Between The Tape
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Between The Tape Added a reply to High vs. Low Tire Pressures: Which Is Faster?
1/28/2025 1:29am In my opinion, the cost of collecting less data (due to the practicalities of a randomised block design) is higher than the cost of not using the ideal randomisation design (again, there is some randomisation built into the testing procedure). Thanks for the discussion and feedback!
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Between The Tape Added a reply to High vs. Low Tire Pressures: Which Is Faster?
1/28/2025 12:52am The whole experiment is published as an R package. The script to generate the visualisations can be found in inst/scripts/images.R. The data were randomised into batches of five runs before data collection, using random batch assignment. So the order of 5 high, 10 low, 10 high, 5 low is the result of a form of valid randomisation, and my preference...
Between The Tape Added a reply to High vs. Low Tire Pressures: Which Is Faster?
1/27/2025 3:30am This test was just a first attempt at collecting some data to see how feasible the whole testing process was. I agree that the transfer of the findings into other settings are limited (I tried to allude to this in the conclusion), and that we need much more data. I would love feedback on how you think the testing protocol...
Between The Tape Added a reply to High vs. Low Tire Pressures: Which Is Faster?
1/26/2025 3:04am The short section of track was chosen because it allowed me to guarantee that I could find the edge of traction and find the limit of grip on each run. Any longer and it would have been very hard to do this without mistakes and other factors such as fatigue coming into play. As a result, I don't think the...
Between The Tape Added a reply to High vs. Low Tire Pressures: Which Is Faster?
1/25/2025 11:34pm The interesting insight for me was the variability between the two pressure setups. I agree, on a loose wet rocky track, I would like to think the answer is obvious, but I would be interested to see the variability with different pressures.
Between The Tape Added a reply to High vs. Low Tire Pressures: Which Is Faster?
1/25/2025 11:32pm For sure I think there is a sweet spot. It would be great to do an extended testing protocol with a broader range of pressures at some point in the future. This was just a first test run to even see how feasible the whole process is. For the new radial casings, I have no idea, but I'm interested to...
Between The Tape Added a reply to High vs. Low Tire Pressures: Which Is Faster?
1/25/2025 3:02am I relate to this. I too think front tire pressure is the more important variable and often end-up with a similar setup where I just run a higher pressure in the back for security.
Between The Tape Added a reply to High vs. Low Tire Pressures: Which Is Faster?
1/25/2025 2:56am No, I didn't find myself having to adapt to the lower pressures. I had a fair amount of riding time on these pressures previously and so nothing came as a surprise. Combined with the fact that I was on a flow trail with CushCore Pro inserts that provide decent sidewall support, it just felt like a more damped version of...
Between The Tape Added a reply to High vs. Low Tire Pressures: Which Is Faster?
1/25/2025 2:52am Good points. Your explanation of higher pressure deflecting more (and being slower) matches the explanation in the Wolf Tooth tire pressure calculator somebody else shared earlier in the thread, and it makes sense. My subjective experience was that the higher pressures rolled faster, but this could be because the trail was not too technical and so there was less deflection...
DServy Liked a reply to forum topic High vs. Low Tire Pressures: Which Is Faster?
1/25/2025 1:41am
I am a 200 lb man and if I ran 20 PSI in a DH casing I would die. I have no idea what Wolftooth is thinking with those numbers. https://axs.sram.com/guides/tire/pressure is a pretty decent one.
This forum topic has 34 replies.
brash Liked a reply to forum topic High vs. Low Tire Pressures: Which Is Faster?
1/25/2025 1:40am
Good test, I'm same weight/height as OP so it's very interesting to me. I find the front pressure super important, I can go 22psi and no ill effects, just good grip. But in the rear, even with cushcore 28psi is about as low as I'll go before I get flats/rim strikes. I just find the confidence and grip in the front tyre is all I need, the rear can be almost whatever it needs to be to stay inflated. Riding style thing probably.
This forum topic has 34 replies.
notthatbryan Liked a reply to forum topic High vs. Low Tire Pressures: Which Is Faster?
1/25/2025 1:39am
This forum topic has 34 replies.
Between The Tape Started a new thread High vs. Low Tire Pressures: Which Is Faster?
1/24/2025 10:10am We all know the theory: lower tire pressures mean more grip, and higher pressures roll faster. But when it comes to real-world speed, which one really wins? I set out to answer this with 30 timed runs down the same track. ◾ The Experiment Two sets of tire pressures were chosen for my 88kg (194lbs) weight: 25/28 psi (front/rear) for...
This forum thread has 34 replies.
az2au Liked a reply to forum topic High vs. Low Tire Pressures: Which Is Faster?
1/24/2025 10:01am
Absolutely excellent post. Obviously you're correct in that it isn't statistically valid across all variables but I do think it is thorough enough to draw a valid conclusion given the outside testing and holistic work that likely led to the an initial hypothesis of slower being faster as a general rule (because the lack of learning/repeated runs needs to allow for more mistakes). The other conclusion I drew from it is that you should also ride what you believe in as the differences aren't likely to be that significant either way. Confidence, and of course competence, likely matters more than...
This forum topic has 34 replies.
gigamike Liked a reply to forum topic High vs. Low Tire Pressures: Which Is Faster?
1/24/2025 10:01am
Great post! It would also be very interesting to see the results of low pressures aligned with the average recommendations and the high pressures above that. My observations over the years have seen a lot more riders with pressures higher then what is recommended.
This forum topic has 34 replies.
Between The Tape Added a reply to High vs. Low Tire Pressures: Which Is Faster?
1/24/2025 10:01am Yeah I would love to collect some more data across a wider ranger of pressures. Something I will consider alongside other research we have in the pipeline. I've always struggled to find recommended tire pressures from an "official" source other than this E13 post. Any ideas?
Between The Tape Added a reply to High vs. Low Tire Pressures: Which Is Faster?
1/24/2025 9:56am In hindsight, my choice of the word "significant" was poor. To statistically validate this claim, we would need to collect a lot more data and then use some inferential statistics (e.g., null hypothesis testing). But I think I agree with you, that there is enough in this exploratory analysis to draw some conclusions. I also agree that riding what you...
Kanista Liked a reply to forum topic High vs. Low Tire Pressures: Which Is Faster?
1/24/2025 9:43am
Straight to the low psi settings i go 😅 really good read, thanks alot
This forum topic has 34 replies.
sspomer Liked a product review First Ride Review - $4,799 Rift Zone EL 1 e-MTB
1/22/2025 12:01am
Marin is no stranger to the e-MTB market and just a few short years ago in 2021, their affordable, simple, fun Alpine Trail E2 was our favorite e-sled of the year. Not one to upset the apple cart, Marin continues their tradition of making bikes that won't break the bank while remaining enjoyable on the trail with the release of the Rift Zone EL line. The "Rifty" EL series use the lauded Bosch SX drive system with a 400wh CompactTube battery and is offered in three different builds. Prices are $6,999, $5,999 or $4,799, and when Marin reached out about...
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