roger89

Hello guys,

I went to the lbs, suspecting the cassette was a bit loose so I wanted it to be tightened. Written there was 40Nm. But the mechanic(probably not the expert type), tightened the cassette 'to the end'. Like till the end of the thread as though it's checked firm. I want to know is this overtightening? Any bad effects will I get from it?

Thanks.

terrymorse 

If you have an aluminum freewheel body, overtorque-ing the cassette lock ring can strip the threads. If this happens, the cassette will come loose at some point, and you'll have to replace the freewheel.

white lobster

I ran into a situation a long time ago with an overtightened cassette that wouln't shift quite right ... I think it was a SRAM cassette with plastic spacers. Turns out the overtightening squished the spacers and moved the cogs closer together.

Shimano cassettes have aluminum spacers, though, that I bet are pretty hard to deform. As terrymorse says, I'd be very careful if the freehub body and/or lockring are aluminum. Stripping a lockring sucks, but stripping a freehub body will be expensive.

Another thing to remember: if the cassette is loose and tightening the lockring a moderate amount doesn't fix the problem, then getting crazy with the wrench isn't going to fix it either. Something else is wrong. Either the outer cog isn't meshed up with the splines correctly or you need a spacer behind the biggest cog to take up some space.

Retro Grouch 

I once encountered a cassette that was on so tightly that I had to dremel the lockring into pieces to get it off.

ImprezaDrvr

Shop guys tend to err on the side of ovetightening. DIY FTW!

roadfix

I never like to really tighten cassette lockrings down too much......perhaps half a dozen or so 'clicks' usually does it for me. It makes cassette removal easy.
This is especially important for tourers out in the middle of nowhere who use those tiny little lockring removal tools to loosen the lockrings in case of trouble.....such as replacing a broken drive side spoke.

Grasschopper

While I will agree that overtightening is a bad thing I will also point out that 40Nm is 2x the MAX torque the Syntace torque wrench ("bicycle specific" torques) goes to. 40Nm is a lot and most people don't tighten their cassette lock ring to that spec, with or without a torque wrench.

IMO the risk here is minimal that there was damage caused.

roger89

Alright, so should I go back to the shop and remove the cassette MYSELF and then reinstall? And, please tell me how much should I tighten by hearing the clicks? since the shop wont bother to lend me a torque wrench I guess..

Anyway, here's my SRAM cassette https://www.sram.com/en/sram/road/cassettes/pg950.php

Grasschopper

I personally think you don't have anything to worry about.

Waldo

First, you know the mechanic isn't the expert type yet you aren't able to tighten your own cassette?
Second, you know that he tightened it "to the end?" I wish I had x-ray vision...

If you're that concerned about it, why not shell out the $30 for a Craftsman torque wrench (beam-type, same as Park's) and a few bucks for a lockring tool and chain whip?

Most shops aren't about to loan a customer a torque wrench, unless you're pretty tight with them. I'm guessing that's not the case here. I'm with Grasschopper on this one but if you're so worried, either go back and let them know or get the tools and DIY.

roger89

grassc, u sure I no need to worry about it? May I ask, based on what u say this?

Waldo, I don't think I would want ot take out some bucks for the tools, since I don't need then that often...

So guys, like 'the fixer' said above, half a dozen clicks? can be made for that 40Nm?

Grasschopper

Ok just because I am curious about this now I am going to have to see if my larger torque wrench has 40Nm in it's range. Seriously Roger 40Nm is a LOT and I know for sure the shops in my town don't use a torque wrench when installing a cassette. Honestly I would say it is more than half a dozen clicks...not sure how many more but I would say more than that.

ImprezaDrvr

Take it to another shop and have them check it to make you feel better.