Just finished off my sixth rear TKC and I’ve started thinking about tyres yet again.

Now, after having tried every permutation of TKC80 that fits the Tenere, I thought it might be of interest to share a little feedback on the differences I found between the various TKC options for the XTZ (and XTR for that matter). It might help someone in making choices about these tyres, especially which sizes and speed ratings of TKC to opt for. This isn’t about comparing TKCs with other brands (that's been done to death), it’s about comparing the different choices of TKC.

So… Over the last six years I’ve used 2.5 TKC fronts and 6 TKC rears of varying rating and size (interspersed with other brands of tyre). Mix of riding is very roughly 80% on and 20% off-road; there’s hardly been any (maybe 5%) motorway miles as we don’t have any in Norfolk!

Fronts Used

2x 90/90-21 54 S (6768 miles & not done yet at 4068 with about 4.5mm tread left)
1x 90/90-21 54 T (7790 miles)

Rears Used

2x 130/80-17 65 S - 3326 miles & 3402 miles (average = 3364 miles)
2x 130/80-17 65 T - 3848 miles & 3942 miles (average = 3895 miles)
2x 140/80-17 69 Q - 2109 miles & 1959 miles (average = 2034 miles)

The fronts were all changed with around 3mm tread left and the rears were all swapped at about 2/3mm.

Of course different riders get different mileages out of the same tyre; you might get more than me, you might have got less, but the question is, what’s the difference between the S, T and Q rated TKCs and between 130 and 140 rears (used on the same bike, with the same rider and same usage)?

Firstly, the difference between S and T rated fronts is about �10 and with the rears it’s about �15, which means the Ts are about 20% more expensive. Interestingly, it would appear that the tyre life with a T is only 15% better, so it’s more cost effective to get the S rated tyres, especially as there seems to be no difference in handling (as far as I can tell).

IMO, steer clear of the 140/80 Q rear (even though Continental have them listed as a recommended fitment). They are about 50% more expensive than the 130s and only appear to last about half the distance. Plus, the 140 seems (to me) to make the steering more twitchy, squares off quicker and seems to spin up more easily under power on loose surfaces. I think the more rapid squaring off is due to the fact that the wider section (on the stock rim) means the sidewalls (at the beads) are effectively being pulled in causing the tyre to take on a slightly rounder of even oval profile/cross-section. This might also explain the slightly more skittish steering with the 140 too?

It must be said though, that all versions of TKC seem to make for nervous steering and straight line stability over an indicated 75mph, it’s just with a 140 rear, it’s more pronounced. Lowering the front pressure to 28psi seems to help in every case.

With all the ratings/sizes grip and handling in the dry is very good for the type of tyre and OK/predictable in the wet, although they take a bit of getting used to. There’s nothing to choose between them. All have been excellent off-road (subject to my limited skills) apart from the 140s tendency to spin up more easily and they don’t work in “proper” mud. They are surprisingly reassuring in sand (which there’s a lot of on the Norfolk trails round the Brecks/Thetford Forest).

They are all easy to change by hand if that’s a factor in your consideration, although the 140 (which is a tubeless fitment) is more of a challenge to break/seat the bead (yet another reason not to get one!)

Also of note is that I’ve had an advisory on two MOTs (where I’ve had TKCs on at the time) for “cuts in the tread”, which is almost certainly down to the sharp-flinty/sandy nature of the dirt round here. Again the 140Q seems to be worse in this respect. I haven’t noticed this so much with other brands of tyre I’ve used, which would suggest the knobs/carcass is on the softer side.

To sum up, IMHO don’t bother with a 140 unless you really need the extra load rating (69 as against 65) or want the “fat-chunky” look; it just isn’t worth it. In fact it doesn’t actually look much wider because the narrow rim pulls it in at the sides as mentioned earlier. As for the others, well you may as well get the S rated tyre, it works out more economical in the long run. If you feel the need for the extra speed the T allows (118mph) and ride a lot motorways and dual carriageways at higher speeds, then I’d suggest you’re either using the wrong type of tyre or got the wrong type of bike!

Anyway, food for thought.

In the interest of research, I think I might try something completely different this time round... Perhaps even a TKC70 when the smaller bias-ply sizes come out in January. In the mean time I’ll be sticking on a part worn K60 Scout I have in the shed.

__________________