The new Rally helmet uses Bontrager's WaveCel technology – that aims to protect against rotational impacts – and is designed for trail riding.

Product Overview

Overall rating:

Score 8

Bontrager Rally Wavecell


  • Good build quality, BOA retention device offers accurate adjustment


  • Heavy and straps need improving


Bontrager Rally Wavecell helmet review

Price as reviewed:


Twelve months ago we tested the Bontrager Rally MIPs but this new version is called the Rally WaveCel and gets Trek’s in-house rival to MIPs. WaveCel is a cellular plastic but is actually pretty soft so fits you head shape better, which is why there’s minimal padding inside this helmet. It also absorbs some of those low-key impacts and as well as dealing with oblique forces like a MIPs liner but it can also act like a crumple zone, absorbing the really big hits. Like the Koroyd honeycomb, you also get the benefit of increase air flow and heat management because the stuff is just an open mesh.

Read more: Buyer’s guide to the best mountain bike helmets

The carrier for the WaveCel is made in the same was as a normal Rally helmet and has the same features like in-moulding, bottom wrapping and embedded straps. The difference is this has upped the weight dramatically, making this the heaviest helmet on test. We could really feel that weight moving around when descending and it’s also a large helmet too.

Like the original Rally, there’s genuine BOA based retention device. BOA technology is normally found on bike shoes but it works perfectly here, offering the most precise adjustment of any helmet on test. There’s height adjustment but it’s pretty minimal.
Bontrager has changed the visor on the new Rally WaveCel because the old used to lift up really high so you could park a pair of goggles underneath, this one only raises a couple of inches. Not that we’d stash any up top with such a hefty lid, it just adds to the weight.
Both buckles also still work loose, the chin strap is especially bad and it even popped off the end once during testing.


WaveCel is a interesting technology because it’s multi-use and that means the helmet is simpler, fits better and is safer. The cost is good too but the problem we have with the Rally WaveCel is the weight and the size and if you don’t over-tighten the retention device it can bounce around but that doesn’t make it particularly comfortable.


Sizes:S, M, L