I'm a champion bike mechanic...

[Duck!]

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.

[Andy01]

..... 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.

[CmdrBiggles]

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!

[OnTrackZeD]

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.

[DavidS]

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

[ningnangnong]

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?

[CmdrBiggles]

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.

[jasonc]

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

[CmdrBiggles]

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!

[CmdrBiggles]

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!

[Duck!]

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

No.

[jasonc]

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

[bychosis]

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.

[jasonc]

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

[Duck!]

^^ 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.

[jasonc]

^^ 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

[blizzard]

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.

[jasonc]

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!

[P!N20]

Wanting to put my hard trash find Focus into commuting duties for a bit, the only thing stopping me is the brakes are a bit...average (Sram Rival hydraulic disc.) I've replaced the pads which improved things a bit, but there's still heaps of travel in the levers, so I'm thinking I need to bleed the brakes.

So I can get the Sram bleed kit for $120, or save a few bucks and get the BBB bleed kit for $60, plus $17 for the Sram fluid. Is there any reason to avoid the cheaper bleed kit? I assume once you get a bleed kit you just need to buy the fluid in future - is that right?

[jasonc]

Is there any reason to avoid the cheaper bleed kit? I assume once you get a bleed kit you just need to buy the fluid in future - is that right?

just make sure it has all the adaptors you need. there's a trick for young players with the non-brand shimano kits that you need to buy the adaptor specific to your series of shifter for the funnel

[blizzard]

Wanting to put my hard trash find Focus into commuting duties for a bit, the only thing stopping me is the brakes are a bit...average (Sram Rival hydraulic disc.) I've replaced the pads which improved things a bit, but there's still heaps of travel in the levers, so I'm thinking I need to bleed the brakes.

So I can get the Sram bleed kit for $120, or save a few bucks and get the BBB bleed kit for $60, plus $17 for the Sram fluid. Is there any reason to avoid the cheaper bleed kit? I assume once you get a bleed kit you just need to buy the fluid in future - is that right?

The EZ-Mtb kits on Amazon / AliExpress are pretty good and very affordable. Just make sure it has the correct adaptors for your levers.

[P!N20]

just make sure it has all the adaptors you need.

Just make sure it has the correct adaptors for your levers.

Righto...how do I do that?

[jasonc]

for SRAM? I'm unsure. what i did was google and see what other parts I may need to do the bleed. by fluke a different part came up

[bychosis]

The EZ-Mtb kits on Amazon / AliExpress are pretty good and very affordable. Just make sure it has the correct adaptors for your levers.

Ditto. One I got seems to have every imaginable variation.


On the braking front, I installed new shimano hydro brakes on my cheapish MTB yesterday. Involved removing the rear calliper to internally route the hose. New olive etc to shorten it a little. All good. Decided I had the olive there so the front should get a trim too, at the lever end. First grab of the lever squirted oil onto myself and the ground. The olive hadn't seated properly. This morning cut off a little more and had another go with a spare olive and with more success.bike stops now.

[bychosis]

Part 2: the quick test ride around the culdesac was insufficient. Chain has popped openand keeps dropping off thw narrow wide chainring. Front hub is not tensioned properly and clunking around. But the brakes seem fine.

The joys of buying a cheap, dissembled MTB with a stuck seatpost and the assembling it with not enough time spent.