Let me first say that the Marathons are fine tyres, and will be going on the Neo in Thailand. Also, what prompted the change was more to do with rear punctures, already difficult enough on the Brompton and not made easier by the sweat involved in getting the Marathons off vthe wheel. I've been caught in the middle of Paris having to do this, and had attracted a large if not helpful crowd by the time I'd broken two tyre levers and reduced one thumb to a bloody mess.

Anyway, so to-day I bit the bullet and swapped the Marathons for Kojaks. There's no question the Marathons are the more solid tyre by a country mile, and the number one choice if you have to deal with crappy, potholed road surfaces. The Kojak's sidewall is positively flimsy by comparison. It is a lot lighter, but I'm no convinced that, on what is already a heavy bike, that would make a lot of difference. They are easier to put on, although I did resort to tyre levers at one point. Also, having reached the point of putting the valve through the hole in the wheel, I did wonder why I hadn't changed the blue tape as well it is both stiff, and, in my case, was broken.

Pumped the tyres up to 90 psi, and headed off on the same run I'd posted about previously.

First impressions is that the Kojaks are quieter than the Marathons, more stable, and give a better feel of the road, though that could be because the tyres on my other bikes do not have treads either and I'm used to them. They also seemed to roll faster, though that could have been more to do with the windless conditions. I would think, however, their rolling resistance is better than their Marathon cousins. They felt quicker, which my Strava readings confirmed, but again that probably had more to do with different condition and a slightly fitter rider. For anyone who is interested, I completed to 20km run on the Marathons in 1hr 3 minutes, and in 1 hour exactly on the Kojaks. Neither is up with the road bike, which shaves 6 minutes off the Kojak time at worst.

Impressions are entirely subjective, so I'm going to sum up simply by saying if you want a rugged, bullet-proof tyre for testing conditions, stick with the Marathons. If punctures are a problem - and the Marathons will puncture, just like any tyre - then the Kojaks allow easier replacement. They may also be the more comfortable and faster tyre on good surfaces.