I've ridden my commuter and touring bike (cyclocross frame, but with mudguards, rack, hub dynamo etc.) extensively for the last six years and a total of maybe 25 000 km (~15 000 miles). It has seen a lot of bad weather and maybe two falls (nothing serious). I have of course done some maintenance, but not very religiously and the bike was never professionally serviced.

Now there has come a point where I think a general check-up is probably overdue. I want to fix some accumulated small problems and at the same time make sure that I address points that I have previously neglected. However, I'm unsure what to look at beyond the the things that are directly obvious.

Maintenance that has been done in the past (not very often, mostly just when clearly necessary):

  • cleaning the bike, lubing the chain, etc.
  • new tubes and tires
  • new chain, brake pads, brake/shifter cables
  • cosmetics: new bar tape, brake lever hoods

Extra things I'm doing now:

  • new mudguards (the old ones are bent/broken)
  • thoroughly cleaned the cassette by disassembling it
  • cleaned and rebuild the pedal bearings because one of them was slightly seized
  • either rebuild or replace the headset bearings because there is some noticeable play

Things I'm unsure about:

  • Should the wheels be trued? (There is no obvious run-out or lose spokes.)
  • Do the wheel bearings and bottom bracket need maintenance?
  • Do I need to replace the brake rotors if they still look and work fine?
  • Do I need to replace the cassette/chainrings? (They are noticeably worn but the chain still runs and shifts very smoothly.)
  • What other things might I be overlooking that should not wait until they become a problem?

Any advice is appreciated. Generally, I'm happy to do whatever can myself and learn in the process, but I'd also consider to leave some things to the professionals at my local bike shop.

my Müsing cyclocross bike

  • 3
    Check your top tube for damage after clamping it there, and in future always clamp the seat post.
    – throx
    Aug 9, 2021 at 3:02
  • 1
    Always put the bike in the rack drive side out.
    – David D
    Aug 9, 2021 at 17:33

3 Answers 3


Start with a wash. Clean the whole bike with soapy water, rinse, and let it dry. If you want to be fancy, use car products to make the paint shine. That alone feels like an upgrade.

Then - think what's not working? If shifting is clanky and skipping teeth, I'd go for a complete transmission overhaul with new chain, cassette, jockey wheels, and probably chainring/s. New inner and outer gear cables too.
It sounds like you're past the point of changing a chain to save the cassette, so wear them out and change both at the same time when things start skipping in your preferred gears.
Your photo shows some pretty severely-worn teeth on the large chainring. I can't see the small chainring very well, but when you do the transmission, expect to replace at least one chainring, probably both.

If consumable items are worn out, replace them. Brake pads, and brake cables. If your brakes are hydraulic, a fluid flush may be in order. Bartape is a consumable, and if its torn then replace it. A simple wash might be all it needs. Your blue tape just looks a bit bedraggled, its not obviously torn and should cope being rewrapped. Or get a new colour and mix it up.

Your pedal is not spinning properly? - service them both, and if that doesn't help, replace both. Consider colour matching your pedals to your new bartape.

Truing wheels - if the rim is running true, then there is no need to do anything. If you have a slight buckle then its worth tweaking the spoke nipples to bring it back into trueness. Disk brakes let you run wheels that are slightly out of true without consequence on braking, but it is better if they are flat.

The loose headset probably just needs a tighten. You can open it and potentially clean the races and bearing balls then reassemble, or just tighten the preload a little and lock it back down. Headsets don't do a whole rotation in their entire life, but the lower bearings do carry around 40% of your weight. Worth looking at.

Mudguards/fenders don't need to be fantastic - they just need to interrupt the flow of water. So they can work perfectly well with some bodgy repairs. The risk is if they break and then lock up your wheel, which is unpleasant.

As for timing, you want to take things in bite-sized pieces that you can finish before you need the bike again.

I'd suggest fixing the thing that annoys you the most, probably the headset or the pedal, if it were me. And when that is resolved, move onto the next problem. Parts availability can be a challenge, so consider getting items in before you tear something apart and can't ride the bike. Or have two bikes.

  • 2
    One additional note from a loose-bearings guy - many of your bike's bearings may be loose (non-cartridge) and so should be at least checked every year. While you have the wheel hub or headset open, you should at least clean out the old grease and repack them with fresh grease (I like the cheap and easily available marine trailer wheel bearing grease).
    – Armand
    Aug 8, 2021 at 18:22

I routinely replace the fork, stem, and handlebar. Simply because I've made the experience that these parts can and do fail due to fatigue. And since these parts are single points of failure that may cause very nasty accidents, I have come to the conclusion that it's better to replace them regularly before they become dangerous.

Note that the amount of fatigue that develops in the fork is highly dependent on how you brake: Cantilever/V-brakes put a lot of torque on the blades of the fork, and will eventually cause the attachment of one blade to the steerer tube to fail (this happened with all three forks that failed me). This is the reason why I use a 10'000km replacement interval for them. Disk brakes do not produce nearly as much torque, so may remain safe longer. And, of course, if you prefer to use the rear brake, you'd get even less fork fatigue. On the other hand, fatigue due to road bumpiness depends only on the roads you use.

Apart from that, bikes don't really need any long term maintenance in my experience. You can simply replace the other parts when they fail.

  • 2
    I'd definitely inspect the bars after stripping off bartape, but I'd not replace any of those items without some specific reason like a crack or bend/dent, or damage from accident/collision. However if that's what it takes to have Confidence In Mechanical Details, then it is totally up to the rider what their priorities are.
    – Criggie
    Aug 8, 2021 at 12:13
  • 1
    @Criggie All the handlebars that failed me had their cracks develop right at the edge of the stem. A developing crack at that place is hard to see when it's (partially) hidden by the stem. And even if you take the handlebars off for inspection, the area is very uneven on purpose to ensure sufficient resistance against rotation of the bars which makes it very difficult to spot a crack. I would not trust myself to reliably spot a developing crack in that place. Of course, I prefer to err on the side of safety, other people have different priorities. Aug 8, 2021 at 20:51

Should the wheels be trued? (There is no obvious run-out or lose spokes.)

A high quality wheel that is true to begin with will stay true. Unless there's an obvious issue, don't true the wheels.

Wheel truing is sometimes advertised by bike shops as something that is done at the first service. However, it's highly binary: most bikes have lightweight riders who never cause any wheel spoking issues, whereas a small percentage of bikes have heavyweight riders who can cause the wheel to completely and totally lose all spoke tension. So for most bikes in the first service, no truing will be done.

A wheel that has withstood the test of time for 25000 km is an excellent wheel. Early-life issues like spokes breaking have been eliminated as a possibility, and you can be far more certain the wheel stays working than for something that has 0 km and no test of time behind it.

Do the wheel bearings and bottom bracket need maintenance?

Bottom brackets don't require any maintenance today. It used to be the case that bottom brackets were possible to be disassembled, but long ago even square taper bottom brackets switched to cartridge-style units (which you don't repair but replace) and today in Hollowtech II cartridges are all we have ever had.

Some higher quality wheel bearings like Shimano are adjustable and repairable. If you have ridden 25000 km, it might be a good idea to disassemble the hubs and put new grease in and re-adjust the bearing play. You need cone wrenches with sizes suitable to your hubs to do this service. Fortunately, cone wrenches are cheap.

Some lower quality wheel bearings from manufacturers that do not have cup and cone manufacturing capacity use standard machine bearings in wheels. They are usually half complement, so they have only half the amount of balls a high quality cup and cone repairable/adjustable bearing would have. They probably fail earlier than cup and cone bearings, and should they fail, the only thing that can be done to them is swapping the bearing units with a bearing press. Most cyclists do not have a bearing press at home, so this is a bike shop job.

You briefly mentioned issues in two important bearings.

Headsets today use 45 degree cartridge bearing units. In this case, the bearing is actually a compound bearing: the 45 degree interface absorbs vibrations that would cause the main bearing otherwise to fail in an "indexed steering" mode. These headsets should be disassembled occasionally, once per 25000 km is fine, and you should add grease on all 45 degree interfaces and re-adjust the bearings. If you fail to keep it greased, it can fail in the "indexed steering" mode, developing notches that prefer to keep the fork straight.

Pedals have bearings too. Lower end pedals might not make sense to overhaul (you replace the entire pedals instead), but if you have expensive pedals, it may be worth the effort. Companies like Shimano that have lots of manufacturing capability tend to use cup and cone bearings that are adjustable and repairable, so you might want to occasionally overhaul your pedals, but companies that lack the manufacturing capability cheap out and use standard half complement machine bearings. The machine bearings probably fail earlier and should you need to swap them, you'll probably need a bearing press.

Do I need to replace the brake rotors if they still look and work fine?

Measure the width of the rotor from an area that touches the brake pads with a micrometer screw. Due to wear they are concave so caliper is less ideal than micrometer screw. Shimano says that 1.5mm thickness, Shimano brake discs should be replaced. Other manufacturers probably have similar wear limits, and the wear limit may be written on the disc itself.

Do I need to replace the cassette/chainrings? (They are noticeably worn but the chain still runs and shifts very smoothly.)

You only replace these if you have issues.

I'm surprised you have managed to get 25000 km from a single cassette. Usually I'd say that 10000 km - 15000 km (after about three chains), the cassette should probably be replaced. If yours is still working fine and the chain doesn't jump on cassette teeth when pedaling forcefully in the smallest sprockets (hardest gears), then don't replace. The moment to replace usually happens when an old chain worked perfectly with the cassette but a new chain refused to work without jumping on the teeth. I suspect the next time you replace your chain, it's time to replace the cassette too so make sure you have one unused cassette in stock, as bike parts are hard to obtain these days. Also you should keep one or two unused chains in stock as well.

Chainrings are a different matter. A high quality chainring can last as much as a typical car engine, hundreds of thousands of kilometers. The teeth can show visible wear yet the chainrings still probably works. You only replace chainrings when you have issues such as chainsuck (chain failing to disengage from chainring). You might want to occasionally rotate the chainring on the crank, so that wear happens at different portions than previously. On 4-pin chainrings, you rotate by 90 degress; on 5-pin chainrings, you rotate by 72 degrees. However, if the chainring has shifting aids they may be at different points if rotating so shifting could suffer but you get more miles out of the chainring.

What other things might I be overlooking that should not wait until they become a problem?

Check that bolts are torqued and stay torqued. Even something as mundane as front fender bolt can be a major hazard as the fender can become loose and jam in the fork, flying you over the bars. If some bolt doesn't stay torqued, put threadlock like Loctite in it. However, don't continuously re-torque the crank bolts if you have square taper cranks. The problem is that they are torqued to 40 Nm, then the crank squirms on the taper and they lose torque. If you continuously re-torque again and again to 40 Nm, the crank squirms on the taper a lot causing potential damage. Crank bolts are items that are torqued only once to their correct torque and then subsequently you can check lightly if it still has some torque on it, but never retorque again to 40 Nm.

Inspect every high load area often for signs of beginning cracks. This includes seatpost, fork, stem, handlebar and cranks. I wouldn't replace any of these components on a schedule. If you are observant when you ride and notice any oddness in handling, and if you inspect these often, you can probably catch a starting crack before it causes the part to separate in half. Clean the part before inspection and use a flashlight aimed from different directions to see if you can find any cracks.

Replace rear derailleur jockey wheels as they wear.

Check your emergency repair kit occasionally. The checks should include:

  • Whether the mini pump still works
  • Whether the spare tube still holds air (a good idea is to insert the spare tube in a sock that prevents the rubber from wearing fast)
  • Whether the vibration of the toolkit has caused unused tube patches to lift on their edges
  • Whether the tube patch glue has dried out

You already mentioned several important things but I'll repeat:

  • Tubes
  • Tires
  • Cables
  • Chains
  • Brake pads
  • Bar tapes
  • Brake lever hoods
  • 2
    Seriously, are you being paid by $hitmano to post this advertising nonsense all over the place? There is nothing wrong with industrial bearings in high-end pedals and they can be be replaced very easily without the need of finicking with balls. No bearing press is needed when re-building CB pedals. Aug 8, 2021 at 14:44
  • 3
    OP has hollowtech cranks, not square taper
    – MaplePanda
    Aug 8, 2021 at 18:12

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