Advice on replacing worn middle chain ring on Spesh Sirrus

Bike2work
Bike2work Posts: 79
edited January 2009 in The workshop
I rely on my Spesh Sirrus to commute. I have just had the chain and cassette replaced a week ago. Noticed today that the chain is slipping when I'm pedalling hard on the middle chain ring, the ring I use most for my commute. I think the middle chain ring is too worn for the new chain. A number of the teeth are quite worn. The other chain rings look OK.

The chainset is a so-called Sugino Comp 52-43-30. I think the chain ring has a pitch circle diameter (PCD/BCD) of 130mm with 5 bolt holes. I'm very happy with the current gear ratios and want to keep a 42 tooth middle chain ring.

Can I use any replacement 42 tooth chain ring with a PCD of 130mm (eg if I buy from Wiggle) ?
Is this a DIY job or should I be taking it into the LBS ?
Is there anything else I need to be aware of before I have a go myself ?

Many thanks for any advice.

Comments

  • explosifpete
    explosifpete Posts: 1,327
    As long as the bcd is right it will fit, replacing it is easy but you will need a crank extractor to remove the crank then a 5mm allen key to change the bolts.
    I wouldn't use the worn ring anymore as it can wear the chain
    http://www.iwaxstudio.co.uk/
  • Bike2work
    Bike2work Posts: 79
    Many thanks for the quick response Explosifpete.

    If the crank needs extracting to remove the middle chainring, I think I'd rather have the LBS do it.

    I just can't figure out if I'd be able to feed the middle crank over the spider and crank....ie replace it without extracting the crank. I don't want to start the job and find I can't finish it.

    I wish I'd had the middle chain ring replaced when the chain and cassette were replaced.

    Thanks again.
  • akcc05
    akcc05 Posts: 336
    explosifpete wrote:
    As long as the bcd is right it will fit, replacing it is easy but you will need a crank extractor to remove the crank then a 5mm allen key to change the bolts.
    I wouldn't use the worn ring anymore as it can wear the chain

    i'm not sure about the sugino cranks but a chainring bolt nut tool might be needed as well.

    http://www.wiggle.co.uk/p/Cycle/7/LifeLine_Chainring_Nut_Tool/5360031521/

    i know that's the case for shimano cranks as i have just put a new dura ace outer chainring on my ultegra cranks.
  • Bike2work
    Bike2work Posts: 79
    In the end I took it to the LBS. All done for me, quickly and for less than £30.

Categories