Thursday, November 26, 2009

Equipment - Frame Fit Session

As planned I made it to the local shop just down the street. Of course, as usual, I was running really late, and instead of getting there at 10 AM, I got there at about 1 PM.

I set up the fit bike thing myself, puzzling over the different settings and such. I brought my pedals, bars, shoes, saddle, and a kit.

For the record, my current bike is a SystemSix Liquigas Replica, 52 cm, with its standard geometry. To save you from flipping back and forth to the geometry page, the important numbers are as follows:

Seat tube: 52 cm, 50 cm to the top of the top tube
Top tube: 53.5 cm
Seat tube angle: 74 degrees
Head tube angle: 73 degrees
Head tube length: 11.5 cm

I look something like this on the bike:

On the green/black Cannondale. My arms hang straight down.

Okay, once you get past my doughy build (perceived 175 lbs on my optimistic scale, which was actually 185 lbs), you may notice that the bike seems really, really short in length. My goal is to get my bike a bit longer.

That other night I took to my bike with a tape measure.

First, I want my saddle to be in the middle of its rail adjustment, not shoved all the way forward. I held my tape measure to the center of the rails, and the line went 2 centimeters further forward than the present seat tube. This meant I needed a substantially steeper seat tube angle.

How much steeper I didn't know, but that's what a builder is supposed to figure out.

The steeper seat tube would move the whole top tube forward by 2 cm. However, based on my current set up, I figured I need at least another 5 centimeters in length - I could put my hands a full Ergo lever in front of the actual Ergo lever.

Based on that number, I figured a 58 cm top tube would work well. It would move me forward a total of 6.5 cm (2 cm from the steeper seat tube angle and 4.5 cm from the 53.5 current length to the new 58 length). This would let me play with a shorter stem, an 11 or a 12 cm stem, not always having to search for the longest possible stems out there.

I also want a short head tube, shorter than the current 11.5 cm, so that I can go buy an 80 degree stem. This would free me from just 73 (-17) degree stems. There are lots of 80 degree stems out there, not a lot of 73s.

And, finally, while I was at it, I wanted to get a short seat tube, something like the 44 cm seat tube (as I remember) on my size S Giant TCR aluminum frame.

Armed with this information, I emailed Joseph at Tsunami Bikes. His initial response seemed a bit hesitant - my ideal frame, after all, would resemble an oversized BMX bike.

We started talking and I described how I arrived at all the numbers. Again, he seemed a bit hesitant. He asked for some pictures of me on the bike, and ones of just the bike itself.

I sent pictures and called to follow up.

Now he seemed a bit more receptive to the whole "tiny frame" concept (as named by Hans). I told him that I'd want to do a sanity check, one where I actually have a regular bar to hold onto, not resting my hands on a plastic tote bin.

I strolled into the shop and got down to business. This new fangled gizmo was a new experience for me, so Hans would occasionally tell me "do this" or "do that".

Fit starts at the bottom bracket, goes up to the saddle, and then forward to the bars. Therefore I started with the seat tube at 75.5 degrees. I raised the saddle (that I brought into the store) to my right height, centered the saddle on the rails.

Then I got the top tube to a more reasonable 56.5 cm. I borrowed a 14 cm stem, a -5 degree stem and mounted a spare set of 3ttt crit bars (Gimondi bend, bars I got thanks to RTC's detective work).

Finally I put my Keos on, trotted off to the bathroom to change, and trotted back in my new kit. I even brought the long sleeve jersey because I didn't want to get cold in the shop.

I jumped on the bike and, BAM, it felt awesome.

I fiddled a bit with the stem height, played around, and realized that, hey, it's pretty much perfect.

On the tops. Left foot forward.

My arms are bent a bit, but outwards. I wanted to keep my arms out of the way of something, not sure what I was thinking. I'm sitting square on the saddle, and the saddle is square on the post. w00t!
On the "hoods". Foot at bottom.

My legs look bulky.

Reminds me of something. I made a comment at the track last summer - I was watching the As and watched as powerful looking racer rocketed off the front. He looked freakin' powerful - big legs, big arms, aero carbon frame, aero carbon wheels, and, man, he was flying.

"Holy smokes, look at that guy's legs."

The guy next to me looked at me and said something unusual.

"Don't underestimate yourself."

Hm.

Drops, and right foot sort of forward.

Imagine, my arms point forward. And my back is kinda sorta level. The position in the drops feels really secure, really good.

I thought I forgot my camera so Hans took a few pics and sent them to me.

I sent the pictures to Joseph and left him a message. An hour later he called back. He said the pictures really helped, and things looked good. He kind of laughed - I'm still not really forward, relatively speaking, and I'm sitting on a 75.5 seat tube angle.

We went over a few details, things like ride quality and such. I have no knowledge about tubing materials so I'm leaving it up to him. I just want a ride that's as rigid as the Cannondale - I'm good for 6 or 7 plus hours on the frame, and I don't want to have something more flexy.

Paint will be later, but I think some kind of a red. I haven't had a red bike since forever ago, and my first race bike, a Basso, was red. It would match the kit and it would look kinda cool.

The other choice would be a blue to match the blue car, but I don't have anything blue in my kit so that's out.

After our talk Joseph emailed one more question - one about seat tube length. I went and checked my two Giants, since I like the aluminum one a lot, and since the carbon one is "fine" (the Cannondale is a bit high for me).

Seems that I remembered wrong. The aluminum Giant has, get this, a 40 cm seat tube to the top of the top tube (44 to the top of the seat tube). The carbon Giant is 4 cm longer.

Whew. I sent my preferences (40 c-to-t, but 44 c-to-t is fine), along with payment.

And now it's up to them.

3 comments:

Anonymous said...

Looks like you went custom.

I'm glad you're getting all this stuff. I can live vicariously through you while I can't ride. Heh.

Now we need SOC to get an SRM.

-RTC

Aki said...

Yep, full custom.

SOC on an SRM, that would be cool. Fact is that he pushed me to the hardest ride I had, the first true 20 min test I did on my SRM. And he waited for me, even turned around, in the middle of that 20 minutes.

jonathansawn said...

Aki, I'm glad you got that fit rig warmed up for me; I'll be down at the shop soon to simulate the two bikes that I'm considering for this upcoming season!