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Haha perhaps, but the longest climb I do in one go is around 320m. I just wondered if they meant something like 1,000m of climbing in one go.
Just like a 7 liter engine doesn't much care if it's a small or big hill, but a 2 liter engine does, I think we need to consider that I'm old. I didn't specify a climbing amount, because it doesn't much matter...it's relative. Rough terrain continually slows the wheel down and you have to re-accelerate it while climbing. A wheel with more mass around the outside edge is harder to accelerate. Even if the whole wheel combination weighs the same, but one wheel has 70% of the mass at the hub and one has 70% of the mass out at the tire, the latter will be harder to get up a hill. That's just basic physics.
Assuming you mean a non-aspirated 2.0l engine, even that can handle a short climb before succumbing to a lack of power - you said "noticeable when you're reaching the exhaustion point of your "I've been climbing non-stop as long as I can" run. I just wondered how long/far said climb is in your opinion.
I don't honestly know how much elevation there is overall, but my ride-from-home ride is ~20 miles and I take one ~1min break during the whole ride. The rest of the time I push as hard as I can. It's ~300m max-to-min elevation, but there are a lot of ups and downs in there. I spend most of the ride(by time) climbing...as is normal.
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This is kinda my area of expertise. With automotive tires +/-4% is achievable. The issue you run into with MTB tires is the web (topped cord) thickness is so low. You'll inevitably have material from the calender start up or some other event where the gauge deviates .05 mm or more. Which doesn't seem like a lot until you start producing topping material specced close to .50 mm or so. Then you're looking at large percentage changes. Similar concept with extruded material. It's challenging to precisely manufacturer rubber products and that gets harder the more you scale down. My guess is the lighter XC tires show larger % variations than the DH tires.
@BlueSpruce Thanks for the insight, can you clarify what is “material from the calendar start up”?
Vittoria did a promo video a year or so ago where they show some of the manufacturing processes, looked like the die-cut rubber casing and tread strips had a lot of variation.
The calendering process is where the textile plys (carcass) are made. They take a roll of textile fabric and coat it with rubber, typically in a 4 roll mill. Calender performance is very dependent on stable operating conditions. Line speed changes, start/stop, etc lead to gauge fluctuations. It's a non recoupable material so manufacturers try not scrap unless they have to. I don't know what kind of tolerances bicycle tire manufacturers use.
Extruded tread and sidewall can be recouped if they're out of tolerance. The issue there isn't width so much as balancing width, gauge and weight all of which are affected by the compound variances. So even if everything had it's width in spec that doesn't mean the gauge and weight are.
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