Jake Harrell is the son of my friend and business partner, Bryan. Fairfax Cyclery!!! Jake and Bryan have been racing a ton of BMX lately and Jake is proving to be a seriously fast kid. He can’t wait to get out with dad and the bros for the downhill rides. Problem: There is really nothing … Read morePodracerOne – Big Evil, Small Package
Simple leverage. Didn’t anybody else do the math? BB30/PF30 has proven to be a complete mechanical failure. It was obvious from the outset and I had made good arguments against it when it was first being rolled out. The Shimano system is clearly superior but for some reason cyclists thing that everything has to be … Read moreBB86 is 30% stronger than BB30
The proper setup of Downhill and long travel suspension bikes often requires the frequent removal of the shock as well as having the system in a topped out AND bottomed out state. These little dummy shocks allow the rear end to be easily fastend in place to adjust things like chain length, cable routing, chain … Read morePVD Dummy Shocks
Ashland Super D, Cat 1 40-55 Men, 42:26, 14th. Super fun race. A poor showing for me. Ran with full fixed high post. I was a bit out of shape for the climbing and could have saved some time with a dropper post. Can’t wait until next year. I would expect at least a 39 … Read moreAshland 12 Mile
Thinking about this today. What about the area under the curve with regard to shock rate? Should the area be similar for differerent types of bikes? The shape can change, the duration and the magnitude but will in the end the area be similar? I’m going to think a bit about this… Here’s the curves … Read moreThe Area Under The Curve.
Cheap stems are rad. They do just fine holding the handlebar in place and come in many sizes. Most are even lightweight. What’s the problem? Tolerances. Most cheap stems are cast or use cast parts in a weldement. These parts have deviations that cause a problem. The issue is that the bottom side of the … Read moreMaking a dollar out of fifteen cents.
I read an artical online about a guy that made a few eccentric reducers for shocks to use for adjusting ride height on bicycles. It was a great idea although his execution was rather poor. I instantly decided to add that option to my PVD Reducers. Pretty cool. 1mm offset at both ends of the shock … Read morePVD Eccentric Shock Reducers
Mary Pralinsky wanted a beater bike to take to the jumps and to the pump tracks. She wanted something cheap and unbreakable. Nothing can touch a Specialized P3 when it comes to that. The bike is heavy and indestructable. She found someone selling a used one with 90% of the parts for $200 and picked … Read moreSpecialized P3, Best shit bike ever!
So…. My friend Matt gave me a call. He had purchased a basket case VW Super Beetle project car. The car had had a lot of work done on it but wasn’t completed and it needed an engine. Matt had a line on a Porsche 914 engine that would drop right in. He purchased both … Read moreSuper Beetle / GTI Strut Modification
A Super D bike is a very special kind of bike. 90% DH Trail with 10% Climbing. Super high speeds on smooth to aggressive surfaces. You need a light bike but something that works right when treated rough. 160mm frames tend to work especially well in this situation if set up well for pedaling and … Read moreSuper D(set) Suicide
Named for NASA Project Gemini, since it’s the bike after Mercury. This is the first of a pair of bikes, one mountain and one road. They will reflect a snapshot in both disciplines of my bike design techinque. They will share several design cues. They will proabably be painted the same color. Since these will … Read moreGemini (Alpha) – 150mm Hardtail Trailbike
This past week has been all about Mary. Two of them in fact. Mary Pralinsky and Mary Moncorgé. Mary Pralinsky is a friend of mine racing DH as an expert this season. Mary Moncorgé is racing PRO in GRT and nationals with Santa Cruz Alliance. Both needed fully prepped race bikes for the season. They were nice enough to come to … Read moreThere’s something about Mary.
My SC Butcher bike has some serious drive train issues that make it less than fun to be on. It functions, but it’s so floppy and loose that it ends up being something that I think a lot about on a ride. That sucks. Gonna fix that. I don’t want to strip the bike down … Read moreRefining gearing for long travel suspension
Hey folks, Juliana Gallin of How-to Night SF was nice enough to invite me to lecture on how folks can build their own bicycle frames at home. Of course! It’s easy. How-To Night at Bazaar Cafe Wednesday March 9, 2011 • 7 pm • How to Build a Bike From Scratch Bazaar Café 5927 California Street, between 21st & … Read moreDIY Framebuilding Lecture
Inspired by products designed and made by Magic Motorcycle in the early nineties. Some wild stuff. Probably not the best, but intriguing to say the least. Especially if you are a machinist type like me. So, 2×10 has taken hold in mountain biking. It has a place but certainly 3×10 does as well. Shimano has … Read morePVD Magic Ring
The radar mount was installed today. I mentioned it in an earlier post. Very cool. It took some planning, lots of rope and safety harnesses but it was installed without issue. A 40 foot drop on one side and an 18 foot drop on the other. No screwing around on this job site.
I’ve been quite busy lately… The modular throttle project is just about done. Final testing takes place this weekend but this revision is assumed to be the last. Prototyping has been a long process for this. The engineering was quite a learning experience for such a simple little part. A 60 degree variable rate cam that … Read moreThese are the fun days of development
This is a neat project from work. It’s a straddle mount that will sit on top of a wall above the water treatment facility on Ocean Beach. It will support a 9′ rotating radar boom against anything the Pacific Ocean can throw at it. 0.375″ stainless steel, plasma cut and welded together.
These are the all new PVD headtubes for the 2011 Gemini bikes. A pair of bikes following Mercury. A road and a mountain. They should be completed prior to NAHBS for all to see. Show bikes made to be ridden hard, put away wet and taken out again and again. Top bearing is Cane Creek … Read moreGemini Conception
Named for the NASA Mercury space program. Seriously rad! The 2011 PVD Mercury Trailbike. Tapered head tube, 2×10 designed, DMFD, ISCG05 w/slider, BB92, with clearance for 3.0″ tires. Like all PVD Trailbikes, this bike is designed specifically to completely dominate Marin California singletrack. The time tested and challenged design sets the standard for high speed … Read moreMercury.
2008 GSX-R750 Tie Down Tabs for rear end. mounts under the passenger peg bracket. A nice feature for transporting or working on the bike.
Math and numbers rule! You can learn a lot from them. This weekend I put my nose to the grindstone and measured the weights for my bike and weight distribution. Bike weight (full of fuel) – 444.5 lbs. Ride weight (no gear) – 203 lbs. Gear weight – 18 lbs. Weight distribution – 49F/51R (note … Read morefiftyfifty
Here’s a fun little project. Motorcycles have engines. We all know that. What few truely understand is that we use our throttles and gearing to access and make use of those engines. Asside from gearing issues that I will cover later, throttles typically need modification so that we can get all that power we have … Read moreThe PVD 60 Degree Throttle Prototype
Here’s the new bike. Soon you’ll be seeing a lot more tuning projects based on this. I’m super stoked.
It’s not easy making things and bringing them into this world. It takes a lot of time, energy, money, devotion, and lonely days in the shop. I’ve got so many projects started right now and many more that I’d love to start. Why not? Life. Lately I’ve been really putting a lot of energy into … Read moreKeeping hope alive and fear in the heart.
It’s been a few months since I’ve build a bike frame. I needed to update my geared trail bike with a few new updates in my design but one issue was lagging. 1.125″ straight steerers are effectively dead. It’s all tapered now. The light carbon forked folks like it. The burly slopestylists like it. Everyone … Read morePVD Tapered Head Tube
As the proud new owner of a 2011 Fox Vanilla 36 160 fork, I finally got around to give it the TLC that it deserved. I had already swapped the stock ‘blue’ spring (039-05-102, 45 lb/in) for a stiffer ‘green’ spring (039-05-103, 50 lb/in). That’s a pretty simple task and takes about 5 minutes. It … Read more“Adjustable suspension” by Fox
This past April I moved to the Bernal Heights neighborhood in San Francisco. Quite a culture shock for me to be sure. Fairfax is a very differnt place. This part of SF is about 15 minutes away from one of the major casual DH/Jump locations in the bay area, Pacifica. An odd thing about Pacifica, … Read moreFancy New All-mountain Bike
Riding at Northstar this past weekend. My trusty steed the Intense M6 finally had an issue. 2.5 seasons of riding and the pivot link pertch broke off. I was able to get a good day of riding in on Friday, but at the bottom of the last run of the day the snap cracks and … Read moreStuff Breaks.
You don’t know anything unless you’ve measured it. A very wise tuner passed that statemet down to me. I learned a lot from him. Dan Kyle. Look him up. People get pretty spooked about suspension. They get lost. They get confused. I used to. Then I bought a spring scale and everything made much more … Read moreYou don’t know anything unless you’ve measured it.