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

magicbastarder

magicbastarder wrote: »

also, anyone have any opinions on BBB (disc) brake pads?
bought a set for my commuter for the rear brake, they were going fine, got a bit contaminated so i took them off, gave them a light sanding with 600 grit sandpaper and degreaser, and they were much worse after.
so this evening i poured boiling water over them, let them sit a while, and then sanded again with 400 grit, and hit them with a heat gun. now i know they've not bedded in yet, but the back wheel simply does not lock up if i put any weight on the bike and rock it back and forth with the brake pulled. i have not had this issue with other brands.

after a thorough clean last night, they're worse than ever. they feel like they need to bed in again, but simply aren't bedding in. no squeal, either, even in the damp so i don't know if they're still contaminated or not.

Large bottle small glass

magicbastarder wrote: »

anyone ever try to tack a mudflap onto a mudguard? i have a decent enough set of mudguards on my bike, but there's no flap on the front one and the bottom bracket and about 15cm up the downtube get caked in mud.
if anyone knows of any decent guides for adding one, i'd be most appreciative.

Almost anything will work; mouse pad, yoga mat, milk carton, dpc etc

Pop rivets look a little neater I think

cletus

magicbastarder wrote: »

after a thorough clean last night, they're worse than ever. they feel like they need to bed in again, but simply aren't bedding in. no squeal, either, even in the damp so i don't know if they're still contaminated or not.

Is the disc contaminated?

magicbastarder

i had sanded that lightly too, so i suspect not, but i will have another go this evening.

CantGetNoSleep

magicbastarder wrote: »

i had sanded that lightly too, so i suspect not, but i will have another go this evening.

Are you supposed to sand the disc?

I have a contaminated disc and thought you need to use isopropyl alcohol to clean it

magicbastarder

i've done it before several times without issue.

cletus

Magicbastardar, at the risk of teaching my grandmother to suck eggs, have you checked that they are sitting right in the caliper, that they are adjusted properly to make contact, and have you checked wear on the rotor?

magicbastarder

all seems OK, though i did examine it in poor light last night. i've had this bike for three years, and done maybe 15k km on it, this is the first time this has happened, and with relatively new pads - so i suspect the pads, but i may be leaping to conclusions there.

LollipopJimmy

I wouldn't have used degreaser on the pads. With race cars if we glazed the pads we took them out and rub them on garage floor (between races when in a big hurry) otherwise just sand them with a heavy grit sandpaper. Adding any chemicals wouldn't be advisable. The material brake discs are made from will soak up any oils. Brake disc cleaner would be an idea to clean the disc but I wouldn't put anything on the pad. High temps kill pads too so the boiling water may not have helped.

- I'm basing the above on my knowledge of cars but I suspect the principals are the same

magicbastarder

high temps? weird, i'd have thought that was one thing that pads would be able to take; someone once told me that the reason car pads don't become contaminated is that they reach temps high enough to burn off oils that bike pads don't reach.

cletus

I was thinking much the same thing, lollipop, again based on cars. I was going to suggest a can of brake cleaner from Halfords or similar, but it's possible that isopropyl alcohol or component cleaner would do for bike discs

magicbastarder

worth reading:

https://off.road.cc/content/feature/whats-the-best-way-to-clean-disc-brakes-on-a-bicycle-2937

LollipopJimmy

magicbastarder wrote: »

high temps? weird, i'd have thought that was one thing that pads would be able to take; someone once told me that the reason car pads don't become contaminated is that they reach temps high enough to burn off oils that bike pads don't reach.

Indeed you're right but there is a limit and the bigger the pad the higher the temp it can handle, bike pads are teeny and boiling water would likely bring way above this threshold

magicbastarder

calculation here shows that braking on a typical descent can raise the temp of the rotors by 130 degrees - i came down kilmashogue on that bike once, and the drizzle at the bottom was spitting off the rotor when i reached the bottom. i'd be surprised if they failed at 100C, they need to be able to take a lot of energy dumped into them (via friction) in a short period of time.

https://bicycles.stackexchange.com/questions/47326/maximum-brake-temperatures

as mentioned, i've been using the above method to clean the pads for years, this is the first time i've had issues. either it's the pads (as mentioned, first time using BBB pads, but i can't imagine they're much different from the other pads i've been using), or my brakes are misaligned.

Have you reset the pistons?

LollipopJimmy

When braking the temp rises gradually, quickly enough but still gradually. Going from cold to boiling water wouldn't be ideal. I'm not saying you're wrong and I'm not saying this is the issue but it's not something I would recommend, it wouldn't be advisable with car discs either and they could see 250degrees easily and in a track situation could be up to 600.

Think about getting into a hot bath, you'll slide in slowly but you won't jump straight in

magicbastarder

Deleted User wrote: »

Have you reset the pistons?

that's on the plan for this afternoon, if i can get away from the laptop for long enough i'm going to take the caliper off and give it a once over.

magicbastarder

well, it wasn't the rotors, and it wasn't the calipers - i sanded the rotors and the pads with 400 grit paper, no difference. stuck on an old pair of pads i'd kept as a just in case, instantaneous change.
so the pads must be contaminated, or else something else wrong with them.

cletus

magicbastarder wrote: »

well, it wasn't the rotors, and it wasn't the calipers - i sanded the rotors and the pads with 400 grit paper, no difference. stuck on an old pair of pads i'd kept as a just in case, instantaneous change.
so the pads must be contaminated, or else something else wrong with them.

How long do you have those pads

magicbastarder

since the summer i think; but it's only in the last while that they'd have had to deal with commuting muck.

LollipopJimmy

magicbastarder wrote: »

since the summer i think; but it's only in the last while that they'd have had to deal with commuting muck.

Very easy to pick up spilled fuel or oil, I was behind a bus on Conyngham Road a while back that was spilling fuel, it can happen when they are overfilled

cletus

Here's a possibly stupid question, not really related to maintanence.

Thinking about changing the bar tape on my bike, and have no idea where to start. Brands, thickness, material...haven't a clue.

The one thing I'm pretty sure of is I'd like black and orange tape (my bike being black and orange). Other than that, I'd love for some knowledge to be imparted

magicbastarder

what's on it, and do you think it's thick enough?
i have a tape on the bike i use as my commuter which is much more of a rubbery/plasticky feel, and on the dry weather bike, i have synthetic cork - and i think your needs may vary depending on what weather it's used in (though if you're asking now, it may not be a dry weather bike?)
for actually wrapping the bars, the park tools video on it is the one i used as a guide:

https://www.youtube.com/watch?v=5MzIiv7pewE

cletus

Thanks. No idea what's on it. Whatever was there when I bought the bike.

It's a dry weather bike insofar as I don't like cycling in the rain

I've looked at a couple of similar videos all right

CramCycle

The park tool one is the best in my opinion, in regards videos to watch about wrapping tape.

As for Black/orange tape, while I dislike the idea, both Fizik and Deda do Black/Orange mix tape and both brands are decent, the more comfy you want your ride to be, the thicker your tape should be is the only fast and loose rule of tape. Both of the above should last awhile in my experience.

cletus

Thanks for that. Is it just the aesthetics that you don't like?

I saw bar tape from Deda that's black, with orange in the perforations, so good to know the brand is good too.

I had also come across Lizardskin, but the reviews seemed to vary wildly

Utter Consternation

I've a 150 euro of a voucher for the LBS. The bike is due a service, it's two years old and i've done around 9000km on it. Is there anything i should look at replacing on it? I changed the tyres last year and also had a new chain and cassette put on it too.

CramCycle

cletus wrote: »

Thanks for that. Is it just the aesthetics that you don't like?

I saw bar tape from Deda that's black, with orange in the perforations, so good to know the brand is good too.

I had also come across Lizardskin, but the reviews seemed to vary wildly

Just the aesthetics. Lizard skin are nice, good grip and aesthetically pleasing but never last long IMO, and I always found a little tougher to put on but not majorly, a little less stretch compared to other brands.

magicbastarder

i have bright orange bar tape on my dry weather bike - as mentioned, it's the synthetic cork type. it gets a little grubby, but not too bad, but i suspect if it was on an all weather bike it'd be manky by now.

cletus

CramCycle wrote: »

Just the aesthetics. Lizard skin are nice, good grip and aesthetically pleasing but never last long IMO, and I always found a little tougher to put on but not majorly, a little less stretch compared to other brands.

This is what I had been thinking, not too egregious style wise



However, magicbastardar seriously has me thinking about that all orange tape...