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

magicbastarder

is there a simple list of chemicals which you should not get near disc brake pads? i.e. would even something like a detergent cause issues with contamination; i was wondering as i was cleaning the bike earlier if i can be overcautious in cleaning the bike near the brakes.

any tips on looking after a steel frame? my latest purchase has mountings for racks and also a couple of unthreaded holes - should i tape those up to keep water out, or leave them uncovered to let the water out should it get in?

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brownian

Hi all,
I've been asked to fix up an old Muddy Fox kids bike. It has V brakes - the kind where the cable goes through a 'noodle' at the end. Anyway, the brakes are mounted on bosses (small sticky-out bars on the frame). One of these is snapped off. The stump (and the non-snapped neighbour) both resist my vice-grips charms; neither has the flat sides you'd hope for, to take a spanner.
Should I
- keep trying the vice grips
- pour on petrol or chain lube, wait and hope
- apply heat or cold
- apply a drill with a HSS bit
- cut a slot and try a flat-head screwdriver
- try to cut two flattish sides?

The frame is painted,the brake-bosses not, so I don't THINK that they are a continuous piece of steel (BTW, why on earth are kids' bikes much heavier than adults' bikes?).

Advice most welcome!!

CramCycle

fixXxer wrote: »

It does have break discs. I've seen puncture resistant tyre mentioned in a few places. Are they genuinely a benefit or a marketing gimmick?

There is only one I know that are completely resistant and they are Tannus, simply because there is nothing to puncture they are filled through. I have Schwalbe marathons and have never had a puncture, remember Audax riders years ago who would get over 25000km out of them. Remember tough, their grip isn't as good as race tires in the wet and they are slower although the difference for most of us would be unnoticeable (hands up I barely notice the difference commuting). In the narrower versions, they are definitely more uncomfortable ( I used ot have 23s), but my current ones are fine (28s).

68 lost souls

Type 17 wrote: »

When looking at a derailleur to see if it is bent, check whether there is good parallel alignment between the surface that faces the hanger, and the surface at the bottom of the parallelogram section of the derailleur that interfaces with the plate of the swing-cage (red lines in the pic). If these two surfaces are not fully aligned across every potential gear position (observe whilst operating it with your hands), then the parallelogram section is twisted, and the derailleur is toast. If the parallelogram is ok, but the swing-cage is not fully aligned (the one in the pic is a bit crooked), it can usually be realigned by clamping the hanger-bolt tightly in a bench-vice (align the derailleur carefully with the vice's jaws, so you can use the vice as a reference point) and using a water-pump pliers to gently align the cage in stages, working in one direction/plane at a time. To align the jockey wheels themselves, if required (they can still be crooked even when the cage they're in is straight), grab the two ends of the jockey wheel bolts tightly (while the derailleur is still in the bench-vice) with the water-pump pliers, and twist them into alignment.

Picked up the new hanger today. didn't come with any screws so have ordered screws as I lost one when the hanger snapped.

Chain and old derailleur have got a bit of a deep clean and took the jockey wheels out to clean and replace. Need to do put some grease into the bushings on the jockey wheels next. There was a few gauges out of the jockey wheels caused by the chain twisting but things might be moving a little better. Cant reallytell till I put it back together.

Deano12345

fixXxer wrote: »

It does have break discs. I've seen puncture resistant tyre mentioned in a few places. Are they genuinely a benefit or a marketing gimmick?

I also find wearing gloves while doing the job isn't a bad idea, the grease from your hands can make the discs squeal if it gets on them.

tomasrojo

I guess you just want to change the inner tube?

You also have the option of patching the tube without taking the wheel off. There are videos on how to do that too. On most bikes it's easier just to put in a new tube though.

Punture-resistant tyres do work. They can't prevent all punctures, but you do get noticeably fewer when you switch from regular to puncture-resistant. If you check the tyres for glass and debris every so often and remove the glass and debris you get even fewer punctures.

fixXxer

magicbastarder wrote: »

as above, but worth noting it's more fiddly getting the wheel back on the bike if you've disc brakes as you've to be more precise lining it up.

It does have break discs. I've seen puncture resistant tyre mentioned in a few places. Are they genuinely a benefit or a marketing gimmick?

magicbastarder

as above, but worth noting it's more fiddly getting the wheel back on the bike if you've disc brakes as you've to be more precise lining it up.

cletus

fixXxer wrote: »

How difficult is it to change a back tyre? Went across something last night and the tyre is completely flat. Was going to do it myself but looking at the gears and all the rest as a n00b, I might just wheel it down to the local bike shop tomorrow and give them the business.

Its very easy, although as you note, slightly more difficult on the back. Once you open the quick release (assuming thats what you have) the wheel should just pop out (well, depending on your brakes, I suppose). Once you've changed the tube, just make sure the chain is on the top of the cassette (back gears) when you put the wheel back on. Have a look at the video below

fixXxer

How difficult is it to change a back tyre? Went across something last night and the tyre is completely flat. Was going to do it myself but looking at the gears and all the rest as a n00b, I might just wheel it down to the local bike shop tomorrow and give them the business.

8valve

cletus wrote: »

I'm a teacher. I'm rarely surprised by stupidity

You, sir, have just won the internet.

cletus

Type 17 wrote: »

You'd be surprised - a few times a year, people come into the bike shop with their rims or discs covered in oil, saying that the brakes had been squealing, and that they had added oil but that it hadn't helped...

I'm a teacher. I'm rarely surprised by stupidity

Type 17

68 lost souls wrote: »

There's definitely some road rash on it, I can see where it took a hit and the chain was wedged in and twisted in it so I had to wrangle the chain free.

Hanger snapped and needs replacing for sure but not 100% sure about the derailleur, I guess I'm just worried that if its bent in anyway it might cause another failure. Theres scratches and marks where I can see it took the brunt of the fall

I might wait until the hanger is replaced and test it on the bike stand and then the turbo before heading out on the road.

When looking at a derailleur to see if it is bent, check whether there is good parallel alignment between the surface that faces the hanger, and the surface at the bottom of the parallelogram section of the derailleur that interfaces with the plate of the swing-cage (red lines in the pic). If these two surfaces are not fully aligned across every potential gear position (observe whilst operating it with your hands), then the parallelogram section is twisted, and the derailleur is toast. If the parallelogram is ok, but the swing-cage is not fully aligned (the one in the pic is a bit crooked), it can usually be realigned by clamping the hanger-bolt tightly in a bench-vice (align the derailleur carefully with the vice's jaws, so you can use the vice as a reference point) and using a water-pump pliers to gently align the cage in stages, working in one direction/plane at a time. To align the jockey wheels themselves, if required (they can still be crooked even when the cage they're in is straight), grab the two ends of the jockey wheel bolts tightly (while the derailleur is still in the bench-vice) with the water-pump pliers, and twist them into alignment.

cletus wrote: »

Disc brakes on my bike, but I make sure to give the disc a liberal application

You'd be surprised - a few times a year, people come into the bike shop with their rims or discs covered in oil, saying that the brakes had been squealing, and that they had added oil but that it hadn't helped...

Seth Brundle

Like this driver...?
NSFW

cletus

Seth Brundle wrote: »

...so the brake blocks do get some? :pac:

Disc brakes on my bike, but I make sure to give the disc a liberal application

Seth Brundle

cletus wrote: »

I would have thought greasing the threads of the lockring would be enough.

Regarding the type of grease, everything gets lithium grease, specifically Holt's Blue Grease, because thats what I have in the shed

*Edited to add* every except the drive train, obviously

...so the brake blocks do get some? :pac:

68 lost souls

magicbastarder wrote: »

as grogi mentioned, it's probably fine. i've probably double that on mine and would consider it in good health.

There's definitely some road rash on it, I can see where it took a hit and the chain was wedged in and twisted in it so I had to wrangle the chain free.

Hanger snapped and needs replacing for sure but not 100% sure about the derailleur, I guess I'm just worried that if its bent in anyway it might cause another failure. Theres scratches and marks where I can see it took the brunt of the fall

I might wait until the hanger is replaced and test it on the bike stand and then the turbo before heading out on the road.

8valve

Seth Brundle wrote: »

Going to start replacing my cassettes. Watching & reading online, some suggest adding some grease to the freehub whereas other sites don't seem to do this.
Should I and if so is there a specific type of grease I should use?

A very fine skim of any lithium grease will be fine on the outside surface of the freehub body, although some people don't bother.

I've only ever come across a couple of cassettes/sprockets that I've had to lever off carefully with a flat large screwdriver but they were purely down to excessive dirt and gunk buildup (or individual sprockets biting into the raised ridges of the softer metal freehub body), rather than any corrosion issue.

cletus

I would have thought greasing the threads of the lockring would be enough.

Regarding the type of grease, everything gets lithium grease, specifically Holt's Blue Grease, because thats what I have in the shed

*Edited to add* every except the drive train, obviously

Seth Brundle

Going to start replacing my cassettes. Watching & reading online, some suggest adding some grease to the freehub whereas other sites don't seem to do this.
Should I and if so is there a specific type of grease I should use?

magicbastarder

what make/model of bike is it? bearings come in two types - cup and cone, and cartridge bearings.

it may be as simple as tightening up the nuts on the axle - though if they've come loose, it might suggest excessive wear.

https://www.youtube.com/watch?v=opommURFB4o

clio_16v

I have a slightly wobbly / loose front wheel. I assume it is thr wheel bearing? How do I know for sure what it is and how do I replace the bearings? Any simple diy vids out there?

magicbastarder

68 lost souls wrote: »

Been on there for coming up on 9000km anyway.

as grogi mentioned, it's probably fine. i've probably double that on mine and would consider it in good health.

grogi

68 lost souls wrote: »

Thanks looks like SS alright from that. Found a replacement online for €36 so might as well swap it out just in case. Been on there for coming up on 9000km anyway.

Are you really sure it's cooked? Derailleurs don't wear that much and should be fine after an incident, as it is the hanger that is designed to absorb the hit.

68 lost souls

cletus wrote: »

Some information here, although the video is no longer available

https://forum.bikeradar.com/discussion/13073081/ss-or-gs-derailleur

Thanks looks like SS alright from that. Found a replacement online for €36 so might as well swap it out just in case. Been on there for coming up on 9000km anyway.

grogi

68 lost souls wrote: »

Finding it hard to tell from the pictures. Also can’t seem to find anywhere a measurement I’m sure there must be a way to compare the distance between pulleys or something? Mine is approx 59mm

If it was the long one, there is hardly any room to make it shorter. Must be the short one.
I would get a long cage anyway (which would open you up for wider cassettes), but I don't really pay that much attention to weight.

magicbastarder

looks like a short cage to me - the gap between the jockey wheels is probably half the diameter of one of the wheels. compare that with a long cage:

https://bicyclebuysell.com/item/455237/shimano-105-r7000-long-cage-rd

cletus

Some information here, although the video is no longer available

https://forum.bikeradar.com/discussion/13073081/ss-or-gs-derailleur

Here's a methoud for measuring cage length.

https://bicycles.stackexchange.com/questions/32729/how-to-find-the-cage-length-of-a-rear-derailleur

I suppose you could find the spec sheets for both and compare

68 lost souls

Finding it hard to tell from the pictures. Also can’t seem to find anywhere a measurement I’m sure there must be a way to compare the distance between pulleys or something? Mine is approx 59mm

Type 17

Probably is a long cage, but Google 'Shimano RD-5701 GS' and look at the images to compare the SS (short cage version) and the GS (long cage) against what you have.

68 lost souls

Had a fall and need to replace the derailleur hanger, may also need to replace the derailleur and not sure which length I have. It’s a 5701RD off a trek madone 2.1 2013 running a compact chainset and 12-30 cassette. I suspect since there’s a 30 in the back it’s long cage?