Changing Schwalbe Marathons for Kojaks on a Brompton
 

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.

Be interested to see if you find what I found when I went to kojaks - that they simply roll over crap that would get stuck in the tread of a marathon (and eventually puncture). At least for me on our lousy roads full of junk, the kojaks "float" over stuff. You can actually hear it fling off underneath; sounds like a small gun! I've heard the folding ones are easier to mount; I've not had to take one off/on yet.

In my eyes the Kojaks are definitively faster than the Marathon. Do yourself a favor and pump them to at least 100 PSI. They are rated up to 115 PSI and the more you put in the better they roll, so if possible go as high as your pump allows. Regarding punctures: Probably you'll have the opportunity to enhance your training with putting the rear wheel on and off a bit more often. :p Over time they get a lot of cuts but that does not necessarily mean they need to be changed. I do not need tire levers with the Kojak at all btw.. .

I suggest training at home to take on and off the tires, rather than in the street with onlookers. Breaking the levers is a clear indication that one is seriously off-track in terms of the sought ability and that the dedicated effort is required to get on track.

Supple tires at low pressure both dampen out bumps and are more resistant to flats than if run at higher pressure. On my Brommie I pump Primo Comets to 70 psi about once a week. So most of the time they are 60 psi. They work well in a city environment.

Kojaks are miles faster and lighter than Marathons, so if you can live with their flats frequency it's all good. Marathons theoretically have better puncture protection, but they're miserable bricks that make up for being slow and heavy by being impossible to remove. Yay!

+1, and I am talking about the plain Marathon not even the plus. I am not sure if they are making the plain Marathons. Yes even those were bricks.

I am sure that from the side of onlookers the event was a further confirmation that mastering English can damage one's mind ;). In any case, I persist in using plastic levers as sensing that they might break signals to me that I am on a wrong path and must retreat. My latest home exercise included putting a studded tire onto Brompton with fingers only. On the road I am lazy and carry a lightweight bead jack. My carrying of any tool tends to have some history behind :twitchy:

32-349 Kojaks, right?
 

if so, i would avoid triple-digit pressures. 100psi on Kojaks, you'll be bouncing along all the time, decreasing braking effectiveness, and increasing likelihood of punctures plus road-side inflation will be a b!tch with a portable pump. This, from my two-year experience with 35-406 Kojaks. And yes, the sidewalls are fragile so ride them carefully.

I would agree with this. Even the super skinny 451 tires on my Mu Uno are only run at 80psi, anything above that is ridiculous unless you're racing on a velodrome. On the street they just ricochet off everything and slow you down.

I run the road bike tyres at 110 psi rear and 100 front, so will bump the rear Kojak up to 100 and see how that goes. The road I'm going on today has a generally good surface, so bumps shouldn't be a problem.

Incidentally, I wore out a Marathon tyre running it at too low a pressure, plus nearly skidded off the road when cornering on the road bike for the same reason, so learnt the lesson and keep pressures at the midpoint or higher of manufacturers' recommendations.

I run the kojaks on my 16" pakiT @ 90 psi. Firm but not rock hard, no flats so far. I don't like the ride when the tires are much lower than that.

OK, but Primo Comets are Cheaper.. & quite adequate.. got a set on my IGH BF Tikit, now..

Marathon K is on the Brompton, the others have reduced the black rubber, displaced , thickness,

over the green and blue bands , so not as much wear life ..

Marathon K discontinued .,Boo !




...

Depends on where you are. Over here Kojaks are much cheaper than Comets. In the US it may be the other way round.

What is a "Marathon K"? Both, Marathon Green and Marathon + are good for a lot of miles, far more than the Kojak and more than the Brompton Kevelar (das has been discontinued). Maybe the Marathon Racer fits your desires better.

What is...anything in that post?

K for Kevlar , its negligible in thickness

Data from site blue displaces 3mm of tread rubber, green displaces 2mm.

less of an issue in a larger diameter wheel .. that rotates less frequently per mile..

How many Marathon Green or Marathon + did you manage to ride trough until you reached their green respectively blue rubber on your Brompton until now?

I had a couple blue patches show through in only a few months , just off center ,
where the black rubber is just a thin 2mm skin over the puncture band..

IMO reducing the casing would allow the tread rubber to be thicker, than a few mm..

But I'm just someone paying for them. same price for a 16 or a 26"

Astonishing. How many miles did you put on them? Blue means Marathon+ and those are typically good for many thousand miles. I've pair of Marathon green on one of my Bromptons and maybe put about 1500 km on them until now. They show barely any signs of wear if any at all.

The whole point of the M+ is puncture protection. If you do not like the thickness I'd suggest using another tire - like the Marathon Green, the Marathon Racer or the Brompton Kevelar... All of those are thinner in that aspect.

Over here I pay (when buying online cheaply) 13,30€ for the Kojak, 13€ for the Marathon Green and 20€ for the Marathon +. Not really expensive. All last at least serveral 1000 kms, with the Kojak having the lowest endurance milewise. I'd assume the Marathons last at or above 10.000 km.