Thursday, October 6, 2011

700x38 and Change

I will admit at the beginning that it makes me a tad squeamish to take the carbon road bike out in the rain, mud, and grit.  It also seems to be a crime to strap a bunch of lights on the front and back when the available light is not sufficient for safety in the spring and fall.  These conditions just beg for the Superfly to come out and play.  It is very happy in nasty conditions and I still get a good workout.  As I stated in  Bike to work commute - the road less traveled if I could only have one bike, this would be it.

I have been running 2.25 tubeless tires on the SF with very good results since June.  But with strictly road riding now I find them to be a tad heavy and noisy.  As a matter of fact, they tip the scales at a svelte 800 grams each which is great for maintaining momentum over rocks and stuff, but not exactly ideal for bombing around the south hill.  After several rides I started thinking of switching to road tires since 29ers are actually 700C wheels on the bike.  That would take care of the road, but I still enjoy hopping on the HD Bluff trails on a regular basis so road tires would be less than ideal for those occasions.

I know some riders who switch to their cyclocross bikes for the tougher conditions this time of year.  This got me thinking about switching to cyclocross tires on the SF as a way to lose weight, reduce noise and rolling resistance while maintaining the ability to ride on dirt.  Rider 1 told me of riders on the pro mountain bike team he used to manage who trained on cross tires because it forced them to pick better lines. Sounds like a perfect fall experiment.

I chose the Bontrager CX0 Team Issue 700x38 tires for their low profile, aggressive side tread and reasonably low weight for this experiment.  A pair weighs less than a single 29-3 MTB tire so I already shed 1,000 grams.  It is curios that these are listed as cross race tires but they exceed the maximum width of 33mm listed in the USA Cyclocross Rules for 2011.

The transition was fairly easy since I just needed to remove the tubeless valve and rinse the Stans juice off the rims.  A couple of things to note with the new tires are that they are directional so you have to pay attention to their orientation and they tend to stick to the side of the rims so they don't seat all of the way at first.

This meant that I had to put a lot of soapy water on the beads to get them to pop in place.  It looked like a Disney movie where the bubble machine was out of control when I inflated the tubes but I did get some satisfying "POP" noises as the bead seated.

The visual result is a bike that looks like a burly commuter or hybrid.

A short run up the street indicates some promise for this setup.  It felt reasonably quick and fast for off-season riding.  Plan on some updates in the near future as I get some miles in on the road and trails in the coming weeks.  I'll be the one leaving a trail of bubbles in the rain.

Until then - See you on the road.


  1. I've just found this - do you have any idea what the width (outside edge to outside edge) of the tyre is when on the rim and inflated? Will be running a similar set up on a bike where clearance may be an issue.


  2. How were these tyres in the long run? Durable or not? contemplating these V Kenda happy Medium DTC in a 40, or continental CrossRide in a 42. Thanks