Design work for #16

Posted: August 18, 2014 in Uncategorized

I am building frame #16 for one of the crazy fast single speed riders in my area.

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This frame will be a small/long XC style bike with modern geometry. A long effective top tube combined with short chain stays will work well when hitting trails hard on a fully rigid setup and floating over the gnar. In particular the short chain stays and 60mm bottom bracket drop help the rider lift the front.

The tubeset will be from NOVA with 38mm down tube, 31mm top tube, and 29mm seat tube, a PF30 style bottom bracket shell (73mm width).  Paragon machine works supplies a 44mm headtube, the dropouts, and brazons. Hydro guides are on the bottom of the top tube and down the underside of the left seat stay. There will be no guides for gears. The water bottles bosses allow two large bottles inside the tight main triangle. Tire clearance will support 2.25″ in the short slider position and 2.4″ in the far back position. The stays will clear a 34 tooth ring on Race Face Turbine cranks. 

P.S, The drawings shows “track ends” but this bike will have 142×12 through axle Paragon Flanged sliders.

Frame #15

Posted: August 16, 2014 in Uncategorized

Frame #15 is part of my new test ride fleet.

The Geometry for #15 uses what I learned from prior builds. I really think of this as a somewhat post modern view of where everyone is going with performance oriented single speeds. The headtube angle is 69.5 degrees, bottom bracket drop is 60mm, and the stays are on sliders with 435mm as the middle position. With wide low bars and a short stem the bike is great for fast twisty eastern North Carolina singletrack.

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In terms of construction, everything on this bike went very smoothly.

The bike is currently setup with Industry 9 wheels, Race Face Turbine Cranks, Endless Cog, Shimano XT Brakes, Shimano XT Pedals, Ergon Grips, Answer Bars, Thomson Post, Thomson Stem.

Depending on who is test riding, I can swap stem, bars, saddle, and fork. Currently, I have a Whisky rigid fork on there now but I also have a Magura 29er fork for the bike.

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Frame #14

Posted: June 19, 2014 in Uncategorized

This year, I am building frames to refine my processes and take my craft to the “next” level.

The complete bike turned out great but there is really not a whole lot to say about the bike. For the most part, changes vs. my green bike are subtle. The changes are hard to see in photos. I made some adjustments to the placement of waterbottle cages. I also flipped the way I did the slot for the seat tube. For this bike I have the slot in the front because it helps keep things cleaner.

This bike also runs the 156mm Q factor SRAM XX1 cranks. These cranks put the rider at a narrow stance compared to the normal 168 Q factor cranks. They also run a 49mm chainline. The narrow cranks and short chainstays require everything to be exact. Builders trade space between the capacity for large tires vs. large chainrings. The chainstays are set so that the chainring can only be 32 tooth or smaller. There is actually a cut out and plate to allow the chainring to pass the stay. I normally run a 2.2″ tire but can fit a 2.4″ rear tire if needed and still have room for mud or space if I need to ride with a broken spoke.

As pictured, the complete bike with pedals and water bottle cages is 23.4 pounds with a shock fork or 21.6 with the rigid fork. This is not super light but it is also not stupid heavy.

PMBAR is an awesome mountain bike adventure race in the Pisgah National Forest. The race is like a chess game. Two person teams use strategy and riding skill to collect checkpoints.

I partnered with Thomas Boylen. We had a good plan but made some mistakes. Our strategy and riding was pretty good but our navigation was quite bad.

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00:35 START OF PLAY
Eric hands out passports, many teams pull out maps to study. We decided on a simple race strategy. Our plan was to simply head out as soon as the first few riders get rolling. Getting out early on the climb before congestion makes it easier to ride sections. Following experianced riders with good local trail knowledge gets us started on a good route. We plan to check the map later and only when needed.

03:35 DEVELOPMENT
After the Black Mountain trail, we descend quickly to the first intersection. Following Rich Dillen we go left on FR5022. Chasing them, we ride FR5058 to Horse Stables. Left on Avery Creek Road to the paved Highway 278. Right turn on Highway 278, we form a pace line. The next bit was FR475 followed by Headwaters road, and Cove Creek road takes for the first checkpoint of the day.

After the checkpoint, we start thinking about strategy. Until we lose them we decide to follow Rich and Zack. Back down Cove Creek to Headwaters then left on Highway 278 and right on Yellow Gap. From there 321 trail and push our bikes up to the top of Pilot Rock then head down trial 110.

03:52 MISTAKE #1
On the way down 110 trail, Rich and Zack use their superior descending skills to distance Tom and I. At the 121 trail intersection, we stop to consult the map. Logically it is pretty clear but somehow we get confused. After a short while we realized our mistake, turned around and corrected course. It was a small mistake and we only lost 10 minutes. With the correction we reached checkpoint #2 on Laurel Mountain at riding for 3:52 so at this point we were still in good shape for the “race”.

After mistake #1 we took time at the checkpoint to plan out the remainder of the day. Our plan was to head down to Yellow Gap road and take Pilot Cove Loop to reach checkpoint #2.

06:31 MISTAKE #2
In areas like Pisgah trail marking can be confusing. From Yellow Gap, we made the mistake of turning on Pilot Cove Slate Rock. We also did something else wrong as well. On my map, I don’t see the connecting trail but after about an hour of hiking up unrideable singletrack we reached a checkpoint only to discover that we were back at the Checkpoint #2. Standing in the same spot where we had been at two hours earlier.

After this mistake, we decided to retrace our steps and take the correct trail and this time we reached the correct location for checkpoint #3.

Leaving checkpoint #3 we rode back down Pilot Cove Loop to Yellow Gap with the plan to ride Bradley Creek Trail for checkpoint #4.

07:53 MISTAKE #3
We missed our turn and rode back up a climb to the intersection of Yellow Gap and Laurel Mountain trail. Some backtracking to get on to the 351 Bradley Creek Trail. We lost about 30 minutes and a bit more energy with the mistake.

351 Bradley Creek and 115 Riverside trails took us to Checkpoint #5. After the checkpoint we took 326 Mullinax, 147 Squirrel Gap, 133 South Mills River, and 103 Buckhorn Gap to reach the intersection of Clawhammer and Black Mountain trail.

We took Clawhammer then went down 5057 to reach checkpoint #6. After the checkpoint, we used 5057 and Clawhammer to return Black Mountain trail.

13:17 MISTAKE #4 (Checkmate)
At the Black Mountain trail intersection we got confused and headed out the wrong way on the trail. Eventually we reached a “T” intersection where we realized that once again it was time to backtrack. We lost a solid hour in this mistake but eventually reached checkpoint #7. The problem is that at this point we realized that it was not possible to make the cut off time using Black Mountain trail because with underpowered bicycle lights we would have to hike/n/bike down the trail.

The game was over and the race had beaten us.

Our exit plan was to ride down Clawhammer and Avery Creek to reach highway 276 for a short and easy ride back to the start finish area.

14:57 MISTAKE #5 (Bonus miles)
When we reached highway 276 we turned right when we should have turned left and rode three miles the wrong direction before we realized the mistake. After backtracking yet again we finally reached the start/finish area with about 100 miles for what we will both remember as a totally epic ride.

Even though we finished outside the time limit I am still very proud of the ride. Of the seven race checkpoints, we got to eight (we collected one of them twice so in my book it counts double).

To see the full route we road check out the Strava GPS track.

Capture

Aside  —  Posted: May 4, 2014 in Uncategorized

PMBAR 2014

Posted: May 4, 2014 in Uncategorized

Every so often there is a ride that surpasses all others. It is hard to measure the special magic that makes a ride great.  This was not my longest distance or fastest ride.  I have done rides with more climbing.  In terms of “racing”, my result was not great. Our team went beyond the time cut and due to our course change we actually did not even officially finish the event.  There is no way to “measure” this sort of ride but on my own personal “awesome” meter PMBAR 2014 is now my top ride.

This was a ride that almost did not happen.  I was not sure of my plans for the year so I did not pre-register for the event.  I have ridden PMBAR in the past but for 2014 I was planning to skip the event as I focused on other races.

The thing that changed for me was how I felt leading up to and at Curse of the Crab.  Focusing a bit on my fitness and watching my diet had given me good legs so I was thinking about how to use them.

PMBAR is a complicated event where you need a teammate who is ideally riding at a similar level.  Putting together a team at the last minute is hard because you need to find someone who is willing to take on the challenge.  I posted on my local forum just to see who would respond.

Tom Boylen put is hat forward and I responded with a mix of excitement and fear.  On single speeds Tom is one of the strongest riders I know.  Having a teammate of such high caliber is scary because you know it will be a big day.  Tom’s is quite a bit stronger than I am am.  I was worried that I would not be able to hold up my end of the team.  On the other hand the idea of riding for such a strong team filled me with excitement.

At the start line, we both knew that our fitness made a big ride possible but as riders from Raleigh, NC our inexperience with the massive park would be our weak point.  The PMBAR event is “complete” and epic mountain biking.  Teams are given passports with seven checkpoints scattered all over the park.  To race well you must be a strong for climbing, descending, strategy, and most important understand how to navigate.

The passports are handed out at the start.  We took ours but did not even look at it because we knew that riders who had better navigation would be available.  Our “race” plan as to head out and follow wheels for the initial stages of the race and hopefully find our way to the first checkpoint.  We figured that if we picked good wheels the plan would ensure that we at least started with sane navigation.

On the first climb we got in behind Rich Dillen and Zak.  I knew Rich had a strong understanding of the park and as such was confident that any choice he made on a turn would be superior to ours.  Rich is a good competitor with a strategic mind quickly figure out plan.  The initial miles were fun as our teams felt each others out to explore our relative strengths and weaknesses.  On the climbs Tom and I were strong enough that while we were fresh we could keep Rich and Zak in sight.  The technical descents in Pisgah are some of the most impresses in North Carolina.  Tom and I realized that this would be our challenge and at some point we would not be able to follow.

Heading into the second checkpoint Zak made the move.  There team quickly distanced Tom and I such that when we reached I “T” intersection they were already out of sight.  This gave our team an opportunity to do some honest navigation.  I don’t quite remember our position but the intersection was near Turkey Spring Gap.  After five minutes or so of map reading we decided to head left thinking we would climb to the checkpoint.  A short while later we asked some hikers if they had seen any cyclists and realized that we must have made a bad choice.

After turning around we found the checkpoint on the other side of the “T” intersection. At this point we took time to “really” look over the passport and come up with a route for the next five checkpoints. The volunteers were friendly and even loaned us a pen. From the map we tried to guess what Rich and Zak would do next and thought we had a good plan.

The descent of Turkey Spring Gap was awesome with fast flowing single track and the occasional technical section. Eventually, I crashed and later Tom crashed but we were not hurt. At the base of the descent we arrived at the cheese sandwich rest stop where we loaded up with cokes and food knowing we would never see the rest stop again.

Our next turn was on a trail that I don’t currently remember. We thought it would take us to the 3rd checkpoint and headed up into what quickly became a very steep and mostly unrideable hiking trail. When we finally arrived at the checkpoint we quickly realized that we were back at checkpoint #2 and had made a two hour mistake.

Checkpoint 2 and 3

We went back down the Turkey Spring Gap descent and this time managed to avoid crashing. Once again we stopped at the cheese sandwich rest stop and headed out to get checkpoint #3. This time we managed to make the correct turn. We turned around and headed to checkpoint #4 but missed our turn for Bradley Creek so once again we arrived at the cheese sandwich stop where we backtracked and eventually we found the proper trail.

We got lost at least once on the way to checkpoints #5 and #6 but they were minor missteps where we caught our mistakes without losing time or spending two much effort.

After checkpoint #6 we got confused and went the wrong way as we navigated to checkpoint #7. We did not realize our mistake for an hour or so and by this time it was getting dark. We eventually back tracked to find checkpoint #7 but knew that we would not finish the inside the race cut off time so we decided to take the simple route back to the race start. We road down to 276, made the wrong turn and road several miles in the wrong direction before once again backtracking and eventually getting back to the start finish with around 100 miles over about 13 hours of riding.

Both Tom and I enjoyed the day. The navigational issues made the ride special and helped us develop a better understanding of the park. It was a huge ride and while Tom was stronger than me as a team we worked well together and other than a brief period of low energy I was pretty happy with my pace. It was a very special day and goes down as one of the best rides of my life.

My bike performed great and as a team we had no mechanical issues. As a single speeder gear selection is critical and I was very happy with my choice of 32/20.

In particular I enjoy riding my own frame and a bunch of “made in usa” parts such as my Endless cog, I9 wheels, and Thomson seat post.

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Getting the bends

Posted: April 25, 2014 in Uncategorized

The bends for a 29er require a good bit of precision.  I was not happy with prebent seat stays and wanted more control over the process.

I need enough bend to provide tire clearance but not too much bend.  A lot of the bending you see on bikes is based on styling but there are functional aspects to consider.  In my case the way I pedal brings my calves close to the bike on the up stroke.  With extra wide bends the inference with the calves can be an issue.  For my bikes, I provide enough space for 2.35″ tires.

The bend at the chainstay is what defines tire clearance.  When I bend the seat stays, my focus is to match the tire clearance associated with the chainstays.  I don’t want to have “extra” space on the seat stays because this “extra” does not help anything and it has the potential to cause annoying inference for riders like me who pedal with our calves close to the bike.

Today, I built an indexing arm for my Pro Tools 105 bender.  The indexing arm allows me to use the output of the first bend as a reference when I establish the second bend.  The arm is attached to the back side of a 7″ CLR bending die and moves with the die.

With the arm, I am able to more quickly setup the bends and keep everything in phase.

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Curse of the Crab

Posted: April 7, 2014 in Uncategorized

This past Saturday, I participated in the the Curse of the Crab race.

I got a cool Twin Six jersey with a single speed theme.

My friend Chris must also have good taste in clothing. We were like twins.
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In the past few weeks, I have been pretty consistent in my riding and diet. My fitness is not great this time of year but I am starting to feel pretty good and losing about 15 pounds of fat over the past three months has helped me ride better.

Single speeders like me really think a lot about our gear. For Curse, I was on 34/20 gearing. This works out to be a 1.7 ratio. Most other riders were on bigger ratios. Crabtree is pretty flat and in hindsight I my ratio was a bit too low. Next year, I will try something bigger.  32/18, 33/19, 34/19, or 36/20 are close to 1.8 ratio.  I could run 35/20 for a 1.75 ratio to get a little more gear and avoid going too big.  Single speed is about riding with one gear and it is fun to consider all the options.

Races like this start with a short road section to thin the pack before we hit the singletrack. With single speed gearing and a low ratio I was spun out right away and watched a fellow racer named Michael take category lead as we entered the single track.

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Michael is a strong rider but I did my best to keep pace. By the end of the first lap Michael was about a minute up on me. In the second lap, he gained another minute on me. In the third and fourth laps I gained a little bit of time back but at this point the race was maturing and I settled into a pace that I could maintain. I was able to catch glimpses of Michael at various points where the trails would fold back upon themselves.

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Crabtree park is a hard place to race because with no major climbs the six hours is one constant and fast effort.  No part of the course is “easy”.  The flat terrain and open trails mean that you are usually riding very fast.  It is hard to eat or drink on a mountain bike and in this race I was on the edge where I was forcing myself to eat and drink something but also trying not to overload my stomach.

I was able to claw back some time in laps 7, 8, and 9. As I got closer on lap nine I could see that Michael was not feeling well. Later I found he had back problems.  I occasionally have similar issues and wish him the best in recovery. The Crabtree race course is hard and once you get struck down with back pain there is not much that can be done. Michael was forced to stop at lap nine although when I passed I actually did not know he was stopping. I thought was simply getting some food at the pit stop area.

I road lap 10 thinking that Michael was chasing me. I went my own pace and really was expecting to get passed at any minute. My final lap was also good and I let myself relax a bit. I did not bonk but my systems were fading on the last lap.  I was very happy to finish 11 laps of the course and meet my goal of 60 miles.

For this race I was very happy with my lap pacing. The very first lap was slightly longer because of the road section. As I expected, my pace for the first three laps was fast with times of 31, 29, and 29 minutes. The middle five laps were consistent with times of 30, 32, 31, 32, and 33 minutes. The final three laps were also pretty good with 33, 34, and 35 minutes. I finished 18 minutes behind the top geared rider.

At the finish, I felt spent but was happy with my effort.  After his back problems, Michael dropped back to third place in the race.  I only saw the second place finisher (also named Mark) a couple of times but found this great photo online. It looks like he was pretty happy on the course and with 10 laps it is clear he put in a strong effort.  Hopefully I will get a chance to ride with him at a future race.

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As expected, the bike performed great. The gear ratio was a little too small I think that is better then going out with one that is too large.

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Photos from the event from Torrenti Cycles and TORC mountain bike club.

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