the help that I can get. When welding a bicycle frame, it needs to be held in a lot of interesting positions … Read more

SRAM Retaining Ring Tool

A week or so ago, I posted my new bike, the 2022 PVD F-16 Fighting Falcon. Within the photoset and the breadcrumbs posted on Instagram was a photo of me finding a missing snap ring that got scuffed off against a rock or something. A discussion ensued on how and what to use to work … Read more

A new headset system

Testing is ruthless business. It requires radical intellectual honesty. Huge investments of time, effort, and money were put into getting something on the ground to test. Nobody wants any of that to be proven to be a waste. But it doesn’t help me in any way to lie and pretend to myself when confronted with … Read more

2022 PVD F-16 Fighting Falcon

In the short time I spent riding on my last mountain bike, the 2021 PVD MiG-31 Firefox, I fell in love. The bike was a stunning advancement in modern mountain bike geometry (PostForward). It felt amazing on the trail. Compared to older bike designs, it was lighter handling and cleaner while at low speeds and … Read more

Platform and Binding Pedals

Contrary to most of my posts, I’m not going to try to convince you of anything or tell you that I’m right. I just want to express some of my thoughts. Sometime in February or March of 2022, I put platform pedals on my mountain bike. Since then, I’ve also attached them to my all-road … Read more

The problem with 35mm handlebars

For many years I’ve been discussing the problem with 35mm handlebars on bicycles. Having them specified on stock bicycles is especially bad. They are rarely a good choice for a custom bicycle. I’ve got piles of these parts in a bin leftover from years of working around this junk, replaced with 31.8mm parts. I’ve finally … Read more

Brad Bingham Interview

We were on our way to Winter Park, CO. Our trip started with a birthday funday for Ronen at Northstar Bike Park and a Tahoe trail ride. The boy I once knew is now 33. Jesus was 33 at the end. Prophetic. The day of riding at Northstar was excellent. It had been a while … Read more

Bean Can 2022

Careful readers of my blog will know about the ‘bean can’. It’s a simple enough device that protects the delicate top tube of a bicycle frame when proper hand grip placement may produce damage in a crash. When everything goes ass over tea kettle, the front end swings around wildly, looking for something to stop … Read more

Windy’s trail crusher

It’s new bike day for Windy! I’m hoping that some of the younger folks read this post and be able to develop a new understanding of how to look at putting commercially available bicycles together. Most of my work is done at the extreme high end of construction and a development level that few can … Read more

Fail Early and Often

This happened. We all get to look and see. The carcass of my soul and pride lays in front of you. The message board heroes get to point and laugh. Public failures are a double edged sword. On one side, they give others ammunition to bring me down. They can point at this and say … Read more

Deeper Custom

We all think of custom differently. I like to take things a lot further than what you see in magazines. Spending money on retail crap isn’t custom as I see things, it’s consumption. Custom should be at your own hands not your pocketbook. It should be about taking risks, to show your style and flair. … Read more

The PVD Wheel Lacing Fixture

I think it was 1990 when I built my first set of bicycle wheels. I was a young man of 20, working at Fat City Cycles in Olive Square in Somerville, Massachusetts.  We manufactured very fancy bicycles there. On the side, I had just constructed a fixed gear road frame for use getting around Boston … Read more

Porting equations from Excel to SolidWorks

I develop a lot of equations for use in my designs. Math is behind most of what I make. Generally, I’m using MS Excel while going through the math and drawings to arrive at the system that I want to use. That gets added to master spreadsheets along with all my other calculations that I’ve … Read more