Shimano mechanical brake levers are now few and far between. The following is a summary of the current model lineup, specifications, and compatible components.
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What is TPU inner tube?
Until now, “butyl” has been the main material used for bicycle tire inner tubes for many years, followed by “latex,” which is lighter and more durable.
Then, in the last few years, “TPU (thermoplastic polyurethane elastomer)” emerged as the third force in bicycle inner tubes.
TPU is a type of plastic, so despite its high strength as a material, it has the elasticity of rubber such as butyl.
Advantages and disadvantages of using TPU inner tubes on road bikes and MTB
The advantages of using TPU inner tubes on road bikes and MTBs are as follows
- lighter weight
- high puncture resistance
- low rolling resistance
- high portability
The first thing that drew attention to TPU inner tubes was their lightness.
Normally, most inner tubes for road bike tires, even lightweight products, weigh around 100g, but most TPU inner tubes weigh around 40g. If used in the front and rear, the weight can be reduced by nearly 100g.
The next major advantage is portability. When using clincher tires, it is normal to carry a replacement inner tube in case of a puncture risk, but the problem is that they are bulky and become luggage.
TPU inner tubes are more than 70% smaller in volume than conventional inner tubes, making them so portable that two TPU inner tubes can be stored in the space of one butyl tube.
Although the TPU inner tube seems to have great advantages, it actually has quite a few disadvantages.
- high price
- weak against heat (some products cannot be used with rim brakes)
- quick deterioration over time (short life span)
- easy to lose air
The price is the biggest factor. Butyl inner tubes can be purchased for as little as $8 per tube, but TPU inner tubes are expensive, costing more than $30 per tube, with the most expensive costing more than $50.
Also, “heat sensitive” and “deteriorates quickly over time” are not to be overlooked. While TPU inner tubes are a strong material, they may not be suitable for use in rim brakes because of the material’s susceptibility to heat.
Polyurethane degrades and deteriorates quickly over time due to moisture and UV rays. Aging degradation of polyurethane depends on the product, but it is generally said to surface 2~3 years after manufacture (after the material, not the tube, is manufactured).
Therefore, although the TPU inner tube itself has high puncture resistance, depending on its operation, it may have the disadvantage of “becoming a tube with low puncture resistance” and a short life span as a tire tube due to aging deterioration.
In addition, if the product has been in stock for a long period of time, as in the case of long-term inventory, there is a risk that “deterioration may have begun at the time of purchase” due to the time that has passed since manufacture.
If you dislike frequent maintenance, you should not overlook the disadvantage of “easy air loss.” It is said that the ease of air loss in TPU inner tubes is similar to that of latex tubes, and it is possible to lose as much as 2 bar in one day.
It is good for those who adjust air pressure for each ride, but not suitable for those who “once inflated, want to ride without air to some extent”.
How should TPU inner tubes be used?
Use it for races and other “critical” situations
Considering the weakness of TPU inner tubes that they deteriorate quickly over time, it is best to use them in races, cycling events, and other situations where you aim to “reduce weight for the ride.
If it is a race, it will be over in a few hours or days at most, so if you replace the tubes with conventional tubes such as butyl after the race, you can ride without worrying about durability and fully enjoy the benefits of weight reduction.
Conversely, it is not really suitable for everyday riders who do not want to replace the tube as much as possible and want to use it for a longer life span.
Replace them reliably over a certain period of time.
It is normal to replace inner tubes on road bikes and MTBs “when you get a puncture” or “when you can no longer repair the tube”. If you don’t get a puncture, you may not replace it for a long period of time, and it is also normal to continue using the same tube for several years if a patch repair can be done.
As explained earlier, TPU inner tubes deteriorate over time and are not suitable for long-term operation like conventional inner tubes.
Therefore, when using a TPU inner tube on a road bike or MTB, it is best to “replace it once every six months or a year without fail”. However, since TPU inner tubes themselves are expensive and have a short lifespan, the running cost will increase compared to tubes made of butyl or other materials.
Major Manufacturers of TPU Inner Tubes for Road Bikes and MTB
The pioneering manufacturer that made TPU inner tubes famous is the emerging Austrian brand Tubolito. At the time of its release, Tubolito was the talk of the town with its vivid orange tubes and shockingly light weight.
Tubolito is not only reliable as the top runner in TPU inner tubes, but also has a wide choice of TPU inner tubes for road bikes and MTB respectively in its lineup. However, the price is high.
Tubolito’s TPU inner tubes can be used with rim brakes as well as disc brakes (some products are only for disc brakes).
Vittoria, a leading tire manufacturer, also produces a TPU inner tube called the “Ultra Light Speed Inner Tube.
The Ultra Light Speed Inner Tube is an ultra-lightweight tube weighing only 30 grams, but it is designed for disc brakes only to ensure safety.
Pirelli boasts the top grade performance in road bike tires with its “SmarTUBE” TPU inner tube lineup.
The “SmarTUBE” can also be used with rim brakes.
Schwalbe, the standard in budget tubes, also offers a TPU inner tube called “Aerothan” in its lineup. However, they are not as cheap as butyl inner tubes.
The Aerothan can also be used with rim brakes.
Magene, a Chinese manufacturer, has made a low-cost entry into the TPU inner tube industry, which used to have the disadvantage of being expensive, and now offers TPU inner tubes for about $10 per tube, the same price as lightweight butyl.
Magene’s TPU inner tubes can also be used with rim brakes.