Mechanics and Fixing Any Questions Answered

Probably the wrong thread but I’ll ask away.

If I’m changing cassette from 12-29 to 11-32 can keep the same chain and therefore chain length?

most likely is the answer, it depends if your chain is the correct length for your current set up.

Easiest way to check is the ensure that the chain can go over the largest chainring and the 32 sprocket with at least 2 link to spare.

big big +2

Any tips for getting a SRAM Red crankset off? Outer bolt on the NDS came off easily, but the 8mm bolt underneath is refusing to shift at all. Attempting to turn counterclockwise, can stand on the crank arm & stand on the Allen key without any movement. Have just sprayed some penetrating spray in there but any other tips gratefully received

You're not supposed to remove the outer bolt as that's the self extracting one it pushes against. The other ones do tend to be quite a dick, put the other one back on and moar leverage, I think the threadlock they use is maybe a bit much.

What he said plus use a toestrap to hold the crank to somewhere in the frame, use your own judgement, chain stays are usually well solid. Insert your 8mm Allen, then use a handlebar or a seatpost as breaker bar and push hard counter clockwise.
Make sure your extracting nut is back in place with all threads well engaged, and put it in the floor. SRAM recommends a massive torque of 50Nm, sometimes I even struggle to remove my own cranks.

Need some 6802 and 6902 bearings to service a couple of hubs.
Any recommendations on good quality/price point bearings that won’t have me spend £100 on 8 bearings?

Look here
https://simplybearings.co.uk/shop/advanced_search_result.php?search_in_description=1&keywords=6802&

Cheers @snottyotter & @Netakure, sounds like I just need to be a bit braver with the brute force. Will leave the penetrating oil overnight and give it another crack tomorrow

Thanks for the link, but no idea what would be the right choice...

I’ve spotted some hope bearings being sold by various companies, I assume they are rebranded skf or other high quality bearings?

What he said plus use a toestrap to hold the crank to somewhere in the frame, use your own judgement, chain stays are usually well solid.

This sounds like a recipe for disaster and totally pointless.

NDS bolt going anti clockwise is like pedalling so you can use the drivetrain/a bit of rear brake to push against.

For your usage, these shielded bearings

https://simplybearings.co.uk/shop/p170036/68022RS-Budget-Rubber-Sealed-Thin-Section-Deep-Groove-Ball-Bearing-15x24x5mm/product_info.html?backstep=1

It's not. Usually you'll have to hold the pedal and push the tool the other way, and that in most cases is enough. This is when everything else fails and the breaker bar is in. Is hard to hold a 175mm crank when the other way you're applying force with a 700mm lever.

That's why I made myself a 700mm long crank extender. It's basically just a 700mm long length of box steel with a foam-lined U-section bit of steel which fits around the crank close to the bottom bracket, with a hole and a custom 9/16" bolt that goes into the pedal hole in the crank to lock it all into place. The effect is to make the cranks 700mm long and provide much more leverage. Very handy for removing cranks and crank spider lockrings when you don't have access to a sturdily mounted vice.

Unfortunately, it's in Switzerland.

Also helpful so that you don’t risk stabbing yourself with the chainrings if you slip...

Is hard to hold a 175mm crank when the other way you're applying force with a 700mm lever.

Which is why using the crank is not the best way to do it.

Use the drivetrain and wheel and the lever on that side is half the diameter of the wheel or around 350mm.

Plus you are stressing everything in the direction its designed to be stressed, not focusing the forces into a 10mm or so (width of a toe strap) patch of the frame that's not designed to take any compression in that direction.

Unfortunately I left this job until last so if I can avoid rebuilding the drivetrain & recabling the rear brake that’d be best. If I can’t get it don’t today then it might be a call to the LBS, can’t see them being that excited about taking it on though & would rather not wait for a month or whatever they’re at at the moment

I’ve misplaced my Vernier- does anyone know the seat clamp size of a cannondale Capo?

If you're struggling with moar leverage I sometimes find it's easier to apply force by squeezing, if you get the allen key in just to the right of the crank, hold both in both hands, squeeze together and push, usually works but then I get the big things out if not.

True. It's not a tool I use a lot, but I'm very glad I've got it from time to time. Cycliste kindly sent a photo of it. And an allen key.

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8mm hex bit in an impact driver....
Is that a terrible idea?

Not for installing, but for removing a stubborn bolt.

Jockey Wheels Hi, I'd like to replace the jockey wheels on my 6800 SC rear derailleur. The chain has a tendency to slip off the bottom wheel. I have changed both cassette and chain.

The standard J-wheels are out of stock every where - can I replace them with another shimano / other set of wheels? I have had the problem for some time and therefore I am wondering whether the standard 6800 jockey wheels are just a bit useless and should "upgrade" them?

Any advice / help would be much appreciated!

Taxc 4050 are a decent replacement.

Rim brake question
I'm using short drop calipers. They are not bringing the wheel to a sharp stop. Instead its feels like the rim is sliding through the brakes and they sound slightly gritty. In the workstand they work fine. I have cleaned the rims carefully and changed the brake blocks. Any ideas?

If the wheel and pads are clean/new and still sounding gritty, I wonder how new the ‘new’ pads actually are.

I once bought a couple nos pairs of cantis and had to change the pads immediately as they had gone hard.

What levers and callipers are you using? Certain combinations of drop bar levers and brake callipers have dangerously low braking force.

(Did the bike work better in the past?)