*to Hanlon's razor: Never attribute to malice that which is adequately explained by stupidity.
Κυνόσαργες

Sunday, 27 May 2012

Q-Factor

The things you learn after you have spent a few thousand dollars on a sport.  When it comes to any of the sports I know anything about, now, I try to stop my friends spending money until I've found out what they want from the sport.  You always buy the wrong stuff without advice: through ignorance, over-ambition, or getting 'up-sold'.

What I did not need is much of what is on my road bike.  It is a lovely bike, but suited for other purposes than mine.  The main thing bothering me at present is the relatively wide 'q-factor'.
It's also called 'tread'.  The picture shows it clearly: the width your feet will be.  There's a lot of argument about what is optimal, but many people prefer narrow rather than wide.  I am among them.  My fixed gear, having just one chainring, is about 150mm, but my triple-ring road bike is more like 165.  I do feel the difference, especially in my right foot.  I did some more measurement and found that the drive-side of the crank (right) is 5mm offset.  That's fucked up.

Nobody needs a triple, but I did not know that when I bought it.  What people need is a double that fits their range.  A double has less 'q-factor', and I imagine, less drive-side offset.  Almost all road bikes are far over-geared for anyone but a 'king of the mountains'.  If you are buying a stock bike with a 'compact double' crank it is over-geared, and there are only two ways to solve this:
- the cheaper way is a massive cassette on the back
- the expensive way is a new double crank, and likely the bottom bracket to fit it
There are only two double cranks I know with the right chainrings: 30/46, or 48.  White Industries VBC, or the Velo Orange ones.  That's going to be your own money and build up.  I'll be doing the cheap or expensive option (VBC) on my next road bike.

But the road bike is going to be used for just another year regularly and left in Japan for riding the few summers I come back.  I need a 'ghetto-fix'.  First thing I did is move the cleat on my right shoe so that I pedal with no more than 2mm clearance; the left shoe has more like 5mm.  I am going to look to find a bottom bracket (Phil Wood?) that is 3mm thinner on the drive-side.  My small chainring should just clear the chainstay still.  'TLAR'!

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