33g Inner Tube - Ridenow TPU

[alanyu]

FYI, those who rides rim brake and climbs/descends a lot should avoid ridenow TPU tubes.

Kirito Zhang (岛野肠粉), who tested the integral bar stiffness, etc., has tested the thermal limitation of this tube. RideNow exploded when the brake track of a carbon rim reached 154.7 C, which is lower than most of the brake track delamination temperature (160-220 C). Since the thermal conduction of carbon is very low, the softening temperature of RideNow is way lower than 150 C.

P. S., Alu has much higher thermal conduction than carbon. Don't risk yourself if you are descending with alu rim brake wheels.

150 Celcius (300 fahrenheit) still seems like an adequate number for most situations.

As for the comment on aluminum, are you saying that an aluminum rim can get even hotter before it fails? Or that hot aluminum will be more likely to melt the tube than hot carbon?

Either way, if your wheels get that hot due to terrain and/or large mass of the rider, that's a problem best dealt with by avoiding rim brakes.

Alu rim will be much more likely to melt the tube than carbon, due to the high thermal conductivity. E.g., if a carbon rim keeps 100 C for 30 sec, the inner tube may be just 60 C, but if it's alu rim, the tube can go more than 80 C.

[SystemShock]

Alu rim will be much more likely to melt the tube than carbon, due to the high thermal conductivity. E.g., if a carbon rim keeps 100 C for 30 sec, the inner tube may be just 60 C, but if it's alu rim, the tube can go more than 80 C.

Huh? I'm no engineer, and could easily be off here, but wouldn't the higher thermal conductivity of aluminum be a good thing here? As in, it would help prevent 'hot spots' at the braking track/side of the rim?

For example, here is a heat warning for latex tubes + carbon wheels:

That said, we strongly recommend against using latex tubes with carbon clincher wheels—a sentiment shared by most major wheel, tube, and tire manufacturers. Since the carbon braking surface heats up more than alloy, it can cause latex tubes to burst and fail. If you're running carbon clinchers, go with butyl tubes.

https://www.competitivecyclist.com/challenge-latex-tube

[alanyu]

Alu rim will be much more likely to melt the tube than carbon, due to the high thermal conductivity. E.g., if a carbon rim keeps 100 C for 30 sec, the inner tube may be just 60 C, but if it's alu rim, the tube can go more than 80 C.

Huh? I'm no engineer, and could easily be off here, but wouldn't the higher thermal conductivity of aluminum be a good thing here? As in, it would help prevent 'hot spots' at the braking track/side of the rim?

For example, here is a heat warning for latex tubes + carbon wheels:

That said, we strongly recommend against using latex tubes with carbon clincher wheels—a sentiment shared by most major wheel, tube, and tire manufacturers. Since the carbon braking surface heats up more than alloy, it can cause latex tubes to burst and fail. If you're running carbon clinchers, go with butyl tubes.

https://www.competitivecyclist.com/challenge-latex-tube

It depends on how long time you need to hold the brake. At a normal/gentle descent, you don't need to hold the brake long, and alu will be cooler, but at a steep and technical descent, where you need to hold the brake for long time to keep the speed low (this is where the carbon rim mostly likely to delaminate), alu rim will make the tube hotter.

[Tifosiphil]

Valve length is 65mm

Is that the total length or just the tube part before the head (don't know the technical name). My Vittoria tubes are listed as 46mm but that excludes the head of the tube

[NiFTY]

[/quote]

It depends on how long time you need to hold the brake. At a normal/gentle descent, you don't need to hold the brake long, and alu will be cooler, but at a steep and technical descent, where you need to hold the brake for long time to keep the speed low (this is where the carbon rim mostly likely to delaminate), alu rim will make the tube hotter.
[/quote]

Alan you 100% misunderstand. Aluminium rims insidr and outside never get as hot as carbon on sustained breaking. Aluminium has higher thermal conductivity which means it sheds the heat (from the part of the rim not in contact with brake pads at that moment) much quicker. Heat production, which is just a form of energy transfer, is IDENTICAL to carbon rims. Heat retention is lower so an aluminium rim which is losing heat quicker will never get as hot. Conduction to inside the rim is irrelevant.

[SystemShock]

It depends on how long time you need to hold the brake. At a normal/gentle descent, you don't need to hold the brake long, and alu will be cooler, but at a steep and technical descent, where you need to hold the brake for long time to keep the speed low (this is where the carbon rim mostly likely to delaminate), alu rim will make the tube hotter.

Alan you 100% misunderstand. Aluminium rims inside and outside never get as hot as carbon on sustained breaking. Aluminium has higher thermal conductivity which means it sheds the heat (from the part of the rim not in contact with brake pads at that moment) much quicker. Heat production, which is just a form of energy transfer, is IDENTICAL to carbon rims.
Heat retention is lower so an aluminium rim which is losing heat quicker will never get as hot [as carbon]. Conduction to inside the rim is irrelevant.

+1, Nift. This is my understanding as well.
.

[alanyu]

Alan you 100% misunderstand. Aluminium rims insidr and outside never get as hot as carbon on sustained breaking. Aluminium has higher thermal conductivity which means it sheds the heat (from the part of the rim not in contact with brake pads at that moment) much quicker. Heat production, which is just a form of energy transfer, is IDENTICAL to carbon rims. Heat retention is lower so an aluminium rim which is losing heat quicker will never get as hot. Conduction to inside the rim is irrelevant.

+1, Nift. This is my understanding as well.
.

How rim gets the thermal is the kinetic energy transfer due to braking. How rim sheds the heat is thermal convection insetead of conduction. How inner tube goes hot is the thermal conduction from the rim.

Sheding heat by thermal convection depands on the convective heat transfer coefficient, surface area and speed. The convective coefficent of carbon and alu at a similar speed is on the same order.
Holding the brake to keep a similar low speed, the energy for heating is the same.
The thermal capacity of alu is ~10% higher than carbon, and alu rims are usually slightly heavier than carbon rims.

These three points result in the alu rim itself being cooler than carbon rim.

However, the thermal conductivity of alu is 1~2 order higher than carbon, which means it transfer the heat to the tube way faster than the carbon rim. The RideNow in the test exploded during the rim still getting hot, which means it didn't reach thermal saturation/balance. Before this point, the tube in the alu rim is hotter than in the carbon rim.

[SystemShock]

Anyone use the Schwalbe TPU tubes yet?
.

I have lots of experience with the [TPU] Schwalbe Aerothans. They have been very good for me under fairly extreme conditions - big descents on some nasty rough roads (Fauniera and Sempeyre among others).

Thousands of kms by now with no problems and just two punctures that leaked slowly as they should. Search, there is a thread here with good info. They are stupid expensive.

Just bought 6 Ridenow from Ali. I like the idea of the longer 65mm valve stem. The Aerothans are only 40mm, so I need a extension for most of my wheels.

Thanks much for the info, Gib.

I do get the general feeling that, quality-control-wise, the Schwalbe TPU tubes are likely to be one of the better-made ones.

I care about that more than the price, though you're right... they ARE stupid expensive.
.

[Treptay]

FYI, those who rides rim brake and climbs/descends a lot should avoid ridenow TPU tubes.

Kirito Zhang (岛野肠粉), who tested the integral bar stiffness, etc., has tested the thermal limitation of this tube. RideNow exploded when the brake track of a carbon rim reached 154.7 C, which is lower than most of the brake track delamination temperature (160-220 C). Since the thermal conduction of carbon is very low, the softening temperature of RideNow is way lower than 150 C.

P. S., Alu has much higher thermal conduction than carbon. Don't risk yourself if you are descending with alu rim brake wheels.

Am I seeing it wrong, or is that an aluminium brake track on the photo?
Anyways, do you know what the maximum temperature for tubolitos is?
I am still riding standard butyle tubes and am looking for a lighter replacement on my aluminium rim brake wheels.

[alanyu]

FYI, those who rides rim brake and climbs/descends a lot should avoid ridenow TPU tubes.

Kirito Zhang (岛野肠粉), who tested the integral bar stiffness, etc., has tested the thermal limitation of this tube. RideNow exploded when the brake track of a carbon rim reached 154.7 C, which is lower than most of the brake track delamination temperature (160-220 C). Since the thermal conduction of carbon is very low, the softening temperature of RideNow is way lower than 150 C.

P. S., Alu has much higher thermal conduction than carbon. Don't risk yourself if you are descending with alu rim brake wheels.

Am I seeing it wrong, or is that an aluminium brake track on the photo?
Anyways, do you know what the maximum temperature for tubolitos is?
I am still riding standard butyle tubes and am looking for a lighter replacement on my aluminium rim brake wheels.

Yes, it's an alu rim in the screenshot, but Kirito said RideNow was tested with carbon rim, while alu rim is used to compare the braking force vs carbon rim.
He didn't test tubolitos. The normal 40 g version should stand higher temperature than the 33 g RideNow in principle, though no one really knows it currently

[Treptay]

FYI, those who rides rim brake and climbs/descends a lot should avoid ridenow TPU tubes.

Kirito Zhang (岛野肠粉), who tested the integral bar stiffness, etc., has tested the thermal limitation of this tube. RideNow exploded when the brake track of a carbon rim reached 154.7 C, which is lower than most of the brake track delamination temperature (160-220 C). Since the thermal conduction of carbon is very low, the softening temperature of RideNow is way lower than 150 C.

P. S., Alu has much higher thermal conduction than carbon. Don't risk yourself if you are descending with alu rim brake wheels.

Am I seeing it wrong, or is that an aluminium brake track on the photo?
Anyways, do you know what the maximum temperature for tubolitos is?
I am still riding standard butyle tubes and am looking for a lighter replacement on my aluminium rim brake wheels.

Yes, it's an alu rim in the screenshot, but Kirito said RideNow was tested with carbon rim, while alu rim is used to compare the braking force vs carbon rim.
He didn't test tubolitos. The normal 40 g version should stand higher temperature than the 33 g RideNow in principle, though no one really knows it currently

Can you post the translation of the post, or give a link, I would like to read the whole thing?
Considering that the temperature was nearing the carbon rim delamination point, how bad can the RideNow tubes be? They advertise them as compatible with rim brakes, but I have my doubts now.
The temperature also doesn't mean much to me, except there is a comparison to other tubes. I assume every tube will fail at some point? Latex and light bytile tubes also aren't recommended for rim brakes.

[alanyu]

Can you post the translation of the post, or give a link, I would like to read the whole thing?
Considering that the temperature was nearing the carbon rim delamination point, how bad can the RideNow tubes be? They advertise them as compatible with rim brakes, but I have my doubts now.
The temperature also doesn't mean much to me, except there is a comparison to other tubes. I assume every tube will fail at some point? Latex and light bytile tubes also aren't recommended for rim brakes.

Here you go:

I added one alu wheel as a reference, when I tested other rims. I found out that the braking performance is not that much better than carbon rim as we thought before.

Applying 50 N (mid force) to the lever, the braking power of quite a bit carbon rims is no less than the alu rim. However, the braking performance of alu rim would be better when applying more force to the lever, due to the harder pad.

A lot of people doubt on the heating issue of TPU, and I tested it BTW. Let us guess at what temperature it will explode, and I will send a box of Pepsi to one who has the best guess.

Condition: RideNow TPU tube, Vittoria corsa control 25c, 100 psi. wheel spinning at 20 km/h, braking power 1000 W, which is close to 110 kg total weight, descends at 20 km/h on -17%.

....(A lot of guess)....

Reply to the best guess: It exploded at 154.7 C. Dude, PM me address, but I don't have Pepsi now, you can choose either Coca, Fanta or Sprite.

...

Reply to one question: It exploded at 54 sec on the carbon rim, the sensor showed 154.7 C on the brake track. The temperature went up slower at high temperature, and it exploded quickly after reaching 140 C, which is lower than delamination temperature, and it more tend to explode on the alu rim. Thus, I don't recommend RideNow TPU on rim brake.

...

Reply to my question: I didn't hold the brake all the time. It was 10 seconds braking with 5 seconds releasing each round, and explosion happend after the fifth round. There was also a fan to simulate the wind, but not as strong as in the real world.

[Mog88]

Valve length is 65mm

Is that the total length or just the tube part before the head (don't know the technical name). My Vittoria tubes are listed as 46mm but that excludes the head of the tube

Hope this helps:

[Treptay]

Can you post the translation of the post, or give a link, I would like to read the whole thing?
Considering that the temperature was nearing the carbon rim delamination point, how bad can the RideNow tubes be? They advertise them as compatible with rim brakes, but I have my doubts now.
The temperature also doesn't mean much to me, except there is a comparison to other tubes. I assume every tube will fail at some point? Latex and light bytile tubes also aren't recommended for rim brakes.

Here you go:

I added one alu wheel as a reference, when I tested other rims. I found out that the braking performance is not that much better than carbon rim as we thought before.

Applying 50 N (mid force) to the lever, the braking power of quite a bit carbon rims is no less than the alu rim. However, the braking performance of alu rim would be better when applying more force to the lever, due to the harder pad.

A lot of people doubt on the heating issue of TPU, and I tested it BTW. Let us guess at what temperature it will explode, and I will send a box of Pepsi to one who has the best guess.

Condition: RideNow TPU tube, Vittoria corsa control 25c, 100 psi. wheel spinning at 20 km/h, braking power 1000 W, which is close to 110 kg total weight, descends at 20 km/h on -17%.

....(A lot of guess)....

Reply to the best guess: It exploded at 154.7 C. Dude, PM me address, but I don't have Pepsi now, you can choose either Coca, Fanta or Sprite.

...

Reply to one question: It exploded at 54 sec on the carbon rim, the sensor showed 154.7 C on the brake track. The temperature went up slower at high temperature, and it exploded quickly after reaching 140 C, which is lower than delamination temperature, and it more tend to explode on the alu rim. Thus, I don't recommend RideNow TPU on rim brake.

...

Reply to my question: I didn't hold the brake all the time. It was 10 seconds braking with 5 seconds releasing each round, and explosion happend after the fifth round. There was also a fan to simulate the wind, but not as strong as in the real world.

Thank you for the translation.

54 seconds is lot less than I would expect.
Well, I am definitely not buying these, not worth the risk.

[Tifosiphil]

Valve length is 65mm

Is that the total length or just the tube part before the head (don't know the technical name). My Vittoria tubes are listed as 46mm but that excludes the head of the tube

Hope this helps:

Absolutely perfect, thank you. Should be able to get it to work without an extender!