More detailed instructions including attaching with 2 bolts are available as a PDF here.
The rear flap (left) aims to stop the high arc of spray that comes from your back wheel and into the faces of riders behind you. The “back” flap is narrow where it attaches which allows it to bend (or flap) without bending your mudguard too much when you turn your bike up on its back wheel and catch the flap.
The front flap (right) is wider to stop splash coming from your front wheel over a wider horizontal area, protecting your bike’s transmission and keeping your feet a bit drier. The wider top takes on the cross sectional curve of the mudguard and gives extra rigidity – it’s only when you take the front wheel out that it needs to bend and you should be careful how you support your bike in that case.
The best way to install RAW Mudflaps is using the bolts, which will require you to drill holes in your mudguard, unless suitable ones exist. The three pre-drilled holes are designed to work with some of the more common mudguards on the market that have holes or some kind of flap attached already.
If you don’t have any holes in your mudguard and prefer not to make any, you can skip to Attaching the flap with adhesive pads. Whilst the pads are hard-wearing and very water and dirt resistant, you should bear in mind this will probably not be as robust as attaching them with bolts. Also you will need to modify your front flap and it won’t be quite as effective.
To install using the bolts continue onto Installation With bolts.
If you have no holes within 30mm of the end of your mudguard, skip to the attaching the flap section.
NOTE: MAKING HOLES IN THE MUDGUARD OR FLAP SHOULD NOT BE ATTEMPTED BY ANYONE UNDER THE AGE OF 18 WITHOUT ADULT SUPERVISION.
Installation with Bolts
If your mudguards have no holes pre-drilled within 3cm of the end of the mudguard you will need to make one.
If you do have suitable holes skip to Attaching the flap.
One bolt is normally adequate and when done up sufficiently tightly it will not rotate easily in normal use. Two bolt fitting offers the benefit that your flap will never rotate sideways but it is critical you get the two holes in line otherwise your flap will not be straight.
WHEN DRILLING THE HOLE YOU SHOULD NEVER DRILL THROUGH THE MUDGUARD WITHOUT REMOVING OR PROTECTING THE TYRE.
Before beginning choose either to:
i) Remove the wheel of the mudguard you are fitting to and support your bike using a work stand.
ii) Loosen off the mudguard stays and insert an old piece of wood between the tyre and the end of the mudguard.
iii) Remove the mudguard completely so you can drill into it on a work bench (probably overkill but the most accurate)
1. Select which hole you will use: for one-bolt fixing use the central or bottom hole.
2. Hold the flap centred against the outside of the mudguard (see pic.1) so that the end of the coloured covering (or fitting line for plain black or club flaps) lines up with the end of the mudguard. It needs to line up at the edges of the flap rather than in the middle so that the narrow top part of the flap is hidden. The back flap is shown here but the same applies to the front flap.
3. Make a mark on the mudguard with something sharp in the centre of the hole you will use (see pic.2)
4. Remove the flap and visually check the mark you have made is in the centre of the mudguard. If not correct with a deeper mark.
5. Drill a 4mm centred on your mark (pic.3). Take care as the shiny surface of the mudguard makes the drill slip easily. The mark in the surface of the mudguard should help.
Attaching the flap
1. Take one or two bolts each with a washer fitted and insert them into your selected hole(s) from the non-logo side of the flap (pic.4).
IMPORTANT: Flat head bolts have been selected as they have a low profile and should be easy to remove even when covered in grime. You should always have the bolt head on the inside of the mudguard so that it is less likely things will get lodged against the bolt and so that you can remove the bolt when required.
2. Thread the bolts through the holes in the mudguard from the inside (pic.5).
3. Attach another washer to each bolt on the outside of the mudguard and then a nyloc nut (pic.6).
4. Tighten the nut (which is 7mm) and bolt using a spanner and a flat head screwdriver (pic.7).
IMPORTANT: You should now adjust your mudguard stays to maintain the clearance between the bolt head and the tyre following the recommendations of your mudguard manufacturer as things could become lodged between the bolt and the tyre and potentially cause an accident. In the absence of those recommendations, ensure at least a centimetre of clearance.
Attaching the flap with adhesive pads
If you are attaching a front flap you need to modify the shape to make the top narrower so that the pad will be effective. Leaving the full width at the top is likely to result in the pad coming unstuck as the bend forced in the flap by the mudguard puts pressure on the adhesion. To modify the shape of the flap:
1. Use the back flap, or, if you didn’t buy one, cut out the diagram on page 4 of the installation instructions leaflet and use as a guide. Position it in the centre of the front flap as in the picture (pic.8), lining up the holes.
2. Draw around the guide with a pencil from where the back flap shape starts to narrow on each side (pic.9). Smoothly connect up to the side of the front flap if it doesn’t reach the sides.
3. Carefully, cut out along your pencil line with scissors.
Now, to attach the flap using the pad. This is easiest attempted with the wheel removed and the bike on a stand. Failing that, loosen off the mudguard stays adjustment so that you have more space between the tyre and the mudguard:
1. Thoroughly clean the inside of the end of the mudguard where the flap will attach, preferably with something like nail varnish remover.
2. Take the pad and peel off the white side.
3. Attach it to the thin neck of the flap align at the bottom to the line or edge of coloured covering as seen in the picture (pic.10).
4. Before sticking, carefully line up the line on the flap with the end of the mudguard and ensure the flap is straight compared to the mudguard when looking from above (you can’t adjust it afterwards) and stick the flap to the mudguard.
Care / Usage
Take care when you turn the bike up on its back wheel. The flap can take a fair amount of punishment but repeated bending and scraping on the floor will cause it to snap off. If you have mounted the flap higher than the level recommended above you may also damage your mudguard.
If you have a front flap attached, take care to lay or position your bike carefully when you take the front wheel out. Try to avoid resting it on the flap and the end of mudguard as this will put outwards pressure on the end of the mudguard and will shorten its life.
If you have a coloured flap, the covering is 4 – 7 year outdoor rated vinyl, which should stand up to the worst water, dirt and grime but, if scratched, dirt will collect in those scratches.
Now you have your flaps fitted and are staying cleaner make sure the rest of your group reciprocates!
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