SSCX Conversion Techniques

Now that we are well into the throws of yet another single speed cyclocross (SSCX) race season, the topic of SSCX bike conversion has come up. Actually, what came up was the topic of zip-ties as a means of converting a normal, geared CX bike into a race ready SSCX bike and how this technique makes the single speed purist cringe. Let me start by giving the definition of a SSCX bike as defined by USA Cycling;USA Cycling National Championships Singlespeed Rules
UCI rules will be applied: exception that the 33mm tire width rule will not be enforced. Riders must have no larger than 35mm tire & compete on CX bike. No flat bars. No spiked or studded tires. Riders must have a free wheel, one cog, one chainring, and drop bars.

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Spacers and cog on Shimano freehub body

Now let me elaborate a bit on the science behind using zip-ties to convert a normal geared cyclocross bicycle into a single geared bicycle. Really, it is pretty straight forward. You simply take a zip-tie and lash the shift lever paddle to the brake lever. This effectively renders the shifter immobile, thus disallowing shifting of the otherwise geared bicycle, sort of, in some cases and with certain brand components. Let me also state that I’m not saying people would necessarily intentionally shift either. However, when you are used to shifting a bicycle, you often have the involuntary response to shift, especially when you are under physical stress and not thinking clearly. It happens all the time even on my dedicated SSCX bike, which has no shifters. I still try to tap them up or down even though they are not there.

The technical, mechanical issues with zip-ties are many. The least problematic zip-tie candidate is SRAM Double Tap as it has a fixed brake lever to which the shift paddle is lashed. Unfortunately, the levers pivot on different planes so in order to not inhibit the brake lever throw, you must zip-tie the shifter paddle to the brake lever somewhat loosely. This doesn’t allow much room for shift paddle movement but it does leave some clear wiggle room. In talking with first time SSCX folks who have run this setup, the bike does tend to shift around. The bigger technical flaw with zip-ties centers around Shimano STI. The STI shift lever is a two part system, one part being the brake lever. Lashing the two together doesn’t prevent one from shifting either the front or rear in one direction (lower in the rear and larger in the front). I’ve seen issues that competitors have had with this setup first hand when then inadvertently shifted their bikes.
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Using brake cable to fix the rear derailleur in place

There are a number of much better mechanical options for converting a bike to single speed, at least in my opinion, that involve using a chain tensioning device. You don’t have to purchase a single speed specific frameset either. Inside each and every geared bike is a single speed just waiting to emerge. All you have to do is remove some of the geary clutter.

Extra long limit screws to fix derailleur in place

The simplest way to convert a stock bike to a USAC legal SSCX bike would be to first, pull the derailleur cables off. This renders your derailleurs useless, at least for shifting. Next, get some spacers and a single cog to replace the cassette on your rear wheel, or better yet, convert one of the countless spare wheels kicking around the basement. These parts are pretty easy to find. Check Bikeman.com out as a good starting place given that they have a whole single speed store front or talk to your local shop. I like this style spacer kit as it comes with a cog and has a large assortment of individual spacers. You can also grab some extra cogs, which are pretty darn reasonable, so that you have options. The cheap Dimension BMX cogs work great for steel freehub bodies buy can chew into alloy bodies. I use the Surly cogs as they are wider at the splines and provide a better interface with the alloy freehub body I use.

Then take a piece of an old brake cable (I say brake rather than derailleur cable as the brake cable is bigger and stronger) with the cable stop and insert it into your rear derailleur cable adjuster barrel such that the cable stop rests in the adjuster barrel. Affix the cable into the pinch bolt such that the derailleur pulley is directly in line with the cog on the rear wheel. Install a chain of the length such that the derailleur cage is reasonably tight and then use the barrel adjuster to fine tune the system, so it feeds the chain perfectly centered onto the rear cog. That’s it.
The next easiest way to convert, which is actually a bit more secure, is to follow all of the steps of the above short cable conversion technique except leave out the cable. Instead, head to the local hardware store and buy a couple ~25mm long 4mm x .75mm thread Allen head bolts. You then remove the relatively short limit screws on your rear derailleur and replace them with these screws. Then use these new, longer screws to fix the derailleur into a position such that it feeds the chain onto the cog perfectly. Note that you want to screw the limit H(igh) gear adjuster first and then once you are centered correctly, screw the L(ow) adjuster down to fix the rear derailleur into that position. This is more secure than the aforementioned technique because when set with limits from both sides, the derailleur can not move in either direction, not just in one.
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Surly Singulator

Of course, there are other methods as well. One of the first methods that we all tried when first getting bitten by the SS bug on the MTB, over fifteen years ago now, was the Surly Singulator. These devices saw limited success though widespread acceptance. We all had them and collectively, we all hated them. That said, some folks still use them. For what it is worth, I much prefer using an old derailleur with either the cable or extended limit trick.

You could also use an eccentric rear hub like the White Industries model that a number of prominent local SSCX racers are employing. I’ve not had any experience with these hubs but they will allow you to convert a normal, vertical rear dropout frame into a dedicated single speed without a chain tensioning device, albeit at the expense of a new wheel build.

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EBB30 eccentric adapter provides throw for chain tension

When you get ready to convert to a dedicated SSCX rig, and if you spend much time racing SSCX you will, you have options. There are some great off the shelf rigs available now that use sliding rear drops, or slotted rear drops or even eccentric bottom brackets. There are also some cool new products available that allow the conversion of newer BB30 or PF30 bottom bracket bikes to SSCX.

These frames tend to be some of the most high tech and lightest on the market if that is your thing but also, have become the norm. You can now buy eccentric bottom brackets that work with BB30 or PF30 bottom bracket shells and a smaller 24 or 22mm spindle crankset to provide the fore and aft movement required to properly tension the chain. This is the setup that Cathy and I have been using for over four years now. From what we have seen it works great, though it is a bigger expense than some of the other methods. We have dedicated, full time SSCX bikes though which are also the bikes that we do 95% of our CX specific training on. That means they do not sit idle other than on race day. In fact, they see much more use than our dedicated geared race bikes.

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Extra protection with chain guides

So there you have it, a few means of conversion. The only other thing I will add is that I like to over do when it comes to security on the SSCX bike builds I do. One the rear, I sandwich the cog between a couple of guide plates, making it impossible for the chain to ride off the cog. Lately I have been making plastic guide donuts that fit as spacers onto the freehub body. I’ve also used old cassette cogs that were larger than the driver cog and ground the teeth off, though you don’t have to do that. I also run an outside guide ring on the crank, for a number of reasons. With it, you don’t need shorty chainring bolts, you also keep your leg cleaner as the chain doesn’t rub against it and of course, it helps keep the chain on the front chainring.

If you have any questions about anything I have written or about any other techniques or best accepted practices for SSCX, shoot me a message. I’m happy to help spread the word of one geared conversion and single speed love. If you are local and need help, I’m easily bribed with beer and readily available to help with your parts spec options or conversion.

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Clean, quiet, simple and reliable

Also, though I’m a bit of a single speed purist, I certainly don’t want to come off as being exclusionary. There is a time and a place for the simplicity of the zip tie. For instance, those just wanting to try it out for the first time or dabbling here and there. That said, I’d like to see a reliable, safe SSCX bike in every CX racers quiver and if you are racing for series or championships, you really ought to be on a real bike, a real SSCX bike, not some silly imitation.

And yes, the SSCX shall indeed inherit the Earth. It will, just you wait and see.

Racing with the Big Boys and Girls – 2014 MTB XC Nationals

PJ descending rock pro shot with bloody knee Nats
PJ descending downhill switchback section littered with roots and rocks.
Given all the “what’s a MTB race like?, why the hell do you do it?, why are you always covered in blood after them?, why don’t you just stick to the road?” questions I tend to get, let me offer the following brief race report via four posed questions:
Why did you race Nationals?
 Somehow I qualified based on CAT1 results at New England Championships and Bikeway Source – Bell Lap Racing teammate Mike Harris said “you qualified for Nats, dude, you just gotta race”.  Game on and thanks for the nudge, Mr Harris. Teammates Mike Rowell and Sue Lynch were also racing, so more ammo to get the gate pass.
What’s a USA Nationals MTB race like?
It’s quite the show as you have the top Pro and Amateur racers in the US all going for broke. You win and you get the Stars and Stripes Jersey – I think you get the picture. My rear tire was mildly leaking Stan’s and it was so cool to just walk up to the Stan’s tent and get a small bottle gratis and have them check to see that I was good to go. Had minor Shimano drive train issue and stepped up to Shimano and they gladly took care of it. Swag city and i was able to grab VW cowbells and sunscreen for my buddy – Dave Genova – a non cyclist who made the trip with me to heckle.
What’s the course like? 
I can’t say teammates Mike and Cathy Rowell didn’t pre warn me, but the course was just horrifying.  Just up and down through the most technical race course I have ever done. Trust me, Bear Creek Nats makes Leadville 100, Vermont 50 and any others look like child’s play.
PJ descending rock section at Nats front view
Bear Creek Nats makes other MTB race courses look like child’s play.
What’s it like racing CAT1 at Nats? 
 The shot above is cool in that if you look at spectator above me at top of hill, you get perspective for vertical drop and technical caliber. I had just traipsed through over 100 spectators at “The Heckle Pit” in the middle of the woods consisting of  guy dressed as Satan (poking you with pitch fork to go faster), a Nun (with long ruler whacking you) and many others including a guy playing trombone. Friends told me he would play “Debbie Downer” song when folks failed to ascend the rocky switchback climb, while I heard “cavalry” song the three laps I made it up – and even had a woman popping sour patch kids in my mouth as a “reward”.
I thought my days of the “PJ Bike Throw”  may have ended (after I snuck to the 4/5 Cyclocross Win at Shedd Park last season), but wouldn’t you know I had another sprint to the line where just managed to beat some dude with bike throw. We are all very much amateurs, but my CAT1 field was pretty stacked and we even race for blood for 26th place.
Special thanks to Chris Li and  The Bikeway Source as my Cannonade Scalpel Black Inc ran superb. I an not worthy of a rig this nice!

Wilmington Whiteface Race Report

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Great weather and 2 challenging races made this year’s Hill Climb and Leadville Qualifier a fine weekend. I rode my Cannondale Super-X on the hill climb and borrowed John’s Cannondale Scaplel for the 100k. Both bikes worked perfectly. As an added bonus having the disc brakes on the Super-X made the 8 mile descent down Whiteface so much easier!!

The Hill Climb started with a 3 mile rollout from the Whiteface Ski area to the bottom of the mountain. The climb, in my opinion, is the most pleasant of all the BUMPS series climbs. It is about a 10% grade the whole way. Never so steep that you are gassed, but steep enough to stand when you need to shake your legs out. Since I had the tougher of the 2 races on Sunday, I used Saturdays race as a joyride. I had to fight just a little bit to capture 3rd female overall. Marti Shea, New England’s climbing legend won easily in an 1:00, 2nd place came in 1:04, I finished in 1:06.

Thanks to John Laupheimer I had a bike to ride at the Leadville qualifier. (my Epic was in the shop with a broken fork) The race in its 4th year has become quite popular. Lots of familiar faces from the Root 66 and EFTA race series. Because my category (female 50-59) is small only the top finisher gets in to Leadville. This always puts pressure on me because I worry about flatting or having a mechanical. The course is mostly dirt and gravel with about 10 miles of pavement. There is very little true mountain biking, but there is a ton of climbing. It is very similar to Leadville. So, this year on the borrowed bike which was not tubeless I ran high pressure in hopes of reducing the possibility of a flat. I had a clean ride, making it to the top of the first climb in 2nd well behind Rebecca Rausch. I quickly lost that on the first downhill. Then managed to trade back and forth with Bryna Blanchard until the first truly steep descent where I was passed by at least 75 people, including Bryna, Jill and Tina Seversin. I spent the rest of the race trying to reel people in on the climbs and not lose too much on the descents. I was not able to catch any of the women, but finished 5th overall and won my age group. I decided not to go to Leadville this year, but will go next year. My finish 5:22 (2 minutes slower than last year in the rain…) this gives me the same starting position for the 2015 race that I’ve had the last 2 years. I think with that staring position and the proper training a sub 9 hour race is possible!

Fat Bike FUN!

I knew the Charge Cooker Maxi was going to be fun in the winter, and it was. What I didn’t anticipate was how MUCH fun it would be in the spring and summer!

???????????????????????????????I woke up today to soggy trails and a steamy feel to the air after a night of rain. A typical Vermont early summer day. This means slick rocks, slimy roots and mud. Not great when you are climbing 1700 feet in 7 miles. The loose rocky climbs are tough in dry conditions. Wet trails make picking the lines critical, one slick rock can throw you off the “best” line and then you’re walking to the next “flat” spot to remount. Not only a waste of time but also a waste of HR…. to be avoided at all costs. Well, that all changes with the fat bike! If you can pedal it, it will over anything.   The fat tires hug the rocks and roots and the low tire pressure gives you amazing traction. Sure it weighs a little more, but with the 36 22 front chain rings and 11X36 cassette you easily have enough gearing to get up just about anything. It’s a little slower but you’re not walking!! The traction on slick mud is unbelievable. I can easily make climbs on it that would be nearly impossible on “skinny 2.2” 29er tires.   Surprisingly, it is also really easy to pick up the front wheel to go over logs and up rocks. It actually seems easier than on my other bikes. It’s a great confidence builder.

The descents are still hard for me. Today, I hit a muddy spot fishtailed, grabbed the brakes skidded into a downed tree and went over the handlebars. A rider error, NOT the bike.   But, the bike is so sturdy I don’t worry about crashing on it. I’ve also noticed that when you catch a stick in the derailleur (another common occurrence on the barely maintained VT trails I ride) it seems to be less likely to break that my Epic. It does take little time to get used to the descents. The tires bounce a little and sometimes pull you left or right. It is forgiving and if you just let the bike go. The rocks and roots make the descent a little jarring, but its great practice for relaxing on the descents and easing off the brakes and letting the bike do the work. Something I need always need to work on.

I ride the Charge almost everyday.   It has become my newest training tool. I definitely feel stronger climbing on my lighter bikes. Not only it is fun to train on, it’s making me a better rider!   Thanks Chris and Bikeway Source for another fun toy in the shed!!