Using two tubes .

Rando_12345

Active member
Nov 16, 2022
358
483
France
I have ignored this thread for so long as i couldn't figure out what it could possibly be about.

The fact that it is 100% what I thought and dismissed, but the content is 10000% more entertaining than any thread on this forum is brilliant.

I don't really see much toxicity in this forum overall, except for the Levo riders going into the DJI thread to troll on it and vice versa. As a mature, respectable member of the community, I participate in both sides of the trolling.
 

KnollyBro

E*POWAH Elite World Champion
Dec 3, 2020
1,015
2,371
Vancouver
Well, during my ban , i did it ,and it works great . In a sharp rocky section of the track [where iv had several pinch flats] it was fine , wheel is more balanced , rolling resistance is better,, and , the dimwit that suggested that the tubes will catch fire from the friction , no it didn't . I do realise MTB riders are couple of sandwiches short of a picnic[e riders more so] , so i forgive you all for the dumbass comments , even the numbnut moderators .

Edit: Congratulations, you’ve just earned yourself another holiday. Mod.
Pics and video or it didn't happen.
I still don't understand the point as if one tube gets a puncture, he would still be running at half pressure. I think I just answered my own question.
 

irie

E*POWAH Elite World Champion
Subscriber
May 2, 2022
2,751
2,827
Chichester, W.Sussex, UK
Pics and video or it didn't happen.
I still don't understand the point as if one tube gets a puncture, he would still be running at half pressure. I think I just answered my own question.
There's a micropump linked to a pressure sensor. When the sensor detects that pressure in one tube is falling it triggers the micropump to transfer remaining air from the deflating tube into the other tube. Any fule knows this.
bdsm.gif
 

steve_sordy

Wedding Crasher
Nov 5, 2018
9,096
9,585
Lincolnshire, UK
Let's assume a 27.5" wheel with a 2.6" width tyre and a 2.6" tube.

To use two tubes, the inner volume of the tyre has still to be filled, but not overfilled.
You could use two tubes that were each half size, ie 2.6/2 = 1.3", but that would underfill the tyre. (Well, no it wouldn't because they would just keep expanding, but the tubes would be over-stretched).

Assuming the tyres will contort to fill the space, the ideal would be 2.6/(sqrt of 2) = 2.3/1.414 = 1.84"

Two 27.5" tubes of close to that size would suffice (I have seen a tube size range quoted of 1.75" - 2.125", so two of them would do).
 

Jackware

Fat-tyred Freakazoid
Subscriber
Oct 30, 2018
2,105
2,323
Lancashire
Let's assume a 27.5" wheel with a 2.6" width tyre and a 2.6" tube.

To use two tubes, the inner volume of the tyre has still to be filled, but not overfilled.
You could use two tubes that were each half size, ie 2.6/2 = 1.3", but that would underfill the tyre. (Well, no it wouldn't because they would just keep expanding, but the tubes would be over-stretched).

Assuming the tyres will contort to fill the space, the ideal would be 2.6/(sqrt of 2) = 2.3/1.414 = 1.84"

Two 27.5" tubes of close to that size would suffice (I have seen a tube size range quoted of 1.75" - 2.125", so two of them would do).
You're taking this way to seriously Steve 😁
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,671
5,231
Coquitlam, BC
Let's assume a 27.5" wheel with a 2.6" width tyre and a 2.6" tube.

To use two tubes, the inner volume of the tyre has still to be filled, but not overfilled.
You could use two tubes that were each half size, ie 2.6/2 = 1.3", but that would underfill the tyre. (Well, no it wouldn't because they would just keep expanding, but the tubes would be over-stretched).

Assuming the tyres will contort to fill the space, the ideal would be 2.6/(sqrt of 2) = 2.3/1.414 = 1.84"

Two 27.5" tubes of close to that size would suffice (I have seen a tube size range quoted of 1.75" - 2.125", so two of them would do).
OMG! Steve.
Your mathing (sic) is impeccable, impressive and confusing to me all at the same time. This is where your engineering background shines.

I need to read this again 👍🏻…slowly.
 

Zimmerframe

MUPPET
Subscriber
Jun 12, 2019
14,052
20,848
Brittany, France
Do you need to simultaneously inflate the two tubes ? Using a standard park tool twin tube parallel tube inflation pump ??

If you fill one first to say 20psi (We'll call it Bert), it will naturally try and fill all of the tyre - forming a relatively cylindrical shape. If you then inflate Tube 2 (We'll call it Ernie) , it will need to push the second tube back, though the two could be twisted all over the place from the tyre mounting process - so they might be contorted all over the place and seem like two snakes in full battle - or possibly two lythe mud wrestlers with all the potential sliding around going on in there.

Inflating Ernie to 20psi would on paper push Bert out of the way to form two perfect half moon shapes.

Except it won't because Bert and his 20psi will now have the same volume of air squashed into less space, so more than 20psi - therefore it will remain larger and more important than Ernie.

In which case we need to address the names. Maybe Walter White and Jesse Pinkman, would be more relevant in this context ? Or maybe it's more a Don Draper/Peggy Olson type balance. I'm leaning more to Frasier and Niles with the size differences though.

I'm thinking it would all be easier with 4 tubes. Then you could have Darth, Han, Leia & Luke for the front, then Chewy, Yoda, C3P0 and R2D2 bringing up the rear. It would be a lot easier to monitor pressures, especially if you used digital tyre pressure monitors plus your monitoring system could yell out things like "We've lost R2, we've lost R2" when you get a puncture in one chamber.

I think I've drifted...
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,671
5,231
Coquitlam, BC
Do you need to simultaneously inflate the two tubes ? Using a standard park tool twin tube parallel tube inflation pump ??

If you fill one first to say 20psi (We'll call it Bert), it will naturally try and fill all of the tyre - forming a relatively cylindrical shape. If you then inflate Tube 2 (We'll call it Ernie) , it will need to push the second tube back, though the two could be twisted all over the place from the tyre mounting process - so they might be contorted all over the place and seem like two snakes in full battle - or possibly two lythe mud wrestlers with all the potential sliding around going on in there.

Inflating Ernie to 20psi would on paper push Bert out of the way to form two perfect half moon shapes.

Except it won't because Bert and his 20psi will now have the same volume of air squashed into less space, so more than 20psi - therefore it will remain larger and more important than Ernie.

In which case we need to address the names. Maybe Walter White and Jesse Pinkman, would be more relevant in this context ? Or maybe it's more a Don Draper/Peggy Olson type balance. I'm leaning more to Frasier and Niles with the size differences though.

I'm thinking it would all be easier with 4 tubes. Then you could have Darth, Han, Leia & Luke for the front, then Chewy, Yoda, C3P0 and R2D2 bringing up the rear. It would be a lot easier to monitor pressures, especially if you used digital tyre pressure monitors plus your monitoring system could yell out things like "We've lost R2, we've lost R2" when you get a puncture in one chamber.

I think I've drifted...
I like your odd-number of tubes theory. 1-3-5-7-etc. makes simple sense to me. I would be concerned with bad harmonics or excessive variations. Even I can understand the benefits of this. 🤔

Btw, your reference to Sesame Street characters helps a lot 👍🏻
 
Last edited:

p3eps

E*POWAH Elite World Champion
Subscriber
Dec 14, 2019
1,983
2,405
Scotland
Do you need to simultaneously inflate the two tubes ? Using a standard park tool twin tube parallel tube inflation pump ??

If you fill one first to say 20psi (We'll call it Bert), it will naturally try and fill all of the tyre - forming a relatively cylindrical shape. If you then inflate Tube 2 (We'll call it Ernie) , it will need to push the second tube back, though the two could be twisted all over the place from the tyre mounting process - so they might be contorted all over the place and seem like two snakes in full battle - or possibly two lythe mud wrestlers with all the potential sliding around going on in there.

Inflating Ernie to 20psi would on paper push Bert out of the way to form two perfect half moon shapes.

Except it won't because Bert and his 20psi will now have the same volume of air squashed into less space, so more than 20psi - therefore it will remain larger and more important than Ernie.

In which case we need to address the names. Maybe Walter White and Jesse Pinkman, would be more relevant in this context ? Or maybe it's more a Don Draper/Peggy Olson type balance. I'm leaning more to Frasier and Niles with the size differences though.

I'm thinking it would all be easier with 4 tubes. Then you could have Darth, Han, Leia & Luke for the front, then Chewy, Yoda, C3P0 and R2D2 bringing up the rear. It would be a lot easier to monitor pressures, especially if you used digital tyre pressure monitors plus your monitoring system could yell out things like "We've lost R2, we've lost R2" when you get a puncture in one chamber.

I think I've drifted...
You surely can’t be serious??



… why on earth would you put Darth in the same wheel as Luke, Leia and Han?!
There needs to be further thought put into this 😂
 
Last edited:

billwarwick

E*POWAH Elite
Oct 1, 2018
666
1,511
warwick
Do you need to simultaneously inflate the two tubes ? Using a standard park tool twin tube parallel tube inflation pump ??

If you fill one first to say 20psi (We'll call it Bert), it will naturally try and fill all of the tyre - forming a relatively cylindrical shape. If you then inflate Tube 2 (We'll call it Ernie) , it will need to push the second tube back, though the two could be twisted all over the place from the tyre mounting process - so they might be contorted all over the place and seem like two snakes in full battle - or possibly two lythe mud wrestlers with all the potential sliding around going on in there.

Inflating Ernie to 20psi would on paper push Bert out of the way to form two perfect half moon shapes.

Except it won't because Bert and his 20psi will now have the same volume of air squashed into less space, so more than 20psi - therefore it will remain larger and more important than Ernie.

In which case we need to address the names. Maybe Walter White and Jesse Pinkman, would be more relevant in this context ? Or maybe it's more a Don Draper/Peggy Olson type balance. I'm leaning more to Frasier and Niles with the size differences though.

I'm thinking it would all be easier with 4 tubes. Then you could have Darth, Han, Leia & Luke for the front, then Chewy, Yoda, C3P0 and R2D2 bringing up the rear. It would be a lot easier to monitor pressures, especially if you used digital tyre pressure monitors plus your monitoring system could yell out things like "We've lost R2, we've lost R2" when you get a puncture in one chamber.

I think I've drifted...
It’s good to have him back……..
 

Jackware

Fat-tyred Freakazoid
Subscriber
Oct 30, 2018
2,105
2,323
Lancashire
Wouldn't you have to carry more spare tubes, Berts and Ernie's if you like, to avoid the disastrous possibility of riding with just one inner tube and not maintaining the tubular Yin and Yang.

1731519646250.jpeg


As Wikipedia says so eloquently;
"Describes the opposite but interconnected, self perpetuating cycle"

Which is what the OP is seeking.
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,671
5,231
Coquitlam, BC
Wouldn't you have to carry more spare tubes, Berts and Ernie's if you like, to avoid the disastrous possibility of riding with just one inner tube and not maintaining the tubular Yin and Yang.

View attachment 150174

As Wikipedia says so eloquently;
"Describes the opposite but interconnected, self perpetuating cycle"

Which is what the OP is seeking.
Is that an actual concept illustration? I feeeeel that could work. 👍🏻
 

BIG-DUKE-6

Active member
Feb 21, 2023
189
128
Usa
Let's assume a 27.5" wheel with a 2.6" width tyre and a 2.6" tube.

To use two tubes, the inner volume of the tyre has still to be filled, but not overfilled.
You could use two tubes that were each half size, ie 2.6/2 = 1.3", but that would underfill the tyre. (Well, no it wouldn't because they would just keep expanding, but the tubes would be over-stretched).

Assuming the tyres will contort to fill the space, the ideal would be 2.6/(sqrt of 2) = 2.3/1.414 = 1.84"

Two 27.5" tubes of close to that size would suffice (I have seen a tube size range quoted of 1.75" - 2.125", so two of them would do).
We need to test this theory


On a treadmill
 

billwarwick

E*POWAH Elite
Oct 1, 2018
666
1,511
warwick
My partner is threatening to call for the men in white coats. She says that I’ve got a stupid smile on my face and keep laughing out loud for no apparent reason…..
I wonder if I can buy the TV rights to this thread?
 

Zimmerframe

MUPPET
Subscriber
Jun 12, 2019
14,052
20,848
Brittany, France
Yeah but this multiple-tube-theory is starting to make sense. At first I was reluctant to drill vent holes in my new carbon rims …not so sure now. 🤔
Are you proposing we expand into Quantum tube theory ??

Could it be that with 2 tubes you can have Schrödinger's Tubes ??? We all have both flat and full tubes at the same time, but you won't know until you look ?
 

RustyMTB

E*POWAH Elite World Champion
Jul 22, 2020
2,875
6,972
UK
That's a decent allegory for this thread. There you are in a galaxy that has light speed travel, laser guns & a moon sized planet destroying weapon but no apparent means of transmitting a relatively modest data file other than sticking it up a robot's flue & sending it off on a perilous journey across the cosmos. It doesn't make any sense.
 

Arminius

E*POWAH Master
Subscriber
Jul 26, 2022
623
1,063
Rhein-Ruhr Delta, Germany
Yeah but this multiple-tube-theory is starting to make sense. At first I was reluctant to drill vent holes in my new carbon rims …not so sure now. 🤔
There is another question! If there is a puncture, how do you figure out which valve to pump? 🤔 I am more for this option that will allow you small air compartments for bulletproof tyres when riding and entertainment when stopping at a pub!

IMG_3559.jpeg
 

EMTB Forums

Since 2018

The World's largest electric mountain bike community.

559K
Messages
28,290
Members
Join Our Community

Latest articles


Top