Mechanics and Fixing Any Questions Answered

Whats the best thing to re-grease shifter internals with?

Has anyone removed a snapped disc bolt before? Head snapped off almost flush with hub.

Often thin white lithium grease, IGH grease or suspension fork bush grease are my go to pots for road STI.

For MTB, depends on the type, either the same as above for mid to higher end, or use shimano/motorex type fluro green stuff for lower end shifters. Pop of the lower casing and jam it in there with a brush, massively improves most Tourney/Acera type low end shifters feel and operation.

Need to strip and re-grease some Sram Rival shifters in this case. Won a set on the bay for cheap but the internals are a bit manky

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With gunked-up shift/brake units I've fixed a few by simply giving the internals a massive drenching in spray WD-40 while doing some enthusiastic shifting. Sorts em right out.

Does anyone know which Shimano square taper bottom brackets are symmetrical and which aren’t? I’m sure there was a post with something off a chart or table but no idea how to find it.

I have a 107mm and a 113mm and the driveside cup flange to end of axle is identical, the extra 6mm is all on the nds. I need about 5mm more on the driveside so maybe a 117mm (118mm is probably the closest actually) would be what I need but reticent to buy one unless I can work out whether or not the extra 10mm axle length will actually mean 5mm per side.

Removed an ancient bottom bracket from an old frame, cleaned and lubed the threads, stuck a new BB in...and this happened. It got in to this point and now no matter which way I thread it's just spinning in place (by hand). I can't remove it and I can't thread it in any more. Safe to say it's all fucked?

Yes this is plastic

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Sounds like the plastic BB is fucked but I'd be surprised if the frame BB threads are stripped. Even with a steel BB cartridge it's difficult to strip the frame threads unless you've only just started screwing it in.

You could smack the spindle with a mallet from the other side. Worth a shot.

Blow torch melt it out or a soldering iron a bit at a time or jam a hot knife in.

Might as well try and save it first. Put the frame on the ground (as it looks to be) and place wood under the NDS axle. Stick a door mat on top of the bike frame and kneel on it - this will apply pressure to the cup to come out. Now unwind the cup, remember that on BSA threads (most) that both cups wind out the same way as the crank goes round when pedaling.

Managed to get this sorted in the end but appreciate the offer

Nvm

I've just cabled up the rear derailleur on this 1x build and the shifter cable is touching/rubbing the underside of the chain stay as it crosses over after exiting the cable guide (see pic). I've put a little patch of adhesive frame protector under there, but I guess it'll rub through that over time? Any suggestions on fixing this more properly? Shim under the cable guide maybe? Or are deeper cable guides which put the cable a bit further from the frame a thing?

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Yes 1.85mm spacer, I forgot and remembered this today. They are quite malleable and can get bent out of shape a little

Would moving the under BB cable guide to the non drive side help? If not I'd run a bit of cable liner stuff that I can remember the proper name for across that stretch of cable.

Ah yes! Moving it over has solved it, thanks so much. For some reason I'd discounted that thinking the angles would be all wrong. Cheers again!

Victory!

"High rise" cable guides are indeed a thing:
https://www.planetx.co.uk/i/q/FSPXMRBBCG/selcof-high-rise-underbb-cable-guide#FSPXMRBBCG
Some of the Planet X frames (London Road, etc.) use them.

Ah good to know thanks 👍 Snottyotter’s suggestion has fixed things (no cable contact any more) but the gap is pretty small. Maybe I’ll give one of these a try too.

Going to have another look at the dropouts on my Hardrock today. I think they'll need need roughed up a bit to give the new QR skewer something to bite in to.
Any suggestions how to do this? Sand paper will just smoothen them.

I'd be surprised if the Shimano skewer didn't just sort the issue.

If it makes you feel better then use some 60/80 grit paper on the dropouts.

I had a lightweight skewer which slipped on my chromed dropouts, sent me flying. I bought an Ultegra skewer and it's not moved since. Rock solid. Shimano holds the patent for internal cam QR skewers, so they are simply way better.

shimano QRs are great, XTs particularly for price/performance. i found the mavic ones to be pretty good too

Got an XT QR through last week. Got it on today.
Took a bit of 80 grit to the dropouts first, as @Ndeipi suggested.
I've been riding it up and down my street for the last hour, stop-starts in the highest gear a lot, trying to get the rear wheel to slip, and it won't! So far so good. It may take a while to gain my confidence on it though.

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Park Tool ct 3.2 chain tool why do Park Tool say it won’t work with 12 speed chains? What did they change when the 3.3 came out?

It’s more likely to slip when you stop and start in a low gear in my experience. That was when I struggled with an mtb with horizontal drop outs. Eventually I needed chain tug and a shimano skewer.