Awesome Double Dare, Rigid 32/20 something like 110 miles of Pisgah spread over two days with John H.
To understand bike fit, you need to think about the size of the rider plus the way they ride and sit on the bike. Especially with mountain bikes, a lot of bike fit is impacted by riding style. It’s not enough to simply reach the bars and the pedals. The rider needs to feel balanced so they have optimal control of the bike in trail condtions.
The key measurements for my process are as follows:
For saddle height, measure from the bottom bracket shell to the top of the saddle in the center. Ideally you should put a bit of tape on this spot so you can use it as your reference point for the other measurements.
For saddle setback, set a level between the saddle and the bars then use a plumb line to drop down to the bottom bracket. The measurement for setback is from the tip of the saddle to the center of the bottom bracket. Every saddle is different so you should also make note of the distance from the center of the saddle reference point to the tip of the saddle.
For bar reach, measure the distance to the center of the bars at the stem then measure the distance from that point to the grips in the horizontal line. This is because the center of the stem is not where your hands go. Different bars have different sweep and what really matters is the horizontal to the point where the grips are. You do not want to measure the direct to the bars because it will actually result in a larger number that is influenced by the bar width. It takes a pad of paper and some basic math but you can determine your bar reach and it is pretty critical in terms of picking the proper frame size.
For bar drop, use a board between the saddle and the bars. Stack material under one side or the other until the board is level. Once you have a level reference plane you measure downward or upward to determine the rise or drop the bars have vs. the saddle.
Some riders like their bikes with high saddles for full leg extension. Other riders prefer a lower saddle especially if they hit the technical areas hard.
The question of ideal fit is complex. Everyone is different. Personally, when riding off road, I use a position that is long and low with a short stem. This position helps me keep the front end of the bike light and makes me feel stable in rough areas.
With various stems and saddle positions, a bike that does not really fit can still work but it is not “ideal”. This can be a problem when frames are build in only three sizes to fit the entire population. Building with seven sizes allows me to have smaller steps between each size to obtain a fit that is almost as good as custom. Since I hand built each frame and don’t maintain a large inventory. This allows me to offer more sizes compared to the big bike companies because I don’t need to bring inventory over on container ships.
This week, I did some detail drawings of a few sizes for my standard frames with different component positions to show some of the range you can get. The following is my “large” frame. I enjoy thinking about position and playing with the CAD program gave me some insights into how to refine the standard sizes that I offer.
Consider my large frame size:
A really pretty small position could be achieved with the following setup. The position could even be made a little smaller with a swap to a seat post that does not include the standard 25mm setback in the clamp area.
A larger position is possible as shown here. An even bigger position could be made with a 120mm stem and sliding the saddle up and back a bit. Notice that I drew this with riser bars and an upward slope to the stem to avoid having a stack of spacers. Spacers generally work fine but in extremes can make the fork steerer tube weaker. If you need high bars for your bike consider a custom frame with a tall head tube or using bars with a bit of rise.
With my size range, I can fit *most* riders using standard sizings. Some riders *need* custom sizing or custom angles for specific reasons and that is also not a problem because I can quickly create a drawing that adjusts one of my standard sizes to meet their needs.
Powder Coat USA has a lot of options for Powder Coating.
On Bob’s frame, we decided to go with “Rock Star Sparkle” from Prismatic Powders because flat black is kinda boring. It was a last minute change and the guys at the powder shop helped me out with a six hour turn around.
The powder effect is hard to photo. I will update this posting tomorrow with some better pictures when I can get it out in the daylight.
Bob Moss can take is 29er and swap out tires to create a MOSStercross bike. For MOSStercross, racing he runs the same single speed 29er he normal uses but with bigger gearing and smaller tires.
Here he is winning a geared category for 35+ at the Spring Hill Cross race. He also finished 6th in the Category 1/2/3 race against geared riders.
The Fools Gold NUE 100 mile race is in the record books.
I had a great race and love this event. This year was extra special because Bob Moss also raced his Farnsworth Bicycles 29er single speed finishing 3rd in the single speed category and 13th overall.
I finished 10th and just squeaked under the wire with a time of 8:57. I am not sure what Bob’s time was but I know it was well under eight hours.
This is my 3rd time racing Fools Gold. The prior two times I raced on an earlier 29er that I built with a suspension fork.
This year, I was racing on a new bike with a rigid fork. This new bike includes changes that I feel help for rigid single speeding. It is setup with a long top tube, short stem, wide bars, and fairly short chain stays. The front tire is a 2.35″ at 19 psi to give me comfort without risking damage to my rims. Both wheels use the new through axle standards and the head tube accepts a tapered fork. The bottom bracket is the new PF30 standard to allow a modern crankset and better support for the bearings. The frame is built with NOVA tubing using a 38mm down tube that includes a factory bend paired with their new 29er “S” bend chain stays. A 70 degree head tube angle makes this bike a little more slack vs. the 71 degree setup I used last year. Compared to my old frame, the new setup is also stiffer at the bottom bracket while still maintaining the smooth ride of a steel frame with 16mm seat stays. The new bike is oriented around my personal riding style with a focus on distance oriented single speeding.
As a single speed rider, I do much of my serious climbing out of the saddle. Compared to a geared rider my style of climbing is to mash so the bike geometry takes this into account. The biggest thing people notice on my bike is the low and short “slammed” stem. This setup works well with my style. Geared riders spinning high cadence with low gear ratios would probably find that my setup would not climb well. With a geared setup the bike might experience inadvertent front end lift from torque. For single speeding when mashing front end lift is never a problem because I am out of the saddle and on the bars.
Where the long top tube really comes into play is when descending. This bike is like a typical “medium” but built longer than many “large” frames. The setup allows me to keep my weight back and use the length of the bike for stability on rough descents. The short stem reduces the tendency for the bars to jump and the long bars mean that I have leverage to control them even at high speed on a trail full of roots. At Fools Gold, I was descending faster on this bike vs. last year and also stayed fresher. Even though I riding rigid, the stability of the bike meant that I was not working as hard to control it on rough stuff. My upper body was relaxed and loose because I did not need to “death grip” to keep the bike going straight.
In terms of fitness, I had pretty good legs this year and kept my weight down. This gave me the confidence to run 32/20 gearing. Gear choice for a race is hard. Picking something light for the course is better than trying to ride something that is too hard. In hindsight, I sorta wish that I ran a tiny bit bigger gear but really the gear was pretty good so I don’t think it cost me anything.
The bike Bob was riding was a prototype frame that I built with a 69.5 degree head tube. He is super strong and was running 36/20 gearing. The frame has been on loan to him while we decide on the exact setup for his next race bike. Feedback from Bob and others who tried the prototype bike was very positive. At first, the plan was for him to use the prototype only in training. Bob already had a separate dedicated “race” bike but after a few weeks of he decided that he wanted to race on the prototype. I am building Bob’s dedicated “race” bike soon and really the only change we are planning is to bump the size up a little bit and build his new frame using Reynolds 853 tubing. We may change the fork around a bit as well.
As you can expect given his performance, I am very excited about the sponsorship.