I'm a champion bike mechanic...

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Duck!
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Re: I'm a champion bike mechanic...

Postby Duck! » Mon Mar 18, 2024 7:52 pm

Verniers nearly always have cutaways at the base of the jaws, so you can get proper readings past any lip that may develop right on the edge of the rotor as it wears.

Rotors with solid steel brake tracks can be worn to less than 1.5mm; like most things, that figure is calculated with a fair margin for safety. However Shimano's IceTech rotors, which have a thin veneer of stainless steel on each side of an aluminium core are very precise about wear limits, because if the steel skins gets too thin, they'll blister, wear through, and you'll hack into the aluminium core very rapidly after that, with an equally rapid loss of brake function. Do not let these rotors get thinner than 1.5mm.
I had a thought, but it got run over as it crossed my mind.

Andy01
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Re: I'm a champion bike mechanic...

Postby Andy01 » Mon Mar 18, 2024 7:57 pm

antigee wrote:
Mon Mar 18, 2024 7:29 pm
..... don't use a vernier to check as there is usually an unswept edge that distorts reading...
For the record most verniers have a gap between the jaws near the slide end of the jaws to deal with just this sort of situation - probably not as good as a micrometer but should be good enough for this job.

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Re: I'm a champion bike mechanic...

Postby CmdrBiggles » Tue Mar 19, 2024 11:01 am

A micrometer is definitely not necessary for checking rotor thickness.
Verniers are fine (I have both Würth mechanical and Stanley electronic), so too are set pincers; skilled techs will often pick up a spent/dudded rotor (heavy scoring, abrasions, worn off laminate etc.) visually well before anything is brought out to measure it!
Last edited by CmdrBiggles on Tue Mar 19, 2024 1:49 pm, edited 1 time in total.
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OnTrackZeD
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Re: I'm a champion bike mechanic...

Postby OnTrackZeD » Tue Mar 19, 2024 1:10 pm

CmdrBiggles wrote:
Tue Mar 19, 2024 11:01 am
A micrometer is definitely not necessary for checking rotor thickness.
Verniers are fine
My verniers measured 1.4mm on disc but not easily repeatable so I bought a micrometer and it's 1.5mm repeatable.
Doesn't make much difference but I like the repeatability that the micrometer brings.

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DavidS
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Re: I'm a champion bike mechanic...

Postby DavidS » Tue Mar 19, 2024 8:28 pm

Vernier should be fine, I bought one to check the pads but checking the disc sounds like a good idea once I have more KMs on the bike.

I'm trying to be a champion mechanic, after finishing work I have just volunteered for Back2 Bikes in Port Melbourne. Remembering how to do things on bikes I haven't done in decades!

DS
Allegro T1, Auren Swift :)

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Re: I'm a champion bike mechanic...

Postby ningnangnong » Tue Apr 02, 2024 9:37 am

What would be the best product to protect my front dérailleur from rust/corrosion caused by sweat?

I'm a heavy sweater, and a lot of it seems to drop down onto my FD. Other than wiping it down after every ride, is there something I can 'coat it' with that will help slow down the rusting process?

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Re: I'm a champion bike mechanic...

Postby CmdrBiggles » Tue Apr 02, 2024 10:23 am

ningnangnong wrote:
Tue Apr 02, 2024 9:37 am
What would be the best product to protect my front dérailleur from rust/corrosion caused by sweat?

I'm a heavy sweater, and a lot of it seems to drop down onto my FD. Other than wiping it down after every ride, is there something I can 'coat it' with that will help slow down the rusting process?

Silicone spray.
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Re: I'm a champion bike mechanic...

Postby jasonc » Tue Apr 02, 2024 11:00 am

Duck - is it a must to replace the olive and barb when changing shifters/brake callipers?

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Re: I'm a champion bike mechanic...

Postby CmdrBiggles » Tue Apr 02, 2024 12:13 pm

CmdrBiggles wrote:
Tue Apr 02, 2024 10:23 am
ningnangnong wrote:
Tue Apr 02, 2024 9:37 am
What would be the best product to protect my front dérailleur from rust/corrosion caused by sweat?

I'm a heavy sweater, and a lot of it seems to drop down onto my FD. Other than wiping it down after every ride, is there something I can 'coat it' with that will help slow down the rusting process?

Silicone spray.
PS: If you (really?) live on Bikini Atoll, your bike will rust and corrode anyway! 8)
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Re: I'm a champion bike mechanic...

Postby CmdrBiggles » Tue Apr 02, 2024 12:14 pm

ningnangnong wrote:
Tue Apr 02, 2024 9:37 am
What would be the best product to protect my front dérailleur from rust/corrosion caused by sweat?

I'm a heavy sweater, and a lot of it seems to drop down onto my FD. Other than wiping it down after every ride, is there something I can 'coat it' with that will help slow down the rusting process?

Silicone spray.
PS: If you (really?) live on Bikini Atoll, your bike will rust and corrode anyway! 8)
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Duck!
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Re: I'm a champion bike mechanic...

Postby Duck! » Tue Apr 02, 2024 12:17 pm

jasonc wrote:
Tue Apr 02, 2024 11:00 am
Duck - is it a must to replace the olive and barb when changing shifters/brake callipers?
No. :)
I had a thought, but it got run over as it crossed my mind.

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Re: I'm a champion bike mechanic...

Postby jasonc » Tue Apr 02, 2024 12:38 pm

Duck! wrote:
Tue Apr 02, 2024 12:17 pm
jasonc wrote:
Tue Apr 02, 2024 11:00 am
Duck - is it a must to replace the olive and barb when changing shifters/brake callipers?
No. :)
woo

trying to get the guts to do the upgrade from grx mechanical to r8070 shifters myself. the di2 bit doesn't scare me I've built a few of them

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Re: I'm a champion bike mechanic...

Postby bychosis » Tue Apr 02, 2024 7:50 pm

Changed tyres on the weekend. Reinstalled the through axles, something I don't do often.

Shifting went to pot in low gears onto he way home, I assumed it was mud in the drivetrain, but no. Looked down and found the rear QR lever open. Took a few turns befdoe it was tight enough again.
bychosis (bahy-koh-sis): A mental disorder of delusions indicating impaired contact with a reality of no bicycles.

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Re: I'm a champion bike mechanic...

Postby jasonc » Tue Apr 02, 2024 8:29 pm

bychosis wrote:
Tue Apr 02, 2024 7:50 pm
Changed tyres on the weekend. Reinstalled the through axles, something I don't do often.

Shifting went to pot in low gears onto he way home, I assumed it was mud in the drivetrain, but no. Looked down and found the rear QR lever open. Took a few turns befdoe it was tight enough again.
Do up the levers when the wheels are on the ground

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Duck!
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Re: I'm a champion bike mechanic...

Postby Duck! » Tue Apr 02, 2024 8:35 pm

^^ That's not really relevant for through-axles, but the ones with a Q/R-type locking lever need to be secured properly to stop them unwinding. Most frames are sprung slightly wider than their nominal spacing to make getting wheels in & out easier, so if the T/A isn't properly secured, the wheel can float laterally, which will stuff up shifting and/or braking.
I had a thought, but it got run over as it crossed my mind.

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Re: I'm a champion bike mechanic...

Postby jasonc » Wed Apr 03, 2024 10:05 am

Duck! wrote:
Tue Apr 02, 2024 8:35 pm
^^ That's not really relevant for through-axles, but the ones with a Q/R-type locking lever need to be secured properly to stop them unwinding. Most frames are sprung slightly wider than their nominal spacing to make getting wheels in & out easier, so if the T/A isn't properly secured, the wheel can float laterally, which will stuff up shifting and/or braking.
I've had a thru axle undo when i did it up on the stand. i now tighten them on the ground

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Re: I'm a champion bike mechanic...

Postby blizzard » Wed Apr 10, 2024 10:25 pm

I serviced my 5800 pedals for the first time ever. There was a bit of play in the body. Pulled the axle out and there wasn't any noticeable play in the bearing, so no adjustment. Filled the pedal body with grease screwed the axle back in, wiped the excess grease off and there is no play now. I did notice that both axles unscrewed with very little force, so I suspect if I just nipped them up the play would have disappeared too.

Basically followed this video, very easy but seemed to waste a bit of grease grease compared to official way of degreasing the bearing / axle / pedal body and only adding 12mm or so of grease to the pedal body.



Last thing was after reassembling the drive side pedal there was a rattle... Luckily a quarter turn on the tension screw took care of it.

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Re: I'm a champion bike mechanic...

Postby jasonc » Sun Apr 14, 2024 9:13 am

jasonc wrote:
Tue Apr 02, 2024 12:38 pm
Duck! wrote:
Tue Apr 02, 2024 12:17 pm
jasonc wrote:
Tue Apr 02, 2024 11:00 am
Duck - is it a must to replace the olive and barb when changing shifters/brake callipers?
No. :)
woo

trying to get the guts to do the upgrade from grx mechanical to r8070 shifters myself. the di2 bit doesn't scare me I've built a few of them
did it yesterday. success!

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