Your Guide to Buying Replacement Parts for a Racing Bike

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Your Guide to Buying Replacement Parts for a Racing Bike

Cycling has never been more popular. There is huge interest in races like the Tour de France and other elite cycling events, which has sparked a rise in popularity of cycling as a leisure activity and a healthy sport. For anyone wanting to emulate those top cyclists, it is vital to find the right racing bike. Equally important is to find a reliable source of replacement parts.. When shopping online, eBay can be an excellent source of replacement parts for a racing bike.

Technology and cycling

Technology is always making advancements, which means that what was current when the bike was bought may not be so state-of-the art now. That’s what makes an online buying site like eBay so valuable. A quick glance at eBay’s racing bike parts shows a vast array of options, from alternative saddles to handlebar grips and from Derailleur gearing to GPS systems..

One of the key factors, though, when buying spare parts for a racing bike, is to ensure the accessories are compatible with the racing bike. Those who have highly specified or state-of-the-art racing bikes might need specialist spares. It is also important to factor in the cost of buying replacement parts and accessories when initially budgeting for a racing bike.

Replacement Parts for Racing Bikes

The spare parts that are replaced most often, that are most subject to wear and that it is recommended are replaced frequently include chainsets, bottom brackets, brakes and Derailleur mechanisms. Replacing these items regularly is as much to do with safety as it is to do with the smooth running of the racing bike. These items can all be found in eBay’s bike parts category.


There are many chainsets available in bike stores and available online at eBay. But it is important to purchase the right one for the bike in question. A chainset is a unit that comprises the left and right crank arms, spider and chain rings.

The chainset forms part of the racing bike’s drive train. Choose smaller or larger sizes of chain ring, and the gearing will be affected. This is not necessarily a bad thing: for those who live in hilly areas, a more-compact chainset can reduce gear ratios and make those climbs less arduous.

Chainsets: Things to Bear in Mind

  • Number of Rings: Checking how many rings are required is vital. The answer can range from a single ring to a triple for most racing bikes.
  • Length of the Crank Arm: For those replacing the crank arm, length will need to be measured. The most popular lengths are 170, 172.5 and 175mm. Normal practice is to buy replacement cranks that are the same size as the originals.
  • Fitting the Replacement Chainset: The chainset will need to be fixed to the bottom bracket axle. Check that the bottom bracket and chainset fitting are compatible.
  • For old-school cranks, a cotter pin is used. On more-modern racing bikes, a squared-off taper fitting is used. It’s wise to note that not all tapers are compatible.
  • On the latest racing bike models, the bottom bracket axle and chainset can be integrated. The bottom bracket bearings can sometimes be found inside the frame, although they are usually in external bearing cups. This new form of chainset is light, robust, and offers great performance.

Chainsets Specifically for Road Racing Bikes

  • Standard Double: This is the standard set-up, with 42/52 and 53/39 the most popular.
  • Compact: The same as standard double but in smaller sizes, such as 50/34 or 48/36. This is for riders wanting to have lower gear ratios without altering other components.
  • Triple: Racing bikes often have a three-ring arrangement, with the inner ring offering low gearing for tackling steep slopes - 52/42/30 is the most popular set-up. Specific shifters and other parts might be needed, so a triple can be a tough replacement on a standard racing bike configuration. Check eBay’s listings for the specific part you need and don’t be afraid to ask questions of sellers.

Buying Replacement Bottom Brackets

The bottom bracket is a misnomer, since it is not a bracket. It connects the crankset to the racing bike and allows free rotation of the crankset.

Bottom Bracket Types

It is vital to understand the type of replacement bottom bracket required. They come in many different forms. 

Factors that should be borne in mind are the chainset brand – Shimano is the most common – the frame width, and axle length.

Bottom brackets also have different styles.

  • Cartridge Unit: This is a one-piece, sealed unit. When they need replacing, it’s not normally a difficult or expensive job.
  • Square Taper: Replacing a square-taper bottom bracket involves doing up the tightening bolt to force the crank arm onto the square taper.
  • Shimano Octalink: These bottom brackets have a large hollow axle and a spline with eight cutouts that intermesh with the crank-arm spline. This set up reduces stress on the crank arm. There is a version 1 and version 2, with the latter more often used in mountain bikes. The ISIS is a more standardised version of the Octalink that can be used by all manufacturers.
  • External: This is the state-of-the-art in bottom brackets for racing bikes. The axle here is divorced from the bottom bracket and is part of the crank, while the bearings fit onto the frame externally. It makes for a lightweight set-up in which cranks can be replaced swiftly using standard tools.

Buying Replacement Brakes

Brakes on racing bikes are without doubt the most important bike part where safety is concerned. Before they get too worn out, it is vital to replace them. There are generally two types of brake systems:

  • Rim brakes: the standard sort of brakes used by most racing bikes.
  • Disc brakes: Used for high-performance of heavy bikes that need a little more assistance when stopping.
  • Disc Brake Pads

These brake pads are designed to cope with the maximum stopping power that disc brakes generate. Brake pads for disc brakes tend to be brand-specific, so look for the recommended pads for your brand.

Rim Brake Pads

The V-Brake is the most common rim brake. They’re cost-effective, lightweight and need minimum maintenance. However, the rim as well as the pads tends to wear down. Pads can be simple and cheap to replace but rims are less so.

Most racing bikes use a caliper system that can be single or dual pivot. A dual pivot is very powerful, with both pads working together to stop the bike. Some use dual pivot for both sets of brakes; others use dual pivot for just the front set. Whichever is chosen, great stopping power is possible and they are practically maintenance free. Pads are simple to replace, with a cartridge system and it tends to be the rubber material that gets replaced, rather than the whole pad.

Buying Replacement Derailleurs

The Derailleur is the mechanism that helps riders shift between gears. Being low to the ground, they tend to be at the mercy of whatever the road throws up. This means they will need replacing regularly. Cycling stockists can help with advice, while plenty Derailleurs are available for online buying on eBay.

Front Mechanism

The front mechanism, or 'mech', moves the chain across the front chain rings, usually between just a few rings. This has a big effect on the gear ratio. The front mech could be the toughest buying decision on racing bikes, due to the number of sizes and varieties.

Buyers of front mechs will need to know whether the fitting is braze-on or band-on. With braze-on, the front mech is bolted straight onto a mounting plate that comes out of the bike seat tube. These are standard sizes, so buying the right type is simple.

With a band-on, there is a clamp around the seat tube. When choosing the size, it’s important to check the seat tube diameter accurately to get the size. Common sizes are 28.6mm, 31.6mm, and 34.9mm.

Rear Mechanisms

The rear mech controls rear-bike gear shifts and prevents the chain slipping. Racing bike rear mechs and off-road bike mechs differ, so always choose a rear mech that’s right for the type of use. The cage on racing bike mechs is short and light, unless there is a triple set-up.

It is important to know also which gear shifters the bike uses. The main candidates will be Shimano, Campagnolo or SRAM for racing bikes. When buying replacement rear mechs, it’s also important to count the number of sprockets on the freewheel – racing bikes can have as few as five or as many as 11. The number of teeth on the biggest sprocket should also be counted – it is advisable not to go beyond the capacity of the mech.

Another factor is the cage – the bit that hangs down – length, which can vary from one set-up to another. Use a long cage with a triple chainset and a short one for double road set-ups.

Find Replacement Racing Bike Parts on eBay

Before you place a bid on replacement racing bike parts on eBay, make sure you are aware of exactly what you need to buy. Do some research on the seller – check their feedback and familiarise yourself with how you’re protected by eBay and PayPal. Check the details in the racing bike parts listings and factor postage and packing into the price you are prepared to pay. If the item you’re buying is valuable, ensure the seller gets appropriate insurance.

Know the eBay Seller

It is up to you to do as much research on the eBay seller as possible before you commit to buying your replacement racing bike parts. Here are some questions to ask.

  • What sort of feedback rating does the seller have?
  • What is their sales history?
  • What do buyers say about their racing bike parts?
  • Does the seller offer money-back guarantees on racing bike parts?
  • What are the terms and conditions?


The type of replacement racing bike parts bought will depend on the type of bike and whether you want the same type of performance or better. Before buying any replacement racing bike part, investigate all the available options thoroughly and learn about the specific parts that are relevant to the bike in question.

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