Ass Savers’ newest Win Wing is targeted squarely at protecting the butts of gravel riders from mud & rain, yet this new strap-on rear fender is much more versatile than just that. With a simple wishbone bracket that securely hooks around your seatstays, the lightweight Win Wing fits almost any road, cyclocross, gravel, or XC mountain bike – including many full-suspension designs – and is built to stand up to the rough & tumble off-road life, secure and rattle-free…
Review: Ass Savers Win Wing fender
The new Win Wing is meant to be a superlight, low-cost, easy-to-attach rear fender.
Right off the bat, the new Ass Savers Win Wing is not a full-coverage fender, so doesn’t offer the same protection that would entail. And of course, this is only protection at the rear wheel too, so at best you could look to their Mudder or Mullet to knock down some of the spray off the front wheel.
Let’s also acknowledge from the start that this is a 1600+ word review with ~30 photos for a simple 4-component plastic product that only costs 25€. That might sound silly, but there’s good reason to read on if you ride in less-than-perfect weather, and on a variety of bikes…
With all of that said, it’s already hard to fault the original Ass Savers fender if you accept its limitations – literally just a simple (and pretty well-designed) piece of folded plastic clipped to your saddle rails… and often copied. A regular Ass Saver doesn’t offer a ton of coverage either, but was/is a ‘better-than-nothing’ approach to at least keeping your butt from getting muddy and soaked on wet or sloppy rides.
Now, the Win Wing improves on that, a lot.
How does it work?
The concept of the Win Wing is tangential protection. Putting the fender just a few millimeters above the rear wheel catches all of those tangential lines of road spray, right at the tire where they originate.
Some of the water, mud, and general road spray off the tire will of course still stay attached and make its way onto your bike and legs… but all of the tangential lines connecting from your wet rear tire to your butt get stopped by the Win Wing.
One trick to getting the most out of the strap-on fender is keeping it as close to the tire as possible. Ass Savers recommends 5-10mm between the U-shaped top of the mounting bracket (not necessarily the plastic fender itself) and your tire.
That seems super tight clearance-wise, but we’ve had no issues on multiple bikes with mud, rocks, or anything else getting jammed in between tire & fender. And in reality, the soft strap attachment method means that anything that did get caught would likely just bend the fender forward & upward instead of jamming the rear wheel at all.
Tech details & Actual weights
Attaching the bracket to your bike is simple, but getting the best out of the setup requires pulling the straps super tight.
One end of the rubber strap serves as the grippy attachment point where the bracket sits on your seatstays, the other end gets belt buckle-like holes to hook into. And you really should pull hard to ensure that the fender won’t move over rough terrain.
The straps seem amply strong though, so it’s probably safe to pull it one hole (or even two) tighter than you initially thought was enough. I go until the hole is visibly elongated when hooked.
Two key selling points for the Win Wing fenders are that they fit a wide range of tires (and bikes), and they are lightweight.
To hit the wide tire compatibility range, two versions are available: Road optimized for 23-35mm tires and Gravel for 35-60mm tires. Real weight for the Win Wing Road including fender, bracket & straps is just 63g. And the wider Win Wing Gravel is just a few grams more at 72g.
Compare those as 3x as heavy as the two sizes of regular Ass Savers 19/26g, which offer less protection.
But a more apt comparison would be to something like the lightweight, almost full-coverage 40€ SKS RaceBlade Pro/RaceBlade Pro XL fenders. Those of course include front & rear wheel coverage for a pretty good value, but even if we split their claimed weights in half to 177/182g (355/365g for F&R pairs), they would still be around 3x heavier again, while being much more limited in tire size – conservatively max 25mm for the RaceBlade & 32mm for the XL. SKS’s Speedrocker gets a little bit wider, but is less easy to manage.
What protection do you get? And where is it lacking?
How much protection can you really get from this small thing?
Effectively, the Win Wing stops all mud & water from about the seat clamp and higher on most bikes.
Have a look at this BMC URS gravel bike and you can see the seatpost stayed totally clean (or at least as clean as it was before I mounted the fender). But everything below that still gets wet & muddy.
This is the real limitation, and probably what will make you decide to buy a Win Wing or not.
The fender offers zero spray protection for anything below the top of your seattube. If you have it on a full-suspension bike (like this Canyon Lux Trail), the pivots are still exposed to spray and the swingarm will still fill up with mud… or in my case pine needles.
The other thing you can see is the dirty bottle cage. There is NO protection for your water bottles, meaning they will still get covered in mud and road spray. And if you use bottles without protective caps, you’ll still be drinking whatever comes flying off the rear wheel. So… hope you don’t ride your gravel or XC bike anywhere near livestock or freshly fertilized fields.
Another Win Wing limitation is that this fender does also require symmetrical seatstays.
While bikes of old all had a lot more symmetry, a number of modern bikes tweak their stays side-to-side a bit to either maximize tire clearance around the drivetrain or to fit a disc brake caliper into the rear end somewhere tidy.
There is not really any adjustment mechanism in the Win Wing’s mounting bracket. So, if the mid-point of the seatstays are not exactly the same height, the fender will either point off to the side or need to be raised exceptionally high to not rub the tire – either of which will negate its tangential protection benefits.
We talked with Ass Savers about it, and they said it isn’t super common, but suggested that a spacer could easily solve the issue. I put a ~8mm thick rubber spacer under the driveside strap mount of this new Canyon Ultimate, and it solved the alignment issue perfectly, staying secure over many wet kilometers so far.
Why not just get some full-coverage fenders?
The most obvious question when deciding whether to add a minimalist fender to your bike is probably just, why don’t you get a proper set of full-coverage fenders and be done with it?
In reality, the Win Wing fits a lot of bikes that simply won’t fit conventional fenders – no fender mounts required. But the biggest compatibility feature might just be that wide 19-60mm tire width clearance range. That covers almost every road, fixie, all-road, cyclocross, gravel, trekking, and cross-country bike out there.
That’s a lot of bikes.
Plus, while many conventional fenders rattle over rough surfaces or any off-road, the Win Wing stays quiet and doesn’t shake loose no matter where you ride it. Even though it seems to sit perilously close to the rear tire, we haven’t had any issue with it jamming even on especially muddy rides.
And, there simply are few fender options with big enough coverage for mountain bikes. Modern knobby 2.4″ trail tires (61mm) push this fender a bit beyond its limits, but essentially anything smaller than that fits fine, offering plenty of room for most XC bike tires.
Extra benefits, too…
An added benefit of the simple strap-on seatstay mount is also full-suspension & softail compatibility. Whether talking about gravel bikes like this URS with a tiny bit of rear wheel travel or the proper travel of the Lux Trail XC/light trail mountain bike – it’s easy to set the fender up so that it maintains tight clearance over the tire throughout the bike’s rear-wheel travel.
And who would have suspected that this road & gravel fender is perfect for protecting your dropper seatpost? This might be my favorite surprise in mounting the Win Wing. The more dropper posts expand beyond mountain bikes, the more riders will have to deal with maintaining droppers.
Stopping mud and spray before it hits your dropper post’s slider and main seal is sure to keep the post running smoother, longer.
Oh, and speaking of dropping…. putting the fender all the way down at the rear tire also means it doesn’t get in the way when you have to get back behind the saddle on a steep descent or technical step-down. Anyone with a conventional-style Ass Saver knows about getting hung up on the fender when you sit back over the wheel. And some will even be familiar with the sound of your Ass Saver unexpectedly rubbing your tire when the dropper is down and the suspension bottoms out. No more.
Final Ass Savers Win Wing thoughts
Is the Ass Savers Win Wing the best fender ever? Well… obviously no.
But it is really good at what it does.
This is not really a fender for everyone. Some don’t like the look of this gray recycled plastic loop hanging over your rear wheel. Some really need the total protection of proper full-coverage fenders. And some – like our own Editor-in-Chief – would rather have a wet butt than nasty muddy water bottles. And those are all valid concerns.
If you are just looking for a lightweight, simple solution to keep your butt clean & dry (or a bit drier if you ride in constant rain) on road, gravel, or cross-country rides… then, the Win Wing is a good option to consider. And if you want to keep mud off your dropper post, that might just be a very welcome added bonus, too.
The Ass Savers Win Wing comes in two sizes and plenty of color options that all sell for between 25-27€. The fenders are all made in Sweden from recycled content. Pick them up straight from Ass Savers, or from numerous retailers and local bike shops.