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M:Part Primoplastics mudguards are a hassle-free solution to keeping your backside dry and your bike clean. With easy fittings and high levels of stability they make a great choice against others on the market.
At first glance the Primoplastics look pretty similar to what could arguably be called the market leaders, SKS Chromoplastics, but as a long time user of those I found the M:Part guards just a little better, in just about every way.
Fitting is pretty straightforward – which is just as well as the instructions on the box are pretty sparse. The front fits to the fork crown using a slotted L-shaped bracket, which is riveted to the mudguard body, while the rear uses a similar bracket which, rather than being attached to the guard, has 'prongs' that clip underneath it, providing adjustment for brake bridge height. The rear guard is also drilled in three positions to allow fitment to the chainstay bridge.
The stays are stainless steel for longevity in a winter climate and are shaped, with the 'elbow' offering a tight position for the bolt to frame fixing.
All pretty standard so far.
The difference between these and the SKS is the M:Parts use clip-on stay fittings, which can be slid into place anywhere along the guard rather than having a permanent position like those on the German brand. This makes them a lot easier to tweak around disc brakes or racks, and with a diameter of just 3.2mm the stays can be bent to shape quite easily.
These clips are also break-away items should anything get stuck between tyre and guard. You have this system on both wheels, not just the front.
You have to cut the stays to length before you fit them, which can lead to a bit of guesswork and there is always the risk things could go wrong. Remember the old adage, 'measure twice, cut once'. Personally I didn't have any trouble and you've always got a bit of adjustment should the worst happen.
Once in position the stays are held there by tightening the plastic clips. It's a quick and easy option that makes things very easy to set up for height and centreing around the tyre. It's secure too: the first 500 miles have seen no need to tweak them, nor the slightest rattle on the roughest of lanes.
Coverage is the same as you get with the SKS Chromoplastics but the added bonus of the Primoplastics is that they come with a mudflap on each guard. It's something SKS used to offer but has since dropped. The flap might be only a few inches long but it's amazing how much extra road spray they stop from hitting the rider behind, and your own shoes from the front. Your feet will still get wet but it takes a little longer.
Width-wise, these are the 35mm versions (they also come in 45 and 55mm widths, and 60mm for 26in wheels), and paired with 25mm tyres it's a nice close fit. That said, you do need to drop them down so that the sides of the guard are lower than the tyre to stop spray coming out around the sides. As far as accommodation goes, I'd say 28mm is about the widest you'd want to go tyre-wise with this 35mm size.
When it comes to price things are a little more tricky. With an SRP of £29.99 they are actually cheaper by a few pounds than the SKS guards, but you'll find the Chromoplastics discounted by a tenner or more. The M:Parts don't seem to be as heavily discounted, so can end up a few quid more. Personally, I think I'd pay the extra.
The M:Parts are more stable, slightly quicker to fit, and feel slightly better quality – though each of these points is by a minimal margin. They offer good coverage for a mid-length guard, and with their easy fitment and rattle-free ride, they're pretty impressive.
Simple to fit and easily adjustable mudguards, which are also completely rattle-free
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road.cc test report
Make and model: M:Part Primoplastics mudguards
Size tested: 700x35
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?
These Primoplastics are full length, narrow mudguards for those winter race bikes that come with eyelets. They offer decent coverage thanks to the added mudflaps, and are easy to fit.
Tell us some more about the technical aspects of the product?
V stays front and rear, with Pop Off safety couplings
Pop Off couplings feature infinite fitting locations, great for tricky disc equipped frames
3.2mm diameter 304 grade Stainless Steel Stays and fittings for long life
Black and white guards supplied with black ED coated stainless stays, Pewter guards supplied with silver stainless stays
Virtually unbreakable polycarbonate guard material
Sizes: 26" x 60mm, 700c x 35mm, 700c x 45mm, 700c x 55mm
No rattles or movement plus overall coverage is slightly better than SKS Chromoplastics due to the mudflaps. You do need to fit them quite close to the tyre to stop spray coming out of the sides.
Stainless fittings and a plastic body should see them last a good few winters.
At 491g they are pretty much the same as the SKS, Tortec and RSP guards we've tested in the past.
A slightly cheaper SRP than the SKS Chromoplastics, but online tend to be a little more expensive. I'd happily pay the extra for the easier fitting and mudflaps.
Tell us how the product performed overall when used for its designed purpose
Rather impressive. They keep the mud and water off and do a good job of sheltering those behind you.
Tell us what you particularly liked about the product
Easy adjustment and rattle-free.
Tell us what you particularly disliked about the product
Having to cut the stays to length before you fit them leaves a chance of error.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? Yes
Use this box to explain your score
I've been using SKS Chromoplastics for years and have always been impressed, but I think the M:Parts are just a little bit better all-round. Apart from having to trim the stays first, the M:Parts are easier to fit and adjust, are sturdier and the added bonus of mudflaps means they perform better.
About the tester
I usually ride: This month's test bike My best bike is: Mason Definition
I've been riding for: 10-20 years I ride: Every day I would class myself as: Expert
I regularly do the following types of riding: time trialling, commuting, club rides, sportives, fixed/singlespeed
With 20 years of road cycling and over 150,000 miles in his legs it's safe to say Stu is happiest when on the bike whatever the weather. Since writing his first review for road.cc back in 2009 he has also had a career in engineering including 3D-CAD design and product development, so has a real passion for all of the latest technology coming through in the industry but is also a sucker for a classic steel frame, skinny tyres, rim brakes and a damn good paintjob.
His fascination with gravel bikes is getting out of control too!