Archive for the Tech Category

I’m attending Oregon Manifest tomorrow as the CX Mag reporter. Unlike my trip to NAHBS, I’ll actually have a professional photographer (Bob Libby) along with me so; 1) there will be good photographs to go with the article and blog entries, and 2) I won’t have to try to do two jobs I’m unqualified for.

Anyway, I’ll be looking for the coolest stuff in handbuilt cross action. While I have a tentative list of builders to talk to, there is one person I simply must interview — Ira Ryan. Ira didn’t have a cross bike on media day at NAHBS but he was nice enough to sit down with me for a while and talk about cross. Since I am such an amateur at interviewing, I screwed up with my recorder and didn’t get any of our conversation. And I didn’t have the wherewithal to contact him afterward for a do-over. Sorry Ira but you are at the top of my list tomorrow.

I hope that anyone that can get to the show will take some time to stop by and oogle the goods.

Candi Murray, the pillar of Oregon bicycle racing, let me in on the process of scoring the Cross Crusade races. It’s a labor intensive undertaking that requires plenty of work during the races and some more work after everyone has gone home. The culmination of this undertaking is full scoring from first to last of a host of potentially muddy cyclocross racers.

Essential Elements:

  • FinishLynx camera
  • Two laptops — one for scoring (Excel workbook) and one for the FinishLynx
  • Clipboards and scoring sheets
  • Five or six dedicated officials
  • Coffee

The big Portland area series is the Cross Crusade. However, there are a few more races not affiliated with the series and to ease scoring, they have agreed to use the Crusade bib numbers. Starting with the Kruger’s Kermesse in September, OBRA starts building a racer database. This Excel file begins with the number series for each category and the officials populate it with riders names over the course of the season. Within a few races, most of the regular racers are in the file.

On race day, Candi copies the most up to date roster into a new Excel workbook. The workbook has several worksheets, the most notable being the “Lap Positions” and “Results.” During each race, there are three or four people with clipboards with lots of lap position sheets. They record, in order, each rider as they pass the finish. After each lap, they give the lap sheet(s) to an official who then enters the information into the Lap Positions Excel worksheet.

Aside: I actually tried to record lap positions at a non-Crusade race a few years ago. There were perhaps 90 racers on the course at once. It was extremely hard to record everyone, especially when racers came past in clumps. The folks who do this regularly are awesome. They can record everyone and know exactly when the leaders are coming through even when folks started getting lapped.

The Excel workbook has a macro that translates the lap positions into results, sorted by category and total laps. In the best of all possible worlds, these would be the final results. However, officials reviews the results and check for discrepancies in lap counts or overall position from lap to lap to attempt to catch scoring mistakes.

So where does the camera come in?

Each race is also recorded by the FinishLynx camera. The camera takes little slice photos and then strings them together. Thus, each race looks like a continuous ribbon of racers crossing the finish line. An official creates a FinishLynx file for each race of the day. If you want to know exactly how the FinishLynx works, their web site has an excellent PowerPoint presentation for scoring cycling events. Using the FinishLynx software, an official tries to mark the front of each rider’s wheel as it crosses the line on each lap and then enter the rider number. Usually it’s not possible to mark all the riders at the event since there just isn’t enough time during a race.

If an official finds a discrepancy in the results or a racer contests the results, she can review the photo record of the race to confirm overall position throughout the race. If all the riders in a race get marked, the timing data can be exported to the Excel workbook (lif file) which will allow officials to harvest lap times for all the racers

Lets do a little math — 800 racers doing an average of five laps means marking and entering 4,000 riders per Crusade race. That’s a lot of work to harvest lap times!

I know that all of you OBRA people out there greatly appreciate the timely and accurate results produced by the OBRA team. And you will all remember to be courteous and patient when contacting officials regarding a potential scoring error.

I now run a continuous piece of housing from the top tube cable stop near the seat post all the way to the rear dérailleur. The great benefit is that mud and gritty water is much less likely to get into the cable housing and gum up the shifting. Most cross bikes route the rear mech cable along the top tube and down the seat stay. This means that gravity greatly assists water (and grit and mud) to travel down the cable and into the housing. Running a continuous piece of housing down the seat stay protects the cable and housing from much contamination.

I’ve used zip ties to attach the housing to the seat stays but some folks will drill the stops and run the housing through them. The long piece of housing wants to deflect under load and that can result in mushy shifting. Therefore, I recommend at least five very snug zip ties to attach the housing and if you drill the stops, I suggest that you supplement them with a couple more zip ties.

Here’s a picture of Andy Askren’s Speedvagen that was built for continuous housing. In the two following photos, you’ll notice that there are four routing points plus the top tube cable stop. I’m guessing that Sasha did this to keep housing play to a minimum.

The shifting on my A bike is still acceptable after an incredibly muddy race this past weekend. I’d bet that there are a bunch of other guys changing out there cables this week. Not me.

Here are the disclaimers: 1) Everyone has their own method that they think is the best. If your method works for you, great. Keep doing it. 2) Josh Snead turned me on to this method so I can’t claim to “own” it. 3) This method works well for me and I race in the PacNW and (usually) experience a significant amount of mud and water each season. 4) This method works well for aluminum rims. I haven’t got any tips for carbon since I don’t run that shit.

Now that’s out of the way, I’ll move on to tape. I’ve tried it. I won’t use it again. First, the Tufo tape sucks. Literally. It sucks up water. And water is going to get to the tape — through spoke holes, around the valve stem, through any tiny gap in the outer glue. And once that water starts bloating the tape, the bond rapidly deteriorates. The Mastik tape is pretty good though. The problem comes when you have to remove the tire and want to reuse either the rim or tire. Cleaning either is a nightmare! Believe me, since I had to do it this year.

A good glue job will hold as well as a glue plus tape job with less hassle and mess. I just found a cut in the sidewall of a Tufo Flexus so I have to trash it. I’ve used that tire/wheel combo for about 30 minutes in the worst mud I’ve ridden in. It was a course full of mud the consistency of pancake batter. Awful. That tire also saw about four hours of full-on racing on dry ground. Oh yeah, I run the pressure in the mid to high 30’s. Anyway, I went to pull the tire off the rim and the base tape was coming off the tire, not the rim. The bond with the rim was solid.

Okay, so here’s the drill. Get a pot of Vittoria Mastik (Conti cement is a good substitute), some acid brushes (plumbing supply at the hardware store), and your truing stand. A handy tip is to cover the braking surface with electrical tape so you don’t have to clean it afterward. This method works best when gluing a wheel set. If you are doing a single wheel, wait fifteen or twenty minutes between applications. Make sure you’ve stretched the tires on some rims for a couple of days.

  1. Apply a uniform coat to each rim. I don’t goop it on but I’m also pretty liberal with the glue. Make sure to get all the way to the edge of the rim.
  2. Apply a uniform coat to each tire’s base tape. I make sure to get a liberal amount around the valve stem.
  3. By now, that first rim you coated should be dry enough for another coat. Repeat steps 1 and 2.
  4. I like three good coats on my rims so do step 1 once more.
  5. You should now have tow coats on the tires and three on the rims. Let stand overnight or until you get around to mounting the tires.
  6. Hand stretch the tires. I’ll step on the tire and pull with my hands. I’ll repeat this at a few positions around the tire.
  7. Goop up a thick coat of glue on the base tape and mount the tire. To mount the tire, place the rim on a hard, clean surface with the valve hole pointing up. Correctly orient the tread direction and stick the value stem through the hole (aligned properly). Grasp the tire at 10 and 2 and push it down onto the rim, trying to stretch it around the rim. Continue this action around the tire until you can slip it over the bottom. If you stretched the tire properly, this should be pretty easy.
  8. Roll the newly glued tire along a broom handle to set the glue along the rim channel.
  9. Repeat for the second tire/rim.
  10. Inflate to maximum PSI (I do 70) and let stand 24 hours.
  11. Race.

If you’ve used enough glue for the final coat and haven’t scraped it all off on the side of the rim, the broom handle trick should have caused some glue to ooze out along the rim/tire interface. That’s awesome because it indicates a good seal around the perimeter

Some more notes:

  • If the rim already has some glue on it, I like to smooth it out a little with some Acetone. Let that sit for a day then layer up some more glue (one or two coats) and you are good to go. In fact, building up the channel with glue will increase the integrity of the bond in that area — which can be a weak point.
  • If you are regluing and there is dirt or mud on the tire or rim, wash it off with a stiff bristle brush and dish detergent. Let dry and go to town.
  • Don’t use and chemicals to remove glue from a tire. You will compromise the bond between the base tape and the tire.

And finally, gluing up tubulars is pretty easy. It’s not rocket science and it doesn’t take much mechanical aptitude.

I didn’t invent this technique but it works pretty well. Put your sticky wheel in your truing stand. Get a long bottle and cut it out to channel the rim. Fill the bottle/trough with mineral spirits and place under the wheel. Put some cards (I used pieces of tube boxes) in the spokes. Turn on a fan aimed below (or above) the hub. Read some bike porn and wipe down after an article or two.

And if you think this looks like a superfund site, you might want to consider Stans No Tubes. Erik V. has another timely update on mounting cross tires done the No Tubes way.

Glue stipper one

Glue stripper two

tektro1257.jpgThere are a two primary methods to hang your front brake cable on your cross bike. There’s the fork yoke which bolts onto the font of the fork crown. The advantages are that you don’t need a housing stop on the headset (and it’s associated stack height). It can also improve cable routing by letting the cable get around even a low handlebar stem without a sharp kink. cable_hanger.gifThe disadvantages are that you can’t run a high straddle and if your fork isn’t drilled, you’re out of luck. Then there’s the traditional headset mounted cable stops. They allow practically unlimited straddle cable height. As were alluded to above, the disadvantages are increased stack height and the potential for some pretty nasty cable bends.

Well, there’s a third alternative. Use a cable hanger designed to fit on the seat post binder bolt and bolt it onto one of the stem faceplate bolts. You can usually get much better cable routing with this setup than with the headset mounted cable hangers and it allows plenty of straddle adjustment. It’s lighter than either of the other two alternatives as well.

I’ve taken a few photos of my setup on the pit bike. They’re part of the slide show in this post. Here’s a close up:

Cable hanger

You can buy them at Nashbar.

I picked up Simon’s Cyclocross: Training and Technique this evening and read a few of the chapters. Even though I’ve read it front to back, I still find it worthwhile to reread sections from time to time. This books is it when it comes to solid advice about technique, race tactics, strategy and training. The good news is that it’s coming out in the 3rd edition this August. The 2nd edition from the late 90’s was becoming a bit dated so I’m looking forward to this new edition.

My advice? Buy it!

… Long live the tubular clinchers. Tufo says that they have ceased production with no plans to produce any more. The ones on the street are the only ones available. I don’t have any word as to the corporate reasons why.

Pedals anyone? Among the usual questions that rookie crossers ask is what pedals are best for cross. First, let me state the obvious — get mountain bike pedals. Road bike pedals are *not* the best choice. Among the various mountain pedals, two stand out; Time ATACs and Crank Bros Eggbeaters (or Candys). Those two pedal systems are the best for shedding mud when a racer is attempting to clip in on a remount. That’s the bottom line in cyclocross, how fast can you get into your pedals and apply power to the cranks on a remount.

I’ve used ATACs and Eggs and prefer the Eggs. I gave up on the ATACs after a race where I was unable to clip in because of a small rock lodged in the pedal clip mechanism. I kept knocking my foot against the pedal in an attempt to dislodge the rock as a couple of guys rode away from me. That single frustrating incident caused me to switch from ATACs to Eggs.

The Eggs are very easy to clip in to. It’s got four sided entry so pedal position is a non-factor. I have a smooth clip in motion where I roll the pedal onto the cleat. It’s gotten to be second nature. However, I’ve found the Eggs and ATACs to have practically identical performance for clearing mud. For full disclosure, on a couple occasions, I’ve gotten a small rock lodged between a cleat and shoe tread which has impeded my ability to clip in. Thus, I don’t think that Eggs are the magic bullet for perfect clips in sloppy conditions. My endorsement of Eggs is primarily based on their overall ease of clipping.

Eggbeaters don’t have a pedal platform per se and that alarms some people. If you’ve got a reasonably stiff shoe, the lack of platform is not a problem. Even with pedals that have a platform, virtually all of the force is concentrated at the cleat so the platform has little role in transferring power to the cranks. While not clipped in I’ve found that I can pedal just as well on the Eggs as I could on the ATACs. So if you are going to go with the Crank Bros, get the Eggbeaters and not the Candy version since the platforms aren’t necessary. (Note: I’ve heard from a couple guys that they found the Candy pedal body got in the way of toe spikes when trying to clip in.)

I’ve heard some mixed reviews of the high end Shimano mountain pedals. Some folks claim they are quite reliable in the mud while others decry their performance in the slop. I’ve not tired them so I can’t offer any first hand observations.

And finally, one more reason to get Crank Bros pedals: rebuilds. After a couple years of use, My pedals had been developing some play and a clicking noise. I went down to the LBS (River City Bicycles in my case) and picked up the $15 rebuild kit. After 30-40 minutes at home, I had a set of pedals that were as good as new. Rebuilding my pedals suits my environmental sensibilities as well as my cheapskate tenancies. Two thumps up!

Tufo makes a tubular tire that fits on a clincher rim. It’s a decent tire and a reasonable choice for cross racers who want to give tubular a try without buying new wheels and gluing up some tires. Tubular clinchers were my introduction to tubulars. The upside of these tires is that they are as good at eliminating pinch flats as “real” tubular tires. The downsides are many.

Tufo is the only company that makes tubular clinchers. That means you are limited to the Tufo tread patter and rubber compound. Tufos shed mud well and hook up just fine on the dry but they lack the really aggressive bite that other tubulars have in the slop. Tubular clinchers are heavier and are less supple than tubulars because of the beefy bead needed to lock the tire into the clincher bed. Clincher rims are also heavier and not as strong as a modern tubular rim.

Chances are, once you try the tubular clinchers, you’ll be hooked on tubulars. You won’t be satisfied with the trade offs and will make the leap to tubulars anyway. So why not just start with tubulars in the first place?

Do yourself a favor, buy some tubies, glue them up, and feel the performance. Tubulars are the single best upgrade you can make for your cross bike.