Feb 23, 2006

Christian Aschebergs 24 hour record attempt in Berlin, my next attempt at the 24, CriticalPower mods, and an interview with Endurance radio

On Feb 21st at 3:14 pm (local time), Christian Ascheberg set off to loop around the Berlin Velodrome 4084 times in a 24 hour period and break the existing 24 hour human powered vehicle record. I was following his progress at a web site they set up in German. I used Googles translator software to (roughly) convert what happened to English.

He was forced to call it quits at about 12 hours, logging 486.75 km, resulting in an average speed of 40.5 km/hr which is 2.05 km/hr slower than the current record of 42.55 km/hr. According to an email I received from Christian, he was having some problems with an approved helmet he was required to wear – one that supposedly did not fit into his fairing properly and caused some discomfort. He also told me that his heart rate was over 150 which is WAY, WAY too high for an endurance event like this.

The Berlin velodrome is a 200 meter loop with steeply banked corners. My concern about using this venue to set a 24 hour distance record in a heavy streamliner is the increased weight caused by the g-forces while rounding the banked corners. Some others I have talked to about that, estimate that your weight doubles and according to my spreadsheet, to maintain 40 kph at 100 watts around the corners, you would need to increase that output to 200 watts. There would be some advantage to the smooth surface with regard to better rolling resistance, but I doubt it would be enough to counter the gravity effects of the banking. For some reason this does NOT apply to track bikes and I have no idea why? Track bikes are faster on a velodrome – perhaps because they weigh less than 16 pounds and the gravity effect isn’t as great as a 60 pound streamliner.

My hat is off to Christian for the attempt! I hear a lot from others regarding what to do, what they would do, what is better, what is wrong, what is right, etc, etc, but over the last 10 years, as far as I know, only 2 people have actually attempted to break this record.

Ben modelled up the revisions I wanted for CriticalPower and ran them through the CFD software. The first mod is a wheel fairing that covers both the front and the rear wheels. We CFD tested two separate fairings, and one long one was more efficient. The second mod is a larger and longer canopy top. The reason for this is to allow my to get in and out of CriticalPower from the TOP rather than waste so much time pulling the left hand fairing shell off.

The CFD software results indicated that the canopy top was no more efficient than our existing small top. So we took a closer look at exactly what it would take to get in and out of the streamliner from a larger hole in the top, and discovered that because of the ‘over the shoulder’ bar, it would be nearly impossible! So I decided to skip that mod and leave the existing canopy top the way it is. Instead, we decided to stiffen the fairing shells with some ribs and come up with a faster way to mount and dismount the left hand fairing shell side for fast entry/exit.

I also decided to skip the extended single wheel fairing. I envision issues getting it attached properly while still allowing the fairing shell to be easily removed. I am also concerned about leaving enough room for the front wheel to turn. I think we need to do a better job smoothing the rear wheel fairing, but I am inclined to leave the front wheel open like it is.

The main issue for me now is not to change something that ends up causing some new, unforeseen problems. I know CP works, and I can live with the CdA as it is.

The important issues are:

1. Communications! – I am looking into motorcycle two way radios
2. Fast entry/exit – we are moving the food, water and battery access areas to the top behind the canopy top so I don’t have to get out every time we need to refill water, food or replace the battery. I might plan on getting out every 6 hours or so rather than every 3 hour interval pit stop.
3. Smoother head light cover – The HID headlight protrudes out from the nose and probably creates some extra drag. I want to recess the light further back and find some transparent dome to more smoothly cover the nose area.
4. CHAIN GUIDES!!! – that’s a no brainer
5. New clincher wheels – I have a feeling that the reason why my actual CdA was higher than what we had measured in Calgary is due to increased rolling resistance from the tubular tires. I am aware that high quality clinchers have better rolling resistance than tubulars due to the squishy glue that the tubulars require. There is a some data that backs that up here.
6. Fairing paint and polish – We need to coat the fairing shell with a thick epoxy based primer and sand and polish it smooth. This will seal up all the pin holes and hopefully improve the chances of obtaining some laminar flow.
7. Wheel shroud for the front wheel – this was something that I had meant to do originally, and never got around to it. Since my front wheel is surrounded by the carbon sandwich board frame, building a carbon envelope for the front wheel shouldn’t be that difficult.
8. Rear wheel fairing finish – check out the less than optimal rear wheel fairing shape in this photo:

I did an interview with Endurance Radio the other day that went quite well. Endurance Radio is a popular pod cast that you can find in Apples iTunes music store by searching for “endurance” in the pod casts category. Endurance Radio home page is here and you can find my interview on the front page, or in the archives by searching for my name: Kolodziejzyk.

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