Not all gravel bikes are blessed with the convenience of proper mudguard mounts, so if you want to add a bit of protection for bad weather riding or commuting you will need to find another attachment method.
There are plenty of options that strap on to the bike but few can offer close to the coverage of a proper set of fitted full-length guards. Topeak Tetrafender G1 and G2 gravel guards come close though, using a quick-fitting universal fitment and accommodate gravel tires between 32 and 50mm.
Design and specification
When it comes to mudguards and wet weather protection, bigger is always better. The Tetrafender G1 and G2 guards offer quarter-wheel coverage at the front to stop you from getting a face full and the same at the rear so you don’t get crud sprayed up the back. The rear guard has a modular design so it can be shortened should you want less protection. I'm not convinced I would ever use the rear guard in its shorter format so I would prefer a sleeker and simpler rear bracket to keep the overall look a bit neater.
Although they are universal fitting, there are a couple of important frame dimensions to check to ensure there is enough space between the fork legs and seat stays. You will need at least a 70-100mm gap between the fork legs and seat stays for the main velcro mounts to attach. I measured the four gravel bikes I currently have to hand (two carbon and two steel) and they all fall within this measurement. You will also need 200mm of unobstructed seat stay (no cable routing or bosses) for the rear guard to attach.
The guards are fitted to the bike using a series of Velcro straps. The front G1 guard’s main fixture attaches around the midpoint of the fork using a soft rubber boot and a large strap, with an additional two thin double-sided straps around the crown of the fork. The rear uses a similar Velcro system for the stays but is beefed up with a longer boot and another two large Velcro straps on each side, plus two smaller double-sided Velcro straps around the top of the seat stay for stabilization. The angle of both the front and the rear guard has a little bit of adjustment to get a better fit.
At the front, the mounts and fenders are made from a stiff injected high-impact resistant plastic with engineering grade polymer, the stays at the front also use this material while the rear guard gets metal stays. The fenders themselves have a matt finish on the outside and a shiny finish underneath.
The guards come with everything needed to fit them although it would have been a nice touch to include some clear frame stickers to protect your bike's paintwork. When fitting I would recommend using some 3M or electrical tape to protect your paintwork. Topeak does include some 3M reflective strips though should you want to add a little side visibility for commuting and road riding at night.
Performance
Attaching mudguards is never a simple process although the initial fitting of the Tetrafender to my Vitus Venon Evo didn't require much more than a bit of patience to make sure the fenders were in line and well-spaced from the tire. The Velcro straps have a buckle that hooks on the outside of the fork leg or seat stay and then hooks and loops on the inside of the mounting bracket before being stuck down. The Velcro is then tensioned with a hex bolt and supplied hex key. The combination of Velcro and tensioner creates a very secure fit although the hook and loop end of the Velcro is on the inside of the fork leg or stay which means if you unloop it, it's fiddly to rethread without removing the guards completely.
It's worth noting that if you have any external cables make sure the velcro is positioned under the cable housing otherwise you might not get a secure fit and it could affect shifting or braking performance. Also, make sure you thread the smaller velcro straps used around the fork crown and upper seat stay before attaching the fenders as you won't be able to thread them through once the guards are fitted.
The use of Velcro makes these guards simple to fit and remove, around 10 minutes to refit and 10 seconds to remove, although the reliance on Velcro begs me to question durability. The main straps on my sample are still nice and grippy despite a good soaking and plenty of muck so far, however, the narrow double-sided supporting Velcro straps at the rear have both snapped. These appear to be for stabilization only so didn't affect performance and should be easy to replace
Out on the wet gravel tracks, the Tetrafender offers a good level of coverage. Even in some properly grim conditions they kept me dry and splatter free. While the quarter coverage is enough to ensure your face, body, and water bottles muck free you're still going to get wet feet, although that's the case with almost all guards unless you have full ground scraping flaps. The adjustability allows a good fit and they can be positioned close to the wheel for a subtle look, or a bit higher for a little more dirt clearance. On the rough stuff, these guards are very quiet, firm fixtures and plastic construction mean these guards have been completely rattle-free.
Although gravel bikes aren’t as inflicted with toe overlap as road bikes, adding a front guard may change that. The Tetrafender has a smooth finish so if your shoes do come into contact there are no edges that could get caught.
Topeak isn’t alone in the clip-on gravel mudguard market, there are alternative long options from the likes of SKS Speedrockers or the Zefal Shield G50. Mudhugger also does a front and rear gravel guard which doesn’t offer as much protection but is probably more robust. AssSavers Win Wing offers a surprising amount of protection for your back although they don’t offer anything complimentary for the front.
Verdict
The Tetrafender can’t compete with proper full-length fenders so if you have the attachments, traditional fenders are the way to go. Unfortunately, many brands seem to forget to include these on their gravel bikes, in which case, Topeak’s Tetrafender is a good alternative for keeping you dry and clean.
They offer impressive coverage, and I had no problems charging down fast, rough, and muddy tracks with them on. I'm dubious of how well they would fit with the max 50mm claimed tire but they offered plenty of coverage with a 42mm tire. Initial fitting is a little fiddly but once adjusted, removing and attaching is a very quick process. Although bikes certainly look better without fenders, the Tetrafender isn’t overly offensive to a bike's aesthetic either.
There are a few shortcomings though. The thin stabilizing Velcro straps on the top of the seat stays snapped although this didn't seem to affect performance and is an easy fix. I think it's a bit disappointing that Topeak didn't include frame protection or any spare straps with the fenders.
Tech specs: Topeak Tetrafender G1 and G2 gravel mudguards
- Price: $74.00 / £64.99
- Weight: G1 (front) 197g / G2 (rear) 341g
