Factory Road Disc Wheelset Guide
How are Road Disc Wheelsets Different?
Wheelsets for disc brake bikes have specifically designed hubs which feature mounts for rotors to be fitted to enable the wheels to be slowed down under braking. Wheels for road and gravel disc brake bikes have ‘beefed up’ 12mm diameter thru axles (instead of traditional 9mm diameter quick release) and fit either 6 bolt or centrelock disc rotors. Bolt through axles add structural strength to the connection between the wheels and the frameset. Aside from the ability to mount rotors, disc wheels have a couple for key differences to rim brake road wheels. Because disc calipers are potentially powerful and are mounted near the hub, disc wheelsets often feature more spokes to cope with the twisting forces encountered under heavy braking. However, the weight of the extra spokes is compensated through disc specific rims being made lighter and stronger because they don’t need a brake track. As with rim brake wheelsets, wheels play a large role in how the bike reforms, this is especially the case with road bike wheelsets as road bikes are lighter, more responsive and the effects of wheels are more noticeable. Whether you are looking for a direct replacement wheelset or an upgrade, this guide will help you make the choice.
Bicycle wheels contains the same three components that they have always had; Rims, Spokes and Hubs.
Most wheel rims are made from aluminium. Rim width has increased in recent times with the move towards wider tyres (25-28mm) on road bikes. Deeper section rims tend to be made from carbon fibre, this is because they require extra material for the deep aero profile, and carbon is lighter than aluminum. However, carbon rims are more expensive to produce. One great feature of disc wheel rims is that they do not effect braking, even if they are badly damaged and very buckled, reassuring if they are damaged out in the wilds, with a long ride home.
Stainless steel spokes are strong and can be made thin and aerodynamic, they are ideal for most bike wheels because of the material’s axial load strength. Spokes come in different lengths to match different hub and rim depths. Most spokes have a curve where they fit at the hub end, straight pull spokes do away with the curve and slot into specific straight-pull hubs. Less spokes usually means lighter wheels and better aerodynamics, however with disc wheelsets, a stronger wheel to combat twisting forces under braking is also important.
Sealed bearing hubs offer fit and forget performance, however for longer term use, Shimano cup and cone bearings are great because they can be cleaned and repacked with grease or replaced. The best hubs are ones you don’t take any notice of they just keep doing their job. Disc wheelsets have either 6 bolt or centrelock mounting for rotors.
Different types of Wheelsets
Wheels which come fitted on new bikes tend to be the most upgraded part. It’s not so much that these wheels are substandard necessarily, but improvements with wheels have the largest effect in performance, in terms of speed and feel, for the money spent.
Lighter wheels will allow faster climbing and acceleration.
Stiffer wheels will feel faster and inspire fast predictable cornering.
Aero wheels will hold higher speed on fast, flat sections.
In an ideal world a mixture of these attributes will make for a great all-rounder set of performance wheels. As well as the above broad types of wheels, there are yet more variables with regards to tyre fit.
Most wheels are clinchers. The tyre and separate inner-tube combination offers reasonable performance and ease of use. Punctures are relatively easy to repair or replace with new inner-tubes, which are easy to source. Lightweight tyres and tubes can offer a high level of performance, while not being too expensive.
The ‘new kid on the block’ tubeless wheels & tyres are becoming popular. They look very similar to clincher wheels, however, they work without inner tubes. The tyre forms an airtight seal to the inner rim, spoke holes and valves need to be airtight. Tubeless sealant gets forced with air pressure into tiny gaps to make the seal complete. Extra sealant in the tyre allows the tubeless set up to do their ‘party trick’ and self-heel punctures. Sealant does need topping up over time as it does dry out.
Tubular wheels / tyres offer the highest level of performance. The inner tube is stitched into the tyre – in one complete unit, they are then stuck onto the rim using special glue or tape. Tubular wheels are often lighter, because they don’t need the extra material on the outer rim (like clinchers and Tubeless do) While tubular wheels & tyres offer the highest level of performance, they are not easy to live with. Fixing tubulars requires a lot of skill and time. Swapping a punctured tubular also takes a lot longer than clincher or tubeless.
Which wheelset should I Buy?
Low-cost, solid and reliable wheelset for road or gravel tracks Even lower cost clincher wheels, featuring an aluminium rim and healthy number of spokes should keep you rolling nicely. Merlin GDA-1 Wheelset is a great example of this type of wheelset, featuring 32 spokes, 25mm wide rims and reliable Shimano hubs, they are built tough for gravel roads. Entry level wheels when matched with tougher tyres such as Continental Gatorskins, can be a great combination for puncture-free commutes and training.
Comfort, longer road or gravel rides A reliable, lighter aluminium wheelset for example the Fulcrum Racing 500 DB. This offers lower weight (under 1700g Pair) and a 25mm wide rim, this combined with a wider 25mm or 28mm tyre can offer high levels of comfort on a lighter, more agile wheelset on the road or gravel tracks. A lighter, more comfortable wheelset will enable you to complete longer rides or sportives, and can even help ‘smooth out’ rougher roads.
Fast riding and racing Aero wheels, featuring carbon rims, provide high level performance and are ideal for keeping for that special race / ride day. Deeper aero wheels usually feature high performance hubs, often with sealed bearings. Aero wheels are available featuring tubular, tubeless or clincher tyres, depending on your preference.
Road Disc Wheelset Nitty Gritty
The freehub body screws into the body of the rear hub and allows the cassette to be mounted. There are two fitting types for road wheels, Shimano / Sram and Campagnolo.
There are two alternative rotor mounting types, Centerlock and 6 Bolt.
Valve Extenders need to be used with deeper rimmed wheels. The extenders screw into the valve core, making it longer to allow enough length to attach a pump onto the tyres.
Rim tapes cover up the spoke holes on the inside of the rim. On tubeless rims, rim tapes seal the rim, blocking the spoke holes much tighter to allow for the perfect seal for the tubeless tyre.
Thru Axles generally come with framesets / bikes and allow for the easy fitting and removal of disc brake wheelsets.
Spoke Key is a little tool which can work wonders in the right hands, it is used for truing wheels.