Ask the experts

[EWG]

I think it would be a blast to charge down that rabbit hole .......... in a totally different thread. I’m of the opposite school, that an out of true wheel with balanced tension is superior. But really, if we’re putting that much effort into the one, we’re probably getting close on the other.
Would love to hear an actual engineers perspective ........... in a different thread.



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Heh. If you make the thread I’m game. Wheel dynamics are pretty damn fun to work through. I also like that reasonable minds can disagree. Leaves some room for art...

[simple]

Send an email to leonard zinn. He loves that shit

[rideit]

Having built and repaired/trued thousands of wheels, I can tell you a customer would never buy into the “even tension trumps true-ness” argument, even if it were somewhat true.
Which I don’t think it is, but I’m no engineer.
Maybe on paper...

[EWG]

Send an email to leonard zinn. He loves that shit

Damn right he does. Anybody remember usenet.bicycles.tech or whatever that shit was? There were some epic throwdowns. If you considers geeks with calculators and graphs capable of throwdowns.

[toast2266]

Moderately uneven tension is fine, as long as the lowest tension is high enough. Shit starts breaking if a hard impact is sufficient to completely detension a spoke though.

[jono]

^That. Spokes at the same angle to the plane of the rim give up tension at the same rate (so same for any given deflection) regardless of their starting tension. Until one loses it all. So minor differences are probably less meaningful than angular differences.

Even spoke tension is a way to tell that the rim is straight: a bent rim needs uneven tension to be true.

I believe it was rec.bicycles.tech? If Jobst Brandt was still around there could probably be a whole thread taunting usenet like mtbr.

[rideit]

I think the only two books that I still have from 1986 are ‘The Bicycle Wheel’ and ‘The Monkey Wrench Gang’. Those two alone got me through some crazy times...

[jackstraw]

I think the only two books that I still have from 1986 are ‘The Bicycle Wheel’ and ‘The Monkey Wrench Gang’. Those two alone got me through some crazy times...

He was a crazy bastard, eh?

"Jobst Brandt Passes Away | Bicycling" https://www.bicycling.com/news/a2001...t-passes-away/

[EWG]

^That. Spokes at the same angle to the plane of the rim give up tension at the same rate (so same for any given deflection) regardless of their starting tension. Until one loses it all. So minor differences are probably less meaningful than angular differences.

Even spoke tension is a way to tell that the rim is straight: a bent rim needs uneven tension to be true.

I believe it was rec.bicycles.tech? If Jobst Brandt was still around there could probably be a whole thread taunting usenet like mtbr.

jm2e: I told ya I didn’t want to get into the “why” argument because I’ve reformed and no longer get into tech disagreements on the interwebs, but this plus Toast’s plus Rideit’s start to explain it. True the rim and it starts in the strongest place. Spoke tension temds to equal when under point strain. So if you start that separate argument thread looks like you better be ready: Us “trues” seem to outnumber you “tensions.”

Though, I have to admit, I do love a good rec.bicycles.tech style pseudo engineering argument. (Thanks for remembering the name jono.). Almost as good as a rec.bicycles.tech argument over weight that questions a combination of strength and measurements on weightweenies.starbike.com. Which shockingly still exists, apparently.

Ah, the good old days, when we choose mtn bike tires based almost solely on weight. And skidded, unintentionally, a lot.

[MagnificentUnicorn]

He was a crazy bastard, eh?

"Jobst Brandt Passes Away | Bicycling" https://www.bicycling.com/news/a2001...t-passes-away/

Inspired me to start “Jobst” rides when I lived in the Bay Area back in the mid ‘90s. Basically gave up mountain biking for 15 years and started doing what the dorks now call gravel rides on my road bike. Moved to Central WA and found dirt road paradise.


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[carlh]

What are these mythical straight rims you speak of? AFAIK they only exist on road bikes.

[skaredshtles]

What are these mythical straight rims you speak of? AFAIK they only exist on road bikes.

Carbon. IME they will stay straight even if you break multiple spokes.

Fuckin magic, I tell ya.

[jm2e]

jm2e: I told ya I didn’t want to get into the “why” argument because I’ve reformed and no longer get into tech disagreements on the interwebs, but this plus Toast’s plus Rideit’s start to explain it.
Blah blah blah ..... I’m Rubber You’re Glue!

Tell it to the countless people on mass produced wheels going from perfectly showroom true to wobbly & breaking spokes.
Of course I’m in the minority. I’m a bastard AND an idiot.


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[rideit]

Well, I was always a fan of re-tensioning properly AND making them as true as possible, but that’s just me...

[volklpowdermaniac]

I don’t much to add, but I still don’t get inserts or DD/DH casing I’m damn near 200 kitted up riding 21/23 on 27.5x2.5/2.4 , no inserts, exo+, Have had probably 2 flats in 6 years and yet to do any serious damage to an alloy rim. I’d like to thing I’m riding with pretty reckless abandon on manny of the difficult PNW trails. I don’t know what I’m doing wrong.

Definitely just jinxed myself though.

[jono]

Try less spoke tension. That should have you bending rims with the cool kids in no time.

[jm2e]

I’d like to thing I’m riding with pretty reckless abandon on manny of the difficult PNW trails .... mostly buffed out dirt you could ride a skateboard down, mixed with long stretches of magical loam, the occasional wet root and a smattering of smooth flat rocks without a square edge in sight

FIXD


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[SchralphMacchio]

^ True dat!!!



But even a 135 lbs dude like me can bend rear aluminum rims ... suspension or not.

[Roxtar]

I already know the answer, but how fucked am I?

Attachment 350997

Proper fucked.
Yeah, a little late but no one else swung after you teed it up so nicely.

[Roxtar]

Having built and repaired/trued thousands of wheels, I can tell you a customer would never buy into the “even tension trumps true-ness” argument, even if it were somewhat true.
Which I don’t think it is, but I’m no engineer.
Maybe on paper...

Yes, tension is more important than true but any decent wheelbuilder can give both.

[Whiteroom_Guardian]

Consensus on fasted riding/training?

That Vegan Cyclist dude has gone deep and will not eat all day and then do 4 hours rides. I like his videos, and obviously have to take it all with a grain of salt, but I know there is something to be said for fasted riding to help the body learn to burn it's own fat as fuel vs. needing to pound gels.

I have been working my way towards getting the body to be more efficient. Doing 90 minute Zwift rides and not needing/wanting gels at all anymore. 3 months ago I couldn't ride for 30 minutes without wanting gels/blocks.

How much/little have you guys experimented with this stuff? I want to be more efficient on the bike (and a nice side effect would be to get rid of the tiny gut fat that will not go away).

[Boissal]

3 months ago I couldn't ride for 30 minutes without wanting gels/blocks.

Wanting or needing? Every attempt I've made at moderating my caloric intake on the bike has resulted in a disastrous bonk. And we're not talking about going cold turkey here, I can taper a bit but invariably I hit a wall and pretty much die after x amount of effort. I might be able to get somewhere at lower intensities but I have a hard time forcing myself to stay in the right range.
The vegan dude obviously doesn't have a lot of extra anything to burn but I wonder if this approach can even work for people with that are pretty bony to start with (and a few exceptions)... And I'm not calling you fat, I just wonder if it's possible to convince your body to go after your unwanted gut pouch.

[mall walker]

I can usually go about 3.5-4 hours of biking / ski touring level exertion (and not chillin with the bros and chatting style, I go alone, I don’t stop and I push the whole time) before really needing to take in calories. But if I do take some in it also helps. It helps a lot to eat decently an hour or two before you go, which can be hard depending. For me drinking more water during every day (not activity specific) has helped more than anything, I try to drink a gallon a day of straight water plus all the coffee soda and beer I drink. But everyone’s different, something to be said for just learning how your body reacts. The dude I did the Grand Traverse with brought and ate pizza slices with him, seemed insane to me but that’s just how he operates, we were the same pace.

As much as I’d like to drink 4+ beers every day and eat fried chicken or burgers or steaks every day (with fries obv), cutting that shit back somewhat has helped as well as I creep into my late 30s... despite all the rah rah you’re a pussy if you don’t eat red meat every day stuff you hear, eating a balanced diet as a matter of lifestyle has had a nice effect for me personally at least. My wife’s a vegetarian so I eat vegetarian out of sheer laziness at least a few meals a week. Not the worst.

[Dantheman]

Paging XtrPickles!

My understanding would be that the fasted rides and subsequent improved fat burning are incredibly useful for long steady efforts, especially at ultra distances. In enduros you're doing a lot of short hard efforts that require glucose, but between stages there's a benefit. Hopefully the resident physiologist chimes in.

[XtrPickels]

Consensus on fasted riding/training?

That Vegan Cyclist dude has gone deep and will not eat all day and then do 4 hours rides. I like his videos, and obviously have to take it all with a grain of salt, but I know there is something to be said for fasted riding to help the body learn to burn it's own fat as fuel vs. needing to pound gels.

I have been working my way towards getting the body to be more efficient. Doing 90 minute Zwift rides and not needing/wanting gels at all anymore. 3 months ago I couldn't ride for 30 minutes without wanting gels/blocks.

How much/little have you guys experimented with this stuff? I want to be more efficient on the bike (and a nice side effect would be to get rid of the tiny gut fat that will not go away).

TL : DR Training while fasted is stressful to the body and the adaptations can be gained through appropriate training. If you decide to do it, no more than 1-2 sessions per week. Additionally, while in a glycogen depleted state, your performance will suffer.

I will start with and I will stress that training / racing in a glycogen depleted state will decrease performance acutely (during the activity) when compared to well-fed exercise. This is a non-negotiable.

Additionally, because training in a glycogen depleted state increases cortisol (stress hormone) response when compared to the same workout while well-fed, it is playing with fire for most individuals whom are not intricately familiar with it. This strategy will push athletes toward over-training, which is a very real and very serious situation.

Given the above, I generally support no more than 1-2 sessions of depleted training per week.

With that said, there are certainly studies correlating increased adaptation with glycogen depleted exercise. Note that I did not say increased performance.

Ultimately there are two stores that can be depleted:
1. Liver Glycogen: This maintains our blood sugar which flows all around the body feeding muscle, brain, etc.
2. Muscle Glycogen: This is locked within the muscle and fuels moderate to high intensity exercise.

The physiological adaptations associated with glycogen depleted training primarily come from training with low muscle glycogen. This strategy seems to increase PGC-1a, which is a cofactor / regulator within the metabolic pathway that causes a shift toward increased fat metabolism by increasing the number of mitochondria.

Truly muscle-depleted exercise is probably most likely to occur as the 2nd workout of a day in which the first was glycogen depleting and the second occurred later after little to no carbohydrate intake. This could either be morning initial ride followed by an evening depleted ride or a evening initial ride, followed by a morning depleted ride.

There are also additional adaptations from training with low liver glycogen whether through training first thing in the morning, prior to a meal, or through long long rides. These tend to be more in the "central governor" such that they increase the ability to push / function without enough caloric intake. aka the decrease in cravings that you noted.

There are other ways to achieve these adaptations which tend to be safer from an over-training / stress perspective and ultimately lead to more robust adaptations.
1. Riding more volume. Training hours are highly correlated with cycling performance.

2. Riding with purpose at appropriate intensities.
Most of your training should be at an "easy" workload. This is 2/3s of your week. This primarily engages you aerobic system at an intensity where fat can contribute a significant (this is relative) amount to the needed energy (carbohydrate will be burned aerobically too, that's ok). This is like driving easy in a hybrid car and only using the more efficient electric engine. Focusing here makes this system (fat oxidizing aerobic system) stronger and that allows it to contribute to higher workloads. Work harder than this system can handle and the gas engine starts to kick in. This is bad, we want the electric engine to do most of the work.

Some of your training should be at a very hard intensity, this is 1/3rd of your week. Hard means hard. Hard means this sucks. Hard means I can't possibly go on, but I have to. Agony. This is the hybrid driver with their foot to the floor going up to the Eisenhower tunnel. Both the Aerobic and Anaerobic systems are now maxed out, (and burning carbohydrate because they're going so hard) which is a good stimulus for adaptation.

Unfortunately most people end up at "moderate" intensities all the time that are "Kind of hard" instead of ever training truly easy or hard. This is because it feels like you are accomplishing something, but it's not distressing. Because this intensity is in the middle, it is somewhat engaging the aerobic and anaerobic system, but neither hard enough to cause them to need to get better.

This moderate training causes riders to be fairly carbohydrate dependent because they're always relying on burning carbohydrate to fuel activity. If you never work easy enough to burn fat during exercise, then your body never gets good at burning fat during exercise.

Asker Jeukendrup is a well known researcher in this field.
His take on muscle v. liver depletion for different strategies.
http://www.mysportscience.com/single...ys-to-trainlow


LM (Louise) Burke and JA (John) Hawley are also great collaborators in this space.
Search scholar.google.com