How marginal are marginal gains?

It’s become less fashionable a term recently, on account of its horrific overuse, but marginal gains is the idea that if you make incremental improvements to your setup or training that it will add up to something significant. It was popularised in the early 2010s by Team Sky (now INEOS) back when they used to win stuff. 

Recently, I’ve been on a bit of a buying spree for my TT bike and have been thoughtfully shopping – aiming to prioritise by Watts saved per pound spent, but while doing this I realised that the thing that matters really is time saved per pound spent.

The marginal gains we will test in today’s simulation will be…

  • Switching from GP5000 to GP5000 TT, both with latex inner tubes

    Independent tests of this set up have shown an improvement of around 1-4W per tyre.
  • Removing the front derailleur and switching to one chainring

    This could save, again, between 1 and 4W in aerodynamic savings.
  • Adding an aero OSPW system

    This has a claimed saving of 2.4W relative to a dura ace set up.
  • Using a super slippery waxed chain

    Wattshop claim their ‘Cratus’ waxed chain can save 3-5W compared to a standard clean chain.
  • Very moderate weight savings

Using a combination of factors, I’ve also managed to shave 650g off my set up and body weight. 

Marginal gains can include aero overshoes that go to knee height and other such accessories banned by the UCI on the grounds of fashion decency.

Before we get started here, it’s worth noting that all of these claims are probably wrong in the context of this specific simulation with this specific setup. However, that’s not really the point of this blog. It’s actually to answer the question of “We know you can accumulate meaningful savings but how much of a difference does it actually make?”

The first step we’ll do is run each saving individually and then finally, we’ll put them all together and see the time difference between the standard set up plus all the marginal gains. 

It’s worth noting that aerodynamic savings scale with speed whereas rolling and drive train resistance savings remain more stable (they’re not actually constant, but for the simplicity of our model approximating them as constant yields acceptable results). 

We will assume that, for the sake of simplicity, saving 1W is the equivalent of riding 1W harder – this is not actually true (as 1W saved at 30kph might be 3W or something at 50kph) so, if anything, this is likely to underestimate the time savings from our marginal gains – especially the aero ones. That said, it makes the simulation much simpler to carry out – so we will make the assumption none the less. 

The final assumption we’ll make here is that our rider is riding at a constant power of 300W – this is not realistic, or optimal, but makes it easier to isolate changes so we’ll do this for illustrative purposes. At the end, we’ll have a perfectly paced simulation – centred around 300W. 

Standard Set Up

Using our standard set up on the almost 87km bike course from Challenge Peguera Mallorca we can see that our rider is able to achieve an average speed of 39.4kph. This was completed with a standard 2X12 drivetrain with a new-ish, clean but standard chain, Continental GP5000 tyres and such. Pretty close to the standard, out the bike shop, set-up. 

After each run, we’ll reset the simulation to the original conditions so when you see a time saving, it’s with respect to our baseline set up.

Weight Savings

As we’ve saved 650g – that’s about 0.7% of our total system mass, we might see a gain in speed as a result of this, considering it’s a pretty punchy circuit. Let’s run the simulation taking 650g off our set up and see what happens. 

We can see here that we’ve saved a total of 11 seconds and had a speed increase of 0.1kph, based on the amount of money and effort that weight loss required I’m not certain it was worth the bother… 

Waxing our chain

Let’s see if the Wattshop waxed chain, with a saving of 3-5W (we will use 4W) can save us a decent amount of time… 

A Wattshop chain typically costs about £70, so we’re paying £1.40 per second saved. Let’s take a look at the OSPW.

Oversize Pulley Wheel

A saving of 26 seconds is decent, but when we remember that the OSPW costs around £400, we’re looking at about £15.38 per second saved which isn’t the best value for money, however it’s a decent saving if money is no object. 

Going “one-by”

Typically, the 1X chainring’s aero savings are dependent on yaw angle but savings between 1 and 4W are common. As such, we’ll see a saving of around 35s here.

Fresh Tyres

This is actually one of the most interesting examples of non-obvious speed improvements. Independent testing has shown the difference to be about 3W per tyre – so a total saving of 6W. Running a simulation with a 6W boost in power we see this… 

A massive 75s off our original bike split, I bought a pair for £120 which is a price of £1.60 per second saved. 

All together

In total, these savings add up to 15W (plus our 650g) saving.

When we put all of that together we find a total saving of almost 2 minutes adding 1kph to our initial average speed. 

Marginal gains AND perfect pacing…

That’s not the end of it though, we all know that riding a course (especially one that’s hilly) with a flat power is not the fastest way to do it. 


You can optimise your pacing for a £20 a year myWindsock subscription, which costs you 19.6p/second saved. 

As much as it pains us to say (not at all, we love it), marginal gains really do add up, without getting any fitter at all we’ve just saved ourselves almost 4.5 minutes simply by throwing money at the issue and pacing properly. 

Save yourself time and money with a myWindsock subscription today.