This is what I wrote elsewhere a few days ago in a different post on tyres:
The original question was about a good touring tyre for use in Western Europe. I also assume that most of this would be on tarmac, with the occasional gravel road etc thrown in. In essence, you want the fastest and most comfortable tyre you can get away with. At one extreme, I think a tyre like the Marathon XR is overkill, and at the other extreme narrow racing tyres mean you are asking for trouble and riding uncomfortably. So let us try to narrow the range a bit further. At the rugged end, I think the Marathon Plus is still nearly always overkill (unless you are riding in a thorny area). I really think that for a solo tyre (tandems are a different story) the ordinary Marathon or the Marathon Supreme are as rugged as you will need in Western Europe. In my family we have used the ordinary Marathon on all our commuting and many of our touring bikes, and they are very reliable (virtually no punctures over many years), and reasonably fast. In recent years we have also had very good experiences with Schwalbe Big Apples (loved the 50 mm, hated the squishy 60 mm). These are significantly faster than the Marathons, more comfortable, and thanks to their size quite grippy on soft terrain. Thus far, we have not had any punctures with them. At the even faster end I think the Schwalbe Marathon Racer and the Panaracer Pasela Tourguard are the lightest and fastest tyres. Of the two I have only used the 26x1.75 Pasela (the Racer is apparently a bit harsher). I know the Pasela is less puncture proof than the Marathon or the Big Apple, but the ride is glorious. So those would be my personal choices: the Panaracer for light loads and for those of you who do not mind the occasional puncture (but it is really not too bad) or fairly rapid wear, the ordinary Marathon (or probably the Supreme, but I have not used that tyre) for heavier loads, for tandems, and for rougher conditions. Those are the two tyres I alternate between, depending on conditions. If you don't want to alternate between tyres, and if they fit, the 50 mm Big Apples are the perfect all rounder, I think. They are fast, comfortable and reliable. Only you can decide what kind of riding you will do, how heavy you and year gear are, and how irritated you will be if you have a puncture. In any case, I would fit the widest tyre that will fit your frame (but not the 60 mm Big Apple - I hated the imprecise feel).
Willem
In your particular case I would think a good quality tyre is likely to improve your speed and ride. Whether you want to spend the money is up to you. These Kenda's do not represent a value of more than a few pounds. On the other hand, if you are already investing heavily in gear, this may not be the right moment to ditch them. In any case, I want to insist that narrower tyres do not necessarily make a touring bike any faster. What makes them faster is a more flexible casing, and that is expensive because much more difficult to manufacture. Also, the fun of touring is increasingly to ride on very minor roads where the surface may be bad, and mixed with gravel roads and the like. So my suggestion is instead to go as wide as you can. I am not sure what your frame will allow, but many bikes that come equipped with 37 mm tyres will also take 42 mm tyres. I have done that with one of our bikes, and the result was very satisfactory. The ride was much smoother, the handling a bit slower and more stable, and its off road capacity much improved. I bet 42 mm Marathons (but please not the plusses) will be quite a bit faster than 37 mm Kenda's. If you really want to ride faster, go for 37 mm Pasela's. However, these are not particulalry cheap, and they will not last nearly as long as a Marathon. If by any chance 50 mm tyres will also fit, by all means go for the Big Apples (45 real mm wide).
Willem
