Body Parts

Frame parts for your motorcycle

Frame parts are everything that sits on and around the frame: fenders, side panels, tank covers, licence plate holders, skid plates, crash bars and frame sliders. They protect the frame, engine and radiator from stones, tarmac and crash impacts, and they define how the bike looks.

A frame part has two jobs at once. It has to absorb the energy from a crash or a stone strike, and it has to fit precisely enough that it doesn't chafe, vibrate or tear a mounting tab off on the next hard landing.

That makes the choice about more than colour. A plastic kit in material that's too thin will crack in the first root-filled enduro woods, and a crash bar with flimsy brackets just moves the damage into the frame instead of stopping it.

This guide covers construction and dimensions, which types suit which riding, the differences between materials, how to spot wear in time, and what to watch for during fitting.

The range includes UFO, Polisport, Cycra, Blackbird Racing, Moose Offroad and Onedesign for offroad, Zieger and SW-Motech for road and touring, plus Zodiac, Drag Specialties, V-Twin, MCS, Heinz Bikes and Factory Effex for custom and Harley.

Use Find your bike on Partsdenmark.com to see only the frame parts that fit your exact year and model — and there's free shipping on orders over €200.

How frame parts are built and sized

Frame parts mount either in the original bracket points on the frame or on the engine's through-bolts. Material thickness, bolt size and torque figure are the three numbers you need to know before you start wrenching.

Bolts, threads and torque

Most plastic parts use M6, while steel and aluminium protection parts typically use M8 or M10 into the engine cases or frame.

• M6 in plastic: tighten lightly, typically 6-8 Nm, and always with the original washer under the head
• M8 in frame or engine: typically 20-25 Nm in steel
• M10 through-bolt: typically 40-45 Nm — always follow the manufacturer's figure for your specific model
• Thread lock on all bolts close to the engine and exhaust
• Re-torque after the first ride, and then at every service

If you use longer bolts for a Crash Bar or a Skid Plate, the thread engagement must be at least equal to the bolt diameter. Otherwise the thread pulls out of the aluminium on the first impact.

Dimensions and markings on plastic and steel

Plastic parts are listed by model and year range, not by dimensions. Steel and aluminium parts, on the other hand, are often specified by tube diameter and plate thickness.

• Crash bars: steel tube typically 25-27 mm in diameter, powder coated
• Skid plates: aluminium from around 4 mm, HDPE plastic from around 6 mm
• Frame sliders: pucks in nylon, POM or UHMW-PE on a steel bolt
• Fenders and panels: polypropylene, marked by OEM colour code
• Licence plate holders: measure against your own plate, not by country code

The year range is critical on plastic. A fender from either side of a generation change rarely fits the year before, even if it looks identical in the photo.

Choosing frame parts for your riding

In short: offroad is about plastics and underside protection, road riding is about slide protection in a crash, and custom is about fit and finish. The table sums up the differences.

Riding style	Type	Advantages	Drawbacks	Brands in the range
Motocross and track	Complete plastic kit with Fender, Panels and Number Plate	Light, OEM fit, easy to swap between motos	Scuffs and scratches quickly, won't survive rocky terrain	UFO, Polisport, Blackbird Racing
Enduro and hard enduro	Skid Plate, heavy-duty Body parts and Replacement Radiator protection	Takes stone strikes and stumps, protects radiator and cases	Weight, and aluminium can trap mud	Cycra, Moose Offroad, Polisport
Road and sport	Frame sliders, axle sliders and a slim Plate Holder	Limits damage in a low-speed crash, discreet	Needs the correct bolt and thread engagement to work	Zieger, Onedesign, SW-Motech
Touring and travel	Crash Bar, engine protection and Cover parts	Protects fairings and cylinder, carries auxiliary lights	Adds width, considerably dearer than sliders	SW-Motech, Zieger, MCS
Custom and cruiser	Fender, Struts, Gas and Oil parts, License holder	Changes the bike's lines, wide choice of finishes	Often needs fettling and painting afterwards	Drag Specialties, V-Twin, Zodiac, Heinz Bikes

If you ride mixed — commuting during the week and gravel at the weekend — prioritise protection over cosmetics. A Skid Plate and a set of sliders save expensive components, where a new plastic kit only saves the looks.

On older bikes it's often cheaper to fit a complete Replacement plastic kit than to patch cracks, because fresh bolt holes and correct fit remove the vibration that caused the cracks in the first place.

If your bike has fairings, the frame parts tie in closely with the front end. Also see windshields and fairings when you're building the front up from scratch.

Materials and variants explained

The material decides whether the part flexes back, cracks or wears through. The three main groups are plastic, aluminium and steel.

Polypropylene and other plastics

Fenders, side panels and number plate backings are moulded in polypropylene because the material flexes a long way without breaking and returns to shape after a crash. UFO, Polisport and Blackbird Racing supply plastics in OEM colours, so they match what's already on the bike.

Resin parts and thicker Body plastics are used where more stiffness is needed, for example on tank covers and airboxes. Plastic doesn't handle abrasive wear particularly well, so a plastic skid plate needs checking more often than an aluminium one.

Aluminium

Aluminium is used for skid plates, radiator guards and brackets. It's stiff, light and takes a hard hit without cracking, but it bends permanently where plastic would have sprung back.

Cycra and Moose Offroad make aluminium parts that bolt into the original points. Be aware that aluminium against aluminium can chafe — use rubber bushings or the supplied spacers.

Steel and slide materials

Crash bars and crash bungs are made from powder-coated steel tube, because steel bends in a controlled way and spreads the energy across several mounting points. SW-Motech and Zieger build their bars around the frame's original mounts.

Frame sliders use a soft slide material — nylon, POM or UHMW-PE — that has to abrade against the tarmac instead of gripping it. If the puck grips, the energy goes straight into the frame, and that's exactly what the sliders are there to prevent.

Wear, service life and maintenance

Frame parts rarely fail suddenly. They crack from a bolt hole, they go brittle from UV, or the bolts work loose over a few hundred kilometres — and all three can be spotted in time.

Cracks around bolt holes

The first crack almost always starts at a mounting point, because that's where the vibration concentrates. Shine a light on the panel from the inside and a developing crack shows up as a pale line in the plastic.

A panel cracked at two or more holes should be replaced. It won't hold together with cable ties, and it loads up the neighbouring points until they go as well.

UV, discolouration and brittle plastic

Plastic that's stood outside for several seasons goes chalky on the surface and loses its flexibility. If you can't squeeze a fender edge together slightly without it creaking, the material has gone brittle.

Graphic kits and decals actually protect the plastic underneath, but they also hide developing cracks. Always check behind the graphics while you've got the panels off anyway.

Loose bolts and worn pucks

Check all bracket bolts after the first ride and then every 500-1000 km off road. A loose bracket ruins the thread long before the part itself fails.

A frame slider is replaced when the puck is worn unevenly or down to the bracket after a crash, and a Pad or rubber bushing is replaced when it's been squashed flat. Both are the cheapest place to start when you're updating your protection.

Fitting in practice

Most frame parts can be fitted at home with ordinary tools, but the order matters. Start all bolts loosely, line the part up, and then tighten in a criss-cross pattern.

If you fully torque one bolt first, you pull the part out of line and the remaining holes won't line up. On plastic parts that builds in stresses that later turn into cracks at exactly those holes.

For crash bars and skid plates you often have to loosen — not remove — the engine's through-bolts. Loosen only one at a time, and support the engine if you need several out at once.

Licence plate holders from Zieger, Onedesign and Heinz Bikes come with brackets for indicators and the light. Check that the plate sits visibly and securely, and that the wiring doesn't pull tight when the rear wheel bottoms out.

For custom projects with Fender and Struts from Drag Specialties, V-Twin or Zodiac, expect drilling and fettling. Trial-fit everything untreated before anything goes off to paint.

Frequently asked questions about frame parts

These are the questions we get most often about fenders, panels, sliders and protection parts.

Will plastics from one brand fit another model year?

No. Plastics follow the model generation, and even half a year's difference can move the bolt holes. Use Find your bike and the range is filtered to your exact year.

Frame sliders or crash bars — which protects best?

Sliders are best on sports bikes and low-speed crashes where the bike slides. Crash bars protect a wider area and carry the weight of a heavy tourer, but they take up more room and cost considerably more.

If you have room for both, together they give the best coverage of engine and fairings. See the range of frame sliders for your model.

Can I paint plastic parts a different colour?

Polypropylene needs a primer made for plastic, otherwise the paint lets go at the first pressure wash. Most people go for a Graphic kit from Factory Effex or Blackbird Racing instead, which stands up better to cleaning.

How thick should a skid plate be?

For gravel and forest tracks, plastic from around 6 mm is enough. If you ride rocks and hard enduro you should move up to aluminium from around 4 mm, which spreads the impact instead of giving way locally.

Should I use thread lock everywhere?

Use medium-strength thread lock on all bolts in metal brackets close to the engine, where the vibration is worst. Leave it out on plastic, where a washer and the correct torque do the job without damaging the material.

If you're putting the whole exterior together in one go, you'll also find fenders and panels under body panels and fenders, while the front end is finished off with windshields and fairings.

All frame parts at Partsdenmark.com are covered by 2-year right of complaint, and we offer a European price match if you find the same item cheaper at a European dealer. There's free shipping on orders over €200.