Not since the Lotus 108 carried Chris Boardman to Olympic success way back in 1992 have I clapped eyes on a more radical-looking bike. The new HB.T has been designed by British Cycling and manufactured jointly by Hope Technology and Lotus with Renishaw contributing 3D printed titanium parts, and is the not-so-secret weapon that British Cycling hopes will win many gold medals at the 2020 Tokyo Olympics.
- Bike at Bedtime: Chris Boardman’s legendary Lotus Type 108 track bike
We visited Hope Technology in Barnoldswick back in 2019 to see the bike in the flesh and speak to the people responsible for bringing this extreme design to reality, why it looks the way it does and manufacturing challenges.
- Great Britain’s £15k Lotus/Hope track bike debuts at UCI Track World Cup event
- The Lotus track bike is back! Hope Technology develops new Team GB track bike for 2020 Olympics
Best of British
It’s called the HB.T and is the result of a collaboration between Hope Technology and Lotus Engineering with support from Renishaw, three British companies combining to provide the best possible equipment for the British track squad.
You all know the Lotus name of course. A car company best known for making lightweight and aerodynamic sports cars and has dabbled in F1 in the past. Founder Colin Chapman was famous for his focus on lightweight, with “adding lightness” his motto.
Hope Technology will be a familiar name to mountain bikers, it has been making disc brakes, hubs and bottom brackets for the past 20 years or so, all CNC machined from aluminium. A few years ago Hope decided to invest in carbon fibre, first debuting a handlebar and seat post, then more boldly it has built two mountain bikes from carbon.
British Cycling has been pushing the tech developments very aggressively in the past decade and the margins for improvement get smaller and smaller. It has already been here before of course, as far back as 2002 Team GB have been riding bikes designed and developed by the UK Sports Institute (UKSI) lead by Dimitris Katsanis, a highly renowned composites expert. These bikes were used in Beijing in 2008 and London in 2012, before the switch to Cervelo for Rio 2016.
Let’s start at the front, and this is where Lotus has been involved, hence the stickers on the fork and handlebars.
A bike can be extremely aerodynamic on its own, but put a rider on it and that all changes. The rider makes up about 80% of the drag, but while the top half of the body is relatively air to make aerodynamic with a skin suit, helmet and crouched position, legs spinning furiously at 150rpm is another matter.
The big focus with the bike has been to manage air around the rider's legs to reduce drag, as Sam Pendred, Design Engineer at Hope Technology explains.
“The whole ides of the bike is that instead of designing an aerodynamic bike, the idea was to have the bike and rider as a unit,” he explains. “You can design a very aerodynamic bike, but the rider is the main problem, once he’s on the bike that’s the main issue for aerodynamics so if you design the bike with a rider as a whole unit you can come to some different conclusions regarding the best way to design the tube profiles and the best way to locate the tubes around the bike. So if you have a rider on the bike you can place the fork and seat stays effectively in line with the rider's legs to help channel air better around something that has to be there anyway.”
They’re trying to push the air out around the rider's legs. Putting the fork blades and the seat stays in line with the rider's legs helps to manage the airflow around them, thus reducing drag.
“If you take a frontal view of the bike you can see that the fork and seat stays are in line with the rider's legs as they are pedalling, so it helps to channel the air effectively around the rider's legs, which obviously have to be there anyway, so it can be very beneficial,” adds Sam.
Normally the fork blades would be very close to the wheel to reduce frontal surface area, but we have seen a move towards fork blades sitting further away from the wheel to reduce turbulent air.
The design is claimed to reduce drag by up to 3% compared to a conventional bike. That might not sound like much, but when races are won and lost by milliseconds, 3% could make a huge difference.
What about the rules?
You’d think the UCI would have a heartache with the design but the small UCI sticker on the seat tube shows the design has been approved by the UCI. The organisation has a thick rulebook governing the design of bikes with strict parameters that all aspects of the bike must fall within. The approval process is a key element of designing a bike but Sam Pendred says they worked closely with the UCI and got approval on the first submission.
“It conforms to all the regulations set out by the UCI and the change from a ratio of the tube profile, with for example the fork blades and seat stays, to change to minimum dimensions and maximum dimensions have helped allow the design of the profiles of the seat stays and fork,” he explains. “And then obviously the width of them is the main difference but it all fits in the overall regulations that are specified by the UCI. We have been in contact with them obviously through the design of the bike and making sure we weren’t going to fall over any hurdles. We’ve worked quite closely with them and had a good relationship to make sure this bike can be approved.”
“So we actually got approval with our first submission. We’d obviously done a lot of work regarding the regulations to make sure they were followed to have the best chance of approval, but yes on first submission, it got approved.”
- What does the UCI sticker on your bike actually mean?
It does beg the question of why no other bike designer has come up with anything as extreme as this new track bike. Will it open the floodgates to imitations? It might well do but it’s unlikely any nation will have time to design, manufacture and seek approval of a bike and have it raced to qualify for the 2020 Tokyo Olympics.
Making the bike
The manufacturing of the carbon frame is done by Hope Technology and the project has been led by Chris Clark, a composite engineer who was involved with the original British Cycling designed track bikes.
Hope manufactures the frames in-house while Renishaw, a British company that specialises in additive manufacturing, supplies the 3D printed titanium lugs that join the seat stays to the mainframe, which is made as one piece out of a single mould. Lotus Engineering meanwhile manufacturers the carbon fibre fork and the titanium handlebar, and the final bike is assembled by Hope.
To look at the bike you’d think it would be a manufacturing nightmare with some elaborate shapes and intricate details, and Sam admits there were challenges making the bike for a company with so little experience working with carbon fibre compared to its 30 years of CNC machining aluminium components.
“For us, there was always going to be challenges because it’s not something we’ve done before. We’d only ever manufactured carbon mountain bike frames as well as some of our other carbon products. But the fact it’s a track bike, it’s using different types of carbon compared to what we’re currently using, and the fact we had to mould the chainstays into the frame as one piece, it revealed itself as a different challenge to what we were currently facing,” says Sam.
“But we had the capability to manufacture our own moulds, actually before the design was confirmed we had manufactured our own test mould and developed our own manufacturing method before we actually went into production to make sure we had the capabilities to produce this bike. So yes there have been challenges along the way but I think having the capabilities we do here, and the facility we have to work in, it enables us to be flexible and overcome challenges quite readily.
Hope’s real ace card was the fact it’s able to CNC machine its own moulds in-house, thus enabling complete control over the entire process and for rapid changes to be made relatively easily and cheaply, as Sam explains.
“The mould is a very complex piece to actually produce for that frame so the fact we can machine them ourselves and we know regarding the design what certain things can be done and certain things can’t be done, and different ways we can get around problems, such as sharp corners for example, but having that capability and having the experience we have here of mould manufacture, it’s allowed us to firstly make moulds of all different sizes to give a lot more flexibility with frames, but it’s also the experience coming through allowed us to make this frame effectively.”
Making a carbon fibre frame isn’t a quick process though, with countless hours required to first produce the moulds and then each frame. We were fortunate to witness a frame being made with the first sheets of carbon fibre being carefully placed into the mould with the sort of precision you would expect for a bike to be used in the Olympics.
“There’s a lot of work that actually goes into it, a lot of man-hours total, it’s a long careful process we have to go through,” explains Sam when asked how long the process takes. “For the mould alone there’s a week or two of machining and converting the actual aluminium billet we order in, to getting the mould created. Then laying up the frame as well is probably about 20 man-hours, that actually go into laying the carbon fibre pieces into the mould, followed by a cycle of curing, and that’s just to get the carbon frame out of the mould. Then there’s the finishing that goes into it, all the bonding for the seat post sleeve and the bottom bracket.”
The frame is beautifully made. With no paint to add weight the quality of workmanship is clear to see. A key part of the manufacturing process we discover from our visit is a desire to ensure as little post-manufacturing work is required, not only to save time but also to ensure the highest quality goals are met in the production. We see carbon mountain bike frames and handlebars being popped out of moulds and the work is incredibly neat with little obvious finishing required.
It’s one thing to design and aerodynamic bike, but it also needs to be stiff and strong enough to withstand the immense power the track racers can produce. Balancing the stiffness and weight of the frame was a key focus as Sam explains.
“Obviously with a very different look design and different tube shapes and profiles it’s all new and you want to have a frame that performs as well as a more conventional one,” he says. “So stiffness and weight obviously come into it regarding performance, so it was worked on and developed so we could achieve the aerodynamic properties that this frame gives us, but also a stiff frame and the lightest possible weight we could make it. So through the use of different fibres, 90% of the bike is made from high-modulus unidirectional fibres so specifically choosing the type of fibres that we use mean we can increase stiffness and reduce weight. So there was a lot of work that actually went into developing that to ensure that all the parameters for performance were met.”
3D printed titanium
Carbon fibre is a wonderful material, but it has its limits. For complex parts of the bike 3D printed titanium has been used. They have been developed by additive manufacturing company Renishaw, who have some experience in the bike world and you might have heard their name before. They’ve been involved with Empire, Robot Bike Co, Atherton Bikes and Reynolds to name a few.
These 3D printed parts are bonded to the carbon structure at the dropouts and where the fork and seat stays connect the mainframe. The 3D printing process allows the creation of very complex parts with weight and stiffness benefits that would be difficult or impossible to achieve in carbon fibre or machining metal. It’s an advantage that Sam says allows them to make the best possible frame.
“The 3D printed titanium pieces are done elsewhere and they are shipped to us to create the frame as an assembly,” Sam explains. “We do this because of the advantage you get with 3D printing. You can have complex shapes and structures, such as the junction between the seat tube and seat stays, it could be inherently a difficult part to manufacture in carbon or machined aluminium. So you can 3D print to easily achieve complex parts with internal structures so we can reduce the weight and get a better part. We chose this route to then bond them to the carbon parts to provide us with the best possible frame we could make.”
There are wheels too
Hope hasn’t just manufactured the carbon fibre frame, it has also manufactured the wheels, for which it has developed a new process to mould each element as a single piece in one mould.
“We’ve actually developed our own new manufacturing process to manufacture the wheels and what we’ve tried to do is, with a lot of our products here we want them to come out of the mould as finished as possible,” Sam explains. “So it obviously reduces post-processing, and it reduces more inherent errors that you can gain from the more processes you apply to a product. So we’ve developed a process where we can make the disc wheel as one monocoque, one continuous part.
“Normally you have to make it in separate pieces and then they are bonded together. So the advantage of this is you’ve got a more structurally sound part because it’s a continuous piece and you’re not having to rely on any adhesives. You can also reduce the weight that is put in from the adhesive which when you’re talking about very light parts anyway, it can actually be a significant addition to the weight of the overall part.”
Typically a carbon disc wheels is made by bonding the two carbon halves, rim and hub shells together, but Hope has developed a mould that produces the entire wheel in one go, producing a carbon monocoque structure. The benefits of this are lower weight, better strength and a rounder wheel.
And you could own one
The new bike has already been pressed into action at UCI Track World Cup events, to meet the UCI’s requirement that any bike intended to be raced at the Olympics next year has to been rolled out before the end of 2019.
That does mean the whole world has seen British Cycling’s new bike but we’ve not seen any other nation respond with anything as dramatic or radical.
Another key UCI rule is that any equipment used by professional racing cyclists is available to buy. Previously the UK Sports Institute track bikes were technically available to purchase, but it’s not like you could walk into your local bike shop and swing a leg over once.
“The frame is currently in production and the majority of them are being made for the Tokyo Olympics, but the general public can place orders from January 1st, which will be made to order, so anybody interested can get in touch directly with Hope and orders can be placed ready for manufacture,” explains Sam.
It’s impossible to predict just how much demand there will be for this bike, and production capacity will be an issue. The company is currently flat out making the 30-40 frames required for the British Cycling team before any customer frames will be delivered. But, it’s not impossible to perhaps envisage other nations turning up to the Tokyo Olympics on the Hope track bike.
Asked if this track bike project will lead to the development of a new line of road bikes to complement its current mountain bike range, Sam says it’s within the realms of possibility.
“I think taking on this project especially with the majority of people here being involved in riding and cycling and having the passion to actually produce something like this, it’s a logical progression for us to make and there are already being talks about different parts we could make, effectively using this as a springboard to help us develop more parts in that market,” he says.
As to whether the stunning bike is giving British Cycling athletes an advantage in the Olympics, we’ll just have to wait and see as the racing continues.
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