Drivetrain Rumble & Grind | Tech Tuesday #218

Can you feel that? There's s a RUMBLE and GRIND in the drivetrain! But which part? Calvin is on the case, and searching for answers one piece at a time. Will his trained eyes and ears yield results? Or, will Calvin's investigation GRIND to a halt?

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[ShellDrop]

This is exactly what’s going on with my bike and it’s been bothering me for over a year now. Pretty cool stuff! Thanks for teaching us so much

[SkyhawkSteve]

any bets on whether there's any grease left in that bottom bracket??

[rangersmith]

In this case, the damage is already done, so unless the bike is going to be used for competition, do the preload adjustment and leave it at that. In a few months or a few hundred miles, it might need doing again. A bike can be ridden many hundreds of enjoyable and/or utilitarian miles with worn balls, cups, and races in the BB.

[newnotification]

My mechanic would have just convinced me to buy a new bottom bracket and have him replace it. 😅

[kaltonian]

again Kelvin another great & helpful maintenance video for those just starting out as well as the less experienced mechanics,
bb's can turn into a big headache without the correct tools.

[MrGrayFox]

#Park Tool

Great video!

I've been waiting for a video with this special contant for years. I know already how it works but I guess all biginners are trying to tighten the crank arm bolt to get rid off that play. I would appreciate a video of how to get rid off that play on BBs where you have to use the BBT-22, because I think that's a very common BB wich many riders have and similar problems too.

[Omnis]

Gotta make sure your bearings are silky smooth so you don't notice the vibrations when you're riding down all those rocky mountain trails.

[HeadBassVTEC]

I have a rumble when using the smallest sprocket on my 27spd MTB, no matter what wheel at the front
it's not BB, it's not freehub so I don't know what it is and why it's only on the smallest sprocket
it's also not the rear hub, that one I serviced as well with clean, new bearings and new grease

[tomnanD]

I like Calvin. His vids have taught me a lot.

[bryanseare]

use the bearings till they breakin half lol

[chenoko]

My bikes that had the same setup, I’ve changed them to an enclosed bottom bracket unit. I use my bikes mainly for commuting.

[michaelbonade]

I almost cursed all of creation yesterday when my new 10 speed jockey wheels didn’t cure the coffee grinder noise coming off my rear setup…..
It’s new chain BS…I should have kept the old one and sourced a new cluster/chain….

[coypatton]

From your description of it going through several kids, bearings are worn and will not adjust out smooth.

[boyinthepenaltybox]

So, if its trashed (pretty sure mine is btw) how do i take it all apart and repair or replace it?

[Mrfiveone]

My GRX 2x on my gravel bike is new and keeps stripping while I ride, spins freely with no chain pull. It works after I pick up the rear wheel and drop to the pavement. Why is this? Matt in Burnsville Minnesota. Enjoy ALL your posts!

[jonyfany]

I'd replace a cheap, worn bottom bracket with shimano SN55.
Fit and forget.

[davesweeney]

Just threw a cartridge BB In my mtb commuter. Races were galled. Probably twice the slop than demonstrated here

[robertmcfadyen]

Calvin, chordal resonance, mentioned in my high school physics class in 1988 is a limiting factor in tight - wrap scenarios for the drive chain . This phenomenon is common on today's best bicycles with chain transmissions .

[robertmcfadyen]

This is similar to pre - loading cup and cone hub arrangements . A good ear and patience are a must .

[roilev]

I am surprised that you didn't regrease these ball bearings - they are probably dry. That's why it turns so freely