5x12 pentomino tiling

Grandfather's Bike


I'm sure you're familiar with the "grandfather's axe" meme1 but my bike (the one I bought in summer 2016) is having a similar sort of journey.

Here it is last Sunday, leaned against a tree on the edge of Culbin Forest looking out across the Findhorn.

Paul's Claude Butler Cape Wrath 02

And for comparison here's the seller's photo of it as it was straight out of the box:

Claude Butler Cape Wrath 02

So what's changed? First the additions which you'd expect on any bike. So it's now got:

  • front, rear, and down tube mud guards
  • a pump and water bottle cage on the down tube
  • front and rear lights
  • a mount for my eTrex 10 GPS on the handlebars
  • a wing mirror on the end of the handlebars
  • a frame bag holding a spare inner tube (far easier than trying to fix a puncture, just replace the tube), a cable lock, an excellent bike multitool, and a rag in case I need to fiddle with the chain. There's usually some chocolate in there too, for emergencies you understand.

But it's the changes which are the fun part.

As I mentioned in my original post to give me a bit more braking we replaced the 160mm front rotor (brake disc) with a 180mm rotor which Beth had the spare from upgrading her brakes. That worked with the original Clark calliper with the aid of an appropriate £5 adaptor.

Being a tall lad with a long reach I've had some problems with the distance front to back so we've replaced the handlebar stem with one with more reach (again a spare from an upgrade to Beth's), seat (ditto), the handlebars themselves with angled ones, and the seat stem with one which moved the saddle back a little.

I was never wildly happy with the original tyres and the rear one wore out quickly so I've replaced the 2.3" rear tyre with a Continental Mountain King II 2.4". This dramatically improved the bike's handling on loose surfaces. My plan now is to buy another one for the rear at some point and move the existing one to the front.

I've been through two pairs of pedals after the originals simply couldn't stand the harsh environment and I kept having my feet slide off the first replacements. I'm currently using a pair of Wellgo B087B pedals which have proper pins and to which my shoes seem to stick to like glue.

But the biggest change has been to the gears. It came with an 8x3 arrangement: a Shimano 11-32T cassette and an Sram 22-32-42T chainset. This wasn't ideal: lots of headroom for road use, but off road it was lacking at the bottom end. On top of this it was unreliable selecting the 32T ring and would jam the chain.

So after some discussion and use of the wonderful gear-calculator.com Beth ended up replacing both ends so I now have an Sunrace MX80 11-50T cassette and a Shimano SLX M7000 24-34T chainset. We had to replace the chain, the bottom bracket, and the rear shifter and dérailleur with Shimano Deore XT M8000 components but I've been able to carry on using the front dérailleur and shifter, so long as I don't try to shift up into third.

The old and new combinations look like this:

Click on image to look at that set up full size on the gear-calculator.com web site

The key points, as that diagram makes wonderfully clear, are:

  1. The bottom end has been extended by two gears and even the third gear up is still slightly lower than the old bottom gear - this is really helping me on steep uphills.
  2. A less obvious benefit is that for each of the two front gears I've got a wider choice of rear gears. That means fewer front gear shifts, which is good news when you're struggling to find the right gear.
  3. I've lost a bit of top end, essentially the top two gears if using the 42T chainring. That I can live with as this isn't a road bike.

The only catch is that the low end of the cassette is big and that's a problem if you are stupid enough to try to select the biggest two while in top on the front as the dérailleur will run out of room to play as there's simply not enough chain. So you do need to remember to change down on the front before things get too steep.

But overall I've now got a much more capable bike ... although I've probably spent more than I originally paid for it in getting there.

  1. "This is my grandfather's axe: my father replaced the shaft and I replaced the head."

Tags: cycling, toys Written 30/01/18

Comment on this article

« »
I am currently reading:

A History of Women in 101 Objects by Annabelle Hirsch Game On by Janet Evanovich

Word of the Day: