tubeless

[Jean]

NOW we can debate what exactly "tube-type" rims really ARE!!
Were they solid rims before the DOT decided there needed to be safety beads near the outer edge, or only rims with BOTH beads to prevent tires going to the center, or just what?
Kinda like the ABS for brakes, or proportional braking from the "front-brake" lever whether you want it or not debate.

[Ken in Oklahoma]

It would seem that a tubed tire has to run hotter than the same tire run tubeless. Stipulating that the heat is generated by the tire side wall flexing (with a possible addition from the tread flexing, i.e. the tube not actually generating the heat by itself) then the addition of a tube still will hinder the heat transfer to the inside of the wheel. It is, in effect, an insulating layer. If one asks where can that heat go once on the inside of the tire/wheel, I would say that the rim, whether steel or aluminum (or magnesium) would be a significant heat sink.

Ken

[vanzen]

NOW we can debate what exactly "tube-type" rims really ARE!!
Were they solid rims before the DOT decided there needed to be safety beads near the outer edge,
or only rims with BOTH beads to prevent tires going to the center, or just what?...

In regards to "what exactly tube type rims really are", there will be no debate.
NHTSA and the D.O.T. (in the US) have explicitly defined the terms.
Every motorcycle rim is stamped with a code that identifies it's intended use ...
as previously explained:

... The difference between a WM2 (tube-type) and MT (tubeless) ?
Just inboard of the vertical part which holds the bead and sidewall of a tire
(virtually identical on WM2, MT, and MTH2 rims)
a WM2 will be horizontal, but an MT will have 5º of upward angle.
This will be the NHTSA / D.O.T. mandated design change intended to hold the tubeless tire onto the rim.
In addition to this 5º angle change, later MTH2 (tubeless) rims also had a "bump" or "bead" just before the drop center
to prevent the tire from dropping to the center of the rim.

[Jean]

I think you have missed the sarcasim in my comments.
I also drive a Corvair...in addition to obviously obsolute, deadly motorcycles.

[vanzen]

I think you have missed the sarcasim in my comments.
I also drive a Corvair...in addition to obviously obsolute, deadly motorcycles.

Sorry, yes, I am very capable of doing that ...
and I drive a '66 VW bug ...
in addition to obviously obsolete, and absolutely deadly motorcycles.

[Deleted User 72]

It would seem that a tubed tire has to run hotter than the same tire run tubeless. Stipulating that the heat is generated by the tire side wall flexing (with a possible addition from the tread flexing, i.e. the tube not actually generating the heat by itself) then the addition of a tube still will hinder the heat transfer to the inside of the wheel. It is, in effect, an insulating layer. If one asks where can that heat go once on the inside of the tire/wheel, I would say that the rim, whether steel or aluminum (or magnesium) would be a significant heat sink.

Ken

The tube is not between the tire and its contact with the rim. I don't understand how it will impede heat transfer between the tire and rim. I can see heat being transferred to the tube and thence to the rim from the tube, thereby increasing the rate of heat transfer with its larger contact area on the rim.

[vanzen]

The tube is not between the tire and its contact with the rim. I don't understand how it will impede heat transfer between the tire and rim. I can see heat being transferred to the tube and thence to the rim from the tube, thereby increasing the rate of heat transfer with its larger contact area on the rim.

Mass will always be a factor in the function of heat retention / transfer
(physics 101 – thermal conductivity)
and increased mass will always adversely effect the ability and rate of heat transfer.
The rim will be a given quantity as defined by the experiment
and cannot not be considered a variable in the equation...
i.e. the difference between a tube and a tubeless fitted onto a given rim
and ridden in a prescribed fashion will describe the difference.
The increased mass of a tube must require more time to dissipate a given amount of generated heat.
Sorry, no way about that !

Exclusive personal examples not withstanding,
the laws of physics will define reality...

[Major Softie]

The tubeless tire in question had the notation on the side - "On tube type rims use a tube."
There was no mention of reduced speed rating.

Given that providing the speed rating on a tire is a mandatory requirement if fitting the tube reduced the speed rating then it would be mandatory to provide both ratings , but I have never seen a tire marked that way..

My recollection is that the the no tube ,err,theory originated when radial tires were introduced - the theory was that the flexible side walls would rub against the tube and heat the tube.

Over the years the story seems to have migrated to all tires, but I have never seen anything authoritative to back it up, and as I said, actual experimentation proves it doesn't happen, at least not with extra heavy thick tubes, and it would appear not with the tires that Metzler test and sell.

There is certainly some truth to your speculation about TT/TL tires, at least from Continental. Their tires labeled that way do not drop their speed rating, except their Z rated radials, however their TL type tires can drop a few speed ratings.

For Continental motorcycle tyres

All TL/TT-sidewalled tyres can be used with a tube without decreasing the speed range (except Z rated radials).
ALL Continental tyres labelled TL can be fitted to rims/wheels marked Tubeless. They can also be fitted on Tubed Type rims/wheels with a correctly sized Continental inner tube.
If Sport Attack, Road Attack and ContiForce tyres (Z rated radials) are fitted on Tubed Type rims/wheels with Continental inner tubes, the maximum speed is then restricted to 130 mph (210 km/h, from Z to H speed rating).
Continental tyres labelled TT can only be fitted on Tubed Type rims/wheels and must be fitted with a correctly sized Continental inner tube.
Please note that the maximum speed for tubeless tyres fitted with an inner-tube is 210 km/h (approx. 130 mph).
http://www.conti-bike.co.uk/default.asp?pid=26

Metzeler says something similar:

Is it possible to fit a tube into a tubeless tire?
Herewith we certificate that METZELER tubeless tires can be used with tubes on the admissible standardized rims. The allowable top speed is 130,43 mph for the "H"- tires and 142,86 mph for the "V"- and "Z"- tires You are bound to use the same product concerning the tubes and the tires on your motorcycle.
Meaning that METZELER-tires have to be used with suitable METZELER-tubes. Existing regulations of the motorcycle manufacturers have to be observed.

Can't find anywhere that Metzeler addresses the TT/TL tire speed rating with a tube.

So, your argument has some credence. I was familiar with the issue with my Ducati GT1000, as it ran Z rated radials with tubes on unsealed spoke rims. Apparently, putting a tube in a TT tire will reduce the speed rating (of an H rated or better), while putting a tube in a TT/TL tire may reduce the speed rating, depending on the tire.

[Ken in Oklahoma]

It would seem that a tubed tire has to run hotter than the same tire run tubeless. Stipulating that the heat is generated by the tire side wall flexing (with a possible addition from the tread flexing, i.e. the tube not actually generating the heat by itself) then the addition of a tube still will hinder the heat transfer to the inside of the wheel. It is, in effect, an insulating layer. If one asks where can that heat go once on the inside of the tire/wheel, I would say that the rim, whether steel or aluminum (or magnesium) would be a significant heat sink.

The tube is not between the tire and its contact with the rim. I don't understand how it will impede heat transfer between the tire and rim. I can see heat being transferred to the tube and thence to the rim from the tube, thereby increasing the rate of heat transfer with its larger contact area on the rim.

I didn't express myself well Native. I used the terms wheel and rim interchangeably, thinking "wheel" when I wrote "rim", and didn't catch it even when I proof read what I wrote.

I hate it when I do that!

Ken

[buffalotankbob]

This is my second season going tubeless on snowflake rims [1982 R100RT] and I'm still alive. I used a common tubeless-rim valve stem [threaded type] like what was shown by Vanzen.

I read the pro/con arguments and opted for going tubeless. There can be no argument as to whether or not going tubeless works. Tubeless snowflakes work. …And my experience with this set-up has been a positive one –so far.

BtB