Bike mechanics 101 – The Four Miles way

With the new bottom bracket dropping through my door this morning and me off work feeling not so well I had the opportunity to fit it straight away, if my concentration could hold up.

First I laid out the bits I’d need:



This was organised for me, but saved running around the flat looking for bits when I suddenly needed them. I also prepared the area, by selecting a suitable bit of the lounge.
Here you can see: (clockwise from top right as they say in photos)
Left hand crank and pedal
BIG spanner (or wrench)
Allen keys
Old seat post for leverage
Tyre lever (not sure where that came from – I don’t need it)
Crank puller for splined cranks
Chain tool (obviously, again, I’m over prepared here)
Crank bolts
Old middle chainring – already taken off in a Blue Peter moment
Doobrie for holding the back of chainring bolts
8mm allen key
Shiny new bottom bracket
Less shiny old bottom bracket
Bottom bracket tool
Crankset featuring shiny new middle ring.

Please note that trying to use the wrong crank puller and cleverly use 1ps as a make-shift wotsit to make it fit does this to coins.



Pretty, but not good in a vending machine.

Next I needed a bike – looking strangely naked without its middle bits:



First half of the bottom bracket went in smoothly:



Then there was a first panic moment when the other bit of the bottom bracket seemed too long. A quick check on the internet and it turns out that it was the wrong size, despite being the same size as the one I’d taken out. A difference of 8mm might not be an issue in some places but here it seemed significant. What to do…?

Inspiration struck and the part from the old bottom bracket fitted perfectly. Although it seems that the bike might have been set up wrongly by the distributors, I was forging ahead:



Please note the use of the BIG spanner here to tighten everything up.

Next onto the cranks, which were fairly easy, with just the small matter of getting them opposite each other to enable easy pedalling to worry about. One on:



This was followed by the other after a quick faff getting the chain back on. Some quick (and seemingly invisible…) work with an allen key and leverage device (formally a seatpost) tightened everything up a treat and I could sit back and contemplate my achievements with a smug air.



Except that as these thing always happen it turns out that the front mech is now not working (although not related to my mechanical prowess) through lack of use (perhaps I should ride a mountain bike not just in the middle ring). Let’s hope that a liberal application of WD40 and some kicks will, in fact, fix it. Otherwise, I only use the middle ring anyway so I’ll just jam it on there until I can afford a new one.

I knew I’d made my ride-to-work bike singlespeed for a reason. That reason is laziness. On that note the “Singletrack” (see how I linked that in…) stickers are for Singletrack mountain bike magazine. Well worth a look.

Now back to reading trashy books and watching programmes about motorways (honestly, BBC4 is amazing) until I feel better.

A