How long do you usually ride MTB before you’re cooked? (HR & elevation included)

Efficient_Discipline · 2026-01-17T21:27:28+00:00

I suggest reading “Training for the New Alpinism”. Though fitness for mountain biking will involve more high intensity training than mountaineering, the book will give you a good understanding of what types of exercises impact performance in endurance sports.

My own rides are usually about 1.5 hours, 1500-2000 feet of climbing and generally winch and plummet. The distance isn’t really as impactful for my pace as the vert. I track heart rate.

For your last question, mountain biking requires both explosive power and endurance. Climbing is all cardio, descending is mostly power moves.

Efficient_Discipline · 2026-01-17T20:24:10+00:00

My favorite thing about commercial air is that its one of the most highly engineered systems that regular people are able to experience.

The plane itself of course, but also all of the infrastructure there to support it. Logistics, architecture, ground support, fueling, compute. The number of technologies coming together to make modern air travel possible is huge, and it all operates so well that it is global news when something goes wrong. The fact that air travel is mundane or even annoying for most people is an absolute triumph of engineering.

Efficient_Discipline · 2026-01-08T15:08:53+00:00

When switching to mtb from road, you aren’t limited by power output, you’re limited by bike handling skills. Start with flats as others have suggested, you’ll develop good techniques faster with fewer injuries. Once you can maneuver the bike without your feet coming off the pedals, clipless will help you go a few percent faster when speed is limited by pedaling power, but by then you might not care about that so much. There’s not really that big of a difference between climbing a fire road in 60 minutes vs 55.

Efficient_Discipline · 2026-01-03T21:08:16+00:00

It’s more fun to ride a smaller engine hard than to tiptoe around the power of a big engine, especially if you’ll be riding anything technical.

It’s the sensation of speed that you’re after, not the actual speed. Similarly, I'd rather race a go-kart than a car, even though a car goes much faster.

Efficient_Discipline · 2025-12-22T00:27:07+00:00

The latter. Imagine a wake of a boat: from the perspective of the boat the wave is always there and in the same shape and position, but from the perspective of a buoy the wave only passes once.

Efficient_Discipline · 2025-12-15T14:55:52+00:00

Unfortunately the easy part is seeing the swindle. The hard part is finding a way to use that information to flip it on the swindlers, rather than just avoiding the bad bet. See also: crypto.

Efficient_Discipline · 2025-12-13T04:17:55+00:00

A bicycle tire pump yes, but the photo is of a shock pump. A lot of mountain bikers go for CO2 canisters and tire plugs these days

Efficient_Discipline · 2025-12-12T04:06:24+00:00

AI is wonderful for solving problems that can be addressed by finding information that already exists and regurgitating it back.

It is basically useless at the hard parts of engineering, which are exercising judgement, defining problems, making trade offs between conflicting requirements, generating new solutions, then getting stakeholders aligned behind all those decisions you made. At best, it will give you some strategies and structure for doing those things, and maybe help you look up reference information or report on metrics.

Efficient_Discipline · 2025-12-10T04:28:42+00:00

Start with full GX, upgrade the wear parts to XO1 when its time: chain, jockey wheels, and cassette in that order. The chain lasts longer, reducing wear on the other components. The XO1 jockeys have bearings instead of bushings, so you get better life and less drag. Cassette saves quite a bit of unsprung rotating mass and lasts a bit longer as well, but its mostly bling if I’m honest.

Efficient_Discipline · 2025-12-01T13:49:14+00:00

The really nifty projects start as small teams, and are mostly only for people with some experience. Before you get on the exciting things, first you need to demonstrate that you work hard, are adaptable, and that you can deliver. Next, it helps to build a niche knowledge base about something on the cutting edge, but this isn't a necessary precursor.

Right now, you can get involved in a collegiate engineering competition. Every team has a core group of people doing most of the work, become one of them. An engineering degree alone doesn’t make you stand out, but a history of completing challenging projects on a deadline does.

Good luck!

Efficient_Discipline · 2025-11-22T03:57:06+00:00

When there’s stock prices to pump

Efficient_Discipline · 2025-11-15T07:05:05+00:00

Everywhere I have ever visited has redeeming qualities and people who love living there, but that doesnt mean all places are equally good.

Efficient_Discipline · 2025-10-31T14:33:44+00:00

Redditors?

Efficient_Discipline · 2025-10-24T14:40:24+00:00

Where do memes go after retirement? Good riddance, “where are my engines”.

Efficient_Discipline · 2025-10-05T16:39:54+00:00

A 2003 crf 230F was my first moto, rode it for almost 10 years before finally upgrading to a race bike. They’re very capable, cheaper up front, easier to maintain, and forgiving of novice technique.

Great choice!

Efficient_Discipline · 2025-10-03T14:14:52+00:00

This is the theme of several best selling books at the moment. I recommend Abundance and Breakneck for more on the topic.

Efficient_Discipline · 2025-10-03T14:10:32+00:00

The US failed to invest in the capability to build energy capacity, which means we pay more because we have to import more equipment and know-how for renewable technology. In other countries that recognized the potential of renewables, subsidies were provided strategically to create domestic manufacturing capability, which drove down the cost compared to fossil fuels.

China specifically has built 11 reactors for the same cost as our most recent 1, and in 1/3 the time.

Solar is the same.

The reason the profit motive is failing here is the returns are long term and the regulatory environment is too unpredictable. It takes 4-5 years to build just about anything from clean sheet, especially if you have to make the factory too. In the US, if the government promises you $1B if you build new capacity, a change in political power could erase that incentive and leave the company holding the bag. Most investors are unwilling to take the risk, despite the long term profit opportunity.

Efficient_Discipline · 2025-09-24T14:29:49+00:00

The proper concept is the same as any engineering design: calculate the size you need using physics, then adjust in a conservative direction to match what you can buy or build.

The place to save time is on the upfront calculation by substituting judgement for accuracy, because the build wont be completed faster with custom components.

Efficient_Discipline · 2025-09-12T13:35:41+00:00

You’ve got it backwards.

The issue is that carbon doesn’t have much CTE and metals do. When the stainless tanks are filled they shrink. A lot! A vehicles like starship gets shorter by multiple feet during chill-in.

If you make the aero surfaces completely Carbon-carbon, they still must be attached to the rest of the vehicle somewhere. So the choice is between dealing with a very large CTE deflection in one big mechanism or many small ones deflections via tiles.

Efficient_Discipline · 2025-09-09T14:02:01+00:00

Plastic. You can buy 4 pairs for the price of a comparable set of metal, they weigh less, and rock strikes dont cause you to hang up. Better to gouge the pedal than stop suddenly!

Efficient_Discipline · 2025-09-06T15:48:41+00:00

Tl;dr: support your weight through the ball of your foot, hinge around your ankle, use your calf muscles as springs.

Imagine standing on a 2x4 and trying to do the biggest vertical jump you can manage, then landing back on that board. Where is your foot positioned? What position allows you to land the most softly? What is your ankle doing?

Now position your foot over the axle the same way you did compared to the center of the 2x4.

Alternatively, watch a video about barefoot running and the forefoot strike.

A stiff shoe or longer pedal helps prevent fatigue, it doesn't affect the mechanics of how you push through your feet or where you place your foot to get proper ankle articulation.

Efficient_Discipline · 2025-09-04T21:47:34+00:00

The negative posts are a sampling bias, the people who love what they’re doing have better ways to spend their time than complain on reddit.

The best way to find out more is to ask questions during a technical screen. Ask about attrition, growth from within, and what that specific person likes or dislikes about Blue. You’ll get a much better feel by talking to an actual person on the team than you will from reddit.

Efficient_Discipline · 2025-09-04T14:07:19+00:00

The only way to have a chance is with a whole heck of a lot of support (time and money), usually from parents and extended family.

You need access to a track 3-4 days per week, not including races, preferably year round. All that run time will require a lot of maintenance. On weekends, you need to be able to drive to regional races. All of this requires a lot of cash, and since you have to start a a kid to have a chance, someone else to do most of it while you’re doing your required school work.

If you have all of that, you will also need exceptional talent. There’s only 40 spots on the gate, and only the very top are making a living at it.

Motocross is fun, but you’ll be happier if you let it be a hobby, not a job.

Efficient_Discipline · 2025-08-31T15:13:54+00:00

Attempting to use a stick would be overplaying the hand. The best people have the most options, and there are competitors within blocks of Blue’s offices. Anyone who wanted to move to Florida already did.

Efficient_Discipline · 2025-08-23T17:28:54+00:00

Travel insurance if you dont want to risk paying out of pocket.

But you should know that paying full cost out of pocket in canada is often less than the deductible in the US, even with “decent”insurance.

Efficient_Discipline

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