My first bicycle love was mountain biking. Getting out in the woods and finding my people was hugely important as I was growing up and learning to navigate life. Lots of crashes and injuries, but the NHS (National Health Service in the UK) took good care of me and, fortunately, young bones heal pretty well.
Road cycling was another whole world, which I only had insight into each July when the Channel Four Tour de France daily half-hour coverage showed an intriguing vision of colour and speed, tactics, and technology. When I pieced together my first road bike, a Raleigh Record Sprint rescued from the garbage, I used the school workshop to build a set of aerobars so I could be like Greg Lemond. For a kid with no connections to the UK road cycling culture, it wasn’t clear that there were local clubs and races happening. So it wasn’t until I moved to Cambridge for university that I was offered the opportunity to race on pavement.
Cambridge University Cycling Club (CUCC) was at that time very time-trial-centric. I arrived with my basic road bike with clip-on aero bars, my one jersey from the mountain bike club, and no clue about anything. My first ever race on the road was the introductory 10-mile (16 km) time trial, where I recorded 23:50. Which, it turned out, was amongst the quickest of the ‘freshers’. Fast forward a few months, and I somehow found myself on the CUCC team time trial squad for the student championship 50 km race … still riding that road bike, but I at least had gained a skinsuit.
One of my teammates was recent cycling convert (and now cycling author and commentator) Michael Hutchinson, who would go on to be the winningest time triallist ever in the UK; at that time I could still trade turns with him. No-one, including him, yet knew how good he was.
Finding the time trial scene
Thus began my journey into testing (the British parlance for time trialling, ‘tester’ was at that time the somewhat derogatory term that road racers would use). Later that first year I would use some scholarship money and some bike shop labour trade to buy a Scott Waimea – a 650C-wheeled triathlon bike (at that time there were not many production time trial bikes around). It was immediately faster. Then came my first aero helmet, multiple different handlebar/stem setups, disc wheel covers, borrowed four-spoke wheels, and even ditching the front derailleur by going to a 1×8 drivetrain.
One of the beautiful things about the British TT scene is the sheer quantity of events. I would typically race around 50 time trials a year – at least one mid-week evening event, then one or two every weekend. Which gives a lot of time for trying to figure out how to go faster!
I was a regular top-10 finisher, but rarely a winner for those years. Looking back I think I wasn’t great with pacing. But I really came into my own with team time trials. After we won the silver medal in that very first TTT, the results were mixed until my final year as a student. CUCC had three of us on a similar level, and we went out to destroy each other – we won the student championships by over three minutes, and I remember being so spent I could barely pedal back to the headquarters.
After graduating, I continued to compete in time trials when I was in the UK. I gradually got faster, mostly through training rather than equipment. During my last season before I moved to the US, something clicked and I managed to turn the previous year’s trend of mostly losing by a few seconds into often winning by a few seconds. I managed a seventh in the national championships, a nice place to wrap up my UK TT career.
A new start in the USA and the MK1
Arriving in Oregon, USA, I had no idea where I would be in the hierarchy of bike racers. It turned out all that practice at racing time trials served me well – I started winning the local events, and was second in the state championships that first year. But now I had access to a bike factory (being employed as the engineer at Bike Friday), and so some of my ideas around time trial bikes had an outlet. After that first Scott bike, I rode a GT TT bike that also used a 650C front wheel – but I still had trouble getting the bars low enough.
On the gorilla test of comparing height to arm span, I am plus two inches in the knuckle-dragging direction, so I need a sizeable drop to get a flat back. Chris Boardman (and later, Emma Pooley at the Beijing Olympics) raced with a custom fork/bar/aerobar on his road-going Lotus; this seemed like a neat solution to me, so I set about designing and building my own version.
I squashed round tubing to a narrow oval for the base bar section, used a one-inch steerer to keep things small, and ovalized the tubes used for the down tube, seat tube and seatstays. I couldn’t find any brakes that would fit, so I made my own – a pulley-driven single-pivot caliper for the front and a scissor-link centerpull under the chainstays.
This was the first 700C bike I built, and would be the first frame to get an ‘ENGLISH’ decal on the down tube. Once assembled, and after a bit of getting used to it, it felt really fast. And then I came down with mono … But still, in my first race back from being sick, I was again second in the state champs, and with a faster time, so it felt like maybe I had managed to build a better mousetrap.
As my fledgling business started to grow, I built time trial bikes for others, but kept racing that original bike myself – it eventually racked up three individual and eight team state championship wins. And I kept thinking about how I could improve it, especially as I discovered the availability of actual aerodynamic steel tubing from the aircraft sector.
Second generation, the MK2
I do my best designing whilst riding. The rhythm of pedaling a familiar route allows a certain amount of autopilot and my brain can focus on problem-solving. The hard part is then finding the time to turn thought into metal – with customer bikes to build I find it difficult to stop and build something for myself. But when a bike show is coming up, that has been my opportunity to carve out the time to work on these projects. And so it was for NAHBS (North American Handmade Bicycle Show) in 2013.
For the MK2 TT bike, the goal was to create the smallest frontal area I could, and have everything be as sleek and integrated as possible. At this time my position was working well for me – essentially the classic Chris Boardman-style flat back and horizontal forearms. The only change I had made from the first assembly of the MK1 was to narrow the aerobar pads so my arms were almost touching.
I perhaps got a little carried away with the MK2, as I started by building a custom aero crankset. This used cromoly aero tubing for the crank arms, a split axle, and a custom carbon 1x chainring. It was all assembled into a special small-diameter bottom bracket shell with (gasp!) pressfit bearings.
With the basebar again integrated into the fork crown, a custom front brake was required – this time I brazed on minimal cantilever studs and machined narrow brakearms to fit behind the fork blades. There is a direct run of cable from the brake lever, but because of the pulley activation, I had to modify the lever to pull double the amount of cable. The levers themselves came with the barend ‘pods’ from USE; I was able to shim the slim steel bar for them to fit. As on all the TT brakes I have made, the springs are created from titanium spokes.
This bike used the original 10-speed Dura-Ace Di2, which was wonderfully hackable before Shimano went to the e-tube system. So I could use a custom internal battery with a Micro USB charging port integrated into the frame, and I made my own minimalist shift buttons for the ends of the aero extensions (which I later got a call from SRAM about, as they were seeking prior art for the design/patent of their blip shifters).
The headset (if you can call it that) was the biggest head-scratching piece. I knew the bearings were going to sit in the stem and fork crown, but had to figure out how they would be installed and secured, particularly when I had a bit of an obsession with having no visible fasteners. And the Di2 cable and rear brake cable somehow had to pass through the middle of all that too, to remain fully internal. The final design features an internal steering limiter to prevent fork-frame impact (and protect the internal cables), and two bolts accessed from underneath the fork crown to secure the assembly together.
On my first test run with the MK2, it felt fast, a little flexy, and the headset came loose. I hadn’t accounted enough for the preload required by the angular contact bearings, and ultimately had to machine the base of the head tube down a little to allow everything to tighten up correctly. But I had that all sorted for the state champs, and rode the new bike to my fourth win, over a minute ahead of second place for the 40 km distance. Whilst it was clearly fast, the frame was not stiff enough – no problem with power transfer, but the flex in the front triangle, while manageable, wasn’t confidence-inspiring. My intention was/is to replace the down tube with the next size up, but that hasn’t happened yet.
I was gradually stepping back from racing, and then COVID hit and accelerated my retirement – I dabble with local events but haven’t ridden a TT bike for quite a few years. However, when Enve asked me if I might be interested in building a time trial bike to display their new products, I was inspired to revisit and evolve my design. And hence the MK3.
Present day: The MK3
Since building the prior bike I’d found a source for custom-drawn NACA-spec aero tubing, and had had a run made of large-diameter, thin-walled cromoly tubes that would provide greater stiffness whilst keeping a narrow profile (up to 24 mm wide from 18 mm on the MK2). Handling improvements came from disc brakes and wider tyres. I hoped to use a little bit of the Hope-Lotus concept of having the fork blades in front of the rider’s legs, so I designed the fork/stem/bar to have the blades sit at the 100 mm width of the front hub all the way up to the basebar. Then I used slightly larger bearings for the headset, in a similar arrangement to the MK2.
I wanted a narrower Q-factor for this bike, and I had a nice Vision aero crankset on hand. After some measurements and figuring out the chainline for a 1x drivetrain with a large (58T) chainring, I determined I could shorten the axle by 16 mm and still have everything fit with a standard-spaced rear wheel. Unfortunately on that crank, the axle is permanently attached to the driveside crank/spider, so this project was tricky, but I was able to do a cut-and-shut on the spindle that left it shorter, but reinforced and keyed together for alignment. It then worked out that I could fit it into a standard T47 BB shell with internal bearings.
The narrow crank then gave me the next problem to solve – shaping chainstays that would clear the chainring, the crankarm, and the rider’s heel. Oh, and the disc rotor. I contemplated using 120 mm rotors (made for BMX), but ultimately decided that keeping things somewhat standardized made more sense. A few scrapped chainstays later and I had managed to do a combination of shaping techniques to get the fit required.
The frame was a little tricky to build, but still a relatively standard shape that fit into my jig (once I had made a modification for the special head tube). The fork, however, was very challenging – I started it in the fork jig but then had to merge it with the frame jig with various clamps and straight edges to try and get everything aligned correctly. Much squinting and repositioning later – and remembering to add all the internal ports needed for routing the hydraulic hoses – and the weird structure came together. The dropouts were machined to fit smoothly into the fork blades, with the thread side blind to keep things as clean as possible.
Enve had sent me the drawings for their prototype aero extensions, so I added mounting points for those on the base bar. The previous two bikes have had fixed saddle heights – this time I decided to give myself a bit of adjustment and settled on using an eccentric saddle mounting hardware (similar to an eccentric bottom bracket used in some single speed and belt-drive frames), which gives me 15 mm of total vertical adjustment.
When it came to the seatstays, I ovalized a set of my usual small-diameter stays, then shaped them to match the curve of the chainstays. But how to join them to the seat tube? With clearance for a 28 mm tire, I needed that wider spacing almost immediately – I found a neat solution by notching a small section of the handlebar tubing to fit the back of the seat tube, and having the seatstays flow into it.
When I was drawing up the frame, since the rear wheel was tucked into the seat tube cutout, I decided to extend the down tube below the bottom bracket to fair the wheel further down too.
Wireless shifting is super helpful for a build like this, especially since SRAM introduced the independent blips that don’t need a control box. But with no wireless brakes (yet!), those hydraulic hoses had to be routed – as I was building I knew this would be challenging when I got to assembly. The narrow steel tubes of the fork/bar don’t have too much room inside. The front hose runs up the inside of the fork leg, into the basebar then out to the brake lever. The rear has a somewhat tortuous route – from the lever, through the bar, through the stem, into the top tube, down the seat tube, bypassing the BB, into the chainstay, and eventually to the caliper. At least with hydraulics the length of hose or the bends in the routing don’t affect the performance.
When clients ask my advice on paint designs, I generally tell them that I am definitely an engineer, not an artist. My personal bikes are mostly just painted one colour and then I don’t think about it again. And they are mostly blue (unless they are white or pink). For the MK2 I asked the designer who created the English team kit to come up with something simple in the same color scheme. For the MK3 I asked my wife what colour it should be – she suggested a light butter yellow. This never would have occurred to me, but we pulled up some Porsche yellows and found one that we liked and we thought would work well with the black wheels and components. With the frame expertly painted by Colorworks, I am very happy with the choice.
Is it fast?
I’m a mechanical engineer with a lot of hands-on experience in manufacturing. However, I’m no aerodynamicist and I wouldn’t even want to play one on TV. In writing this article, I took the opportunity to ask the tech editors of Escape Collective to gain the insight of someone who may know how my MK3 may stack up in the wind tunnel. They went straight to the top, asking JP Ballard of SwissSide.
Only so much can be gleaned from photos, and Ballard was quick to state as much. “Of course, it’s very difficult to give an accurate assessment without seeing it in the flesh, or testing it, but a couple of general comments come to mind,” said the F1-turned-cycling aerodynamics expert.
“It’s a beautiful and clean piece of metal engineering with obvious character. There is nice integration of the rear wheel and a clear seat tube / seatpost concept. However, it’s just not all that aerodynamically optimized.
“Aerodynamically the fork and head tube concept will be quite draggy. Quite a lot of frontal area but short profiles so will all just separate the flow. The short down tube profile will be too aggressive for the flow to remain attached. So this will be quite draggy. And while I like the seatstay connection concept, again the profile is too aggressive and will just be separated. So it won’t be as aero as it looks.”
Ballard recognised the limitations of my choice of extruded steel as a material in a segment of cycling now dominated by moulded composites and 3D-printed metals. As you may imagine, for me, building these bikes isn’t about making the world’s fastest bike, but rather it’s largely about the challenge of doing it.
I have now been able to ride the bike a few times – I don’t currently have the sort of fitness needed to really see what it will do, but crucially everything is working as intended. It feels stable in the aerobars, easy to handle, and having the hydraulic discs is a revelation for TT bike braking. The frame doesn’t exhibit any flex, and responds very well when accelerating out of the saddle. I will get the bike set up on the trainer soon, so I can experiment with adjusting the position. And then work on getting used to it!
The feedback from Ballard is useful, and it’s already stirred my mind about what an MK4 may eventually look like. I am curious about moving away from UCI double-diamonds and revisiting the Obree replica bike I built some years ago.
The ‘egg’ position is truly horrible to hold, but my fastest time on our local course is on that bike. When I built it, I allowed in the dimensions for it to be compatible with a regular aerobar and also a Superman position – it would be very interesting to do some Chung-method testing to compare both of those to the MK3, and see if the testing suggests some directions to explore further. Fortunately racing in Oregon does not have much in the way of technical regulations!
Hopefully having the new bike and wanting to see what it will do will give me some motivation to do some structured training to get ready for the local time trials in the spring.
The Whys of Bike Tech is a column from American-based custom framemaker Rob English of English Cycles. This column looks to mix opinions from hands-on experience with a mechanical engineering background to break down commonly misunderstood subjects and myths in the world of cycling tech.
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