Do patched up inner tubes slow you down?
03-23-20, 11:40 AM
#27
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FWIW, I don't play baseball, so I don't understand all the fuss about the designated hitter, but I don't find it necessary to go to baseball forums and tell them how stupid the issue is.
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03-23-20, 11:46 AM
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I've been wondering this for a while. I asked Josh Poertner on his Marginal Gains podcast about it: he thought it would but he hadn't tested it either. OTOH, Tom Anhalt thinks it won't. If you know these two guys you'll recognize that they rarely disagree, so I'll take it that the question is currently unresolved. I'll probably test it at some point but I haven't yet had a chance.
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03-23-20, 01:43 PM
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About 3w a pair for going latex over butyl. Not ground breaking outside of Ironman or long TT.
I'd assume patches would be even less by far since the patch is only compressed or dealt with for a tiny fraction of each rotation of the wheel whereas a tube is all the way around.
So, super negligible.
I'd assume patches would be even less by far since the patch is only compressed or dealt with for a tiny fraction of each rotation of the wheel whereas a tube is all the way around.
So, super negligible.
03-23-20, 04:42 PM
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Not a great idea to descend Mont Ventoux with patched tubes, might fail if you didn't do a good enough job. On the other hand, I play the "how many patches can I get on a single tube" game.
03-24-20, 02:13 AM
#31
Rhapsodic Laviathan
03-24-20, 02:20 AM
#32
Rhapsodic Laviathan
I don’t see how adding a patch can not increase rolling resistance. After all, we know thicker butyl tubes result in higher RR than thinner ones. What is a patch other than a localized thickening of the tube? Now what the magnitude of that increase is and how difficult it would be to detect is another matter; but I don’t see how there could be any doubt about the direction of the change.
But giving Tom and Josh their due respect, I would be hesitant to rely solely on what is essentially a hand waving argument by analogy.
But giving Tom and Josh their due respect, I would be hesitant to rely solely on what is essentially a hand waving argument by analogy.
03-24-20, 06:38 AM
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If you're not a racer, there's no reason to care, but if you're racing every single watt and every single fraction of a second matter.
FWIW, I don't play baseball, so I don't understand all the fuss about the designated hitter, but I don't find it necessary to go to baseball forums and tell them how stupid the issue is.
FWIW, I don't play baseball, so I don't understand all the fuss about the designated hitter, but I don't find it necessary to go to baseball forums and tell them how stupid the issue is.
You should ride naked while you're at it. You'll save a few lbs. Why don't you use worn brake pads that'll only last the race, you'll save a few grams there as well.
OP is not a racer, he's a guy who wants to save 2$.
Last edited by eduskator; 03-24-20 at 06:44 AM.
03-24-20, 09:01 AM
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I have no idea if he's a racer or not, but the question was "I was wondering if this would increase my rolling resistance?". It's an interesting question. People do a lot of things to go faster, and they add up. The concept of marginal gains has been around for a while and for a reason.
You have a great day.
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03-24-20, 10:29 AM
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The original post: "So i wanted to save some money and just repair inner tubes with a patch kit. I was wondering if this would increase my rolling resistance?"
I have no idea if he's a racer or not, but the question was "I was wondering if this would increase my rolling resistance?". It's an interesting question. People do a lot of things to go faster, and they add up. The concept of marginal gains has been around for a while and for a reason.
I have no idea if he's a racer or not, but the question was "I was wondering if this would increase my rolling resistance?". It's an interesting question. People do a lot of things to go faster, and they add up. The concept of marginal gains has been around for a while and for a reason.
There isn't any clear reason to expect that there would be any marginal gain at all related to having patches tubes.
It doesn't seem worth discussing the effect of patches without knowing what tires he's using.
03-24-20, 10:42 AM
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No, all things don't always "add up". There is also not much reason to worry about tiny things if larger contributors are not being done.
There isn't any clear reason to expect that there would be any marginal gain at all related to having patches tubes.
It doesn't seem worth discussing the effect of patches without knowing what tires he's using.
There isn't any clear reason to expect that there would be any marginal gain at all related to having patches tubes.
It doesn't seem worth discussing the effect of patches without knowing what tires he's using.
As to whether is it worth discussing, I can only note that you apparently decided it was worth discussing and opted to post an opinion.
BB
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03-24-20, 10:52 AM
#38
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The original post: "So i wanted to save some money and just repair inner tubes with a patch kit. I was wondering if this would increase my rolling resistance?"
I have no idea if he's a racer or not, but the question was "I was wondering if this would increase my rolling resistance?". It's an interesting question. People do a lot of things to go faster, and they add up. The concept of marginal gains has been around for a while and for a reason.
You have a great day.
I have no idea if he's a racer or not, but the question was "I was wondering if this would increase my rolling resistance?". It's an interesting question. People do a lot of things to go faster, and they add up. The concept of marginal gains has been around for a while and for a reason.
You have a great day.
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03-24-20, 10:52 AM
#39
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No, all things don't always "add up". There is also not much reason to worry about tiny things if larger contributors are not being done.
There isn't any clear reason to expect that there would be any marginal gain at all related to having patches tubes.
It doesn't seem worth discussing the effect of patches without knowing what tires he's using.
There isn't any clear reason to expect that there would be any marginal gain at all related to having patches tubes.
It doesn't seem worth discussing the effect of patches without knowing what tires he's using.
03-24-20, 11:09 AM
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No, all things don't always "add up". There is also not much reason to worry about tiny things if larger contributors are not being done.
There isn't any clear reason to expect that there would be any marginal gain at all related to having patches tubes.
It doesn't seem worth discussing the effect of patches without knowing what tires he's using.
There isn't any clear reason to expect that there would be any marginal gain at all related to having patches tubes.
It doesn't seem worth discussing the effect of patches without knowing what tires he's using.
Technically, it may be Spring, but functionally it is Winter,
so we need marginal topics to consider.
Continuing to be house-bound, there may be ample time for discussions of
wheel balancing, tire sprue clipping, and aero cable housings.
03-24-20, 11:23 AM
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I was really discussing your notion that every "marginal gain" was worth it (which is certainly false). But it's not surprising that point went right by you.
Last edited by njkayaker; 03-24-20 at 11:37 AM.
03-24-20, 11:39 AM
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BB
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03-24-20, 11:44 AM
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I think the Continentals have reasonable rolling resistance but there might be tires with significantly lower rolling resistance.
Is there any rolling resistance difference between 25mm and 28mm tires?
I suspect if there's any effect of a patch or two, it's very tiny (I would think it's much less than the difference between the rolling resistance between models of tire).
Do you have a wheelset that you only use for racing? If so, use the patched tubes for training.
If you think the patch might keep you from winning third or better, you should definitely use unpatched tubes!
Is there any rolling resistance difference between 25mm and 28mm tires?
I suspect if there's any effect of a patch or two, it's very tiny (I would think it's much less than the difference between the rolling resistance between models of tire).
Do you have a wheelset that you only use for racing? If so, use the patched tubes for training.
If you think the patch might keep you from winning third or better, you should definitely use unpatched tubes!
03-24-20, 11:55 AM
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Glue around the whole circumference of the wheel is not really anything like one patch. So, using glue as a justification for worrying about a patch doesn't make much sense.
A "possibility" is really weak. "Everything is possible", so saying it's "possible" is rather useless.
In any case, the interest doesn't seem to be whether it is "conceivable".
It would seem the real interest is "whether it has a real/practical effect".
"The questions of exactly how much <whether> it matters" is really what people should be trying to answer.
It seems very likely that it wouldn't really matter at all.
Given that some of the better minds in cycling and engineering have acknowledged the possibility of a patch having a measurable effect (see R Chung's post above), it is clearly conceivable. The questions of exactly how much it matters remains to be answered, but it isn't an inconceivable issue.
In any case, the interest doesn't seem to be whether it is "conceivable".
It would seem the real interest is "whether it has a real/practical effect".
"The questions of exactly how much <whether> it matters" is really what people should be trying to answer.
It seems very likely that it wouldn't really matter at all.
Last edited by njkayaker; 03-24-20 at 12:06 PM.
03-24-20, 01:16 PM
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From this, road glue (flexible) shows a significant increase in rolling resistance over track glue (stiff) and clinchers.
There is little difference between the rolling resistance of track glue and clinchers.
(There's nothing in this that would seem to be applicable to the effect of a single tiny patch.)
03-24-20, 01:22 PM
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This is what I call the "standing on a sheet of paper argument". In theory if you are taller you can see farther. So does standing on a sheet of paper enable you to see farther?
There are many things like this that in theory should matter but the effect is so small as to be impossible to measure.
There are many things like this that in theory should matter but the effect is so small as to be impossible to measure.
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03-24-20, 01:27 PM
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03-24-20, 02:07 PM
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Huh.
So if the patch is about .75" it would be about 1/112 of the wheel circumference and about 1/4 of the tube circumference.
The thickness of a patch is similar to the difference in thickness between a standard tube, and a lighter tube.
The difference in rolling resistance between those tubes is about 1 watt for pair of tires at 45kph,
so a patch could theoretically require about .0022 watts at 45kph.
https://www.aero-coach.co.uk/inner-t...ing-resistance
Then, if I have the math right, they suggest a 4 second difference in a 40k TT for 1 watt of RR,
so a tube patch could cost you .0088 of a second over a 40k time trial at 45kph.
So if the patch is about .75" it would be about 1/112 of the wheel circumference and about 1/4 of the tube circumference.
The thickness of a patch is similar to the difference in thickness between a standard tube, and a lighter tube.
The difference in rolling resistance between those tubes is about 1 watt for pair of tires at 45kph,
so a patch could theoretically require about .0022 watts at 45kph.
https://www.aero-coach.co.uk/inner-t...ing-resistance
Then, if I have the math right, they suggest a 4 second difference in a 40k TT for 1 watt of RR,
so a tube patch could cost you .0088 of a second over a 40k time trial at 45kph.
The effect of the very small area of the patch is probably lower than the simple linear scaling you are using. So, your estimate might be a large exaggeration.
If his tires don't have low rolling resistance, it's odd to worry about the tiny effect the patch is likely to have.
In any case, it doesn't seem the OP should be spending any time worrying about 0.0088 of a second.
