Adjusting the Fit

Yes, I’m fiddling around with things again. Although I really love the look of the gold anodized bars, stem, and levers that have graced my 1971 Raleigh International, I’ve run into a problem recently: The stem no longer wants to snug down. Now I don’t know about anyone else, but having the bars come loose as I’m barreling down a steep hill is not a thrill I want to experience. In fact, having them come loose as I pedaled from a dead stop through an intersection at about 2 MPH was freaky enough. (For those interested in a first hand account, let me just say that I felt like I’d hit an oily or soapy patch on the road…no control whatsoever.)

I gritted my teeth and pulled over. This was the third time in a couple of days and I had finally come to the realization that if I wanted to ensure a future where I could grit my teeth at other things, I’d better reconsider my cockpit. I already knew that my optimal setup, like my Boulder, involved randonneur handlebars and more rise. I prefer the feel of rando bars while I ride. And as it happens, I had an unused set of bars and a long rise stem hanging about.

The first bike tool I reached for was my camera. I needed to make some precise comparisons between the control (my Boulder Brevet) and the bike I wanted to adjust. After a lot of adjustment and experimentation, the Boulder fits me better than any other bike, so it operates as my baseline.

In this photograph, notice that I’ve placed guidelines to indicate the top of the bars and saddle position, as well as the location of the bottom bracket. These the the relevant points of contact for me. The bottom bracket, regardless of location on the frame, isn’t a variable. The pedals meet my feet, and that simply doesn’t change so I make two photographs of the bikes in exactly the same position, then superimpose the images with the bottom brackets oriented to the same location. Because everything else is a variable, I can compare the bike I want to adjust to the variables on the bike I want to adjust.

Notice how in this superimposed image the two bottom brackets are aligned, but that the other points of contact – i.e., the saddle and bars – are clearly located in different places relative to the bottom bracket. Because I already know that the Boulder is an optimal fit, I can begin my analysis with this information.

A couple of notable observations can be made here. First, the saddle is lower on the International. Raising it is easy, of course. But doing so would play havoc with the reach and drop to the bars. But that’s ok because the second thing of note is that the bars need to be raised in order to better match the fit of the Boulder. Seems simple, but there’s not enough rise on the gold stem…and heck, it’s not staying secure anyway.

Assuming I had adequate rise with the original stem (which I don’t), simply raising the height doesn’t come anywhere close to matching the rise or grip points of contact on the Boulder. This is where the randonneur handlebars come into the picture: because the curves rise and the bars themselves have a more forward position, my points of contact are higher, with a more stretched out and longer reach. I happen to like longer reach, and raising the original bars would effectively shorten the reach.

All of which takes me back to the photo at the top of this post. Replacing the lovely, but unworkable gold bars and stem with a tall Nitto and rando bars combination left me with a ride that rivals my Boulder. The superimposed photos are precise enough to have helped me adjust the new setup with almost no additional adjustments after the initial installation. Yesterday, I pedaled up and down the street feeling like I was riding a completely different bike. Please remember that I already liked the ride of this International, so discovering that the comfort and bike position was now almost the duplicate of my Boulder, and then realizing that this adjustment left me with a significantly more efficient pedal stroke… well, let’s just say that I’m more than pleased.

An afternoon shakedown ride today confirmed my initial assessment, by the way. A quick fifteen mile route of hills, mixed terrain, and flats; stopping and starting, curves, etc. takes away some of the chagrin I feel at having to put the gold stuff up on the wall.

Think I’ll celebrate this win over an excellent glass of wine. Enjoy your Valentine’s Day.

 

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2 thoughts on “Adjusting the Fit

  1. Prowler says:

    Well done and quite scientific and all. I do a similar thing but in a more primitive way. I’ve made a ‘story stick’ (woodworkers term) that captures the key measurements for my preferred fit. Place one end on the pedal spindle and a pin at the other end seeks out the poop deck of the saddle – where my sit bones reside. Adjust saddle height as needed. Place that pin on the poop deck with the stick reaching across the stem and a mark on the stick indicates were the back of the brake lever housings should be. A ruler and a level tells me the drop of the bars from the saddle height. This gives me seat height and reach, et al. I still use a plumb bob to set the fore/aft position of the saddle.

    You see I have no computer out in the shop so I cannot apply all your ‘tomfoolery” – nyuck, nyuck, nyuck – but this gets the job done too. BTW: hope your weather is a nice as ours here in eastern PA. Nice riding all winter.

    • A friend of mine uses a story stick, and I’ve used a similar device when I’m working on frames (pictures, not bikes).

      And yeah, the weather is shaping up to be incredible for February. Global warming? Could be…all I know for sure is that we’re in the 60’s and flirting with mid-70’s on a couple of days. No humidity. No skeeters. No ice storm – at least for the next week or so….

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