How wide is too wide, is hookless pointless, are carbon spokes worth it and what aero innovations are coming next? We ask Parcours’ Dov Tate the big questions about road bike wheels

The dynamic British wheel brand talked to CW exclusively about a new study it's conducting on how to quantify aero wheel handling stability - the first of its kind - and we picked founder Dov Tate's brain about the other stuff, too

Parcours Chrono
(Image credit: Parcours )

“You’ve got to be more than just ‘faster’ because everybody is doing faster now,” says Dov Tate, the founder of UK wheel brand Parcours (opens in new tab)

“A wind tunnel will tell people how fast they will go but now we’re looking at a way to quantify how stable they are,” he continues. “But there’s no unit for handling stability. There is for drag. Most people understand what a watt of drag is. I want to be able to put a relatable figure on stability. Is a saving of 3.5 watts worth £1,000? But if it’s 3.5 watts plus 15% improved stability how does that change things? And what does that 15% feel like?"

A marine sensor fitted to a time trial bike fork leg

(Image credit: Parcours)

Three years ago Tate, an Oxford-educated engineering graduate, worked with Nottingham Trent University to develop a differential rim profile that he arrived at via real-world studies using marine wind sensors attached to the front and rear axles (opens in new tab)

Parcours was first to market with a wheelset - the Parcours Strade (opens in new tab) - that featured a wide, U-shaped front rim paired with a narrower, more V-shaped rear. His testing had shown that the ‘dirty’ air hit the rear wheel at an overall shallower angle compared with the front, in clean air, and the Strade was optimised using data collected with the marine sensors and validated in the wind tunnel.

Now, Tate has started working on what he believes will be the new crucial measurement for the best road bike wheels (opens in new tab) along with watt savings - handling stability. He talked to Cycling Weekly exclusively about how he plans to implement it. This time using accelerometers fitted to bikes with different wheels and wheel combinations and again tested in the real world, again with Dr Steve Faulkner and Nottingham Trent University’s sports engineering department.

Fitting an accelerometer to a time trial handlebar

(Image credit: Parcours)

“Essentially the way we tested it was to fit an accelerometer to the bike, fit the wheels that we’re testing and then ride an out and back with a controlled effort aiming to maintain power, speed, position. Runs are done back to back so in theory weather conditions should be close to the same and the idea is that if you run enough of the tests it normalises.

“We used just one on the edge of the handlebar because that's where you get the most motion. One of the biggest challenges with the accelerometry data was trying to squelch out the ‘noise’ from turns and bumps. It has taken a fair amount of time to get to that point. And we had to set a threshold so that an acceleration below a certain G-force doesn't count as an ‘oh sh** moment.”

Tate explains that alongside the data from the accelerometers the test riders were asked to fill in a questionnaire with a ‘perception scale’.

“The idea is that when you mark your perception you can score it numerically. The questions are designed to cross-check each other: how stable does the bike feel? You can cross check that by ‘how safe do you feel?’ and you can cross check that by ‘how much effort is needed to concentrate?'"

Two time triallists riding on a runway

(Image credit: Parcours)

When the testing is complete, the aim is to be able to accurately give riders options for a range of scenarios. “So a more nervous rider may choose to 'bank' the improved stability and keep with their existing front wheel, maintaining aero benefits. Whereas a more confident rider may choose to offset that improved stability and run a deeper/faster front wheel for the same level of stability,” Tate explains.

"From a design perspective, that means that we can potentially go a little further than say we have already with the Chrono Max front wheel and say that if paired with a Disc² rear we can 'afford' to reduce handling stability a little more without going too far for riders but with the option of a faster front wheel.  More than likely this would be deeper to be faster."

Course modelling for wheel choice

Parcours team looking at a laptop

(Image credit: Parcours)

Concurrently with the accelerometer testing, Parcours has been doing more testing with the marine wind sensors which could make up the other half of the picture - modelling courses and weather conditions that could in the future accurately give riders wheel options for a particular race.

Tate took the wind sensors to the Ironman World Championships in Hawaii last month and was able to demonstrate that wind conditions on Kona’s famous Queen K Highway almost exactly matched a flat ride to Windsor he did earlier in the year.

“We’ve been proving that we could rely on our existing data library to model roads that we've not been to,” says Tate.

The modelling of the course and the conditions, says Tate, come from the 75,000 data points taken by the wind sensors in the original project. 

“So we can say, let's take all of my data points and standardise it to a ride speed of 30kph. Or we can take all of our data points and standardise it to a 40kph wind speed. We can say to a rider, these are the yaw angles you'll be looking at and this is what you'll optimise [wheel choice] around and we can do that based on 75,000 data points from all sorts of different rides - so you can model a scenario that we've not tested.”