Is bigger faster? New thoughts on road speed

Do bigger wheels make you faster? If you’re a mountain biker there is no doubt that 29ers are much, much quicker. So much so that I really ought not be too proud of my Strava records as, without much effort, I am bound to be quick with the bigger wheels. So hats off to you guys still riding 26ers. But what about the road? Traditionally the thought was that smaller was faster. 23mm being standard and some TT boys opting for 20mm front and 22 rear. Small, light and hard. But could bigger be better. Sometimes convention wins over science.

Continental GP400s being made
Continental GP400s being made

Last week I was lucky enough to be invited to Continental’s plant in Korbach, Germany. IMG_8450 The tour began with a technical presentation and lo and behold they said that the science proved that bigger is better and that the pros are changing over. 25s as standard and 28s for the Roubaix. We’ll have to wait and see if they do. Anything to make me quicker, I thought that I’d give them a try so I got myself a pair of Grand Prix 4000s with Black Chilli and road then today. First problem, easily over come, they didn’t fit under my mudguards. I removed them and pumped the tyres up to 120tpi. They looked massive. Remember the first time that you saw a 29er?

GP4000s 25mm - think I need new bar tape
GP4000s 25mm – think I need new bar tape

I have also changed my cassette to an 11-23. I have not been having a problem climbing and thought that I’d get away without a 25. My brother has just bought a Scott Foil 30 with a 53/39 so I thought that I’d need an extra gear at the top end to keep up with him on descents. My 50/11 is actually bigger than his 53/12. All I need now are the legs to push it.

Ouch! Bike, tights and skin scraped
Ouch! Bike, tights and skin scraped

Today’s ride was relatively gentle as we are nursing a buddy back to fitness after a very nasty fracture of his leg so I can’t report that I was faster. I did, however, find the climbs easy despite not having the lower gear, the 25mm extra volume was really comfortable and the Black Chilli kept me upright. Joe, on his brand new Foil, went down. You could blame the wet road, the mud but more likely was his over excitement with a new bike combined with lesser tyres than he is used to. If you wonder why riders are happy to pay over £40 for road rubber it is because when you only have 23mm of tyre and probably only 15mm in contact with the road you need the best rubber you can buy.

Cento Uno covered in mud
Cento Uno covered in mud and with big tyres

On our return to Worthing we met a bunch of mountain bikers road riding. They had less mud on their bikes and bodies than we did after our ride north of the Downs.

Here’s the ride, short and sweet in freezing mist north of Downs and glorious, warm sunshine south of Downs. Strava

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