Tubeless tyre inserts claim to offer additional protection for your mountain bike rim, so you can run lower tyre pressures for improved traction. The Rimpact Tyre Inserts are a relatively new option, so we got our local rim-dinger, David Hayward, to put them through the grinder as part of a tubeless insert group test. Over to David for the review.
We’re quite far into this tyre insert grouptest and I’m running out of things to say about foam. The smartly named Rimpact is another such foam tyre insert, with a bigger cross section than some, but a much lighter weight, coming in at just 89g per wheel. Plus 6g each end if you get Rimpact’s valves too.
Rimpact does a couple of different versions, and this is the downhill/enduro/trail option that’s designed for 2.3-2.6in wide tyres. Rimpact also does a wider version for plus tyres.
The inserts are only available in pairs, as Rimpact reckon you get maximum benefit from running them in both wheels at once due to the change in handling characteristics. They do however come in combos to suit pretty much every mountain bike, including mixed wheel sizes.
These are fairly difficult to fit on narrow rims. I tested them with a variety of ~25mm internal width rims, and a variety of tyres from a burly 2.4in Panaracer Pandura that feels almost like a downhill tyre, to a much lighter 2.3in Maxxis EXO semi-slick ( the Pandura, mentioned in the review here, is incompatible with bigger foam inserts, though Rimpact’s wedge shape gives just enough clearance for the foam not to grip the inside texture of the tyre carcass).
All of them were slightly challenging, the burlier tyres in particular requiring quite a bit of bead stuffing. But if you watch a load of different manufacturer’s insert insertion tutorials, you’ll pick up a whole bag of tricks to make it easy.
Unlike the Panzer insert, which brings a similar cross section to a point that sits against the rim well, Rimpact has a flat base. It hugs the rim and doesn’t make a massive amount of room for tyre beads, so you may need to do a bit of stuffing.
Rimpact’s valves are among the best in this grouptest – in fact, joint first place with CushCore’s valves, because they seem to be identical. They have wide tapered bases that seal well, flat bottoms to lift the inserts and create an air gap, and cross holes to allow airflow and minimise clogging. The lockrings are also bulky with spanner flats. They’re really well designed to seal and work with inserts. You can buy the valves by themselves, or (at time of writing) they add just £4 to the price of inserts.
Sealant beading was a bit weird. They don’t seem to absorb any, but after a couple of weeks in a tyre, on first removal there were surface patches going a bit gummy. This didn’t become an issue in the months of this test though.
I’ll caveat this by immediately pointing out that, despite hearing rims contact rocks while riding on Rimpact, by the end of the test I’d had no punctures, dings, dents or flat spots.
If you do happen to notice a flat spot in any of these photos, that was from a monster impact, done through ProCore last summer. As such, it’s a rim I’m ready to replace and don’t care about, so I didn’t hold back in any of these insert tests.
In keeping me rolling, Rimpact ran well and flawlessly. I ran it at a variety or pressures, mainly from 15 – 20PSI. The audible pings and dinks I heard were spread pretty evenly through the test.
For the very last descent before taking it out to photograph, I dropped the pressure in my rear wheel, to the point it felt too soft and developed an unpleasant rollover in corners. Later on I measured it, finding it was at just 9PSI. Yikes.
Despite that, the bike felt controlled and nigh invulnerable to rocks. Even hammering that low pressure through switchbacks, it didn’t burp, so bead retention seems decent. Like most tyre inserts, Rimpact gave enough leeway to go down to lower tyre pressures, increasing overall grip without compromising cornering.
Removing Rimpact is easy, though you will probably need tyre levers. In the event of a ripped tyre, it’s also one of the inserts that’s easier to fold down, then possibly strap to your pack or frame if you need to use an inner tube.
Popping a bead off, the insert looked fine at first, but on pulling it all the way out, I could see it had been nicked and chewed up a bit near the edges. As with Huck Norris, there seemed to be a bite mark for every audible dink I’d made. Each nibble was a slit going all the way through the insert. There were no marks in the thicker centre section though.
It’s worth restating at this point, for fear these were tested unfairly, that a lot of the audible dinks I got were done with the tyre around 17PSI, not 9.
It did prevent damage to the rims and tyres I ran it with, but being lighter than some of the other inserts in this grouptest, seems more sacrificial. It definitely does more than a chunk of pool noodle or backer rod would, and also locks beads in place better than lighter, flatter inserts like Huck Norris.
On the website, Rimpact states under “normal conditions” people would have to replace their inserts once or twice per season. The key here is in the weight. At 89g, Rimpact is less than half the weight of some other foam tyre insert systems, and as such the lower density does make it less resistant to rock strikes. That said, it consistently decelerated impacts to the point they didn’t damage my rim.
Easily one of the best value sets of inserts in this grouptest, especially with Rimpact’s excellent valves.
At this price almost a rimpulse purchase. If you’re a massive gung-ho bruiser who dents rims a lot, that could become false economy and you’ll need to rimplement a more expensive, heavier system. If you rarely ding anyway but just want a little security to experiment with lower tyre pressures, this could work well. Rimpact will likely wear out faster than some other foam inserts, so it’s ultimately rimperfect rather than rimpeccable.
Interested to see what other tubeless inserts are available and how they perform? Check out all of our tubeless insert reviews right here!
|Product:||Rimpact Tubeless Insert|
|Price:||£36.99 (pair including valves)|
|Tested:||by David Hayward for 2 months|