This category is a repository for information around the PVD Samantha Bicycle Frame Fixture and other associated work.
Warning! Some of the information below has been superseded by new information. What’s old is new again. Circa 1997. The Hayes 22mm caliper mount. Believe it or not, this is what changed mountain bike braking forever and truly brought disc brakes to every day mountain bikes. Back in ’97 or ’98, I bought a bike … Read more
I started this project last fall and I’m finally getting it done. I’m trying to clear the counters in the shop and I’m hoping to stay on track. I like to use my PVD StepDown brake mount on frames and forks. After welding, some calibration of the mount is good to do. This will help. … Read more
Making the rounds this last week was a photo of a 4.5kg “mountain bicycle”. It can’t possibly function, but I’m sure few realize that. Last week someone I know was bragging to me about how amazingly light their bike was (although, they get a pass, being pro AF). I’ve been planning to get around to … Read more
This is a big deal for me. For years, I’ve been looking for a way to mark my bikes. The careful observer may have noticed that close to none of my bicycles have had any identifying marks on them other than the fingerprints of my design aesthetic. No decals. no logos. No marks. Why? Because … Read more
There are very few bikes that get used on dirt that don’t require a bent seat tube to work properly. Tires have grown, chainstays are short, and pretty much everything uses a dropper post. Today’s dropper posts stroke around 150 mm to 200 mm, 170-185 mm is preferred. These factors combined with the need to … Read more
I do a lot of fancy parts for bikes. I want the bikes I make to turn out just as I imagine them. Each one differs from the last. The problem with each bike being different is that it’s often not worth making tooling. This time it was worth it. I’ve been using yokes for … Read more
Every now and then, someone comes up with the great idea to build a bike frame with straight gauge tubes. This is silly and a dumb idea. Here, I compare with a True Temper VER01 .8/0.5/0.8 butted tube with a section of straight gauge 0.035″ thick 1.125″ diameter 4130. Why compare a 8/5/8 tube with … Read more
More Blackbird parts are going through the system. It’s so good to see this all come toghether. This is getting very close to happening. Soon. TurboRamJet, baby. The power at the heart of the beast. After the monster job of getting chainstay yokes completed, it’s now on to the smaller parts. Head tubes will be … Read more
Currently, the next “big thing” in mountain bike marketing. High trail MTB. Specialized, Transition, and White have already begun marketing 29er bikes with 42mm offset forks, thus, higer trail than the 51mm forks produce. I’m sure many more marketing departments will be pushing this soon as well. This is another topic that Chris Porter has … Read more
♬It seems I gotta start the explaining, bust it♬ For the Red Baron project, I’ve been working with some custom steel forks. It’s been a while but forks are fun little projects that don’t involve the same investment of time or money that a full frame does. For high performance, carbon is the way to … Read more
I’ve been saying it for a while but yesterday it happened (again)… We were about to start a mountain bike ride on Sunday. My third in as many days and all deep into poaching territory. Thanks Cesar Chavez! (SF Official holiday) The morning turned into an utter train-wreck. I like to be very prepared before rides. … Read more
Fit is something few cyclists pay any real attention to. Dispite all of the chatter. Despite how important it is that a rider be placed well over a bike (and the bike placed well beneath them) very few riders or shops put much effort into the subject. Rarely do I have a conversation that leaves … Read more
I didn’t come up with the idea of Forward Geometry. Sure, I’d been working on improving how my bikes worked and getting them to a modern state for a while. Still, other folks have led this particular charge. Quite a few people have been working on moving this concept forward. The two people in the … Read more
Today, we don’t design on paper… I was recently reminded of this topic by a message board thread. A kid wanted advice advice on drawing a frame. Countless people chimed in giving horrible advice. I often find that the less someone knows the more they will pass off their opinion as truth, while lacking any … Read more
This is a bit of an update post. I posted a graphic online back in 2011. It showed the comparative leverage between a BB30/PF30 bottom bracket bearing configuration and a PF4186/T3568. It made it instantly obvious that geometrically, the PF4186/T3568 was 31% stronger than the larger, heavier BB30/PF30 configuration. The bearings had a superior working angle and … Read more
Bent seat tubes on bicycle frames are nothing new. They have been used for years in both mountain and road bike design. The rear wheel often needs to be forward of what space would otherwise allow. The seat tube is adjusted to give tire clearance. In recent years, it’s become almost impossible to build a quality mountain bike … Read more
Warning! Some of the information below has been superseded by new information. I figured that I’d have a little fun with this since I, once again, worked out this system. I call it StepDown. It allows a frambuilder to design a rear dropout that is a little more compact than the existing IS would allow. … Read more
Following my last post where I was able to adapt and move forward in development, I produced an offset insert for the 55mm Euro lower headtube on my new 2016 Scott Genius LT. One of my goals is to see how long I can run this thing so it goes super fast down hills. It’s interesting how … Read more
I’m a pretty dumb guy. Really. I learn new things every day that make me step back and say, “Dam Pete! You’re a dumb mutherfucker! You should have seen that long ago. It’s obvious.” I get kinda down sometimes. I feel like I’ll never catch up to what’s going on. I have to try and … Read more
I cruise various bicycle frame builder message boards and the frame builder’s Facebook page. I haven’t had any interest in posting there in a while but I did a lot in the past. The topics that get brought up are often topics that have been covered over and over so there isn’t much to offer in terms … Read more
A while ago I posted about drilling holes in aluminum frames to add stealth routing for dropper seatposts where they didn’t exist. Folks were so concerned. How dare he? What gives him the right? Bike frames just can’t handle this!?!! Well, I’m at it again. Carbon! So fuck y’all. The recent acquisition of a cheap Chinese … Read more
Here’s something fun and useful. I love when I get to get all math-y… A long time ago (2006), I put a blurb up on my wiki. It was a re-post from long ago that I had posted onto a skateboarding message board, probably back in 1998 or so. My web site, wiki, and now … Read more
Things have been changing a lot with modern mountain bike specifications. Dropper posts, long front centers, cable routing, and 142mm rear spacing to name just a few things. When it comes to dropper posts, it’s settled that internal or ‘stealth’ routing is the standard and preferred way of doing things. Bike frames that are just a year or two … Read more
The stem is an incredibly important detail on a bicycle. It places the handlebar in the proper position relative to the bottom bracket and the saddle regardless of what lies beneath it. Where the stem holds the handlebars can make a bike fast on climbs, or fast on descents, or great for all day comfort. There … Read more
I absolutely love trigonometry. It’s how we come to understand circles and curves. I work at the Physics & Astronomy Department at San Francisco State University. Every semester a few students will express their unease, confusion, and problem doing trigonometric work. Over the years, it’s been shown that, all of them, have never been given … Read more