Sunday, September 26, 2010

Sunday - Softly, softly, catchy monkey.

From Evernote:

Sunday - Softly, softly, catchy monkey.

With a new course and a different set of riders I've been thinking a lot about race strategy. This year it looks like fast riding out to the nuclear test site at Emu then sand after that. The fatback has an advantage on sand, but not the handicap that everyone thinks on the hardpack.

In addition, we have seven fat bike riders including some seriously fit people. While I'd like to win, I won't win soley on fitness or on bike advantage.

Choices in strategy would be go hard at the start and try to stay in contention or to take it easy and ride your own race. Each has pros and cons.

It would be a real shame to loose the entire race on the first day because you went too slow and lost time you could never make up. This could well be the case if the course turns out to be super fast and easy. By contrast if the course is hard and you burn too much on the first day the rest of it will be a ordeal; it might be hard to finish, let alone win.

The second plan is to go slow, look after yourself and ride at your own pace. This has a number of benefits; it's less painful for a start, you keep some energy in reserve to use if things get hard and if they do, your not competing in the early days against people you who fail to complete the course on later days.

Softly, softly is the more intelligent plan, it lacks testosterone but has applies more gray matter. I'll ride my own race, it's just the risk of being left far behind that scares me.


Tuesday, September 21, 2010

Known Unknowns

From Evernote:

Known Unknowns

Sitting here waiting for the cab I've set to wondering what it's going to be like. I've done the obligatory Google search for Anne Beadell highway and found an old 2006 Australian Geographic magazine with a map of the area and an article of the nuclear tests that took place in the woomera testing range. Strange to think well be cycling past 'ground zero' for a 10kt nuclear bomb.

Back on the race, what's it going to be like? The 4WD website exploreOz rates the trail 4 out of 5 stars for difficulty. That's the same rating as the Simpson Desert Rig Road. I think the dunes are smaller and the track narrower. After the rain we have had (and there has been some along the Anne Beadell) I think there will be plenty of vegetation that will make the track appear narrower still. This will limit the ability of competitors to do the Indian Scout trick, I.e. get out of a sandy trail and pick your way through the vegetation along the side. If there is sand on the track we'll all have to ride through it.

Corrugations also feature notably in the information I've managed to gather. There are plenty of stories of vehicles limping into Coober Pedy with damage from corrugations. On a fully rigid bike that could be interesting, though the suspension last year didn't really help! Sometimes a bicycle can pick a clear line through corrugations given it's so much thinner than a car. Still, I'm sure they will be a literal pain in the arse.

Weather is the last consideration. The Simpson is famed for it's dust storms. They are what built the dunes in the first place. We had two major storms last year and it was on these that the rest of the field had trouble. The Anne Beadell looks to have more vegetation and better weather so we should see less dust flying. I'm happy with that, especially if it's radioactive dust.

All in all then, what can we guess in foresight that we might know in hindsight? If the race had moved to the road you could quite easily say that the fittest guy with the fastest bike would come first. It hasn't. 600km is a long way off road whichever way you look at it. Add in soft sand and a remote desert location it's going to be tough. Same as last year, I think it's going to the simple things that stop people; not drinking enough, not eating enough, getting a puncture, pumping your tyres too hard.

Monday, September 20, 2010

Mind over matter

From Evernote:

Mind over matter

Some people ask 'how did you manage to keep going?'. That's precisely the wrong question to dwell on.

Sure, you might wonder how long you can keep pedaling, how long you can endure the heat, how long you can push through the sand before it stops you but then you're focusing on the negative things, the very things that are going to stop you.

Personally, I like to realize that it's not serious. You can stop anytime you like. Compared with rock climbing, canyoning, mountaineering, caving there are no serious repercussions if you stop.

For example, even hill walking in Scotland incurs onerous liabilities; turn an ankle and you'll need to hope that a member of your party can get out. It can be four hours walk to the nearest road before they can raise the alarm. At best, it will take a couple of hours to mobilize the rescue services then potentially another four hours for them to walk back in. Without the right gear you'll be freezing cold in an hour, hypothermic in the next. Quitting on a Scottish hill will not be more comfortable than walking four hours on a busted ankle. It may actually prove fatal.

Compare that to the Simpson cycle. Quit here and an air-conditioned 4WD will be along shortly. The car contains all of your (likely) desires; water, food, shade, cool. Sling the bike on the roof and relax.

Once you recognize how easy it is to quit, it makes it easier to keep going. You can quit at any second, but have you actually made that choice yet? No? Well, recognizing that there is a certain level of discomfort at the moment, what can you do to help yourself? A sip of water, always a good start. Some food. Good. Have a look around. Is this track you've been riding for the last half hour really the firmest? What about that beautiful clay capped line three feet to your left? Dumkopft. There we go, far better.

Suddenly, you're focused on the things that will get you through.  

  

Sunday, September 19, 2010

Memories of 2009 - the last day

A last ride on the beach

Everything changes, everything remains the same

From Evernote:

Everything changes, everything remains the same

The Simpson Desert Challenge is a race of contradictions.
It's not how fast you can ride, but how slow you can go without being caught.
It's not the lightest wheel that wins, but the biggest.
It's not the toughest rider that wins, but the one that can take the most tender loving care of their body.
It's not good food that's important but how much you can force down your neck.
It's not what you drink but how much.
Many people think that deserts are hot places but the correct definition is actually a dry place. The ultimate contradiction is that the Simpson Desert is actually underwater this year. While it would be good to see the wildlife it would be a pretty tough trip to get a vehicle through. Running a cycle race is out of the question.
Instead, we head north to Coober Pedy and then turn right. The Anne Beadell 'highway' runs due west towards WA.
I've been thinking about this race for a year; training, buying bicycles, testing, fettling, re-testing. After all that careful planning and preparation we're right back in the same position as last year - heading into the unknown!
Everything changes. Everything remains the same.

Sunday, June 20, 2010

Tubeless Endomorph

And in the end a pretty easy conversion to tubeless. I used the ghetto style with 20x3 inch BMX inner tubes from Schwalbe. I went for Schrader valves as last year - it's easy to get a cheap, accurate gauge for car type valves. I used an expensive quantity of 3M double sided foam tape.

My bike has Uma 2 rims. I used one wrap of duct tape, one wrap of 50mm x 1.5mm double sided foam tape as a base then an extra 2 wraps each side of 19mm x 1.5mm double sided foam tape. In effect I brought the sides up by 4.5mm and the middle by 1.5mm. If I was trying to do this again, I think the middle wrap is the most important because until you get this in place it's hard to inflate, even with a compressor.

You can still fit the tyre by hand but once on the tyre will not spin around the rim; even though it's in the low centre of the rim the foam makes it too tight to spin. After that a track pump and some soap and water were enough to set the beads. I unscrewed the valve core and added 180ml of Stan's sealant per tyre. Contrary to what I've heard on the web, my Endomorph's were already almost airtight. One 'Shake and rotate' sequence was enough to have them all sealed up.

I've taken them for a spin at 8psi/12psi. I'll lower that then do some experiments on the sand to see if they burp.

Saturday, June 19, 2010

Training On Manly Beach

The faty, tubeless on manly beach. In testing I took it down to 3psi in the front and 5 psi in the back to prove the tubeless conversion would not burp.

At 3psi if you stand up you can push the rim through the front tyre and onto the road.

Thursday, May 20, 2010

Saturday, April 24, 2010

You want to be Soft and Fat

Pumping up road bike tyres is more challenging to the nerves than to precision; you attach a track pump and keep going. 100psi, 120, 125. How much safety margin did the manufacturer leave between their recommended maximum pressure and the point of explosion? In contrast I usually inflate mountain bike tyres to below the manufacturers minimum limit. The difference between 25 and 30 psi can be hard to see on a small gauge. A squeeze of the tyre is subjective, not objective.

I went for Schrader values on the Simpson Desert Challenge because you can get cheap, accurate pressure gauges. You can't control what you can't measure and I wanted to know what different pressures would feel like. What was the minimum pressure I could use before the tubeless setup failed? Once I had completed my ghetto tubeless conversion I tested it on the beach and made a note of the pressures that worked. I also tested it on my long 100km cycle; there are plenty of boulders on the descent from Andersons to Bedford Creek and if the setup would handle these I figured that it would stay together on the Simpson.

Tyres on fat rims have a very different feel to same tyres on narrow rims. For example, 25 psi might feel soft on narrow rims but feels as hard as nails on a fat rim. I think the answer lies in the profile. Fat rims give the tyre a much flatter profile which has to defect less in order to present the same surface area to the ground. Soft, fat tyres roll over small stones that would normally have you bouncing around.

It took a couple of goes to find some good sand. The ocean beaches around Sydney are too soft - the waves constantly lift and re-lay the sand. The sand on the harbour beaches is more settled. In the end I used Clontarf for my testing, in the early morning to avoid cycling over sunbathers. I started from 25 psi and worked down from there, repeating the same loop across the beach and back through the kiddies playground, loosing a couple of psi, then riding again.

What I found was this.

If you can't steer (the front wheel ploughs and bucks you off) you need to loose some air from the front tyre.
If you have too much drag you need to loose some air from the back tyre.
Small changes in pressure have big effects (15 psi is very different from 18 psi)

There are other considerations. Testing on the sand leads you to lower and lower pressures. When you cycle on the road again these soft tyres feel SLOW :- there is a compromise there. Tyres with thin sidewalls tend to crease when they get too soft - you have to worry about their longevity and wether they will delaminate during the race.

In the end, with 2.4 inch tyres holding up 95kg's of primate I settled on starting pressures of 15 rear, 12 front. I knew that 12 and 10 would go a little better on the sand, and that 10 and 8 would still hold together. I never got low enough to check the burping pressure of my ghetto setup.

As a final check I rode the Double Double @ 15 and 12. It was my fastest ever trip and proved to me that the rolling resistance was not a real handicap off-road.

When you think about it, the SDCC is basically flat. On a hard, flat surface anyone can cycle @ 12km per hour - you can even run at that pace. The real problem is the sand dunes that lie across the track. A bike that rides well on the sand is a great help.

Wednesday, March 10, 2010

Right bike, wrong course

From Evernote:

Right bike, wrong course

It's ironic that, after spending 12 months and several thousand dollars building a bike to ride on soft sand that the desert flooded and the course had to be changed. The SDBC committee did an excellent job in getting permits at the last minute for the Great Victoria Desert, a process that normally takes eight week. The race director plotted a 587km course along the Anne Beadell Highway from Mabel Station out to Annes Corner. The course included the nuclear test area of Emu - it's not everyone that can claim to have raced a bike across a nuclear blast zone. Lead might be a better material than titanium.

The highway has mainly hard surfaces with little sand. It's renowned for it's terrible corrugations. These were harder of the 4wd convoy that the bikes. Over the event the convoy destroyed four tyres, dropped two fuel tanks, broke the power steering on two vehicles and blew a complete set of shocks on a Pajero that then wobbled like a jelly.

On the bikes you could usually find a line around the worst of the corrugations, though if you miss judged it the deep ones would buck and thump until you lost all your forward momentum.

If you were building a bike for this kind of terrain you'd go for something with large springs front and back. That said, the Fatbikes were not disgraced. Simon and I came in 2nd and 4th. Rocket Ron had thin wheels but fat thighs. I saw him at the start of each stage and at the presentation when they handed him first prize. Lynton, winner in 2008, repeated his role as the man that would never give up. We passed him a couple of times only to have him come back in the last moments of the stage.

As well as wheel prints in the sand there where camel tracks. Simon surprised one that intelligently took off down the road. Simon followed it for 10km and got it up to 29kmh at one point. It was foaming at the mouth, which I believe is a sign of sexual excitement in the male camel.


Saturday, February 13, 2010

On the Road

The last few weeks have been hot and humid. You may have seen Sydney on the news with it's heavy rain and flooding.

Rain means I'm back on the road. Manly dam shuts when it is wet. Even if it didn't, riding a mountain bike in the wet is just too damn expensive. The sandy trails around here eat chains, blow seals on shocks and buggers gears.

I got an invite for a bunch road ride this weekend to Ettalong. In the end the roadies didn't turn up and Mat and I cycled together through the rain and humidity. It's a great route and one that should have some great views on a day with less mist and rain. Mt White wasn't really a hill but I had some back-wheel-sliding action on some wet overbanding on one of the bends downhill.

All in all a good day out, though the 4:00am wake up call is a kicker.

Friday, January 15, 2010

We're in!

I've entered the Simpson Desert Challenge once again. So has Alex (#10). David and Trevor are coming back to support us.

It's the same team over again - I couldn't be happier.