Flat mudguards

[ianatstanage]

Hi,
Has anyone used flat mudguards?
On my 2016 Mercury I have 700x35 tyres. In normal use there is sufficient room between the tyre and the mudguard (SKS I think).
However, when on bridleways and off road trails, especially in damp conditions, debris often builds up.
Occasionally this can be enough to cause considerable friction and it is difficult to remove.
I was thinking of trying some alloy Contec mudguards.
My thinking is that debris, especially mud, is less likely to build-up. If is does, it should be easier to remove.
Any thoughts?
Many thanks,
Ian

[Danneaux]

I can offer a data point: Many years ago, I bought and mounted a set of handmade thin wooden flat mudguards, made in Denmark. Beautiful things, they looked like furniture. I had in mind the same goal as yourself and for the same reasons. It is also easy to made flat 'guards from aluminum strip.

The trouble with them was the very virtues you mentioned were also their downside -- they contained direct spray but everything beyond that was pushed to the sides and back/up/every direction onto me. Not pleasant and nearly as wet as no 'guards at all in the rain at speed. The same happened with mud.

I switched back to standard mudguards with an arc shape on that bike and they did indeed address all these problems...and also clogged. I sprayed the underside with "PAM", an aerosol vegetable oil intended for cooking. It helped release the mud buildup when they did clog.

One "solution" I found helpful on that bike was to switch to road slicks. Strangely enough, they did not work significantly less well on mud, but far less clung to them because there was no tread for it to build up upon and get carried 'round to pack up under the 'guard.

On my Nomad, I have pretty generous clearances and if I anticipate a desert tour with wet playa, I crank in some extra clearance by removing spaces between 'guards and bridges/fork crown and extend the eyebolts on the stays (I long ago replaced the flush-cut stays with ones that extend beyond the brackets and are safety-capped to allow extra adjustment).

Best,

Dan.

[PH]

It's one of the reasons I no longer have an Audax bike, even on mucky winter roads, 28mm tyres and deep drop calipers left too little clearance to keep them clear.
One thing to consider is what's causing the blockage, I find the less clutter and fittings on the inside of the guard the better. Once you've picked something up, you want it to make it's way round as easily as possible, or it just builds up.  The SKS brackets are pretty poor in this regard, I used to move them from under to over the guard.  The direct fitting on Thorn bikes also benefits from a low profile button head (At the risk of making it harder to remove in several years time) You can also control to some extent where the blockage occurs, the brackets holding my mudflaps are the first thing to clog, that was accidental, but a happy accident I'll repeat, it's an easy place to clear.
I'm not familiar with the guards you mention, or with what's currently available, the designs change so frequently. I've had the Bluemels Matt 45mm on both Mercurys, Over 35mm Supremes on the first and 40mm Supremes or Almotions on the MkIII, they're not perfect, but better than the standard SKS Cromoplastics.  On another bike I have the SKS Edge Al. these have a different profile with a flatter top and deep edge, I have them if the 56mm size, the 46's should fit a Mercury, but I haven't tried. On the bike I have them there's no shortage of space, but I think on a bike where it was tight, they'd maximise the clearance.

[mickeg]

I almost always use as much clearance as I can between tire and frame or fork when I install fenders (mudguards).  I have been fortunate to never have enough mud or other debris build up in a fender to be noticeable, but if I planned to go somewhere that I was concerned about it, I might remove the fenders first.

In the photo below, no fenders on the bike.  But I had enough mud on my rear V brake cable and noodle that the brake stopped releasing.  When I stopped I had to get off the bike, manually pull the brake open and then could go again.  Thus, only used the rear brake when the front was not enough that day.

That is the only time I have had a mud problem that impaired the bike operation.