Keen to try a bit of DIY bike maintenance but worried your ‘can-do’ approach might end up as one big ‘can-D'OH!’? Check out BikeRadar's top 10 DIY 'Don’ts’ to keep you out of trouble.
- Spoke key
- Grease, oil
- 3, 4, 5mm Allen keys
- Chain tool/measuring tool
- Pressure gauge/pump
- Torque wrench
- Pedal spanner
1 Torque it over
Don’t over-tighten fragile bolts. In this day and age of lightweight carbon components and puny 5mm titanium Allen bolts, it’s deﬁnitely worth developing a sensitive touch when tightening things up. Consider investing in a decent torque wrench set with the appropriate torx and Allen sockets; 10Nm ain’t much, and 5Nm is even less, which is often now the recommended torque range for seatpost, steerer and bar clamps. Always grease the threads and base of the bolts ﬁrst, including both sides of the washers. On twin-bolt setups, nip each one up gradually, holding the tool with your ﬁngertips. Stick to short handled tools and never use a cheater bar extension or grab a ﬁstful of Allen key and go for broke because things will break.
2 Maladroit mechanix
Learn how to adjust your headset correctly and understand how it actually works. First, never tighten the top cap without loosening the stem bolts, because you’ll simply damage the cap and star-washer or expander wedge located inside the steerer tube. At the very least, the wedge will pull up level with the top of the steerer tube and prevent further adjustment. If this is the case, re-position the wedge back down a good 1.5in/2cm. Next, make sure the top of the stem or a spacer protrudes about 5mm above the steerer edge. Place the cap on top and nip up the adjuster bolt, as pictured, but without the Neanderthal grip. There should be no bearing play, but free movement. Refer to step 1 for tightening the stem.
3 Tension headache
Don’t just true your wheel by only tightening spokes. A common error is to attempt a wheel true without fully understanding the process and consequences. Of course, the only way to learn is to try it yourself, so have a go, but only after arming yourself with as much information as possible. The ﬁrst port of call will be to attempt to remove any left and right movement. One revolution of the non-driveside spoke nipples has about twice the effect laterally as one revolution of a driveside nipple. So to keep spoke tension from ramping up excessively, split any lateral adjustments by tightening one side a bit, while loosening the other side a bit. If you’re deforming nipples, you’ve gone way too far.
4 Point brake
Don’t ignore wear limits on rims if you're using rim brakes. The consequences could literally be lethal. Many rim manufacturers provide some sort of wear gauge – a shallow groove running along the circumference of the braking surface or small shallow holes drilled at strategic locations, usually indicated with a sticker. Find these markers and inspect them regularly. Once they disappear, the rim needs to be replaced. Another clue is a distinctly concave braking surface. If there are no wear indicators, measure the wall thickness by placing a small length of 2mm cut spoke ends on either side of the rim wall and measure across with a vernier calliper. A total of 5mm means you have 1mm of wall thickness. Anything below 1mm should be replaced.
5 Knuckle under
Don’t give in to the pressure of rushing things and get injured in the process. When tightening and loosening any type of ﬁrm thread, be aware of where you’ve positioned your hands and what your knuckles might strike if the tool or thread were to suddenly break loose. With a tight crank arm bolt or pedal, as pictured, always place the chain onto the big ring ﬁrst to cover the teeth, which can inﬂict very nasty injuries if struck at full force. Consider wearing some protective gloves or simply use your riding mitts for busting tough threads loose. Never hurry. Try to position your body so you always pull towards you with your arm rather than pushing with your body weight, for better control if the threads suddenly give way.
6 Last post
Don’t leave your seatpost in the bike forever – forever means three to six months. A seized post will make it impossible to change saddle height or to sell your bike without getting it repaired at considerable cost. Even if it’s been greased, over time the grease will break down and eventually allow oxidation to occur, as it’s virtually impossible to prevent moisture from entering the frame. Not only will metal seatposts and frames seize, so will carbon ones, even when both the seatpost and frame are carbon. With metal, a generous dollop of grease or copper slip should be applied to the areas of contact after cleaning and ensuring everything is grit-free. For carbon, use an assembly-paste formula such as Finish Line or Pace.
Don’t put pedals in dry and too tight. Installing pedals dry is sure to cause headaches later on when you want to remove them. Overtighten them as well and it'll probably mean a visit to your local bike shop and about £20 labour or more, as the crank will often have to be removed and clamped in a vice in order to get a safe purchase on the pedal. In addition, once corrosion has been allowed to become established and ‘weld’ the pedal threads together, those threads can become brittle and crumble when the pedal is removed. So, plenty of grease, a protective washer when required (if the pedal axle has ﬂats only – with no protective ﬂange abutting the crank arm), and ﬁrmly tight, without overdoing it (30Nm or around 25ft/lb).
8 PS: Psi
Don’t ignore tyre pressure. Riding around with soft tyres can open up a can of worms, full of inconvenience, as well as dragging down your spirit and top speed. Always check your tyres before heading out on a ride; some thinner walled inner tubes can lose between 5 and 20psi a day. Either give them a squeeze by applying ﬁrm pressure to the top with your thumb or ping them with a ﬁrm ﬂick of the ﬁnger. They should produce a drum-like hollow sound and feel very ﬁrm when at the correct pressure. Use a good ﬂoor pump with an accurate gauge to get the correct inﬂation, then learn to identify by feel when you’ve reached that correct pressure, for those times you’ll be using your hand pump by the road- or trailside.
9 Hurt locker
Don’t ride with your wheels loose. Lock down your quick-releases or through-axles before every ride and prevent a world of hurt. A common mistake is to treat the quick-release as a wing nut by winding up the lever. To make matters more confusing, DT skewers, along with some aftermarket anti-theft types, actually use this method to ﬁx the wheel into the fork. Only use that method for those particular brands. With all others, the cam action of a traditional quick-release is still the only secure locking method, and will be best at preventing your wheel from getting wrenched out of the bike when put under sudden extreme loads. Adjust the skewer nut to allow the lever and cam to swing past top dead centre and ﬁrmly into the closed position.
10 Chain smoker
Don’t ride with a badly installed chain. Many manufacturers as well as home mechanics will damage a chain while installing it and leave it on in the false hope that it will hold up during ‘normal use’. This is wishful thinking as most chains usually endure nothing but abnormal use during their short lives. Assume that any damage, as pictured above, will always lead to catastrophic failure and possibly injury. Follow joining pin instructions to the letter, or consider using a universal joining link, which are available for most chains. Furthermore, don’t neglect chain wear. This could lead to early and uneven cog and chainring wear, so use a chain measuring tool to check periodically, or replace every 1,500 miles or so to be sure (approximate for road use, halve that for mountain).