cxagent

1 hour ago, rockshins said:

That was really cool! Some amazing riding and locations! Also makes me realize I have no style.  Brett Rheeder is on another level! Someone got a sweet XTR drivetrain!

Thanks - I already knew I was slow. But now I know I have no style while I'm slow. 😞

I wanted to enter this raffle instead of working it.  There was some really really cool stuff. Maybe if I wait 10 years I will be able to afford a 12 speed XTR group. But probably not.

This event was a BIG success. Thanks to everyone who attended.

The movie was very much like Warren Miller ski movie but about mountain biking. Really cool when it rains too much to ride trails.

ARR raised about $700 which will go to trail development. Some of the big items that were raffled off were 2 Lazer helmets, 2 printed on metal still pictures from the movie (waaaayyy cool to see) and a Shimano XTR 12 speed group set. I wanted to enter the raffle instead of running the raffle.

A special thanks for Bicycle Sport Shop, Shimano and Vallarie & Ken Sinclair for making this possible.

I spent my teen years summers working in the oil field in East Texas. The days when I rode in the truck from well to well were nice. The days we were working over a well or cleaning up a spill were miserably hot.

Late high school and part of attending UT I worked for apartment complexes. One of the worst summers ever was when we were reroofing the complex. I was up at 4:00 AM pumping the freon out of ac condensers that were on the roof. I left the AC running thru the night so the tenants had cooling thru the night. About dawn the roofing contractor would show up. They would help me pick up and move the ~300 lb condensers to a part of the roof that was not being worked that day. While they were tearing off the roof I was pushing sheets of plywood up the ladder to the 2nd floor roof. Once they had a part of the old roof removed I was replacing any rotten decking. As quick as I got one part done, they were putting down the new hot asphalt roof. The temperature was already 90+, in blazing sun and now they were working with 150F+ asphalt. By 2:00PM it was too hot to work on the roof any more and the roofers would stop for the day. As they were leaving I would get one or more of them to help me move the condensers back to on the new roof section. At about 3:00PM I would take a nap in my cool apartment. By now I was EXHAUSTED and sun burned. EVERY SINGLE DAY. About 6:00 PM I would start reconnecting and recharging the condensers we had removed. About 9:00 PM I was done for the day. Every single day. For about 2 months.

The worst was the day I shut down my AC. I did not get a cool nap during the day. Then before I get my AC running again, the vacuum pump died. At about 8:00 PM. No parts or vacuum pump available that time of night. I slept on an air mattress in the pool that night. And I over slept. I didn't wake up until the roofers were there. They called off work for the day and I got a new vacuum pump and caught up. 

I built a lot of muscle and heat tolerance that summer.

Now days I still have to work on AC's on roofs and in attics. Most roofs are about 120F during a summer day. Most attics are more like 150F. It is not uncommon to come down out of an attic and get a chill in the 100F summer afternoon cool. I try to not do much attic work in the heat but there is rarely a choice. AC is down and the problem is in the attic. I makes me want to KILL the architect who decided to put the AC in the attic.

1 hour ago, Chief said:

I work outside on hot pavement in the summer working on even hotter cars. What I can say when it's hot is be sure to have plenty of cold liquids on hand and some type of rag or cooling towel and cold water available. When I start to feel the heat more than I'd like I soak the towel in cold ice water from my cooler ring it out a bit and wrap it around my neck, super effective at getting core temp down a few degrees. The cold towel helps to cool your blood passing through your carotid artery helping to drop your core temp a bit. Works wonders. I know, I know we can't do that on a bike but might be handy info for some when working in the yard.

Actually - we can. When it gets really hot or I am feeling the heat more than normal, I pull a mouth full of ice water out of my Camelbak and spit it onto a rag. Then wrap that rag around my neck for a short ride. Rinse and repeat as needed.

Why do I pull the water into my mouth first? I get a little drink and warm the water up just a bit. And I don't waste any water dripping it onto the rag from the hose. YMMV

Call that section a "Rock Garden". 😂

3 hours ago, AntonioGG said:

@cxagent take a look at my ride from yesterday https://www.strava.com/activities/2475474003 in the hottest part of the day.  It was a bit of an experiment (stupid one) after following this thread.  I wore my Pearl Izumi sun sleeves and a club jersey.  The sleeves were drying even though I was sweating.  The jersey and my skin (other than my arms) stayed moist.  It mostly felt OK except for the 620 climbs (with some tail wind) and some of the 360 climbs where the south headwind was being blocked by the hills.  The worst was the climb from the dam to past Marshal Ford (and the two stupid super long lights in a row there) the Garmin-indicated temp at the dam wad 93°F and at the top it was 100°F.   The sleeves definitely did their job but the "technical" fabric of the jersey did not work as well as the sleeves.  I had to stop 3 times to get water even with 3 bottles when normally I could do the whole thing without stopping.  The best was the Chevron on 2244 that had sprinklers running on the bit of grass with a picnic table.  

The sleeves I think help pull moisture off the skin, and increase the surface area for evaporation.  What I don't know is if it's possible for a material to increase the rate of phase change of the water.  I know they make nano-materials that increase condensation or make it possible when it isn't condensing anywhere else.

My sleeves are a few years old, but when they were new, the amount of cooling was freaky.  I mostly got them to block the sun since I hate putting on sunblock, but now I wish I could get a whole kit made out of this material.

I'm not sure what the dew point was yesterday, but I'm curious what my experience says about evaporation cooling based on the conditions.

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.

5 hours ago, Ridenfool said:

If I were to visualize "phase change" as a part of the movement of heat it would look like a layer or a step in the process.

Example: Sweat absorbs heat from body, pores move sweat to skin surface, phase transition changes heat in liquid to heat in vapor, convection moves the vapor into the surrounding air, carrying heat away from the skin.

Phase Transition is like a part of the path, much like the thermally conductive compound between CPU and Heat Sink is a layer the heat must efficiently move through before being carried off by convection from air passing over the fins of the Heat Sink.

The wet bulb effect is interesting. This essentially determines the maximum potential cooling that could be achieved under perfect conditions. So, if 82 is the daily low (wet bulb/dew point), and the OAT is 94, under routine conditions with reduced (lets use 50%) efficiency there may only be 5 or 6 degrees of cooling, at best.

If the OAT is 100 with an overnight low of 85 the cooling effect might only be just approaching that 93 degree F point where no actual cooling of the skin occurs. (change the numbers based upon whatever the realistic percentage of cooling under these conditions might be)

(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.

14 hours ago, Ridenfool said:

The Wiki doesn't really say whether there is any effect upon the transfer of heat during the phase transition. If the same amount of heat exists, only spread out over the greater area the vapor occupies that would not really change anything. It seems to me that convection of the evaporated water is what moves the heat away from the body.

If there is a component of the phase transition from water to water vapor that makes some significant difference in how the heat moves away from the skin I'd be curious to know about that.

If heat loss is slowed to make this phase change happen that would be interesting. Likewise, if heat loss speeds up in the process of changing from water to vapor that too would be good to know more about. If the the phase transition has little to no effect on a body getting rid of heat, that would be less interesting.

 

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

I agree with Cody's comments but will add a few - 

Use your training to figure out your nutrition. Some people do fine with lots of Gu, Cliff bars and some kind of energy drink. I would puke. I usually eat rice cakes (skratch cookbook), mostly water and maybe a Gu or two. If rest stops have banana or oranges or cantaloupe, those worked well for me but I could not carry many of them.

Altitude hits everybody who is not used to it (us lowlanders). Whether riding, skiing or hiking - just SLOW DOWN until you can breathe while you keep moving. Some of those climbs may be an hour long. You can't blast up them. So slow down and spin. I read somewhere that you offload your legs by spinning but spinning loads your cardio. Mashing unloads your cardio by loading up your legs. So switch back and forth to rest one while using the other.

Find that happy place. I call it my 'most efficient pace'. I am covering a lot of distance at minimal effort. I have to keep up shifting to see if the current pace is that most efficient pace or not. If I up shift and the effort does not change much I stick with that. If I up shift and feel the effort increase a bunch - I shift back down and know I have found where I need to be at that time/location. And the pace will change at different times/locations.

Good Luck and have fun!

Bicycle Sport Shop is sponsoring a mountain biking movie the evening of Thursday 6/27/19. There will be a raffle of mtb gear to benefit the Austin Ridge Riders. This is a great way to see a cool movie and support local trails!

More info and tickets at - https://www.eventbrite.com/e/shimano-presents-return-to-earth-by-anthill-films-austin-tickets-62246140883

15 minutes ago, mack_turtle said:

I really need to dig into some interviews to see how people pull off stuff like this. I am lucky if I can leave my immediate neighborhood for more than a few hours to ride, let alone take a month + off to ride the whole country top to bottom. I'll have to start with a weekend excursion to a state park to start because this kind of thing appeals to me more than brappin berms.

You know we have two TD finishers right here in Austin. I have seen the Sheila's several times on SATN. You might want to talk with one or both of them.

Posting so everybody sees the news - https://www.kxan.com/news/local/williamson-county/mountain-bikers-will-go-full-gas-saturday-at-cedar-park-race/2073603464

I always upgrade piecemeal when I have money / time. I would not think twice about installing the fork this month and the shock next month.

This question is a different version of "upgrade my existing bike or replace my existing bike"? Do what ever works for you!

On 6/11/2019 at 4:55 PM, mack_turtle said:

A track to where? Inquiring minds!

Doing some planning in Reimer's Ranch. That is all for now. Probably have more details in about a month.

I want to have something solid to report before I report it. Otherwise it starts to sound like Fake News.

You guys are going down some of the same roads I did. I finally gave up and posted for help.

But then I found a different way to get something useful even if I didn't understand what those numbers meant (they were listed on a drawing as "Coordinate Points". I suspect you have to have the secret decoder ring to figure out where those were.

I found a KMZ file. I converted that to GPX file. My Garmin still could not figure out what was intended in the ~ 5 meg file. I tried Strava and TopoFusion without much luck. But when I imported the GPX file into Ride With GPS - it read the file and gave me something I could work with. The GPX file was about 30 short segments. My Garmin only took the first one. RWGPS listed and previewed each and everyone of them. I was able to look though the files and pick out the ones I needed to combine to make what I needed.

So even though I still don't know what those numbers meant - I have a track I can use.

I Hope somebody can help me figure this out. I have a location shown as 2997010.75E 10096432.05N. I thought this was the lat/long or GPS location. I can't figure what it is or how to convert that to anything I can figure out. This location should be in Reimer's Ranch.

Can somebody point me in the right direction?

I hope you could find your way around the trail.

That NEVER happens to me. I must not be living 'right' like you are.

On 6/6/2019 at 7:37 AM, HoneyBadger said:

Stopped 7 people riding on Peddlers last night. All were newbies (except 1) and didn't know not to ride muddy trails. They were all nice and apologized.

GET READY FOR A RANT.

But that one guy that knew better...eeeerrrrr. It's always some variation of the conversation below with experienced riders when they are busted riding muddy trails.

ME: Trails are too muddy to ride.

THEM: You think so?

ME: Yes.

THEM: I thought so too, I noticed it was a little muddy, but I wasn't sure. I was going to get off the trail in a minute cause it's to muddy. Do you really think it's that bad?

ME: Yes, it's too muddy to ride, look at your wheels they are caked in mud.

THEM: Yeah, I saw that, but didn't think it was that bad.

ME: It's bad, look at the rut under your tire. It takes hours for me to fix all the ruts.

THEM: Thanks for all your work. Ok, I'll get off the trail around the corner.

Of course they don't offer to help, they don't get off their bike and walk, they ride off creating more ruts.

Another funny thing that happens is when an experienced person sees me working and it's too muddy they will exit the trail before they get to me to avoid the conversation above.

Good job. That is a very polite conversation compared to the ones I have had.

I would cut that second stump back and leave the new "feature". But that is just me.

What makes sense for one person may be totally wrong for someone else. That said, here is what I recommend -

I would not sink money into your old bike. It is outdated and limiting at this point. Bike standards are changing so fast right now that what you buy today may not be usable on a new bike. You may find it hard to find parts for the old bike already. If you can get 'upgrades' on closeout or other wise low cost - it might make sense for you. But be careful how much you spend on that old a bike.

I don't find a GPS very useful for navigating trails. Even a 'high end' GPS does not have trail maps in it like they do for roads. So even if I load a GPX file into my GPS, I have to go past a turn before it tells me I am off course. And it CONSTANTLY tells me I am off course even when I am on course (GPS error? trail changes? Aliens?). What a GPS does best is record your ride so you can look at it after the ride, load it to Strava, etc.  Maybe the technology has improved to where a GPS can communicate with Trailforks or MTB Project and I don't know about it. But my experience is that GPS units don't help much with trail navigation.

Phone navigation of trails works much better than my GPS unit. But I keep my phone put away so it does not become a victim of a crash. To use the phone for trail navigation I have to stop, take off my Camelbak, dig out the phone, dry the sweat off my hands, etc etc etc before I can get navigation info. All of that and I still find it more useful than my Garmin 800 GPS. Your mileage may vary.

So what is my recommendation? The GPS unit WILL transfer to a new bike. If you want a new upgrade now - that is where I would spend my money. Just recognize the limitations. And I would be looking for a new / used bike in the near future. I would probably save my money to put into the new bike.

I rode the Zilker to first creek crossing today. There needs to be lots of work on this section. I suspect on other sections as well. I will start the approval process.

2 minutes ago, AustinBike said:

This is the only trail in the area where we are getting new trail on a consistent basis and seeing the support of the city. Yeah, we get trail work at WC (I've done some myself this year) but it is not really adding much new trail (we got a bit of it over the past few years) but work now is mainly repairing trail from water damage and bonewipe riders. Somehow WillCo is doing a better job than CoA on supporting trails.

The land manager at Walnut Creek has decided that there will be NO new trail. We can replace trail that has been or had to be closed - but no 'additional' trail. Why you ask? Has anybody noticed that Walnut is getting to be almost all "trail" (actually trampled brush - not actual trail). When there is no brush left to separate trails, people will walk everywhere until nothing can grow anywhere. I know, I know. It is not the MTB'rs doing most of this. But this is how the land manager is trying to deal with the problem. The best thing we can do is try to help them.

A lot of the "new" trail (most is over a year old now) is from where the big sidewalk replaced existing trails. And some trails had to be closed for safety reasons like not having high speed MTB crossing the sidewalk. The old Powerline Downhill and Ski Hill are examples. The City allowed us to replace those trails with 'new trails'. So we tried to make the newer trails more fun that the old trails.

IMHO - Wilco is in a very different situation than City of Austin. Places like Walnut are getting overrun with users of all sorts. Wilco is not seeing that problem as bad. Not yet anyway.

15 hours ago, AustinBike said:

Saw a rat snake on the GB again today, snake week continues. 

I can't wait for shark week.