New Maxxis Aspen ST and 170tpi casings available
The Maxxis Aspen ST has been released along with the Team Spec 170tpi casings finally coming to market.
If you're a big XC fan you would have seen the Aspen ST on the wheels of top riders for at least two years. The likes of Nino Schurter has been running the Aspen ST since at least the 2022 Cape Epic, and numerous Maxxis athletes have been seen using the ultra low profile tread at select events around the world.
At the same time, Maxxis have also made their 170 tpi casing available to the general public – this was previously reserved for Team Spec tyres, save for use on some road tyres and mountain bike models from over a decade ago. The higher thread count means the threads are smaller, there's less rubber needed to fill the gaps, and you get a lighter and more supple tyre as a result. This is approximatelt the casing that Nino won on in Rio in 2016 – although that was an Ikon and we hear it didn't have the EXO protection. It could easily have been close to a 500g tyre!
All about the Maxxis Aspen ST
By their own account, the Maxxis Aspen ST is a race-day tread. Tread is an interesting choice of words as well as there really isn't much of it. The Aspen is fast with low profile tread and reasonable edge knobs – and at 762g in a 29 x 2.4" width (60.5mm measureed) it is a light, high volume tyre in the 120tpi MaxxSpeed model.
The Aspen ST has taken a knife to that tread. A lot of the centre tread is gone, replaced with a file tread pattern reminiscent of a cyclocross tyre. The edge knobs remain very similar, and Maxxis have kept some tiny lines of tread across the tyre, and in the transition area.
The 170tpi casing
Threads per inch, or tpi, has an impact on the weight and compliance of a tyre. Typically, a 120tpi tyre has a more supple feel than a 60tpi tyre. With a higher thread count, the tighter eave has less gaps for rubber to fill and usually a finer thread. So typically they weigh less, and can deform more for greater compliance and grip. 60tpi can win out on strength, and some brands use double (or triple) layers of casing to get the strength and ride quality they want.
The 170tpi casing has been pro only until now, and that is why you will see the Team Spec badge on the sidewalls.
The 170tpi models we have on test weigh 604g for the 29 x 2.25" Aspen ST, and 700g for the 29 x 2.4" Aspen ST. They inflated to 58mm and 61mm on 25mm and 30mm rims respectively.
The OG Aspen is also available in the 170tpi casing, and the Aspen ST models are also available in 120tpi casing, so Maxxis really let you pick the tread, tyre width and casing to suit your end use.
Setup of the Maxxis Team Spec Aspen ST 170tpi
After cutting the tyres off the backing plate, I threw the packaging right into the recycling. It is great to see Maxxis move towards recycleable packaging with minimal inks. Do this more, bike industry!
The tyres feel supple in the hand, noticeably more so than a 120tpi casing XC tyre like the Maxxis Severes I was removing. I fitted the 2.25" models onto a rim with 25mm internal width, and the 2.4" models onto a set of wheels with a 30mm internal width. I did use my compressor to seat both tyres, with Joe's Elite Racer sealant inside each. I did try my track pump with a valve core removed, but I didn't get an immediate result – hence I grabbed the compressor.
The beads popped into place easily, as you would expect from a Maxxis TR (tubeless ready) tyre. They have also held their pressure overnight.
The tread has a very round profile once inflated, and the edge knobs do sit a bit inboard based on their respective widths and aforementioned rim widths. But this should be expected – they're not billed as a tyre to have insane off-camber grip – they're put out there as a race-specific tread for fast, hardpack conditions.
The edge knobs have some sipes cut in, and the design is about putting lots of fine edges onto hardpacked terrain. This tread won't suit much loose over hard, but it will love hero dirt in select conditions. Loam and wet roots will not be fun – and I'd say very late, aggressive braking points won't be rewarded. Throw some Aspen STs on for a short track race or fat tyre crit, a hill climb time trial or maybe an old school marathon course in good conditions, and you'll be flying.
The weight is a great saving for the fast kids of XCO and marathon racing – but the 2.4" Aspen ST in 170tpi is a similar weight to than a Pirelli Scorpion XC RC in 29 x 2.4" (699g) which are a class leader for grip and support. Still, the Aspen ST is about low weight as one thing, but also low rolling resistance thanks to the minimal tread. For the instances where fast rolling speeds count more than aggressive tread – the Aspen ST will make an impact.
For now, it's time to put them on the dirt, so check in for a full review later this year.
From: KWT Imports
RRP: From $99.95
