Day: January 20, 2010

Finally the ice has (almost) cleared from Holyrood Park, so I was able to do my homebrew “fitness test” to start my training. I figure that timing myself over three laps of Holyrood Park / Arthurs Seat will be a good yardstick. I can come back and do the same course in a few months and see if I’ve got faster. There’s little in the way of traffic lights or junctions, and it’s a mixture of steepish climbs, fast descents and a fair bit of flat road too.

Date: Jan 16th 2010, 15:00
Route: Holyrood Park loop (3.3mi including 100m ascent)
Distance: 3 loops of 3.3mi, plus 2mi there and 2mi back = 14miles.
Bike: Courier Nexus

Lap 1: 13m50s, 153bpm average => 14.3mph average
Lap 2: 14m22s, 155bpm average => 13.8mph average
Lap 3: 14m26s, 155bpm average => 13.7mph average

Notes: Start/end at zebra crossing near Holyrood Palace. Snowgates were shut at bottom of hill, requiring a short muddy/icy excursion. Lots of pedestrians around, but didn’t have to stop for traffic.

Heartrate was 160-163 climbing the hill, which felt sustainable. Went up to 167 after the final steepest bit of the climb, which didn’t feel so sustainable! Tried to keep at 150-160bpm round the rest of the lap, but ran out of gears on the downhill.

I went to re-setup the gears on my bike (Gary Fisher Hoo Koo Ee Koo) last week and couldn’t get them working. Now, this is a bit frustrating because I’ve set up gears many times before and, although it can take a wee while to get them indexed right, the recipe is simple and pretty foolproof.

But for some reason, shifting wasn’t happened right. After a while, I realised that it wasn’t really an indexing or limit-screw problem; the bike would eventually go into every gear. Instead, it was as if the bike had developed memory. If I’d previously been shifting up, then the first down-shift would be ignored! Subsequent down-shifts would work fine. It was as if the bike could remember whether the previous shift has been up or down.

My first suspicion was that the derailleur pivots were corroded or gunked up. I was just about to go ahead and strip it down – but, upon releasing the gear cable from the derailleur I realised that the derailleur itself was moving completely smoothly. Hmm, strange, can’t be that then.

My next suspicion was that the ratchet mechanism in the shifter had gone funny. But, by watching the cable move as it came out of the shifter, I could see that it was doing its job correctly – each click of the gear lever moved the cable out/in by the same amount every time.

Finally, I watched the gear cable along its length. Near the handlebars, it moved in time with the shifters. But at the other end, it wasn’t moving at all on the first shift. Suddenly, I suspected the cable itself. Releasing the gear cable from the derailleur again, I wiggled the metal cable back and forwards through the last ‘loop’ of the black outer. It moved, but it certainly felt a little bit sticky. Sticky enough to cause the problem? Perhaps there was enough resistance to counteract the tension released by the first click, but not enough to resist two clicks.

Lacking any objective means of measuring the friction, I decided to replace them. With a bit of help from Sheldon and my trusty Dremel, I soon had the new cables cut to length – using the old ones as a pattern.

And, guess what? I now have silky smooth just-like-new gear shifts all over again. Woo! 🙂

I started 2009 with the aim of riding LEJOG in May. I’m really glad I blogged it all, because now I can return to the posts as a spectator and enjoy a different side of the ride.

In 2010, I’m starting with a different aim – to race in round one of the SXC (Scottish Cross Country) mountain biking series at Kirroughtree, plus the Ten Under The Ben endurance race in May. I also intend to blog my preparation and training and, being lazy, I’m just going to reuse my LEJOG blog and continue tacking on new posts to it.