Quite hard to find in the market: a 650c racing bike. Who needs this size of wheels? People who are not tall. And to build a custom bike, 650c wheels can be a choice. But there are some pros and cons, mainly given by the availability on the market of wheelset and components linked to them. So let’s see some pros and cons of this particular size of wheels.
First of all: what are 650c wheels? These are the 26 “wheels for racing bikes. Attention, they should not be confused with the 26 mtb wheels or the 26 wheels of a city bike! All these types of wheels are commonly called “26”, but they have different diameters. In fact, while the 26 mtb bikes have a diameter of 559mm, the 26 race bikes – the 650c – have a diameter of 571mm. The 26 “city bikes, on the other hand, have a diameter of 584mm. These measures make them incompatible with each other for changing tires and inner tubes, but also for positioning the brake pads.
Rolling Resistance
Wheel Rolling resistance is determined by the amount of energy required to overcome the friction between the tire and the ground. It is often erroneously generalized that narrower tires reduce rolling resistance. In reality, rolling resistance has more to do with the consistency of a tire’s contact patch with the ground. Spreading the impact over a larger contact area reduces the tire’s momentum and thus reduces rolling resistance. Since 700c wheels have more extended ground contact zones than 650c, they usually have slightly lower rolling resistance. Likewise, very narrow tires may have higher rolling resistance than slightly wider tires because narrower tires have less rubber in contact with the ground and therefore are unable to absorb shocks and other road imperfections.
Acceleration and climbing on 650c
650c wheels are smaller and therefore lighter on the outside of the circumference. This is the most crucial topic that can give the best sensations when using a more reactive and snappy wheel. These wheels are therefore to be considered more responsive. Not only. This quality translates into a better ability to climb hills. For example, this was one of the big problems when mountain biking ditched 26 “wheels to 29”. In that case, the overall benefits far outweighed the issues plagued by the loss of performance on the climbs. However, the fact remains that a smaller wheel performs better uphill.
Tony Rominger obtained a historical win on Passo Selvino at Giro d’Italia 1995 with 650c wheels
Tyres availability
The 650c wheels are not in great demand. This also creates a shortage in the market of related spare parts and components. As for tires, for example. The choice of tires to mount on the 560c wheels is quite limited. For instance, we will almost exclusively find widths of 23 mm. Moreover, it will be challenging to find anti-puncture or super light inner tubes. In short, this choice requires a dose of adaptation.
External look and proportions
It is undeniable that a short person can be ungainly seen pedalling on a too-large bike. The construction of a custom frame with classic 28″ wheels helps a lot. But sometimes it is not enough. Then the 650c wheels are necessary. Not really for bike fitting, perhaps also reachable with 28″ wheels, but rather for the general look of the cyclist seen on his bike. And we cannot deny that the look has its importance when pedalling.
