Bike Maintenance & Repair
MOTORBIKE DIY MAINTENANCE & REPAIR
What was once your brand-new pride and joy is now slumped in the shed looking like a refugee from the recent Queensland floods. Guess it’s time to rekindle the love affair…
A new bike in the shed is a wonder every rider needs to experience at least once. The smell of never-roosted tyres, the shine of un-scratched plastics and the tack of virgin handgrips are pleasures that often have the lifespan of a Mayfly (those lil’ suckers sometimes only live for half an hour – not ideal pets, then!). To increase this fragile existence, many riders will perform the ‘New Bike Beer Night’ with like-minded homosapiens, talking for hours about the shape of a bracket or the curve of a lever. It’s at this time that the ‘Man-shed’ truly lives up to its lady-mystifying billing.
But when does new become not new, then used and then secondhand? Putting around 10 hours on a bike will test the love you feel for her and by another 10-20 hours (about six month for most of us), it definitely feels as used as the fake ID in a drunken teenager’s pocket. So what happened?
From the moment your take your tentative first ride, Mother Nature is trying to turn your moto-love back into whatever it was made from. Alloys corrode, steel rusts, rubber goes brittle. The sun and UV radiation aren’t on your side, either.
So how do you keep the new bike feel and look while the hours rack up? Luckily, there’s not a lot of cash that needs to be parted with; just shed time and some simple tools. The freshen-up of this Honda CRF250X would cost between $200 and $700 in parts, depending how far you go, and about a day on the tools.
BASIC BIKE MAINTENANCE
A Clean Bike is Crucial
It’s amazing when a bike is wheeled into a workshop dirty. Most owners reckon ‘She’s clean as, mate!’ Obviously, we all have different views on ‘clean’ but if it doesn’t resemble showroom clean, you’re only fooling yourself.
Dirt is not an inert substance – it’s minerals wrapped-up in a bit of moisture. The longer you leave it on, the more corrosion occurs. That’s why race teams wash their bikes straight after the last moto, even though it’s dark, cold and everyone just wants to go home. They know that dirt left on the bike for even a day or two will dull the shiny bits and make the job harder. As we all don’t have a semi to wash out of, why not drop by a 24-hour self-serve carwash on the way home? You’re already dirty and the bike is probably on an open trailer and easy to get to. They even have foam spray!
- Soapy tank wash. Truckwash can be high in alkaline, which is deadly for anodized alloys and can strip the cadmium plating off spokes and bolts. Use a bike-specific wash.
- Dirty bottom. As most of the dirt collects on the underside of your bike, it’s vital to lean it over and wash its undercarriage. If you have a plough for a bashplate, remove it, clean well behind and use Dzus fasteners for quicker baths next time.
- Strip and plug it. Getting the seat and tank off it are essential, especially if you’re adjusting valves. Clean well before opening any covers, as engines and dirt get on like flood victims and bad insurance companies. Buying and using an air filter cover and exhaust plug are wise investments.
Maintain Your Bike's Damage-Prone Parts
Yamaha’s WR-F and Honda’s CRF both come into Oz with a headlight and tail light only, and the ADR-legal stuff is added here, via a piggy-back harness.
Dirt bikes are road-legal off the showroom floor but blinkers, horn, mirrors, speedo and the associated wiring are all damage-prone in the bush. It’s not difficult to simply remove the ADR parts and get the bike back to how it was manufactured, with just front and rear lights and a brake-light switch. Sure looks cooler and will save you heaps in a crash, but not exactly legal. But then, neither are doing high-street wheelies and roosting your mates.
Having been pulled over a few times by the law, I can tell you that with working lights and registered bike, a responsible, licenced rider is unlucky to get booked. However, roosting cars in the gravel by the road will see you with a nice fat fine and the scorn of all riders who try to debug the myth that we are all brainless hoons looking for an early meeting with the big fella upstairs.
When you get decals made, get your bike’s registration plate printed on the rear guard. Illegal as a priest in kindy, but better than the RTS-issue alloy item cracking and falling off, or ripping you open like a filleted fish.
If you really must run a speedo, use a pushbike number – with the sensor on the rear wheel. This lessens the chance of wiring failure and the wheelspin factor is not as bad as you’d think.
Lastly, keep it quiet – 94Db should be considered a maximum, so that means mufflers – like the DEP S4 and FMF Q-Core range – not open race pipes. The stock mufflers on some models are very good, with WR-Fs and EXCs excellent.
Maintain Your Bike's Bearings
Bearings have a hard time on a dirt bike. Manufacturers don’t help by using open (no external rubber seal) units in wheel bearings. NTN bearings are a very respectable brand and their LLU sealed bearings are perfect for dirt bike wheels, drivechain rollers and brake pedals, providing excellent movement, along with great dust and mud sealing properties.
Linkage and swingarm bearings are not hard to disassemble and grease, so do them after the initial break-in period and then every 40 hours. If your world turns to rust, companies such as Pivot Works and All Balls offer great replacement kits complete with spacers, seals and bearings.
There is nothing difficult about removing linkages for maintenance – your bike is basically just a big Meccano set. The key is a well-washed bike, a good stand, a brightly lit work area and a modest toolkit. A swingarm-out type grease-up would take most people a couple of hours.
Steering head bearings can ruin a great ride. Any corrosion or brinnelling (small wear marks from sitting still or small movements) means it’s replacement time. As prevention is better than cure, this is best fixed in the shed and not bodged out on the trail.
Check Wheel Bearings
Wheel bearings have a hard life as we only tend to look at them once the poor buggers have collapsed. It’s no fun wrecking a bearing on the trail and even worse when you realise how cheap and easy they are to replace. The common bearing check is to feel for movement by grabbing the top of the tyre and rocking the wheel side to side. If you feel play, it’s new bearing time. This movement also causes brake pad ‘knock-off’ as the pads are punched back by the rocking disc. Wheel bearing replacement is a simple process of removing the outer dust seals, moving the internal spacer tube between the bearings over slightly and driving the bearings out. Rear bearings can be retained by a locking collar or clip so check before taking a run-up with hammer.
If you can push down on the seat and the suspension stays down, it’s normally the linkages, almost never the shock at fault. To remove the whole rear suspension, place the bike on a stand and take the seat and tank off. The rear subframe can stay on if it’s too hard to remove (like on a Suzuki DR-Z400 where there’s a mass of wiring); just remove the bottom bolts and then pivot it up and use a tiedown (stretching to the bars) to hold it up. Remove the rear wheel, take the chain guide off and drop the rear caliper off the swingarm. Two bolts will get the shock out and that will give easy access to remove the linkages. Drift the swingarm pivot bolt out and inspect it. Don’t allow the roller bearings to drop on the floor. Any rust in here is bad, missing rollers worse. To replace the press-fit swingarm bearings, you can use a vice as a press with a few sockets to act as press tools.
Check Steering Head Bearings
The steering head bearings are checked by holding the front brake on and rocking back and forth. Any clunks means it’s time to tighten or replace them. If you do not know the condition of your steering head bearings, disassemble and check them. The fear you feel when blasting towards a corner, only to have the steering head locking up because watching another episode of Two and a Half Men was more important than working on your bike, is somewhere between ‘Oh shit’ and ‘I wish I packed my PJs for the hospital stay’. Removal is simple – get the front wheel off the ground, remove the bar clamps (no need to take the bars, throttle or controls off) and loosen the steering stem nut. Remove the front wheel and forks. Loosen the bearing adjuster nut and, voila, the bottom triple crown slides out. Gaze in horror at the lack of lube and vow never to be such a slack grease monkey again.
MECHANICAL TWEAKS
Engine Servicing
In this modern four-stroke world, if you have a two dinger you may well think yourself lucky. But 4-stroke servicing is simple. First rule is change the oil. The second is to perform the first rule often. That’s 500km max for spirited trailriding (or about 15 hours). Cut that in half if you race. Check the valves every 1000km (30 hours), 500km if racing. Think about a piston at 50 hours for a 250cc and 100 hours for a 450. Ideally that would be it, but occasionally engines drop (break) valves, bearings fail, oil galleries block and well-meaning owners put oil filters in backwards while trying to look after their bike.
A two-stroke requires more regular engine work but is less prone to wallet-busting disaster, unless you forget to mix oil with the go juice.
Maintaining Spokes
Spokes used to give us all hell but that’s almost a problem of the past. On the initial run-in, they stretch slightly as the wheels ‘settle’, requiring a going-over after each ride. Spokes don’t need to be dead tight – it’s easy to discomfort the nipples, especially if they are aluminium. The best way to tighten them is with a spoke torque wrench, as the setting is quite low compared to what you think they need. The downside of not maintaining them is damage to the rim and hub from the spokes moving around. The tell-tale for this is a blackening of rubbed alloy dust due to the wear of the hub and/or rim. Worse yet is a complete collapse, but that’s relatively rare outside of MX use. The most common problem is a broken spoke puncturing the tube. This can be cable-tied up on the trail to get you home.
Changing Suspension Fluid
We all know about changing engine oil but spare a thought for your suspension fluid. There’s about 300cc of oil in most shocks and by the time the first 15 hours are up, it’s looking more like a milkshake. That’s because the factory bleeding process is never great, plus the bladder that holds the gas is permeable, meaning that the oil slowly ends up full of gas. Within a year of the shock being built, it’s overdue for an oil change. Not a big cost, as it’s just a fluid change, about $90-120 from suspension tuners. The forks are similar, normally being built a month before the motorcycle is assembled. The fork seals and dust wipers stretch on the tubes over time, so don’t expect your first set to last – but the second set is usually good for 40-50 hours, the working life of the fluid.
MAINTAIN YOUR BIKE'S FRAME & PLASTICS
Bless the alloy-framed dirt bike! In years gone by, you had to keep a can of touch-up paint for the steel item and even then it had more bare metal showing than paint by sales time. Now a Scotch Brite pad takes care of the dull, rock-blasted alloy – just give it a gentle rub while you wash (the bike that is, not you). Same treatment for the engine side covers.
The plastics also look faded and rough after a very short time. Need more reason to get a full decal kit? They don’t scratch, resist fading, have your name on them (in case you forget) and can give your ride a custom look. Prepare to say ‘sayonara’ to $200-$400.
Grips get torn so replace them as they’re under $20. Levers bend, but stock levers are forged and can be bent back, though cheap aftermarket items are cast and snap like a chicken being eaten by a hungry croc. Some riders like the multi-bending levers from ASV and the like, but they’re pricey at about $80 each side.
Handlebar Basics
Bars get cluttered-up with mirrors mounts, switch blocks and kill/start buttons. Head to a bin and get rid. Mount Barkbusters off the top triple clamp, then they won’t spin round in a crash. Fix them horizontally so they cover your hands and won’t steer the bike when hitting trees. $100 will buy you some good replacement bars with a more personal bend and then stick your new grips on with spray adhesive. Remember to lube the lever pivots.
Punctures are Avoidable
Ditch the stock thin tubes on the first change and put some heavy-duty ones in that resist pinchflats – and drink less beer to offset the weight increase. Lube the spokes while you have the tyres off. Rim tapes are okay until they stretch – Duct tape is ok, too. Treat yourself to some decent tyres – ones that last forever rarely offer decent grip, and you do want to have fun, don’t you?
Clean and Oil the Chain
No more Duckhams’ chain wax in 2011! Clean the chain with a stiff brush then oil it as soon as you have finished washing the bike. I like gold chains when you go for a replacement, as they have great corrosion resistance and are usually only 15 bucks more than an uncoated chain.
As seen in Transmoto Magazine.
