A few months ago PH2 tested Dunlop's new
D212 GP Pro
tyre, a black and round object that offered quite remarkable levels of grip and dominated the Isle of Man TT podiums. Having previously visited Dunlop's Birmingham R&D facility where we saw the tyre being made, PH2 was introduced by Dunlop to a new technology called JLT. Far from a poor imitation of a boy band, JLT is a very neat process of getting the rubber (compound) onto the tyre.
New SportSmart gives added dry confidence...
It stands for Jointless Tread; where conventionally a tyre's carcass is 'wrapped' in a single layer of compound which then has its ends stuck together before being cured to finish the process and set the compound, JLT is a new technique.
Dunlop 'wind' a single strip of compound onto the carcass as it spins on a machine in much the same way a sewing machine winds a bobbin of thread. What's neat about this is that the single strip of compound is only about half a centimetre thick, meaning Dunlop can stop the extrusion of one compound, replace it with a different one, continue the wind, then replace the compound again.
Basically it can vary the compounds across the tyre's surface with a high level of accuracy, giving the tyre sticky edges and a hard wearing centre compound for mileage. So what's this got to do with the new SportSmart2?
... it's still a hairy ride in the wet though!
At its European manufacturing plant in France, Dunlop has just invested in a brand new JLT machine which is being used to build the new SportSmart2 tyre. Replacing the old SportSmart, the SportSmart2 (SportSmart x SportSmart = SportSmart2, see?) features JLT technology, a sharper profile front tyre that is seven per cent lighter, has a new tread pattern and a performance rating of up to 187.5mph. Retailing at around £225 it is also cheaper than the old tyre and remarkably comes with a 100 per cent satisfaction guarantee, meaning if you don't like it then you can get your money back. Although PH2 suspects that if you blast out 3,000 miles and then decide it isn't for you Dunlop may reject your claim...
Sharper and sweeter
Dunlop gave us a selection of Suzuki GSR750s to ride on the road with some bikes fitted with SportSmarts and others with the SportSmart2 so we could back-to-back the tyres.
Swapping between the two tyres the SportSmart2 made the Suzuki feel slightly more agile to turn thanks to its new profile. Where the SportSmart felt more like a touring tyre as it 'rolled' across its profile when you turn into bends, the SportSmart2 was definitely sportier with a quicker steering action and softer feeling carcass construction. Where the SportSmarts felt quite solid, the SportSmart2 seemed to soak up small bumps better as well as offering very impressive levels of dry weather grip with a very confidence inspiring feeling. But what of the wet weather performance?
New tyre is sharper on a dry track too
Having blasted around the roads in the south of France, Dunlop then let us loose on its wet weather test track. Covered by 0.8mm of water, we splashed around on the GSRs desperately trying not to drown. Was the SportSmart2 an improvement over the SportSmart in the wet? To be honest I was too worried about falling off to really notice much difference, but as I didn't crash on either tyre I left the track wet but happy...
Having survived the experience, the next part of the Dunlop Krypton Factor challenge was a series of track session on R1s and CBR600RRs with the new and old tyres fitted. Bearing in mind the SportSmart2 is a road tyre predominantly the grip levels on track were good; however, if I was planning a track day I would fork out for a set of D212s and go ballistic rather than opt for the SportSmart2. The more road-biased tyres felt like they were getting near their limits of adhesion quite quickly.
As I couldn't really detect any difference in grip levels between the SportSmart and the updated SportSmart2, I asked a Dunlop person what the variations in compound were, only to be told there was basically none, just the way it is put on the tyre.
SportSmart2s look good value at c. £225 a set
Having generally ridden on Pirelli or Metzeler tyre of late, I am hugely impressed with Dunlop's latest range of tyres. A few months ago I fitted a set of SportSmarts to my bike and they are a lovely road tyre that gives you loads of confidence in both the wet and dry. The SportSmart2 takes this feeling and adds a bit more sporting potential, something I didn't actually feel was lacking in the SportSmart. At £225 a set the SportSmart2 is well priced and I'm intrigued to see how this guarantee works out for Dunlop; I can't see anyone asking for their cash back.
NOTE: Dunlop's tyre is the SportSmart2 (with the '2' there to represent SportSmart squared). Unfortunately, our CMS doesn't allow us to type squared numbers, so it's just a regular 2 in the story!