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

wheelo01

For the second time within a week I p,an to prove the thread title wrong:D

Does it matter what colour mineral oil is? Any of the videos I've seen show it as red, I ordered this https://www.bike-discount.de/en/buy/barbieri-mineral-oil-1-litre-for-hydraulic-disc-brakes-1064525 , and when it arrived, the fluid is yellow.

Cheers

cletus

wheelo01 wrote: »

For the second time within a week I p,an to prove the thread title wrong:D

Does it matter what colour mineral oil is? Any of the videos I've seen show it as red, I ordered this https://www.bike-discount.de/en/buy/barbieri-mineral-oil-1-litre-for-hydraulic-disc-brakes-1064525 , and when it arrived, the fluid is yellow.

Cheers

Mineral oil doesn't have the same types of standards or regulations as DOT fluids.

The colour shouldn't make any difference. The HLP stand for hydraulic oil with additives to prevent wear, the 10 is the viscosity of the oil. Do you know what viscosity the oil in your system is?

Edited to add: 10w seems to be the standard viscosity

Type 17

I've never read any accounts of where things went wrong from mixing different brands of mineral oil*, but you always see in manufacturers' notes that you shouldn't do it.
The only real-world issue is that it's hard to tell if the previously-mixed fluid is actually dirty/old, or just a strange colour because it's a mixture of two colours.

*Just to confirm though, putting DOT fluid in a Mineral system, or vice versa, will destroy all of the seals of either system, making it beyond economic repair, unless it's a very expensive system, where it's worth buying all of the seals again and flushing the system before replacing them all.
This also happens with hydraulic power steering in older cars - some are mineral, eg: VW/Audi, and if you put ATF (automatic transmission fluid, similar to DOT brake fluid, correct for many other cars) into the system, you'll need a full rebuild for the pump and steering rack and all plumbing properly flushed.

8valve

wheelo01 wrote: »

For the second time within a week I p,an to prove the thread title wrong:D

Does it matter what colour mineral oil is? Any of the videos I've seen show it as red, I ordered this https://www.bike-discount.de/en/buy/barbieri-mineral-oil-1-litre-for-hydraulic-disc-brakes-1064525 , and when it arrived, the fluid is yellow.

Cheers

lash it in, and keep lashing it in, until it's yellow going in from the syringe on the lever and yellow going into the syringe from the caliper.


there's well documented info of a lad online who filled his system with baby oil and used it for a year without issue, to prove that we are all slaves to what the manufacturers tell us to do!

cletus

8valve wrote: »

lash it in, and keep lashing it in, until it's yellow going in from the syringe on the lever and yellow going into the syringe from the caliper.


there's well documented info of a lad online who filled his system with baby oil and used it for a year without issue, to prove that we are all slaves to what the manufacturers tell us to do!

That's all fairly much true. I'm of that same opinion with motor oil, and as I may have mentioned before, general use lithium grease, among other things.

Having said that, I wouldn't necessarily follow Seth's (Berm Peak) bike hack there. It would be interesting to see wear at the two and five year period.

wheelo01

cletus wrote: »

Mineral oil doesn't have the same types of standards or regulations as DOT fluids.

The colour shouldn't make any difference. The HLP stand for hydraulic oil with additives to prevent wear, the 10 is the viscosity of the oil. Do you know what viscosity the oil in your system is?

Edited to add: 10w seems to be the standard viscosity

I don't know, all I know is its whatever came with it, it's a Cube Attain GTC Disc

https://www.cube.eu/en/2019/bikes/road/road-cyclocross/attain/cube-attain-gtc-sl-disc-carbonngrey-2019/

8valve wrote: »

lash it in, and keep lashing it in, until it's yellow going in from the syringe on the lever and yellow going into the syringe from the caliper.


there's well documented info of a lad online who filled his system with baby oil and used it for a year without issue, to prove that we are all slaves to what the manufacturers tell us to do!

So basically, I should flush out the whole system rather than just topping up? Is there any amount of time as to when you should flush? Bi-annual, annual?

8valve

wheelo01 wrote: »

I don't know, all I know is its whatever came with it, it's a Cube Attain GTC Disc

https://www.cube.eu/en/2019/bikes/road/road-cyclocross/attain/cube-attain-gtc-sl-disc-carbonngrey-2019/



So basically, I should flush out the whole system rather than just topping up? Is there any amount of time as to when you should flush? Bi-annual, annual?

Annually is a good place to start, unless you're doing serious MTBing weekly.


I'm open to correction from the mud-pluggers on here, though.


The last time I went mountain biking was the early 90s, where I crashed spectacularly, ripping ligaments in my groin and giving myself a black eye by hitting myself in the face....with my knee.



I'll stick to tarmac, thank you very much.

cletus

I'd imagine mixing mineral oil brands has about the same affect as mixing battery brands in your remote control.

Having said that, if you've never flushed the system before, now is as good a time as any

wheelo01

So I flushed out the old hydraulic oil as described by 8valve above, followed a YouTube video for removing air bubbles, etc. But I seem to have the same "spongy" feel to the brakes, by this I mean that I can gently pull the brakes and feel the brakes biting, when thIs happens, I can just about fit my finger between bars and brake levers.
I had hoped that the brakes would bite earlier (about 2 fingers)

I tried taking the wheel off, took out the brake pads, inserted the spacer that came with the bleeding kit, went through the steps in the video again, and the gap was where I wanted it to be.
When I took out the spacer, put back pads and put wheel on, and the gap was back to one finger.

Am I being unrealistic? Or am I doing something wrong?

cletus

Is there much wear on the pads? What's the adjustment at the caliper like.

wheelo01

Still plenty of life ( I have a new set here waiting, and I'd say the ones on the bike are about 1/2 way worn) now please explain the adjustment at caliper, I'm not sure what you mean.

cletus

wheelo01 wrote: »

Still plenty of life ( I have a new set here waiting, and I'd say the ones on the bike are about 1/2 way worn) now please explain the adjustment at caliper, I'm not sure what you mean.

Can you adjust for wear of the pads at the caliper, like you would on a mechanical caliper

wheelo01

Not that I know of, I sort of asked this question recently, and the information I got was that there is no such adjuster.
It is what I thought initially that I would be able to do.

Type 17

Hydraulic brakes adjust to pad wear automatically, because the pistons creep out as the pads wear, which is why you need to press them back in before fitting new pads.

If you're getting a lot of lever-travel, one of the pistons may be sticking in its seal and not moving out as it should.

Have a look at this vid to see how the seals work, and how to clean the callipers and seals as required (the piston/seal area should be cleaned before pressing them back, otherwise you'll damage the piston surface and/or seal with dirt).

Qrt

My bike is just over two years old now, it gets frequent enough usage, maybe 30-35km a week. Recently the gears feel...loose, like I pretty much always find myself using the third (and largest) gear, and I’ve find myself nearly using the highest on the rear cassette too. Anyway, does this sound like wear? Or am I just...getting fitter?

Cheers

07Lapierre

Qrt wrote: »

My bike is just over two years old now, it gets frequent enough usage, maybe 30-35km a week. Recently the gears feel...loose, like I pretty much always find myself using the third (and largest) gear, and I’ve find myself nearly using the highest on the rear cassette too. Anyway, does this sound like wear? Or am I just...getting fitter?

Cheers

Both

lissard

Sounds like the spring is gone on your rear deraileur - it ensures that there is chain tension when it is on small rings.

CramCycle

What do you mean by loose? Do you mean easier or like they are rattling/skipping?

07Lapierre

After two years, the gear cables probably need to be replaced. Your chain and/or cassette could also be worn, which also affects shifting.

magicbastarder

not clear whether when Qrt says the gears feel loose, do they mean the gear *shifting* or gear *ratios*.

Qrt

magicbastarder wrote: »

not clear whether when Qrt says the gears feel loose, do they mean the gear *shifting* or gear *ratios*.

The ratios I‘d say. So it’s a fairly standard Giant Escape; 3-speed chainset, 7-speed cassette (my terminology is probably all over the place). I used to never find myself on 3 (ie the largest ring on the chainset) but now it’s standard... I feel I’m always hitting 3 on the front and 5 on the back. Shifting seems fine, especially after the oiling I gave it today. Maybe I just didn’t do it enough and it’s showing.

gaffmaster

Qrt wrote: »

The ratios I‘d say. So it’s a fairly standard Giant Escape; 3-speed chainset, 7-speed cassette (my terminology is probably all over the place). I used to never find myself on 3 (ie the largest ring on the chainset) but now it’s standard... I feel I’m always hitting 3 on the front and 5 on the back. Shifting seems fine, especially after the oiling I gave it today. Maybe I just didn’t do it enough and it’s showing.

Sounds like you're getting stronger.

wheelo01

Type 17 wrote: »

Hydraulic brakes adjust to pad wear automatically, because the pistons creep out as the pads wear, which is why you need to press them back in before fitting new pads.

If you're getting a lot of lever-travel, one of the pistons may be sticking in its seal and not moving out as it should.

Have a look at this vid to see how the seals work, and how to clean the callipers and seals as required (the piston/seal area should be cleaned before pressing them back, otherwise you'll damage the piston surface and/or seal with dirt).

So I cleaned the pistons using this video, before I did it, it did seem like I had one "laxy" piston.
Now both are moving freely, but theres still a lot of travel before the brakes bite.
It is not that I dont trust them to work, I do, it's just I'd like less travel before they bite.
It may well be that this us the norm, and if it is, then so be it, it is my expectation that's wrong.

At least I learned how to replace the oil.

cletus

wheelo01 wrote: »

So I cleaned the pistons using this video, before I did it, it did seem like I had one "laxy" piston.
Now both are moving freely, but theres still a lot of travel before the brakes bite.
It is not that I dont trust them to work, I do, it's just I'd like less travel before they bite.
It may well be that this us the norm, and if it is, then so be it, it is my expectation that's wrong.

At least I learned how to replace the oil.

Is there definitely no air in the lines?

Type 17

Other things to check are lever reach and free stroke adjustment - not all levers have a free stroke setting, but most will have a reach setting. Google <your lever model> + lever reach and free stroke adjustment

cletus

Was just about to ask the above. Has there always been that level of travel at the brake lever. Some of the mover may be 'free travel', before the brakes are engaged

wheelo01

cletus wrote: »

Was just about to ask the above. Has there always been that level of travel at the brake lever. Some of the mover may be 'free travel', before the brakes are engaged

Yes, it's always been like that, it just not what I expected from disc brakes, and may actually be the correct way. This is my first set of hydraulic brakes.

Type 17 wrote: »

Other things to check are lever reach and free stroke adjustment - not all levers have a free stroke setting, but most will have a reach setting. Google <your lever model> + lever reach and free stroke adjustment

Will do, they're Shimano 105 ST-R7020

cletus

Here you go, think the info you need is on page 54

https://si.shimano.com/pdfs/dm/DM-RADBR01-03-ENG.pdf

Type 17

Your levers only have reach adjustment, so don’t worry about free stroke adjustment.

wheelo01

Thanks for that manual, the 7020 doesn't have the free stroke adjustment just the reach as type17 says., I've just found a different more complete video on YouTube that explains bleeding, etc. I'll follow his steps and see how I get on.

https://youtu.be/NhTGk6b-E-k

When I had the block spacer in, I could get a really good feel, but as soon as I put the pads /wheel/rotor together again, I lost it again and he hits on it in this video. He seems to use a lot more oil than I expected (but I bought a litre, so I can mess around for quote a bit )

I'll keep playing around, thanks again.