Rear mech hanger of the Ridgeback Meteor 2004

I found out that all bicycles with gears have a single Aquilles heel. The rear mech hanger of my Ridgeback Meteor has a crack. It is unsafe to ride the bike. The piece is made of aluminium.

Position of the hanger on the bike
Position of the hanger that attaches the chain system to the frame

The store where I bought the bike in London (Evanscycle) cannot locate its reference. Ridgeback does not does not provide the information online nor answer to emails enquiring about the hanger.

I ordered a gear mech derailler hanger on ebay to a French merchant, Alpine Bikers. They do not answer to questions on ebay but they do ship spares made of aluminium.


Reverse rear mech hangers Ridgeback Meteor 2004
Rear mech hangers Ridgeback Meteor 2004
rear mech hangers Ridgeback Meteor 2004 reverse
Reverse rear mech hangers Ridgeback Meteor 2004

If you think of the hanger as having the shape of a seahorse, the replacement piece has a mouth a bit too long. It cannot be attached to the frame for that reason. My local key-maker trimmed some 2 mm off the piece and the trick work: my bike is on the road again.

Bicycle tyre Schwalbe Marathon Plus

The Schwalbe Marathon are remarkable tires. I think that I inadvertently rode for at least 100 kilometers (in consecutive riding sessions) with a grain of quartz embedded in the tyre.

Schwalbe Marathon Plus tire
Schwalbe Marathon Plus tire with a grain of quartz

According to a friend who regularly enrols in cycling expeditions in exotic countries, the tire is the primary choice for a world-trip because it’s so reliable.

igraph to calculate the internal PageRank of websites

plot graph website for SEO analysis
Graph of an ecommerce website where the nodes are webpages and the edges, links between them
Analysing websites internal linking is key to understand their architecture of information and web structure and thus their potential of Search Engine Optimization, SEO.

Graphs are made of nodes and edges. In SEO nodes are webpages and edges, links directed to them from other webpages on the graph.

dat=read.csv(file.choose(),header=TRUE) # choose an edgelist in .csv file format,directed=TRUE)

Transitivity or clustering coefficient is the probability that the adjacent vertices of a vertex are connected.

Count vertices vcount(graph)
Count edges ecount(graph)

The diameter of a graph is the length of the longest geodesic.

Graph density
The density of a graph is the ratio of the number of edges and the number of possible edges.

Find more about plotting directed graphs here.

Disconnected notes from an amnesiac