TUBULAR

 

Used mainly by professionals and serious road racing enthusiasts.

The wheel to suit tubular tyres has an enclosed rim onto which the tubular tyre or is mounted and glued into position. The tubular wheel cannot accept clincher type tyres.

The Tub tyre has a latex or butyl rubber tube inside the tyre with the inflate valve protruding from the underside of the tyre. The tyre is stitched tightly together ensuring that the innertube cannot protrude through the stitching when inflated. Often there is a cotton strip seal applied over the stitching and the valve.

The entire Tub tyre is normally purchased as described.

The Tub tyre is fitted onto the rim of the tubular wheel ensuring that the air valve has been inserted through the wheel valve hole only after the rim of the wheel has had glue applied to the surface and allowed to cure for a short, pre-determined time.

Once properly fitted, aligned and matched true to the rim and the valve locked in place (not essential, but advised) the tyre is inflated to high pressure using a foot / track pump and or gas cannister or compressor often to 8bar or higher pressure.

In the event of a puncture the complete tyre must be removed from the rim and replaced with a new tub tyre as it is impractical to repair a punctured tubing assembly at the roadside.

 

ADVANTAGES:                       

Very secure when fitted

Good rolling resistance

Perceived to be faster by comparison to other wheel tyre types when used at high pressure on smooth road surfaces

Bike may still be ridden on a flat tyre

 

DISADVANTAGES:      

Difficult to fit onto rim

Expensive wheel/tyre/glue costs

Difficult to repair tyre

Transmits road vibration due to high running pressure

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TUBED

 

This is by far the most common wheel / tyre combination for road

cyclists and comprises of an open tyre with a latex or butyl rubber tube inserted between the tyre casing and the wheel rim well.

The open edges of the tyre (beads) locate and grips into the hook wall of the wheel rim and traps the tube that has been located in the wheel well with the air valve inserted through the wheel valve hole and normally locked in place

With the trend towards wider width road tyres, tubed tyres tend to be inflated and run at slightly less pressure than tubular tyres.

Tubed tyres can, in most cases, be easily repaired at the roadside in the event of a puncture (using a patch on the damaged tube) or, more conveniently, replacing the entire tube for a new one and refitting the tyre and tube and inflating to the required pressure.

 

ADVANTAGES:                       

Less expensive and more readily available than tubular tyres

Is available on most common road bikes using standard rims

Easy to carry out roadside repairs / replacement

May be able to run at lower pressures compared to tubular tyres

 

DISADVANTAGES:      

Tends to puncture more easily compared to tubular or tubeless systems (typically punctures are often identified as snakebite punctures, i.e. a double puncture when wheel goes over a pothole and the rim traps the tube between the, momentarily, flattened tyre and rim edge)

High rolling resistance due to friction between the tube and the inside of the tyre, therefore perceived as a slower running wheel

Sometimes can be difficult to remove tyre from wheel rim (tyre levers needed)

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TUBELESS

 

Sometimes referred to as UST, meaning Universal System

Tubeless and  is the same principle as the modern day car tyre using the wheel rim and with beading on the tyre edge to make a seal and hold air pressure. No tube is use or installed, only a tyre fitted onto the wheel rim and then inflated.

It is strongly recommended but not strictly essential, to use specifically designed wheels (often termed 2 way fit), tyres (often decaled as Tubeless Ready), valves and sealant.

The tubular ready wheels have precise, machined rims with tight tolerances and the tubular tyres have beads (meaning the two edges of the tyre) that hook tightly under the Two Way Fit wheel rim to ensure an airtight seal.

A separate valve is fitted through the valve hole in the rim and should be locked in place. These valves usually have a removable valve core and this is often removed to allow latex sealant to be poured into the tyre but it is not necessary as the sealant can be inserted from elsewhere.

The tyre has to be rapidly inflated to effect a seal between the wheel rim and the valve and the wheel rim and the tyre.

 

ADVANTAGES:         

Can be a slightly lighter wheel / tyre combination compared to a    tubed wheel. Many factors control the weight such as tyre choice, rim tape, if used, and wheel weight

Risk of Snakebite punctures totally eliminated

Overall risk of punctures greatly reduced

Rolling resistance greatly improved as there is no friction build up due to there being no inner tube therefore increased wheel speed is possible

Use of fibre impregnated latex liquid in the wheel well helps the tyre to stay sealed as the latex will instantly block any small holes that may develop in the tyre by flocculating at the hole where air starts to escape

Tyres can be run at very low pressures compared to tubs or tubed systems, 5 or 5.5 bar is common for road bikes and this puts more rubber contact on the road although it is argued that this may slow road speed

Road vibrations very much reduced

 

DISADVANTAGES:      

Requires a greater degree of technical know-how to successfully install and inflate 

Latex liquid, whilst not essential, should be used to reduce chance of roadside punctures

Tyre needs to be rapidly inflated either by using a compressor, charge pump or CO2 cartridges therefore unless rider is fully competent and assured, even using CO2 cartridges and particularly at the roadside has a medium to high risk of failure to inflate

Spare inner tubes must be carried so that in the event of a puncture the wheel can be converted to a tubed system

Latex liquid should be replaced every 3 or 4 months, is awkward to work with, can be expensive and does slightly add to the overall weight of the wheel 

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(c) mjr ALBA2017