Mucky Nutz Road Butt Fender

Like an Ass Saver or a butchered water bottle equivalent, the Mucky Nutz Road Butt Fender isn't a a substitute for a full-length mudguard. It's there to stop you getting a soggy chamois. In that respect, it both lives up to its billing and exceeded my expectations.

The Road Butt Fender is a 15g bit of plastic that fits to the saddle rails without tools. The end loops hook under the rails while the 'wings' at the side go over the top. Mucky Nutz say it's "compatible with all standard double steel rail saddles, so long as they don't have any daft bits hanging off the rear". That ruled out four of my bikes: two with saddle rail clamps for seatpacks; one with a saddle-rail mounted CatEye Volt 50; and one with a Rido R-Lt saddle, on which the Fender would fit only droopily. In the end, I put it on a Pinnacle Dolomite... after removing its perfectly good SKS Chromoplastic full-length rear mudguard.

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Fitting was fiddlier than I expected. I struggled to get this bit under the rails and that bit over the rails simultaneously. Once in place, though, it seemed secure and didn't budge during the test. So it was considerably more useful than Mucky Nutz's Rear Fender. It was a lot less useful than Zéfal's Swan road mudguard, which provides greater coverage. And for spray protection for club rides, training, or commuting, full-length mudguards obviously outclass the Road Butt Fender.

I've seen pictures of the Road Butt Fender folded up under the saddle when not needed. This seemed liked unnecessary faff to me, given that's it a 15g bit of plastic that sticks out about 20cm from the back of your saddle. Folding it might also put more strain on the fixings where they wedge under/over the saddle rails.

Once the Road Butt Fender is attached, it's awkward or impossible to fit a seatpack, depending on the pack. There are bare rails underneath the Fender, but the side wings bear down on top of them to hold it in place so there's precious little room to play with. My Ortlieb Mudracer seatpacks wouldn't fit; a seatpack that straps to the saddle rails might.

If you've got a bike that won't accept proper mudguards and you don't want to use SKS RaceBlades, Crud Roadracers, or a seatpack, then the Mucky Nutz Road Butt Fender is worth a punt. It's only £6.49. It does what it claims - if that's enough for you.

Verdict

Bike too racy for proper mudguards? This one at least keeps your bum dry