miscellaneous

Shimano Ultegra 6800 Wheelset: an evidence-based review

Earlier this year I bought some new wheels for my commuting bike. They certainly felt like they made it faster, but did they? Since I record all my rides on Strava and go the same route between Witney and Oxford everyday I have a good dataset. In theory, changing the wheels was the major difference between 2015 and 2016 so if I compared the same period (June to Sept), it should give me a pretty good idea of how much of a difference the new Shimano Ultegra 6800 wheelset made.

First, let’s look at just after Wolvercote Roundabout to just before Cassington, a distance of 2.6 miles. It is all cycle path with no interuptions, with just a few gentle lumps in the form of two bridges. As the wind typically blows from the south-west and strengthens during the day, I usually have a light tail-wind in the morning and a stronger head-wind on the way home. In 2015 the out and return legs took took me, on average (excluding the fastest and slowest 10% of rides to remove outliers), 10 min 17 sec and 9 min 24 sec, respectively. This was a surprise, since it meant I was nearly a minute faster on the way home, despite tending to have a headwind. Perhaps I put more effort in the afternoon compared to the morning. Note that the Python code detected between 39 and 86 rides for each year/direction combination, so that is a good number of rides.

How did the wheels do? Well, the averages for each leg decreased by 24 sec and 23 sec, respectively, a reduction of around 4%, which doesn’t sound like a lot, but over a 50 min commute is, on average, 2 minutes, which is noticeable.

Wolvercote to Cassington, afternoon, tends to be a headwind

Averages though can hide a lot, so let’s take a peek at the distributions. These more clearly show that on the way home, the rides are more tightly bunched and I cover the distance in between 8 and 10 mins, whereas on the way in there is much more variation in how long it takes me to cover that segment, with most days it taking me between 8 and 12 mins. Both cases clearly show, however, that I tended to be faster in 2016 with the new wheels, than 2015. But, as both distributions overlap, there were many days when I was faster in 2015 with the old wheels than I was with the new wheels in 2016.

Cassington to Wolvercote, morning, tends to be a tail wind

In conclusion, the new wheels did speed up my journey. Perhaps more important is something I can’t capture with data: the bike “feels” faster and is more fun to ride.

Interestingly, given my previous wheels were old, fairly heavy and came with my Dawes Galaxy about 9 years ago, shifting to Shimano Ultegra should be about as big an upgrade as one could reasonably make, yet the improvement is “only” 4%. Food for thought if you are doing a more minor wheel upgrade.

I’ve moved…

Today is my first day as a Senior Researcher in Modernising Medical Microbiology in the Nuffield Department of Medicine at the University of Oxford. Practically I’ll be based at the John Radcliffe Hospital in Oxford.

I was a Postdoctoral Researcher in the SBCB Unit at the Department of Biochemistry for ten years, working with Professor Mark Sansom. During that time I used computer simulation to study the function of a variety of membrane proteins, focussing mainly on cell signalling, transporters and ion channels.

Now I will be leading efforts to predict whether novel bacterial mutations lead to antibiotic resistance (or not). The key idea is to examine the effect of each mutation on the binding of the antibiotic to its target protein. This boils down to calculating how the binding free energy changes when you make the mutation — something that alchemical free energy methods, such as thermodynamic integration is well-suited to.

More soon.

Dr Firdaus Samsudin

Congratulations to Firdaus Samsudin who successfully defended his DPhil thesis on Tuesday 10 November 2015. His thesis is titled “Improving Oral Drug Delivery: Computational Studies of Proton Dependent Oligopeptide Transporters”. He has been published one paper, another has been accepted and a third is in preparation.  I will update this post as our papers are published.IMG_9989

Goodbye Hans Krebs Tower

When I first started in Oxford our lab was based on the top floor of the Hans Krebs tower. Since 2008 we have been in the imaginatively named “New Biochemistry Building” which is actually only half a building, but that is another story. To make room for the other half, the Hans Krebs Tower is finally being demolished. In celebration and/or memory I’ve posted a stop motion video I took from my desk out of the 7th floor back in January 2008. You can see several of the characteristic spires of Oxford as well as the plumes from Didcot power station. This too has recently succumbed – 3 of the 6 cooling towers of the old Didcot A power station were demolished three weeks ago.

View from the Hans Krebs Tower