Anyone tried this? ...
 

[Closed] Anyone tried this? Reconditioning a worn cassette with a dremel

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As cassettes get more expensive (and supposedly wear faster) has anyone else given a go to reconditioning one as described in the link below? Sounds perfectly feasible in theory and if it really does work two or three times could save a good chunk of cash but to mention reducing landfill.

My concern would be that it's hard to get the shape just right but the person in the link seems to have managed which suggests accuracy isn't critical.

https://www.velonews.com/2018/09/bikes-and-tech/technical-faq/technical-faq-chain-hops-and-grinding-cogs_478553


 
Posted : 11/09/2018 8:39 pm
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As cassettes get more expensive (and supposedly wear faster) has anyone else given a go to reconditioning one as described in the link below?

My last 2 expensive ones have outlasted regular ones by being made from steel. Value is there and ride the last chain to the death.


 
Posted : 11/09/2018 8:41 pm
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and supposedly wear faster

Do they? Not ime


 
Posted : 11/09/2018 8:50 pm
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FFS 😉 hence the 'supposedly' caveat. It doesn't matter either way. If they can fairly easily have their life extended, saving money and or waste, that's the point


 
Posted : 11/09/2018 8:57 pm
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Mine defiantly wears the bigger cogs faster. In the same way I used to get through several middle rings to a big ring and it wears out chainrings faster too.

How ever at 25 quid for a cassette I'm not sure I'll bother grinding them


 
Posted : 11/09/2018 8:59 pm
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Large rings should wear less as there is more of the chain wrapped around it than a smaller sprocket.


 
Posted : 11/09/2018 9:21 pm
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Can't see how you could grind them . They start out quite square and as they wear they become more like triangles or 'sharks teeth'.

Grinding more material off could only make them worse, surely?


 
Posted : 11/09/2018 9:34 pm
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"Large rings should wear less as there is more of the chain wrapped around it than a smaller sprocket."

Doesn't matter how much wrap if it's used significantly more than previously .


 
Posted : 11/09/2018 9:44 pm
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Surely if you grind them the diameter gets smaller, so the circumference does too. Moving the chain closer to the hub will mean the teeth are too close together. 1mm on the radius is 3mm (technically pi mm) on a half circle; if you had that much chain stretch it would be very likely to slip.


 
Posted : 11/09/2018 10:10 pm
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I've yet to find a dremel bit that magically adds material so nope...


 
Posted : 12/09/2018 12:10 am
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Dependent on what you consider to be worn out I'm sure you could, I've run chainrings both ways in the SS to get more life out of them. I'd far rather just run a drivetrain I can afford to replace than mess about with a Dremel that much though. Plus if there's any hard coating you're starting o<span style="font-size: 0.8rem;">ff with it already worn away, so you will get less time out of it after reshaping.</span>


 
Posted : 12/09/2018 12:42 am
 Bez
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Large rings should wear less as there is more of the chain wrapped around it than a smaller sprocket.

It's not so much chain wrap (the forces at the rollers will fall off quite quickly as you move back from the last point of engagement) as the fact that there are more teeth over which the wear is spread.

But it'll be more than offset by the fact that (a) lower gears tend to see more use than higher ones and (b) there tends to be more force in the chain when using a lower gear, especially if you have a multi-ring chainset where a smaller chainring means more chain tension for any given force at the pedal. More concisely: you don't tend to mash the pedals hard when going at speed and you can't freewheel on the climbs 😉

So generally you'll find that the big sprockets are the first to croak.


 
Posted : 12/09/2018 11:01 am
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Love all the experts saying it's not possible.

Presumably didn't even read the link.


 
Posted : 12/09/2018 11:09 am
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I’ve yet to find a dremel bit that magically adds material so nope…

You wouldn't need to, as the chain 'stretches' (pins wear) it sits higher and higher on the teeth, which are also wearing out, so the load on the last tooth engaged is always going up as the chain get's longer than the teeth it's supposed to engage with (on a new chain it would be spread more evenly around the cassette). I'm guessing he's re-profiling the teeth so the chain can sit a bit lower again. The whole chain then engages a few degrees further around the sprocket, it doesn't matter where the other edge of the tooth is as it's not going to contact the chains rollers, so you can keep grinding away until you come out the other side.


 
Posted : 12/09/2018 11:14 am
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Mine defiantly wears the bigger cogs faster. In the same way I used to get through several middle rings to a big ring and it wears out chainrings faster too.

It depends on which gears you sit in, which is why everyone gets a different experience from cassette wear. Personally, I have quite a fast cadence when on the MTB, and never ride it on the road, so the smaller sprockets never wear out as they rarely get used. I also like to go reasonably quick (it's all relative, of course!) so I don't tend to use the crawler gears very much. This results in me always wearing out the centre of the block first on every cassette I've had on the MTB.

Being honest, It's about time I re-evaluated what gears I actually need and adjust the ratios accordingly.


 
Posted : 12/09/2018 11:16 am
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Read the link - don’t see why it wouldn’t work but I think it depends on your definition of ‘fairly easily’ - it seems very faffy and time consuming to me.  At my age, life’s too short to be messing about with this sort of stuff.


 
Posted : 12/09/2018 11:26 am
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Your better off using the dremel to grind off the pins holding the cassette together and flipping the sprockets so the chain engages on the unworn side.


 
Posted : 12/09/2018 12:18 pm
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i assume you then reshape also the profile where the cassette engages with the freehub given that they are a one way fit ? or do you flip it round - then fit the cassette back to front so the big cogs nearest the frame and the wee cogs at the flange 😀


 
Posted : 12/09/2018 12:38 pm
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No you can't do it.

I'm an engineer so that's that.


 
Posted : 12/09/2018 12:47 pm
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Presumably didn’t even read the link

True - but in my defence I didn't realise it was a link (even though the OP says 'in the link below'). Still used to ignoring anything that looks like an ad, even though I now have a P. Does make more sense now I know what it's about.


 
Posted : 12/09/2018 1:09 pm
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Managed to get 5 chains over 2 years on an XT M8000 by fettling the teeth with a chainsaw file.


 
Posted : 12/09/2018 1:13 pm
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I wore out my 1x11 Sunrace 11-46 with a single chain, replaced in good time.

The 46 had two of the 'uplift' teeth (where the material is thinest) break off.  The 46 ring still worked with a new chain but the next sprocket down (42? wouldn't hold the new chain).


 
Posted : 12/09/2018 1:21 pm
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Your better off using the dremel to grind off the pins holding the cassette together and flipping the sprockets so the chain engages on the unworn side.

Have you tried that? Given the sprockets only have to work in one direction, it may not work. And of course all the shifting ramps will be out/off...


 
Posted : 12/09/2018 1:40 pm
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Read this as:

by fettling the teeth with a chainsaw.

and was very impressed!!!


 
Posted : 12/09/2018 1:58 pm