The SKS S-Guard is a small but surprisingly effective mudguard that will help keep your back dry. It's cheap, easy to fit (mostly) and solid in use, but it won't fit all saddles and is showing signs of early wear after multiple fittings.
This style of quick-fit mudguard is designed to fit directly onto the saddle rails, with SKS claiming that it will fit 'nearly every saddle'. This might be true, but unfortunately I had one that it didn't fit.
For those it does fit, the first time you try can be frustrating as there is a certain way to do it, and this also changes for different saddles... Although the SKS video makes it look easy, your first attempt may take a little longer.
Fitting is also more difficult if you have a saddle set up with the seatpost clamp near the rear of the saddle rails, or a large saddle clamp generally, as it can get in the way.
Once the guard is in place, there is the option to use a zip-tie (not included) to make it even more secure. I didn't feel the need, as it was always stable, even off-road and on mountain bikes, plus I think the big attraction of this style of mudguard is that you can grab it and fit it quickly if it's raining, and the easier you can do that the better.
I tested the mudguard on multiple different saddles. For saddles where there is no connection or material between the rails at the rear (as there is on the Ritchey Skyline WCS) it will fit fine. With the Ritchey, the mudguard is angled too far downward to be effective. Another one to note is Fizik, with the Integrated Clip System, as it won't work with the clip in place, though you can at least just remove the clip on many Fizik saddles and clear the area.
Another issue for fitting will be if you use any form of saddle bag, light or something else that attaches to the saddle rails. In most cases it will make fitting impossible.
Many similar mudguard types won't fit on ovalised carbon rails, but the S-Guard will, and actually seems more solid in use with them than standard round rails, the slightly larger rails holding onto the plastic cutout areas a little tighter.
The design of the S-Guard includes several engineered bends and these make it very stable and secure, with no flapping up and down and very little side to side movement, as can happen with more basic designs.
For such a small mudguard it is quite effective, so long as expectations aren't too great. It won't give anywhere near as much coverage as a full mudguard, but I was really surprised how effectively it kept my back and chamois dry, even when used on wet road rides and off-road on gravel and forest tracks. After returning from rides there was a cleaner area on the middle of my back, from around the jersey pocket area and down.
The S-Guard is also effective on a mountain bike, although the extra width of the tyres will mean water and mud can get past it; but compared to not using a guard at all, there is still a positive effect.
I have fitted the guard to multiple saddles and there are a few sections starting to show wear, and some folds forming in the material where it isn't designed to. This amount of wear is almost certainly more accelerated than it will be for most people, but could be a factor if you plan on swapping the guard frequently and using on different bikes. If you leave it in place on one bike then wear should not be a concern at all.
The design is shorter than some similar mudguards, at 290mm, but it is also wider than many, with only a few exceptions, such as the RRP Rear Guard, which is dramatically wider.
Some, like the Mucky Nutz Road Butt Fender, are a bit cheaper at £6.50.
For such a small, unassuming part it is quite effective, more so than some I have used, and at a price that makes it very reasonable. It is showing some signs of early wear, but it's been put through a bit more fitting and refitting in testing than I'd imagine it would in typical use. For less than a tenner, it is an effective guard that is easy to fit, once you know how.
Cheap and effective rear guard that should fit most saddles
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road.cc test report
Make and model: SKS S-Guard Rear Mudguard
Size tested: One Size
Tell us what the product is for and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
SKS says: 'Not only for road bike cyclist: This super lightweight (24g) and small mudguard protects your bottom from mud and water. Made of super soft material it fits to nearly every saddle. Additionally you fix the S-GUARD with a cable tie.'
Tell us some more about the technical aspects of the product?
weight: 24 g
length: 290 mm
wheel size: 20", 21", 22", 23", 24", 25", 26", 27,5" (650b)", 28", 29 "
tyre width: 0.8"-4.8"
Effective for the size and style; keeps you drier and cleaner than not using any rear mudguard.
After multiple fittings, parts of the plastic have bent, but it's unlikely to be an issue unless you fit/remove regularly.
Beats or equals most others, and for the performance it's certainly worth the money.
Tell us how the product performed overall when used for its designed purpose
Reasonably quick to fit, works on most saddles and is suitable for virtually all styles of bikes from road, to gravel and mountain biking.
Tell us what you particularly liked about the product
It seems more stable and gives a little more protection than most other similar quick-fit mudguards I have used.
Tell us what you particularly disliked about the product
Fiddly to fit on bikes where the saddle rails are clamped near the back and also larger styles of seatpost clamps.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
It's the same price as a regular Ass Saver and a few quid cheaper than both the RRP Rear Guard (£9.49) and the Zefal Shield S10 (£9.99). Some, like the Mucky Nutz Road Butt Fender, are a bit cheaper at £6.50.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? Yes, assuming they can't fit full mudguards or are looking for an easy to install/remove option.
Use this box to explain your overall score
The SKS S-Guard is above average. It performed well on all types of bike, although it didn't fit one of my saddles. Once I had grasped the process, it was mostly quick to fit, and works better than some competitors.
About the tester
I usually ride: My best bike is: Cannondale SystemSix
I've been riding for: Over 20 years I ride: Every day I would class myself as: Expert
I regularly do the following types of riding: road racing, cyclo cross, sportives, mtb, Lots of gravel style riding