July 12, 2010 at 11:13 pm #92967Keymaster
For the second post on my series of Bikes From the Forum, we’ll look at Rob English’s custom Time Trial bike. I live in Portland, Oregon, where the term boutique, when applied to bikes, conjures images of tweed rides, artistic frame building and custom paint jobs. Here at Fairwheel Bikes, boutique takes on a different nature — a minimalist viewpoint oftentimes not just in weight but in aesthetics.
Rob’s bikes, fabricated under the name English Cycles, adds an entirely different nature to the boutique term. His bikes are boutique in the sense of craftsmanship, yet they’re still focused on being utilitarian. Not in the cargo-bike sense, they’re utilitarian in the quest to go fast. Rob is a problem solver, tackling engineering goals that change a lot of what we took for granted about frame and component design. This bike is a combination and ever evolving solution to Rob’s TT needs. We’ll look more into the, low handlebars, aero yet stable front wheel, and brake placement, I hope this gives you a good insight into this frame.
One of the most striking pieces of the TT bike is the unusual handlebar setup. Rob explains that at his size it’s hard to get a traditional time trial position low enough. Several professionals took a different approach and instead changed their position to incorporate their arms into their face / head frontal area, think Levi L. and Floyd L. Rob, however, decided that going lower and maintaining a traditional position was optimal and decided to run a “negative” mounted handlebar setup. The handlebar is therefore incorporated into the top of the fork below the lower headset race, leaving the top of the head tube looking pretty bare with a Chris King Headset on display. The resulting effect is that Rob has an ultra low TT position.
According to Rob, the front wheel was born out of another rider-size related issue. But truthfully, I’m a bigger guy and I’ve been blown around enough on a time trial to understand the need behind this line of thought. Rob’s goal was to make a wheel as aerodynamic as possible while retaining control over it in windy conditions. Rob had been getting blown around on a Zipp 1080, so this was his aerodynamic target. The idea here is to hide the spokes from the air as much as possible. Easton did this with measurable aerodynamic improvements. But after having already brainstormed the idea, and emboldened by Easton’s venture, Rob went to the extreme. The width, from flange to flange, is a scant 32mm. Although no wind tunnel data is available, which I would like to see, Rob claims the new wheel feels as aerodynamic as his deeper option. As for lateral rigidity Rob raced the wheel a couple times during road races and never noticed any undo flex. Loaded with tried-and-true 6900 bearings, the hub — more as a side effect than anything intentional — weighs a feathery 66 grams.
Rob’s custom brakes seem to be born out of something more common to most of us. It goes something like this, “Well, I built this frame, time to hide the brakes away to keep them out of the wind.” The only thing is that Rob didn’t take a standard brake, mount it backwards and then attach a tight brake noodle too it as we see in so many TT bikes. Rob actually went out of the way to create two different brake designs, going as far as using completely different mounting styles. The front brake, a single bolt design, uses a pulley and a pinch bolt to “scissor” the brakes closed. It weighs in at a scant 66 grams. The rear brake mounts more like the old U brakes, but I’d be inclined to call it an “M” brake. Explaining this is a little bit harder, so here’s an image (complete with fancy arrows!). As the cable pulls, the pinch bolt moves away from the wheel, effectively increasing the length of the “cross bar” and moving the pads in. This brake weighs a little more, I assume from the extra mount, but still comes in at an impressive 92 grams. Although the rear brake gives a bit more stopping power and both are suitable for TT demands, Rob says he wouldn’t want either in a road race situation. Something I’m inclined to agree with.
One last thing that you might be wondering is, “well how much?” And all I can say is I shied away from that question. When a frame builder builds himself a bike like this, it’s impossible to add all the man hours of work together and get an answer that the builder feels comfortable being quoted at. In fact, Rob shied away from giving a price on the front hub, letting me know that if there is enough demand he might make a small production run. Although, I’m sure that if you do want to talk to Rob about undertaking such a project with him he’d be more than happy to chat with you.August 11, 2010 at 1:06 pm #92968Rob
Any chance to find out why he went for a sloping geometry though?August 11, 2010 at 4:47 pm #92969Participant
thanks! When laying out the frame, I ran the toptube so it met the seattube at the same height as the rear wheel – my logic being that sloping the toptube doesn’t increase the frontal area, but it does leave more seatmast clear above the frame, which might be better for the airflow through the middle. Plus I like the look, and the smaller front triangle is stiffer.
Rob.August 12, 2010 at 9:37 am #92970Rob
Hmm ok, I’d thought a horizontal toptube might look better, for the aero bars being horizontal too. Just aesthetics though …