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How many muslins does it take to change a wet bulb? I couldn't think of a punchline. I'll sharia if I think of anything.

Phase change is an extremely efficient method of heat transfer. That is why large air conditioners use cooling towers (evaporate water to cool it) instead of the smaller units (residential) air to air heat exchangers. In an ideal world (read - does not happen in the real world), getting your jersey wet by any means would get the jersey temperature down to the "wet bulb temperature" which is just slightly above the dew point temperature. Adding salt from sweat raises the temperature just a bit (couple of degrees) so you will never reach the wet bulb temperature. As water continues to evaporate the jersey temperature will stay locked at that temperature heat transfer coefficient is improved by a factor of 10's to 1000's. So phase change is EXTREMELY helpful in lowering body temperature. But as said above - if the wet bulb temperature is already too warm and at best you can get down to the wet bulb temperature - you are not cooling off. A couple of other notes from an engineer who deals with these data as part of his job. The absolute moisture content in the air (also known as "dew point temperature" by those of us who like talking whole numbers like 65F to 75F instead of decimals like 0.001 to 0.1), really does not change during a 'typical day'. Unless a front blows thru or there is a rain event, the dew point temperature will be about +/- 2F all day. If you don't have anything else to go by, the low temperature of a summer day will be close to the dew point temperature in Central Texas. Now back to MTB. I prefer to do night rides during the heat of the summer. Early morning rides may get me a slightly cooler temperature but it also gets me a constant stream of spider webs across the face. My vision seems to like the transition from some daylight to nothing but lights better than the 'nothing but lights' to dawn transition. But I also ride early mornings when that is what the group wants to ride. But now days I mostly ride alone so I pick nights. ETA - info on wet bulb, dry bulb and dew point temperatures is at - https://www.engineeringtoolbox.com/dry-wet-bulb-dew-point-air-d_682.html

Wondering how nut powder plays into the thermodynamics of a wet bulb...

The Peddlers Pass Trail Fund GoFundMe page is doing really well. As of this morning, $3,627 has been raised for trail improvements. Thank you to everyone that has donated. We've got some really cool stuff planned.

Welcome to 2007, its funny to hear the last 29er holdouts make the same statements we made back a decade ago when the "big debate" was taking pace. Signed, "no camel backs for me", -CJB

I hate how easy and small everything seems in pictures. I am very comfortable doing this drop but I still get a nice adrenaline rush every time. This was this Saturday.

Yeah, back in 06' I had a good friend who was sponsored by Orbea. Ronnie Points (former Cen-Tex racer) was the brand manger for Orbea and convinced the company to release the aluminum Alma HT 29er (in 1 size only). My buddy was given a pre-rproduction bike to ride/race for half the TMBRA season. He talked about being conflicted about the situation. Because as a sponsored rider he needed to givn accolades and talk about how great the bikes was....but he didn't really want to do that because he felt it was *that* much of an advantage over his competition. It was shortly after that, I believe, that I bought my first 29er (Surly KM) and ended up winning the Excruciation Exam (Torture Test) that same year on it. Good times! -CJB

@CBaron I think I've told you this story. In 2011 I did the Cohutta 100 in Georgia. By then 29ers were already a common bike in Austin. But in Georgia they seemed to be rare. I remember a pack of 26er guys watching me fly through a root garden yelling "look at those big wheels go!". @JRA , your first impression of 29ers is exactly my impression. They are a big advantage in most situations.

It's for the slow children:

This bike is a total slacker

very true...I had severe heat stroke about 4 years ago and it still affects me to this day. Don't fucking do it

Angel Fire Bike Park. Rented the Evil Wreckoning and got in 8 laps of pure sweetness.

Indeed - you get heat stroke even once, you may never be the same again. It's certainly not likely to make you stronger. I make sure I avoid it, which isn't too hard.

Not true when it comes to heat. Heat stroke and even heat exhaustion can have long-lasting ill effects on your body. There are plenty of ways to stay strong during the summer without risking heat-related illness. But hey, if you actually enjoy riding in the sweltering heat - have at it. For me, it's just not fun.

there are other mechanisms like phase transition which is also evaporation. It is conduction from direct contact of your skin with sweat and then a phase change of the sweat from water to water vapor. https://en.wikipedia.org/wiki/Heat_transfer#Advection

I'm not a lady, but my comment is pretty much universal. If you've not been riding much (at all?), then there really won't be a saddle thats truly without discomfort. Now I ride a traditional WTB saddle and I can do multiple 6hr rides a a few days in a row without real issues. Thus I know my saddle works well for me. However, if I take 6 months (or more) off of riding, when I come back a simple 2hr ride will leave me in some form a discomfort. We are simply sitting on sensitive parts of the human anatomy. All that being said, I'm sure that there are some specifics to the female makeup that some of the female rides here can help WRT saddle fit. But IMHO there's just no way to get around *some* discomfort until she gets toughened up. 🙂 Oh, all that AND MAKE SURE SHE HAS A QUALITY PAIR OF RIDING SHORTS. That actually can make a noticeable and immediate difference. Later, -CJB

Not a lady..but I got my wife a Specialized BG Mimic and she loves it. She should go to the LBS and try different ones. Go to a shop (if there is one around these days that loans out saddles) and try different saddles for extended rides. At the very least get the sit bone measurement.

I looked at it. I'm not sure what I was looking for. Technical (wicking) fabrics do great for encouraging evaporation. The move the moisture from your skin to the surface of the fabric where it can evaporate more easily. Other fabrics (e.g.cotton) soak up the water (sweat) and hold it. They don't encourage evaporation by getting the water to the surface where it can evaporate. And as they hold the water they block more and more of the air flow that would help to cool the skin. Some (many?) of the technical fabric are treated with a coating that gives them the wicking function. As they are worn and washed the coating gets stripped away. Eventually they don't wick any more.

(I typed this once before the power went out and it all disappeared. So this will be the 'lite' version.) Heat transfer is a "layered" process. Typically one or two of the 'layers' dominate the process. Think about it as each 'layer' being a resistance to heat transfer. some of the 'layers' has a resistance of 1. Some of the layers have a resistance of 3. But one of the layers has a resistance of 100. (numbers for engineer types Rtotal = 1+1+3+3+100 = 108) You could half all of the other 'layers' so they each have 1/2 the resistance as they had before, but it would make almost no difference as long as the 100 resistance layer is not changed (Rtotal = .5+.5+1.5+1.5 = 104). The convection heat transfer coefficient is typically the 100 resistance value. Evaporation makes the ~100 convection coefficient more like 0.1 (Rtotal = 1+1+3+3+.1=8.1). So even though all of the other layers and their resistance is still there, the total resistance went WAY down. Central Texas low temperatures rarely vary much. Normally in the 65F to 75F range. It might be 80F by the time we get out of bed and ready to ride - but that is not the low temperature for the day. The Central Texas dew point temperature is also in about that same range. If we get a summer cold front or a summer rain shower it might change for a short time. But then it goes right back to that range. Mentioned before but left out of the recent discussion is the impact of sun exposure on body temperature. I don't think I have to tell you that being in the sun makes you feel hotter than being in the shade. That feeling is real. The sun is transferring a lot of heat by radiative heat transfer. Radiative heat transfer generally takes "larger" temperature differences. Five to 10 degrees F does not move much heat. The sun at a few thousand degrees moves a lot of heat to our puny bodies at under 100F.

Because Al Jazeera is far less left-bias than Fox news is right-bias. https://mediabiasfactcheck.com/al-jazeera/ https://mediabiasfactcheck.com/fox-news/

Dawn, I have a decent loop that goes from Oskar Blues to WC, over to Balcones Park and then back. ~10 miles or so, either on dedicated bike paths or mostly on roads with bike lanes.

73+

Posted on OB FB page an 1 hour ago: Here’s what is going in your Oskar Blues Taproom this week... Wünder Pig Barbecue Co. Cookin’ up the grub Tues - Sun Tuesday | $2 Can Tuesdays!

Alexandera is a badass. Now first in Women's class and pacing the other two Singlespeed leaders. Ii she's racing to finish, and she finishes first, well, I guess that's cool too. 😎

you are correct on YBP being closed, will toss them in my trunk

Nice detective work and that makes sense with the trail names, but I'm unfamiliar with that particular sign and the "Back Basin." I know AF pretty well, which is why I was/am puzzled. I did recognize the area code, but didn't google the phone number. Headin' Home is a ski run and Highway is a bike trail. Plus, I know nothing about slow skiing.

Googling the phone number on the Patrol sign indicates Angel Fire.

Anyone need 25.4mm stems? Heading to yellow bike today to drop them off if nobody wants them.

From Sofiane Sehili on facebook, six hours ago:

Fix-It Sticks attach under the cage mount: https://www.backcountry.com/fix-it-sticks-original-tool-with-bracket This bad boy will hold your tube, tire tools, CO2, band aids and probably your phone. Mine is mounted on the top tube below the saddle. https://www.specialized.com/us/en/top-tube-pack/p/155212 At this point, it's just down to the water. I've been riding all our central Texas trails, including the Green Belt, without a pack for 2+ years now. I also have a waist pack, and it's way better than a backpack - you really don't notice it. Cons: less water volume, and they haven't figured out how to clip the tube on properly (I tuck it through the belt strap).

I’ll take the hat 🎩 😛

It's ok at WC, not sure I would ride anywhere else without a CB. I'm definitely weighing options for waist packs, water bottles, steer tube multi-tools, seat bags, etc. I'm done carrying all that shit on my back.

Yeah, I have not mastered the leaving the pack behind but I need to get on that. Every ride has enough tools to fix any major issue but at WC you're never too far out (unlike the GB) so I just need to suck it up and start risking it a little more.

That Ritchey is exactly what my bike stable/life has been missing. Shakedown ride at Walnutz was flawless. This is the 1st 29" wheeled bike I've owned and I have to say, it's almost like cheating. Was especially nice to ditch the camelbak and just return to the lot to refill a water bottle. I bet it's been 20+ years of every mountain bike ride with an extra 10-13 pounds of crap on my back.

Thanks for noticing

Beware of that thinking. Many have died before they picked up on their bodies signals. Dehydration and heat stroke will sneak up on you like Mittens🐍

I will be riding as well. This is no different than altitude training, getting your body in sync with the environment.

I'll be back out tomorrow morning. I'm probably losing my mind since I turned 60, but...I'm riding.

Built me a wheelie machine.

You're not thinking of starting a thread about E-Kayaks are you?

Had my first close encounter with an e-bike last week riding in California. I had arranged a regular MTB rental through one of the local bike shops in San Luis Obispo and asked if any of the shop staff would be interested in riding / guiding for an afternoon. The guy meets me at the trailhead with my rental bike (Trek Fuel), along with a Rocky Mountain eBike from the shop that he was intending to ride. Now that I thought was actually an excellent application for a pedal assist ebike. After all, he was packing plenty of gear for trailside repairs, had extra snacks / fluid in case I didn't bring enough, and frankly was doing it for the fee I agreed to pay vs. strictly for fun. Also, in that role he knows that he has to keep up on the climbs and frankly climbing did not appear to be his forte. So in the end, it was a really great experience for both of us. He got to put a little extra cash in his pocket and I got to ride some sweet singletrack without having to do extensive research on the trail system and never having to pull my phone out to navigate the trails. He even offered to let me try the eBike, although I respectfully declined.

Wow, Mittens is slumming it down on Picnic now

This is the last feature, #5, we're building on this trail Code Named Tarantula. The trail length is around 1,000 feet, so you'll get wooden features pretty much back to back. This one starts with a 16' gentle ascent that you can gap to off a dirt entrance to a level board walk that rises 18" over 6' to a 6' level pad, up another 3.5' to a 24' level boardwalk. If you got the pull, you can gap to the top. From the top, it will descend slightly to a level pad to another down ramp to a dirt transition. You should be able to gap from the top to the dirt if you have the gumption. We're hoping that we can make the finishing touches to the trail and have it open next week.

Crack Cocaine and Mountain Dew

Apparently Lael Wilcox was racing to win; she scratched in the last few hours.