World records are such grist to the mill of Hope Technology that co-founder Ian Weatherill had forgotten that Bradley Wiggins’ recent triumph was his company’s second successful assault on The Hour.
Turn the clock back 15 years (or two, if you want to broaden the sphere of Hope’s accomplishments to include Guy Martin’s British speed record) and it was Mike Burrows placing a call to Lancashire on behalf of a rider called Chris Boardman.
“I couldn’t remember that,” Weatherill chuckles. “It was one of the lads who works for us who said, ‘I put those bottom brackets together for Boardman.’ I said, ‘Did you?’ He said, ‘Mike Burrows had four sets: four different bottom brackets.’”
For lesser outfits, commissions such as the BB for Boardman’s career-closing tilt at Merckx’s 1972 record might stick in the memory. Not so Hope.
“It’s ironic, really: we keep getting involved with these speed records. We did the Boardman one, the Guy Martin one, and now Wiggins. It’s a small world and there are not many people in Britain who make things, are there?”
Weatherill concludes his statement with a bitter chuckle. He makes little attempt to disguise his contempt for British firms who claim that Far Eastern manufacture is the only financially viable model, or worse still, that it is the only place where the required engineering skills still exist.
Words are one things, but deeds are another, which is precisely why Hope is engaged in producing a range of carbon cycle products at its vast and spotless facility in Barnoldswick.
The endeavour has brought them into contact with Pinarello, and it was a source from inside the Italian marque who asked Weatherill if Hope would manufacture the chainrings for Wiggins’ Bolide HR. No problem.
Weatherill recalls the first drawings received from Wiggins’ people as depicting a “spindly” design with lots of “pockets” in the rings: material cut away in the name of weight saving.
This specification changed rapidly and drastically. Immediately after Hope had made three “spindly” rings, a second drawing arrived at Barnoldswick. “Straight away we got a drawing back saying, ‘We’re going to make them solid for aerodynamics.’”
Weatherill and co-founder Simon Sharp are engineers of some pedigree. You do not work for 15 years as a toolmaker at Rolls Royce without knowing something about precision engineering. Little surprise then that they set their own toolmakers to work on the Wiggins’ commission: the men who, in Weatherill’s words, make the jigs and fixtures; the “one-offs”.
“We had the most skilled engineers that we have on it: the specialists,” he says, in a matter-of-fact tone. “Any prototypes that we make, we have them doing it.”
Hope’s toolmakers set to work on Pinarello’s revised design: a solid chainring, cut by laser from a sheet of 7075 aluminium, a high-quality, lightweight grade, typically used for aerospace applications and known for its hardness. Critically, the surface of each ring was left uncoated, where for standard commissions, Hope would apply an anodized finish.
Feed me slowly
It would be accurate, but misleading to describe the finish of the chainrings produced for Wiggins as raw. “The surface finish is absolutely perfect,” Weatherill says. He is not boasting, but speaking in engineering terms. His frame of reference is function, rather than aesthetics.
Hope had slowed the “feed” – the speed at which the milling cutter moves around the tooth profile – to eliminate even the smallest chance of deflection.
“It’s cutting every little bit,” Weatherill explains. “It’s a high quality finish. You don’t want any peaks and troughs. You want it absolutely smooth. You cut aluminium at high speeds, but not necessarily high feed rates.” Hope’s three-axis milling cutter operates at 13,000rpm.
“With something that’s been profiled, you can see the teeth marks, the swirls, where the cutter has been across it. There are peaks and troughs in the surface finish. If they’re closer together, it gives you a really fine finish. There’s less chance of friction.”
The elimination of any possible source of friction from Wiggins’ drivetrain played a crucial role in his successful record attempt, and clearly was no less a concern for Hope than it was for Muc-Off, working 300 miles away in Dorset on the chain.
“In theory, the chain takes it away,” Weatherill says of any minor imperfection left from the milling process. The chain’s sideplates and roller are in contact with the teeth, however, and with a task as serious as the Hour Record, must suffer no impediment.
“Sprockets [chainrings] are ‘punched out’ You don’t normally CNC machine them, which is perfectly ok for your normal person, but when it comes to this [the Hour Record], it’s absolutely critical.”
The net result of such precise machining was to create a perfectly smooth, perfectly flat chaining. This last quality had a direct impact on the interaction with the bottom bracket and the frame: another area defined in the case of Wiggins’ machine by minute tolerances.
“Minuscule things can make a massive difference. Imagine if the chainring moved from side-to-side, and you’ve got that for an hour, he could lose distance. It’s so critical. It [the chainring] was machined perfectly true.”
The tooth profile might be considered still more important, and was the same employed for the two 60-tooth rings used by Guy Martin to reach a British absolute speed record of 112mph, but Weatherill makes no great claims for the shape.
“I’d love to say there’s something absolutely amazing about it, but it’s just a fairly standard tooth profile that we used. It’s just making sure the tooth is the right shape. If you get the pitch of the teeth out, it could be stretching the chain all the time, and energy can be lost in that.
“You want a perfect pitch, so you don’t get any extra strain on the chain. There’s enough strain from the rider, without the sprocket [chainring] being wrong. It’s got to be spot on. It’s CNC-machined, so it’s a very accurately machined profile.”
Such precision engineering might be thought to have eliminated any last-minute hitches, but one factor proved beyond the control of Hope’s sophisticated machinery, and even beyond Wiggins and his inner circle of coaches and engineers – atmospheric pressure.
“We did three 61s, three 60s, and three 59s,” Weatherill remembers. “We did them very quickly, working through the night to produce them. We shipped them down, and then the Wednesday before the attempt, they were testing, and they contacted us and said, ‘Can you make us some 58s? The air pressure’s changed.’”
Hope’s toolmakers worked through another night and the newly minted 58-tooth rings were shipped to Wiggins without delay. The change in barometric pressure was widely blamed for limiting Wiggins to “just” 54.526km.
Weatherill wonders whether Wiggins’ comparative difficulties with air pressure might inspire Alex Dowsett, briefly the record holder after setting a mark of 52.937km last month, to make another attempt.
Weatherill, watching from the stands with his wife Tracy as a guest of Pinarello, greeted the new record with a mingled sense of pride and relief.
“We’re quite proud, but you also think if the chain drops off, you’ve got to panic very quickly,” Weatherill chuckles. “The pressure for everything to be perfect is phenomenal. When it all finished, it was a case of, ‘Thank goodness for that.’”
Dowsett’s clothing supplier Endura, who worked with aerodynamicist Simon Smart to produce 57 iterations of the skinsuit he wore in Manchester, believe they have more to offer him, should he be so inclined.
The recent assaults on the Hour Record by British riders has inspired some fine British craftsmen, whether it be Hope, Muc-Off, or even Rapha’s couturier, carefully stitching pre-embroidered numbers from Hand and Lock, lacemen to the royal household since 1767, to the ceremonial jacket he wore in the immediate aftermath of his successful attempt. Little wonder then that Weatherill’s phone rang when chainrings were required.