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

magicbastarder · 15-03-2019 11:46PM

Re the pump, get to a lidl and you might get one of the seven euro track pumps - if they've any left.

CramCycle · 15-03-2019 11:49PM

I have access to liquid nitrogen if your feeling stupid some evening

16-03-2019 12:41AM

CramCycle wrote: »

I have access to liquid nitrogen if your feeling stupid some evening

This + a shiny new stream cleaner could have some potential for some capers :pac:

crosstownk · 18-03-2019 03:35PM

Lately the I’ve noticed what felt like chain skip. The chain was staying put on the correct sprocket but the rear derailleur cage was moving back and forth (not in and out) like it was being pulled forward by the chain. Suspecting a stiff link, I went to replace the chain as it is worn but I discovered significant lateral play in the jockey wheels - especially the lower one. I’m sure this is my problem.

My question is, am I better off to buy a complete RD (105 5800) for €50 or is it worth my while replacing the jockey wheels. CRC have a pair of BBB jockeys for €12. I’m well able to replace them DIY.

Has anyone done similar and do the BBB jockeys do the job?

magicbastarder · 18-03-2019 04:37PM

if you're happy it's just the jockey wheels, just replace them. it's a simple job. i'm 90% certain it was BBB replacements i used before.

i would disassemble and regrease my jockey wheels a couple of times a year anyway.

saccades · 18-03-2019 08:58PM

Weepsie wrote: »

I nearly would just to see what it could do.

I feel stupid most evenings. As I said, i've considered caustic soda. Living in an apartment block though, the only outdoor areas are shared, and that wouldn't be wise.

It's drain cleaner... Do it in the bath then flush with water. It'll clear all the hair and gunk out.

bsb1971 · 19-03-2019 12:53AM

I've recently cold forged an old 531 frame in order to fit a 10 speed groupset to it. Everything seemed to go ok. But now I have one problem. When I try to cycle it, the rear wheel is coming out of centre, and rubs off the rear stay. I've tried tightening the wheel as much as I can, but it still seems to be coming loose. I've checked all the obvious things to me, but am now wondering if something is wrong with the frame since I increased the rear spacing. The frame was ok before this, as I had used it as a single speed. Anyone any ideas as to what might be wrong?

John Hutton · 19-03-2019 11:21AM

bsb1971 wrote: »

I've recently cold forged an old 531 frame in order to fit a 10 speed groupset to it. Everything seemed to go ok. But now I have one problem. When I try to cycle it, the rear wheel is coming out of centre, and rubs off the rear stay. I've tried tightening the wheel as much as I can, but it still seems to be coming loose. I've checked all the obvious things to me, but am now wondering if something is wrong with the frame since I increased the rear spacing. The frame was ok before this, as I had used it as a single speed. Anyone any ideas as to what might be wrong?

Is the rear wheel actually coming out of centre or are you having to put it in off centre to avoid rubbing?

bsb1971 · 19-03-2019 11:52AM

John Hutton wrote: »

Is the rear wheel actually coming out of centre or are you having to put it in off centre to avoid rubbing?

Seems to be coming off centre, but when I put the wheel in, I have to move it about to get it centred. Then clamp it. It seems to be spinning ok, but as soon as I try cycling, wheel goes to the left and starts rubbing off rear stay.

fat bloke · 19-03-2019 12:07PM

Question:

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

CramCycle · 19-03-2019 12:15PM

Charman921 wrote: »

Recently the pedals on my bike started to 'slip'. I knew immediately it was something to do with the cassette on the rear wheel. I brought the bike to the bike shop (one I've used for 10 years) and they inform me that the 'body' of the cassette has worn out but to replace it, the entire wheel has to be replaced. That's because the body is part of the hub on the rear wheel.

I'm now a pensioner but I raced almost 50 years' ago. Those days if the cassette (the 'block' as we called it then) gave trouble, you had a tool with which you could unscrew the block off the hub and replace it with another. Indeed it was even possible to repair the block in maany circumstances.

Now, we are in the 'use-once-and-dispose' era. Which, as far as I'm concerned is a step back, not a step forward in cycling technology.

A decent modern cassette, if that's all that's needed, costs about €60. A new rear wheel costs from €100 to €250, for a decent 'sportive' wheel

bsb1971 wrote: »

Seems to be coming off centre, but when I put the wheel in, I have to move it about to get it centred. Then clamp it. It seems to be spinning ok, but as soon as I try cycling, wheel goes to the left and starts rubbing off rear stay.

Sounds like the wheel is slipping, maybe the dropouts are worn a bit or the QR Skewer is not as tight as you think (it maybe slipping with age). Have you tried taking the springs out of the skewer and over tightening without them present, this solved an issue with an old skewer of mine

Alek · 19-03-2019 12:40PM

As I said, i've considered caustic soda.

Be SUPER careful with the stuff. Don't mix with hot water (may boil explosively), wear long rubber gloves and eye protection (!!!). Watch for splashes on your clothes, in case of skin contact wash under running water, or better apply vinegar.

Also, you need to have it fairly concentrated to dissolve the seatpost. Get the frame upside down in the bath and pour from the BB.

Alkali burns are nasty and heal ages, or so I've heard.

Alek · 19-03-2019 12:56PM

What's the size of the frame? Name your price too

Peter T · 19-03-2019 01:01PM

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

John Hutton · 19-03-2019 03:00PM

bsb1971 wrote: »

Seems to be coming off centre, but when I put the wheel in, I have to move it about to get it centred. Then clamp it. It seems to be spinning ok, but as soon as I try cycling, wheel goes to the left and starts rubbing off rear stay.

I had a similar problem after I cold set an old frame and it turns out that with the stays moved what looked centered actually wasn't and the wheel would slip to being "actually" centred resulting in rubbing. I didn't think too much about it and just put a smaller tire I had on it which I had planned to do anyway in order to fit fenders on.

I would suggest ditching the skewer and going old school just with bolts and really tighten it and see how you get on. As another poster said, skewers can wear out.

TychoCaine · 19-03-2019 08:30PM

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 · 25-03-2019 09:48AM

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?

triggermortis · 25-03-2019 10:06AM

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

irishrover99 · 26-03-2019 12:44PM

Can anyone tell me if these bearings are the right ones for a CAAD 12 and if they are any good.
https://www.chainreactioncycles.com/ie/en/rotor-bb30-steel-bottom-bracket-kit/rp-prod130493?gs=1

CantGetNoSleep · 27-03-2019 02:39PM

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?

Miklos · 27-03-2019 02:52PM

I had a 50/34 and 32/11 for a hilly week away and used the same chain as I had with 53/39 and 28/11 so I'd imagine you'd probably get away with the standard length.

Type 17 · 27-03-2019 02:55PM

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 · 27-03-2019 02:56PM

CantGetNoSleep wrote: »

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?

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.

CantGetNoSleep · 27-03-2019 03:20PM

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

Mickiemcfist · 27-03-2019 03:38PM

Anyone know if I should look at changing these tyres now or have they a lot of life left in them? Theres sidewall cracks but other than that they're fine, plenty of tread & not losing much air. I've only had them for about 2k kms.

Alek · 27-03-2019 04:52PM

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?

Mickiemcfist · 27-03-2019 04:56PM

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.

Type 17 · 27-03-2019 05:43PM

Should be fine in the short to medium term - as Alek says, the textile beneath is what gives the tyre its strength.

It's the UV in sunlight breaking down the rubber, so it cracks rather than stretching.

However, in the long term (some years' time), the cracks do allow rainwater into the tyre, which eventually rots the textile cords, leading to failure. But don't worry, the rest of the tyre looks really poor by then, and it usually only becomes an issue with tyres that are constantly ridden soft and for short distances (tyres get old and weathered before wearing out through distance - it's common on ladies' shopping bikes), with cracks around the tread blocks letting a lot of water in.

brownian · 29-03-2019 02:39PM

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!

Alek · 29-03-2019 02:47PM

If it pulls the RD, it may be the freewheel mechanism locking and tensioning the lower part of the chain.

Does it happen exactly when pedalling / applying pressure, or rather when you stop turning cranks for a moment?

When / how does it unblock?

But then it would most likely drop the chain off the front, as the top part of the chain gets loose.

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

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