HELP! My crank has died and I have no knowledge to help

Mason_wardd Posts: 4
edited September 2019 in The hub
I recently bought a scott aspect 970 29 inch for £40, I thought it was a bargain but it needed some work. The crank is wobbly as hell and need something fixing. I have been told its the front bearing, the bottom bracket, the lockring, everything. So today I thought i am going to fix this, went to try and take the crank arms off, but needed the removal tool, went and got one and not i need a 20 pin tool to take the bottom bracket out. Basically it wobbles like mad and screeches if you pedal wrong, there looks like there is a ring missing on the right side of the crank as there is a gap between the crank arm and frame with some threading. I have a shimano 175 fc-yr501 crankset if this is any help, please just let me know what could be wrong and if its even worth fixing, thx.


  • keef66
    keef66 Posts: 13,123
    I cannot tell what the issues are based on your description. Photographs would help.

    ( no need for an account, just upload image and use the url it gives you to embed in a post)

    But to be honest if you don't know what you're doing it might be simpler, and possibly cheaper, to take it to a bike shop?
  • monkimark
    monkimark Posts: 1,514
    So i'm gathering that you have a square taper bracket and you've got the cranks removed like the first half of this video?

    Is the spindle of the bottom bracket wobbling/not turning? That would mean new bottom bracket time and you'll need a special tool to remove it or just take it to a bike shop and get them to do it - very quick job with the right tools.

    Not sure i understand the bit about the missing ring, a photo would probably explain it very easily.
  • The reason I don’t want to take it to a bike shop is firstly, I want to learn about the mechanical side of the biking world, and this bike is going to be a bit of a project for me, not only that, I took it down to my loca bike shop and he’s a notorious scammer, he said I need a complete new bottom brocket, and even though it’s lose, it’s spinning. He then said the part would be £30 when online they’re £8 plus labour and to make the job a bit longer, said it’s not a 2 minute job and went into a load of bull, that even with my knowledge I could tell. I’ll post pics when I’m home, and understand I’ll need the special tools, I just need to know what exactly it is I need to fix the issue as my budget isn’t exactly big, thanks for the support however and I’ll have this pics uploaded asap.
  • monkimark
    monkimark Posts: 1,514
    Fair enough.

    Once you've established what the problem is, Youtube is your friend for jobs like this. If nothing else, at least you'll know what is involved for a bike shop to do it for you.
    You can get a pretty small BB removal tool to use with a spanner for not much over a fiver.
  • keef66
    keef66 Posts: 13,123
    With the right tool and a long enough lever, swapping a square taper cartridge BB is only a 10 minute job. So if that's all that's wrong with it, persist with the DIY option. (your description of visible threads made it sound more serious though) Just remember which way each side unscrews.

    Make sure you buy the correct size BB (english vs Italian thread, same axle length as the original) and grease or copperslip the threads before inserting / tightening
  • JBA
    JBA Posts: 2,852
    Post this in the correct forum - MTB Workshop and tech - and you'll get more responses.
    “Life has been unfaithful
    And it all promised so so much”

    Giant Trance 2 27.5 2016 ¦ Sonder Broken Road 2021¦ Giant Revolt Advanced 2 2019 ¦ Giant Toughtroad SLR 1 2019 ¦ Giant Anthem 3 2015 ¦ Specialized Myka Comp FSR 2009
  • Ok thx
  • If the crank is wobbling the bb may have gone and needs changing. The online price can be cheaper than trade for some parts. Why people think a shop can sell parts at a loss and stay open is beyond me. -wheel building and other stuff.