Monday, August 3, 2009

Steelwool All-road Build Log #1: Design

At the end of July, Will and I sat down for a few hours to design my new 'all road' bike. Those who have a sense of my present 'stable' of bikes will, quite reasonably, question why I need another. I won't list them, but I can say that I have my bases pretty well covered. This really boils down to me being a complete nerd when it comes to the performance of my bikes; I am not a big fan of 'jack of all trades, master of none' bikes. You know the joke about how many bikes are enough...whatever you have now plus one? I think that holds for me, and will likely hold for some time. I am ambivalent about the degree of consumption that accompanies this obsession, but I seem to justify it with the love I have for cycling. Or something like that.

So why a new bike? Numerous reasons, some interesting, others less so. As a Tall Tree team member, I want to do what I can to help the shop and Steelwool grow. Riding a Steelwool rather than my Specialized in team colours is less confusing to would-be customers, and helps promote both shop and brand. But building a new bike also affords me the opportunity to improve on the set-up I have now in important ways.

The two most important aspects of the new bike are the tire clearance and ride quality. Both will differ from my present bike just enough to make a significant difference. The Roubaix has clearance for 28c Grand Bois tires. These are fantastic tires, as I've mentioned before. However, for most of the riding I do on the road bike, bigger is better. That is, 30c is better. Consensus is that the 30s lose nothing in speed to the 28s; they work better where roughness factors. I will suffer fewer flats while plummeting dirt/rock descents, dent fewer rims. So the new bike is designed around these tires. It will also take fenders with the 30s, which will be key in the spring and fall. I don't plan on subjecting this bike to winter for some time. For races like the OBC's Paris Roubaix, the Hell of the North, the Tour of the Battenkill, D2R2, Hastings Highlands Hilly Hundred, and the Tour of Flanders and Paris-Roubaix sportives, this bike will be in its element. For the Grand Prix, a little less so, but hey, that's where a no-holds-barred road race Steelwool will figure down the road. Like I said: One more than what I have now.

The second aspect of the design that is key is the ride quality. It will be tig welded by Sam Whittingham of Naked Bicycles and Design in BC. Sam is a well respected and incredibly talented builder with a real creative flair. His bikes have won awards at the North American Bike Show two years running. It is an honour to have Sam build my bike, and it will be a great learning experience. The frame is intended to improve on the ride quality of the Roubaix. This is no small feat, as the Roubaix is an unflappable bike that handles the rough extremely well. At the same time, it accelerates well and does not feel noodly in sprints. It is a very sound bike. However, a high end steel bike should, in theory, be able to outperform a carbon production bike like the Roubaix. This is the challenge I have set for the project. I will delve into the ride quality goals in the next installment of this build log.

Now, you might be wondering how the design process unfolded. I've been thinking about the finer details of this frame's geometry got a while, but until it comes to life on 'paper,' a lot of the ideas are just that, ideas, tentative. Will and I sat down in front of his computer for a session on BikeCad, an incredibly detailed program that allows the designer to 'draw' frame-sets and to fit a vitual rider. This program is used by many builders these days.

So, step one, measure me up. This was not a prescriptive step. That is, we were not working out from my dimensions. Since I've already spent a lot of time on a bike that works well for me geometry-wise, we took my measurements to create a virtual rider for the program.

Step two, measure my Roubaix. This step had to be taken very carefully. We checked my bike's measurements against the geometry Specialized publishes. The key angles that we were starting with were 72.5 degrees for the head-tube and 73 for the seat-tube. From there we tweaked the top tube length, adding 5mm. We ran a longer fork than the Roubaix, as we want to fit 32c tires with fenders. This length must be very accurate, as being out either way can mean too little clearance for the fender or not enough adjustment for the brake pads downward. Since the new bike will run larger tires than my Roubaix, we had to spec more bottom bracket drop. This is the distance from the centre of the bb shell to a horizontal line bisecting the wheel axles. My Roubaix ran 70mm drop; we went with 80. Many builders I hold in high esteem run 80mm on their bikes, both road and 'cross, so we felt comfortable with the number. Naturally, this means the chainstays must be longer than for a 70mm, but this should not be a problem. I have yet to hear anyone complain about the handling of their RIchard Sachs with an 80mm bb drop, so I think I'll be ok. Dropping the bb allows me to accomplish the long and low fit I am seeking, which should add up to stability and sure-footed cornering. I can think of a few gravel corners where I'll be able to test this!

With 'me' on the screen, we were able to gauge toe overlap quite accurately. We measured the exact location of my cleats in relation to the toes of my shoes and were able to tweak things until we had no overlap with the fenders installed. I had wanted to go with a 73 degree head angle for the sake of a little quicker handling, but we wound up back to 72.5 in order to avoid overlap. No loss there. The seat-tube on the new bike will be longer than the Roubaix. It was a little tricky to get the right length for the 3T post I have, which is designed for compact frames. I think the graphics will line up the way we did it. Speaking of graphics, Greg and I came up with an excellent scheme. I will not reveal them now; come back to see photos of the frame when it is complete.

All told, Will and I spent about 3.5 hours on the design process. This is a little shorter than typical. For customers looking for a new frame to fit their dimensions because they have never achieved a good fit on a stock bike, the process would work out from the customer's dimensions. In cases where customers have bikes they love, but want to work in special features like rack compatibility, light mounting, fenderability, larger tires, etc, working from the existing bike tends to fast-track the process a bit and will likely result in a very familiar fit. Because I've gone into this process with specific ideas about what I want, I am obviously setting myself up for a possible disappointment. While there is nothing a particularly odd about this bike, I nevertheless consider it a test-bed, a prototype. I do not expect to achieve the ultimate ride quality with this particular frame. Few people are fortunate enough to hit it out of the ball park with their first custom frame. Typically, riders come up with tweaks they'd make if they were to do it again. Knowing this, I am not concerned about whether this frame will be the 'perfect.' It will be the first iteration of a design that will evolve through time. As I change as a rider, so to will my demands of the bike. As I learn more about the art of bicycle design, so to will the bike. As Will, Thom and Brad get into production of Steelwool frames in-house, opportunities for experimentation and innovation will unfold. Taking the long-range view, I am happy to get the ball rolling now and see where it goes.

The next installment of the build log will detail the ride characteristics we are aiming for in the new frame.


Anonymous said...

you boyz build a bike I can't break and I will buy it. My Carbon fiber bike just busted (not a tall tree bike). This is my second road bike in just 3 years that I have busted a frame!
(plenty of mtb frames - as I expect, for the fatigue limit on Al just stinks... Ti, bring on the Ti!!!)

Lots of crap out there. I surely hope you boyz build good stuff, cause the rest of it out there is a lot of crap.

We need some good hard core long lasting kick azz canadian stuff!

I'll test it... for free if you want...

Anonymous said...

I was interested in ordering a custom Steelwool cross last week but I missed the order deadline and have now ordered a steel Marinoni...I should have it in about 6-7 weeks, just in time for the races.


Matt Surch said...

Too bad you missed, but nevertheless, you 'noni will be great. Steel baby! Looking forward to cross!

rob.parniak said...

Speaking of Sam Whittingham... I just read an article about him in -- of all places -- the Reader's Digest about his amazing Human Powered Vehicle feats... you know those weird aerodynamic recumbents... He can pedal 130kph on a flat road! Yikes! I assume it's the same guy. Vancouver Island right? The legend grows!

Matt Surch said...

Yep, that's him. 130k is astounding, simply astounding. Sam must be a heck of a motor. I wonder what he eats? I should find out. Imagine descending on his aero machine! Madness.

Rodd Heino said...

to the sam whittingham comment.
he's a monster
he received a big payout for going one tenth the speed of sound!
deci-mach they called it
kind like the x-prize for HPV's