New Crankset and BB for mtb

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SemiLevel

New Member
Hello all,

I'm new to this forum, and I was hoping someone could give me some good suggestions here, I'm pretty well acquainted with a railway forum, so if anything I say or post is odd, presumably it's a custom from there that I've inadvertently brought over - Apologies!

Anyway, I have a Btwin Rockrider 520, I purchased it second hand in January of this year, currently, the threads to remove the crank arms are completely bugggered on the left, and are in a pretty sorry state on the drive side as well. The bottom bracket has been very loose for a while, and I was originally hoping to remove the crank arm on the non drive side and hopefully be able to resolve any issues. This was rather optimistic as, it seems the previous owner glued both crank arms to the BB and this meant that in the process of partially removing both crank arms, sliding off maybe 50 or even 60% of the way on the non-drive side, I completely stripped the threads in the crank arms.* My current intention is to saw the bb off at the point where it is now partially exposed, and replace it as it is wobbly and seems to knock in some positions (I can slide the whole thing side to side while riding now that the crank arms are partially off, but still firmly on, exposing more of the bb).

The two lower speeds on my SRAM S200 chainset are also worn, so that would be two additional chainrings needed too, so given the amount of replacements needed, I have decided it'd be best to replace the whole thing, cranks arms, bb, chainrings, the lot.

So with that in mind, and a budget of say up to £80, what should I get?


Thanks in advance, apologies for the longwinded story and

*I have also attempted to use a 3 jaw gear puller to remove it, which achieved very little for the time and efforts involved .: going down the full replacement route.


https://www.google.com/search?q=gbp+sign&safe=active&sxsrf=ALeKk00H7I4-uRMgNb8zEFwrN3kRxLCc6Q:1624555132410&tbm=isch&source=iu&ictx=1&fir=BhIVKdFtMRPyRM%2CFT93fh_FXgYigM%2C%2Fm%2F01nv4h&vet=1&usg=AI4_-kRKAMFWeRnY9KkBnLfY9IG7RY1E0A&sa=X&ved=2ahUKEwiy6da847DxAhURqaQKHVYDBRYQ_B16BAgSEAE#imgrc=BhIVKdFtMRPyRM
 
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Cycleops

Legendary Member
Location
Accra, Ghana
Have a look at Decathlon's site for chainsets, they do some good cheapies. I think you have a square taper BB. Make ure you buy one with a 42t big ring otherwise you'll need to adjust the front derailleur height.
Am I getting you right? You want to saw the square arms of the BB off? That's going to be to a job.
 
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SemiLevel

New Member
Have a look at Decathlon's site for chainsets, they do some good cheapies. I think you have a square taper BB. Make sure you buy one with a 42t big ring otherwise you'll need to adjust the front derailleur height.
Am I getting you right? You want to saw the square arms of the BB off? That's going to be to a job.
Adjusting the deraileur isn't something I'm too concerned about, in fact the chainrings are currently non-OEM spec as they are 22t/32t/64t.
Thanks for the advice, I shall have a gander.
And yes, that is the current plan, unless I am able to get the crank arm off, which, I have been on and off attempting since April without much luck. I realise this situation is rather ridiculous.
 
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