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Bike Components

A bicycle is made of many small and large components. Some components require replacement due to wear and most components benefit from regular maintenance.

Understanding components can also help when ensuring a correct bicycle fit, choosing a new bike or upgrading an existing bike.

Tyres

Bicycle tyres are fall into several main categories and they all have their strengths and challenges.

The type of riding surface (road, gravel, mountain bike) has a significant influence on tyre choice. Rider confort and tyre maintenance are other major factors.

  • Clincher tyres that require an inner tube to hold the air pressure, used by the vast majority of cyclists.
  • Tubless tyres which use a thick bead on the edges of the tyre to create an air tight seal, use sealant to minimise the effect of punctures
  • Solid tyres that do not use air (no flat tyres)

For good road conditions, the performance of Clincher (inner tube) tyres is hard to beat, especially when using TPU inner tubes and the tyre is inflated to the correct manufacturer recommended pressure.

Riders seeking to use lower pressures, 75 PSI or lower, may find comfort benefits with Tubless tyres especially where roads are littered with potholes and very poor surfaces. Greater benefits of Tubless come with Gravel riding and rougher terrains.

Clincher tyres

The most commonly used tyre with a very long history of effective use.

If the tyre is punctured and the object breaches the inner tube, then the air will escape causing a 'flat tyre'.

Repair can be quickly achieved at the road side by replacing the inner tube or repairing it with a patch (use a patch suitable for the material of the inner tube).

Many models of clincher tyre include enhanced puncture protection within the tyre itself, e.g. thicker rubber or kevlar mesh embedded in the tyre.

Common Size Clincher Tyre ranges: 23C to 32C

Benefits

  • the most widely used tyre by a large margin
  • much simpler maintenance
  • lighter than tubless and solid tyres (especially when used with TPU inner tubes)

Challenges

  • incorrect tyre pressures lead to increased risk of puncture

Continental tyres mix performance with good puncture protection

Consider Grand Prix 5000 for hight performance. 4 Season if conditions are changable or often wet. Gaterskin for maximum puncture protection, sacrificing a little performance.

For club rides, any of these tyres would be suitable.

Tubuless tyres

A tubless tyre has no inner tube, instead relying on the tyre itself to keep in all the air.

A liquid sealant is added as the tyre is fitted to repair punctures whist the bike is riding. Small punctures should seal before too much air escapes, avoiding the need to stop for a repair.

If a larger puncture occurs that the sealant cannot fix, the rider will need to stop for a repair. A 'plug' can be inserted into the wheel to help the sealant completely block the hole, allowing the tyre to be fully inflated again.

Tubless tyres run at lower pressures (to avoid blowing off the wheel rim). A lower pressure can give a more comfortable ride. A lower pressure is less effective at flicking away flint and other sharp objects that cause punctures, but the sealant should hopefully compensate and keep the need for road-side repair.

Common Size tubless tyre ranges: 30C upward (only limited by the size a frame can support)

28C Tyres and smaller require too high a pressure for tubless

Benefits

  • run at lower pressures for comfort
  • automatically seal punctures (when sealant regularly maintained)

Challenges

  • slightly harder to remove and fit due to the thicker bead needed on the wheel
  • fitting tyres can be messy if the tyre doesn’t bed correctly when inflating
  • sealant can leak if tyres are deflated when travelling (airlines require tyres to be deflated
  • wheel balancing is harder with sealant in the tyres
  • sealant must be changed regularly to stop it from becoming hard
  • sealant will harden quicker if a bicycle is not regularly used (or sealant replaced more often)
  • require wheels that are designed for tubeless tyres

Tubless Compatible Vs Tubless Ready

Tubeless Ready wheels have a solid inner surface (no holes to access spoke nipple heads), with only one hole for the valve stem.

Tubless compatible wheels require tubless rim tape fitted. Using rim tape for clincher wheels on a tubless compatible wheel will result in air and sealant leaks once the tyre is inflated (quickly leading to a defalted tyre and broken rim tape)

Solid Airless Tyres

It can take more time to fit a solid tyre initially. Once fitted though, a solid tyre requires no work until the tyre is worn (about 8,000 km).

Benefits

  • never need to stop for a flat tyre
  • no maintenance once fitted (except cleaning them of course)
  • tyres seem to last a lot longer (not affected )
  • never need to carry a pump
  • excellent for commuting or touring as no maintenance is required

Constraints

  • a little more expensive (although prices have come down to near that of tubless)
  • tyres are very hard to remove without damaging them
  • may be difficult to replace a broken spoke if access inside the rim of the wheel is required
  • tyre stiffness cannot be adjusted (no air pressure to adjust), handling may feel different especially when accustom to a different air pressure (PSI)

Tannus Airless tyres are a modern 'solid' tyre that never goes flat. Tannus also has thick amour tyre inserts that prevent punctures.

Tannus Airless Tyres

Tannus tyres on Brompton for commuting

I have used Tannus tyres on a 6-speed Bromtop to regularly commute over 40km per day (20km each way). They have been very durable and work well in all conditions.

I took of my Brompton pump and left in in my bicycle spares draw.

Community Reviews

Derailleur pulley wheels

The rear derailleur arm contains two small pulley wheels that manage any excess chain length when in smaller diameter gear chain rings.

These pulley wheels are often referred to as "Jockey wheels".

A new derailleur typically uses black-coloured plastic (nylon/resin) pulley wheels with 11 teeth and typically weigh around 16 to 26 grams for a pair of wheels.

Shimano pulley wheels weight (estimates)

  • Dura-Ace RD-R9250 16g
  • Ultegra RD-R8150 22g
  • GRX RD-RX810 24g
  • 105 RD-5800 22g

For the majority of riders, the default pulley wheels are just fine and will last a long time (years, a decade or more).

Replacing with larger pulley wheels (usually the bottom wheel) with ceramic bearings can provide small performance improvements (several watts).

Why fit Custom pulley wheels

Many colours of wheel are available, making a visual enhancement to a bike (so long as you keep them clean).

The main benefit is smoother drivetrain performance when using wheels with larger number of teeth. The chain turns through a smaller angle which reduces friction as it traverse through the derailleur arm and on to the rear cassette. A larger pulley wheel should save a 1-3 watts of energy when peddling the bicycle.

Wheels with ceramic bearings should generate less friction, also saving a few watts of energy.

NOTE: very low cost pulley wheels that have ceramic bearings may not be any better than steel bearings, but they shouldn't be any worse.

Aluminium wheels should be more durable than plastic wheels, especially in terms of being hit by stones or other hard surfaces.

These wheels do not have a heavy load placed upon them, so wear should not be an issue so long as the wheels are kept clean. Mud and grit could increase abrasive wear of the wheels (just like it does on the chain).

Aluminium is typically used to keep the main body of the wheel light. It is unlikely there will be any weight saving, but there should not be a weight penalty either.

NOTE: regularly cleaning the drivetrain (chain, pulley wheels, rear cassette, front rings) will provided greater performance

Which pulley wheels

Most existing derailleur cages will fit 11 and 13 teeth pulley wheels.

NOTE: check if pulley wheels are for up to 11-speed drivetrain, or for 12-speed drive train (usually have thinner pulley wheels)

For larger "oversized" pulley wheels, check if the derailleur cage has chain stoppers. These are parts of the cage which prevent the chain moving off the pulley wheel.

Off-set pulley wheels can be used where chain stopers of a cage prevent a larger center axle pulley from fitting.

Alternative pulley wheel cages are available that are designed for 15T or greater pulley wheels.

AliExpress has several low cost options for replacement pulley wheels

For larger "oversized" pulley wheels, a new cage should be obtained (these usually include the pulley wheels.