Old 05-24-20, 09:48 PM
A Roadie Forever
79pmooney's Avatar
Join Date: Oct 2014
Location: Portland, OR
Posts: 8,685

Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder

Mentioned: 100 Post(s)
Tagged: 0 Thread(s)
Quoted: 2413 Post(s)
Likes: 0
Liked 846 Times in 572 Posts
Originally Posted by oldbobcat View Post
Selection of a spindle length depends, however, on the crank spec, the bottom bracket shell width, and the chain line. That is, the middle ring or the space between double rings must should align with the center of the cassette or freewheel.
My knees do not like high Q-factors. (Chrondomalacia patellae) The doc who diagnosed me 40 years ago told me to listen to them His advice has been spot on so I do. I started noticing the bikes my knees liked best and least. Best? My fix gears. Least? My best bike, custom ti with triple Hollowtech 105, Hmm, that says something! I started on a low-Q campaign on all my bikes but the two fix gears. I went to the old straight Japanese cranks of the '80s and short spindled asymmetrical BBs. (I love and thank Phil Wood regularly.) Chainrings came inboard. OK, chain line might make a few purists cringe, The $$ cost to me of poor chainlines is far, far less than the cost of the simplest knee replacement and I would need two.

I now have all of my bikes but one under 140mm Q. (That one is 150, down from a Shimano 164) But the best bike is still a work in progress, I now cannot shift the chain onto the inner chainring. Need to figure out a way to add an 1/8" steel plate to the inside of the FD outer cage plate to assist in the push. (I use friction, A very narrow FD cage that needs a lot of adjustment is no big deal.) Ideas anyone? I could drill and tap but that's not a whole lot of metal. I tried epoxy but apparently it was too brittle to go with the FD bending and it fell off mid-ride and I did not notice it leaving so no postmortem. Anyone know of a glue with epoxy-like adhesion that allows more flex?

One challenge is that the seattube is 31.8mm,pushing the FD out that much more. I"m happy to grind the FD so the cage can come in more but that only goes so far on some FDs. I could settle for a wider Phil Wood BB (right now it is the absolute minimum that can fit that narrow crankset on this frame. Q-factor of 139 with a 50-38-24 triple. My knees so want to make this work. (I did not measure the old Shimano 105 Hollowtech Q-factor but it was big! Cranks missed chain and chainstays by a cm or more. Felt like I was riding bowlegged.

Until I get this mastered, I am stuck riding fix gear. Not all bad. Did 60 today and have a body that feels like it is buzzing all over. (Tomorrow morning getting out if bed is going to be a slow process.) Knees know they did something but feel OK.

79pmooney is offline