Tuesday, November 27, 2018

C.O.G. 100 Update: News On The Course & Single Speed Cranks/Gearing

Today I am going to give you some news about the course and then delve into my personal opinions and observations on single speed set up for an event such as this. Many of you dedicated single speeders will already have a lot of this stuff figured out, but some "rookies" to single speed are rumored to be considering this event and I thought I'd pass along my thoughts.

Course Update: I have re-routed the course to avoid a bridge that we discovered was out during recon a week or so ago. The mileage will be 111.87 miles. There will be an option to hit a convenience store at Mile 43 where you could leave the main course, and take a little over two mile detour to a convenience store. So, out and back to the course again you're looking at almost 5 bonus miles to make a pit stop. That would bring your total to approximately 117 miles for the day, barring any off course mistakes, etc...

Otherwise you'll have to pack water and food to make it to Mile 87 where there will be a convenience store just a few paces off the route. That will be a store that is pretty obvious as you are riding along, so there shouldn't be any issues finding it. But, those are the only suggested resupply options. Remember- There Will Be NO AID STATIONS- NO OUTSIDE SUPPORT ALLOWED- YOU ARE RESPONSIBLE FOR YOU! 

We'll have more details on the event coming soon....

Okay, so I had a couple of topics I wanted to cover which I will discuss using knowledge I have gained doing single speed riding in gravel events. First up is crank length. I am pretty convinced that you should use the longest crank set you can get and is reasonable for your size/height. I am a bit over 6' tall and with pretty long legs, I have found 180mm length cranks to be the bomb for a steady cadence up and over the rollers. Shorter cranks seem to put me into a situation where I loose momentum and end up working harder because the part of the arc I am making power in during my pedaling is shorter than it is with a longer crank. Dead spots in the pedaling arc can cause you to lose momentum. That's my theory. Your mileage may vary.

180mm Race Face cranks, 38 X 17 gear.
The next is concerning gearing. I always shot for something in the neighborhood of 38T chain ring and an 18T rear cog, sometimes a 17T.  That's in the high 50's for gear inches with a skinnier tire. (Gear inch calculator here) Keep in mind that 29" tires will increase your gear inches since the diameter of the wheel/tire combination is larger. So, since I used a 2.1" tire, typiclly on my 29"er single speeds that I used on gravel rides/events, my gear inch figured out in the low 60's. If I ran a 42mm tire, I'd likely bump up to a 40T chain ring to keep the gear inch in the low 60's. Again- your mileage may vary. This is what worked for me in 100 mile rides/events. I used this gearing in Nebraska on their rolling hills and in Iowa on hills similar to what the C.O.G.100 will have.

So, you may have to experiment, but in talking with other gravel single speed freaks, I seem to be on the lower end of the gear inch chart. Many are running mid to high 60's for gear inches. So, play around with the combinations to see what works best for you. I would hesitate to recommend anything "higher" than this since you're going to build up a lot of fatigue running the non-stop climbs on this course. A "big" gear will wear you out faster. Plus, March is a windy month in Iowa, and added into this is the very real possibility that the roads will be softer or that there will be precipitation which could increase rolling resistance dramatically.

Finally, if you have the choice, use the biggest diameter gear and chain ring combination that you can. So, instead of using a, let's say, 32 X 12, I'd opt for the larger 38 X 18. Bigger cog/chain ring combinations are more efficient, but you will have to see if your particular bike is compatible with bigger chain rings.

A very nice and very complimentary post concerning the C.O.G. 100 was published by Craig Groseth. Read it HERE.

Stay tuned for more on the C.O.G. 100 in the coming weeks.


CrossTrail said...

Not everyone would consider "crusty curmudgeon" as a compliment. I guess that's all part of it. Hope to see you in March.

Unknown said...

Yeah, that is a compliment to him. I’m hoping to see some people in March too. But behind my camera.

S.Fuller said...

Hoping to get into this. Have my ride figured out already, just gotta get a couple of things taken care of to make it all work properly.

tim said...

Can you give us an estimated date to expect registration to open?
(Like your IG mentioned; theres a lot of event registrations opening this time of year.)

Looking forward to it!