the 'there's no such thing as a stupid question' bike maintenance thread

Nice move Alek, freak them out and then move in with the offer

fat bloke wrote: »

Question:

Do direct-mount (rim, roadbike) brakes only go on a direct mount frame / fork?

Yes. You need a direct-mount specific frame

Ray Bloody Purchase wrote: »

I took off the mudguards on my bike. Do i put the screws back into the frame to stop stuff getting in and rattling around the place or just leave them out?

I’d leave them out. Make sure you bag them and keep them with the mudguards for when you refit them though

I'm putting together a bike with a compact chainset and 50-34 derailleur - how do I tell which length chain I need to order?

The size of the chainset, cassette and capacity of the rear derailleur don't define the required chain length - the length of the chainstays also counts, but even measuring that won't give you an answer (there are no charts).

Unless it's an extremely long-chainstay bike coupled with a huge cassette (probably a touring frame or other long wheelbase type) and if you can fit more than three fingers between the seat tube and the rear tyre, then it might be an issue, but otherwise almost any chain you buy will work.

If it's a compact (ie: not a triple chainset) and not a huge cassette (>32t largest), then the handiest way (Shimano's method) to size the chain you're fitting is to put the derailleurs in the highest gear (big ring/smallest sprocket), thread the chain through, and then measure the overlap so that the bolts for the two jockey wheels of the rear derailleur are vertical (go a tiny bit shorter if things are less than two links out).

07Lapierre wrote: »

It depends on the size of cassette you intend using. I usually order a 116 link chain and I have a 52 chainring and 28 sprocket.

Knew there was something wrong with my original post - meant to say compact and an 11-32 cassette

Alek wrote: »

I wouldn't worry about it. Its the textile casing that keeps the pressure in (or the tube from bursting, in other words), rubber coating on sidewalls is mostly a protective measure against abrasions. If the threads underneath are fine, these tyres have plenty of life in them.

Unless you're running them tubeless... but then you'd notice a loss of pressure and sealant before.

BTW, what is the usual pressure you're running? They are 33-35mm aren't they?

Ah thanks a lot. Yea I'm running them with a tube. The tyres have a recommendation of 60 - 87psi written on them so I aim for about 70 usually, then top up again a few weeks later when it hits 60.
32mm tyres i think.

Hi all,

I'm cycling along cheerfully, uphill or down, pedalling. Suddenly, the chain locks up. I think it pulls the rear derailleur (RD) forwards when it does this. Bike stops (when the momentum runs out, or when I brake). I get off the bike, spin the cranks - all good. What's happening here, and how do I stop it?

It's VERY intermittent - three times in 5km, then 100+km with no issue (I took the wheel on and off, which seemed to 'fix' it...until yesterday).


I have tried
- the chain is the right length, and is moving fluidly, with no stiff links.
- the RD seems fine, both jockey wheels are smooth.
- the wheel spins, even with the chain locked up, so the freewheel seems ok?

While 'new bike' or even 'new RD' or 'new freewheel body' or 'new wheel' seem possible approaches, there is nothing obviously wrong with any of the existing parts.

A look-over by the LBS also saw nothing. But maybe a boardsie had this, and will say 'ahhh....that's the extra-rido-nubbin-screw'...or whatever?

Thanks!

One of the teeth on one of the front chainrings (take note of which one you’re using when it happens) has a burr on it, and when a narrow link goes down over it, it gets stuck when it should release it at the 6-o’clock position- the chain rides up past 6 and locks the cranks when the derailleur reaches full stretch. It’s random because the burred tooth may sometimes get a wide link over it (this is randomly decided when you shift the FD to the problem ring).
Find the damaged tooth and file off the burr, and you’re all set.
PS: the burr may be tiny, so make sure the chainring is clean and look closely on each side in turn.

There's no point changing the inner ring unless you change the big ring too, and there's no point changing the big ring unless you can spin out your biggest gear. You'll just end up with more overlapping gears between the two chainrings. Stick with what you have. You'll need that 30x34 some day....

magicbastarder wrote: »

you mean '34 to 25' as in the range of cogs on the cassette, or do you mean 34 on the chainwheel to 25 on the cassette?

if the former, it's not wasted if you're using it where it's intended to be used?

Yeah on the cassette, I never use the 34 or 30 cog with the 30 ring as I dont climb steep enough hills. I mainly use the 27 and 25 cogs with the 30 ring on climbs. Once I get to the 23 cog I move to the 46 ring which I have not spinned out yet.

Weepsie wrote: »

Notices a bit of wobble/judder when braking at the front. Thought it was the brakes as I got wider rims and had to adjust them a bit so figured I'd not done a great job on it.

However when I stopped and applied the front brake and rocked it there was some play in the fork. All seems to be as tight as it should be,.

Assuming something wrong with the headset, or maybe worse, something I didn't pick up when I came down in September. Could possibly be the brakes, but shouldn't be play I imagine, however marginal?


Only been out in it once since October and didnt notice anything cycling it in September/October

Headset bearings are first port of call. Take the fork off, check the headset bearings for roughness, pack the bearing races with grease and put it all back together.