David checks out this pair of Goodyear Newton tyres, the latest MTB rubber from Goodyear.
Despite starting out making bicycle tyres at the end of the 19th Century, from the mid-seventies, Goodyear took a 40 year break from bike tyres. That was, until they signed a deal with Kent International, who own Rubber Kinetics LLC (Rk).
After two years of development, Rk has some high end mountain bike rubber in the form of these Newton tyres, of which I’ve been testing a Newton ST EN Premium in 27.5in and 29in, and a 27.5in Newton EN Premium, which is slightly faster rolling with a different tread pattern.
The naming on these gets slightly confusing, as they’re basically different tyres, with very similar names, that use a lot of two letter acronyms. The “EN” in EN Premium refers to the casing, which is the most robust they offer to go with these tread patterns. “ST” is a mystery (Staggered tread? Super tyre? Silly title?), but of the pair, it designates the front tyre.
Up front, the Newton ST has staggered centre knobs to give better cornering performance. They’re not too tall, ramped to reduce rolling resistance, and fairly widely spaced. The rear tyre Newton (non-ST) centre knobs are aligned laterally into rows, disposing it less to cornering than the ST one, but maximising braking traction by presenting plenty of edges at a right angle to the bike.
Both have the same side knobs.
On first poke, these had a kind of waxy surface texture that felt like it might be mould release compound. More on this later.
These are really not easy tyres to fit and, while that was frustrating, it does also seem to have some benefits when it comes to bead and air retention.
The 29in tyre had been fitted and ridden by Ross for a few rides before I got hold of it, and went on and up quite easily as a result. The brand spankers 27.5in ones though, sheesh! Things I did while trying to get the first of these on:
- Started with a carbon wheel.
- Resorted to zip ties just to stop the tyre ejecting itself from the rim
- Honest to god double-checked it wasn’t a 26in tyre.
- Pulled it back off, syringed the sealant out, and added a tube to try and stretch it out.
- Nearly cried.
- Gave up on that wheel.
- Swapped to a wheel with a Stan’s Flow EX.
- Took an hour off for my poor thumbs.
- Straightened or snapped most of my tyre levers.
- Nearly cried getting the second bead in.
Weirdly, adding copious soapy water to the beads seemed to hinder rather than help. I was at the point of giving up when, on the off chance it could make a difference, I dried the tyres out and tried inflating with no soapy water and no sealant. Pop, pop, pop, pop. It felt like a miracle. A weird miracle.
These tyres aren’t UST rated, but seem to be most of the way there. Impressively, they all mounted and stayed up for several days without any sealant. When they eventually went down, I saw the beads were so tight that they’d dismounted and migrated back down into the rim well.
I decided to inflate them like this for a few days more, to see if they’d stretch a bit. Answer: Yes, a little, making them easier to pop on and off wheels.
Add rim inserts and 25mm internal width rims to double the fun. With all of that in the equation, on new tyres I had to use zip ties to stop beads popping back out. Ouch. Second mount was much easier, but still required levers. I don’t think these will ever be a baggy fit.
They’re fairly heavy tyres too, with the Newton 27.5in weighing in at 1074g and the Newton ST at 1065g. While it is a folding tyre, the beads and sidewalls are so reinforced with rubber that it feels like a downhill tyre.
On a selection of Stans and Mavic 25mm internal rims, measuring corner to corner on the widest side knobs, they came up at 2.3in rather than 2.4in.
On The Trail
As can happen early in the UK year now, during this test we got an extremely wide variety of weather conditions: a dry spell culminating in February dust, then ice, hail, snow, torrential rain, and of course, mud.
Ross briefly ran one of these as a front tyre, but swapped it after an off-camber rock took out both the tyre and his confidence in it. I suspected this wasn’t down to the actual tyre, but the waxy feeling coating mentioned above. A quick scrub with some soap, followed by a few miles of road on the same tyre resulted in very different feeling rubber, and I’m pleased to report no similar issues.
I kept giving it little off camber tests, with no slippage, but still, what Ross had said was in the back of my mind. That was, until I accidentally lifted the rear wheel clean off the ground going into a corner. The front tyre bit in and held my full body weight all the way round to the exit. No slips. Cue hysterical laughter and a newfound confidence in these tyres (to do: months of practice to repeat this, intentionally and consistently).
The Newton ST isn’t the spikiest tyre, but that does help it roll pretty fast, and it clears mud well too. Rider preferences vary so much – some people run a mud spike all year round just in case there’s a bit of drizzle, while our very own Daz can run Maxxis Ardents front and back for the winter, and still be fast as the proverbial off a shovel downhill.
I’ve found the Newtons a good in between. They’re not quite as toothy in the centre as my usual rubber up front, but that’s taught me just how much I seem to rely on side knobs over centre tread – not that I’d ever get away with a semi-slick on the front.
Goodyear/Rk don’t publish any shore durometer hardness ratings for them, but along with the tread pattern they seem like a good compromise between stickiness and rolling speed.
The Newton out back had plenty of climbing traction, and even impressed me on a frozen day above the clouds. A particular rocky traverse had deep puddles that had been turned to solid ice. Normally putting too much torque down and spinning the rear wheel on ice would result in the back of the bike rapidly going sideways. These Newtons, I found, would quickly bite back in as I eased off the pedals, minimising those slips and keeping me mostly on lines I intended.
At the bottom of a snowy but fast descent on the same day, a friend exclaimed “That was sketchy!”. I hadn’t noticed. Likewise in mud, front and back they had a good mix of bite for climbing and turns, plus fast mud clearance.
Hannah is another person at the office who’s ridden these, as her rather beautiful Stanton Switch9er FS arrived wearing them, though they evidently had a lot of miles on them. As a result, Hannah hasn’t had as much confidence as me, finding them a bit too keen on going sideways. That could be said of any tyre once it’s lost its edges, but I suspect the low centre knob height of Newtons exaggerates the effect.
Aren’t us mountain bikers a sensitive bunch? When I were a lad, we ran tyres until ‘ tube ‘erniated through ’em. Anyway. The Newtons I’m running aren’t showing any excessive wear after a few hundred kilometres of riding. Just beware, if you’re the kind of rider who runs tyres until they’re almost bald… well, you’re probably not that worried about tyre performance in the first place, eh?
Finally, getting back to that burly carcass: They held up really well to rocky Calderdale riding, and between those reinforced beads and sidewalls, seem to have good flat and burp resistance.
Goodyear has positioned these as enduro tyres, and their relatively high weight certainly points to them not being for XC. These are quite far from the cartoony extremes of mud spikes or file tread. For winch and plummet riding though, I found them to be good, tough all rounders for a very wide variety of weather conditions.
|Product:||Newton and Newton ST|
|Tested:||by David Hayward for Two months|
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