How to fit aftermarket bodywork

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Why bother?

Genuine bodywork is expensive to replace. A simple topple over on the road when turning around can cost more in damage repair than a whole pattern bodywork kit. Trackdays increase the chances of tipping off by some degree, so again cheap pattern bodywork makes sense. Race bodywork (no holes for lights and indicators) can come with one large fairing panel rather than small individual panels so they’re easier and quicker to remove.

What you’re dealing with

Bodywork panels made of cheap glass-fibre and resin mix – sometimes lighter but more expensive carbon-fibre or carbon-Kevlar mix – which retain the bike’s original silhouette. They aren’t always a perfect, easy fit, especially if there are no mounting holes for fasteners to fit through.

Stuff you’ll need

A socket or combination spanner set (8-19mm), ideally front and rear paddock stands, electrical tape and an electric drill with a high speed – with drill bits (HSS 1-10mm minimum) to suit and some very fine sandpaper. You’ll also need Tippex liquid paper, a pencil and black felt-tip pen (save costs and acquire them from your mate’s desk at work) and aftermarket fasteners (you’ll need quick-release Dzus items if race bodywork is used).

What can go wrong?

The most obvious thing is drilling holes in the wrong place on the body panels. Also, drilling wrong sized holes which makes fitting difficult. This can also lead to total misalignment of all the body panels so part of the rolling chassis fouls the panels.

What else do I need?

A positive mental attitude, the ability to follow instructions carefully  and a warm, dry place to work in.

1. When it comes to fitting replacement bodywork, it needs either the original mounting brackets for road bike panels, or basic lightweight race use only replacements. This Ducati 748 has been condemned to trackdays and has a simple racing upper fairing stay as it doesn’t need a speedo and other road legal gubbins.

2. Always, always start by fitting the upper fairing. Road-going bodywork (above) is easier to fit because it comes with pre-drilled holes and cut-outs for headlights, fasteners and indicators. On race bodywork, these holes are blanked off. If there are marks on a panel which look like they are for drilling out, never assume they are in the right place.

3. Make sure the upper fairing is aligned correctly. Hold it in place with grips, clothes pegs, tape, or simply chock it with wood, then check for alignment. Measuring from a central reference point, eg  the top yoke nut, is best. When it’s perfectly placed, check the bars, levers and hoses don’t foul when the steering is on full lock.

4. To drill a hole, you must accurately mark the fairing where it needs to be drilled. Using a felt tip, Tippex or a 3mm drill bit to scratch the material, mark the panel from the rear through the mounting hole/bracket. If it’s impossible to mark the panel, drill small (1mm) pilot holes as close as possible from the front – the second go is usually spot on.

5. Don’t drill the marked holes in the fairing to suit the size of the fastener. Drill the holes with a 3mm bit first. This is so you can mount the fairing with thin bolts and washers so that if the fairing needs to be moved to make sure the lower panels line up, you aren’t left with a panel resembling Swiss cheese.

6. Ensure panels, especially their edges, don’t interfere with coolant hoses, the radiator, frame or wiring loom. If necessary trim the material to suit. Use a multidrill, hacksaw or jigsaw and do it in a ventilated area (outdoors) and use gloves – glass-fibre shards and dust are bloody sharp. File or emery cloth the cut edges smooth.

7. Any panels to be drilled for mounting to brackets or joining to other panels must first be done with a 1-3mm pilot hole. If it lines up drill the holes up to a maximum of 2mm bigger than the fastener to allow for minute adjustment. Set the drill to maximum rpm and stick some tape over the area so the drill doesn’t skid over the shiny plastic.

8. Quick-release Dzus fasteners (above) – clips made from spring steel which use a central locking pin to hold the body panels in place – are for panels which overlap. ‘Rivet-type’ fasteners do the same job but are particularly useful to fix on to any new/additional brackets which you may have to make.

9. Fitting a screen is done in exactly the same way as the bodywork. Position it then secure with tape, grips or clothes pegs. Mark the fairing using the screen’s mounting holes as templates. Remove the screen and drill the fairing: remember to make a pilot hole first. Use numberplate plastic nuts and bolts to attach the screen – they’re cheap to buy.

10. If the bellypan is a race item it won’t have vent holes, so it can retain oil if the engine blows. But it will also fill with water when it’s raining, which then sloshes out on to the back tyre. Drill a hole at the lowest point and plug with a rubber blanking grommet (try Halfords). Remove the grommet to drain water out.

11. The holes used to mount road replacement panels can be slightly out of line – don’t attack them with a larger drill bit because the standard fasteners might not be big enough to cover the holes. If you use a small rat’s tail file (thin and round) you can neatly extend the holes in the direction they need to be.

12. The glass-fibre construction of the panels means the outer face will have small porous holes which can bubble paint. The panels need to be primed and rubbed down with wet and dry (very fine sandpaper) to seal the holes. Pre-coloured or painted panels like the Vimori fairing shown are more expensive but save a lot of aggro.

MCN Technical Staff

By MCN Technical Staff