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Bash ring compatibility sanity check!

Corners R UsCorners R Us Posts: 214
edited June 2013 in MTB workshop & tech
Shimano LX hollowtech cranks set (vintage unknown!), triple ring setup currently.

Plan to remove outer ring and apply one of these as I never use the outer ring off road:

http://www.ebay.co.uk/itm/160971367970? ... 1423.l2649

Whilst this ad doesn't specifically state 104 bcd I'm sure thats what the Hope ones are.

Am I correct in thinking all Shimano or at least my cranks are 104 bcd? Measuring crank bolt centre to bolt centre seems to be 114mm. Is the 104 bcd measured to the edge of the spider?

I'm pretty certain this will be fine but need a sanity check as per the title!

Another presumption....the chain ring bolts will be long enough won't they?

Cheers, Corners

Posts

  • nicklousenicklouse Posts: 50,675 Lives Here
    LX cranks did come with a number of BCDs but if 4 arm then it should be 104mm but a part number will help ID that or a picture.

    and yes hope only do 104mm at the moment
    http://www.hopetech.com/page.aspx?itemID=SPG345
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  • Corners R UsCorners R Us Posts: 214
    edited June 2013
    IMG_2356_zpsf2717187.jpg

    FC-M580 stamped on the inside of the chainring side crank arm, FC-M 580/581 on the inside of the left crank.

    Cheers, Corners
  • Corners R UsCorners R Us Posts: 214
    http://techdocs.shimano.com/media/techd ... 608889.pdf

    104 BCD confirmed I think! Thanks for pointing me in the right direction!

    Corners
  • The RookieThe Rookie Posts: 27,804
    For ref that is Hollowtech2, not Hollowtech... (Hollowtech just actually referring to hollow arms).
    Current steed - Whyte T129, 2013 frame, mongrel Revelations, Giant dropper, Stans S1 wheelset. 12, Magura Trail Sport brakes, 1x11. 12.8Kg
  • Corners R UsCorners R Us Posts: 214
    For ref that is Hollowtech2, not Hollowtech... (Hollowtech just actually referring to hollow arms).

    Thanks for clarifying. I'm coming from old school land of hardtails, 8 speed and square taper axles so this array of 'modern' kit is all a bit bewildering! I'm now trying to work out which tool I need to buy to remove the end cap to enable me to take the cranks off to fit a bash gaurd!! One of these?

    http://www.chainreactioncycles.com/Mode ... delID=3785

    To make matters more confusing I have a mates 2009 FSR XC sat in my garage and his has Hollowtech II XT cranks on it but the centre nut looks slightly different to mine! I think he has a tool to remove it so I'll try his first.....or do it without removing the cranks as it looks like I can access the bolts sufficiently!!

    Then theres shock pumps, air pressures, sag and lots of fast/low speed compression to understand on the shocks on my new steed........

    Corners the confused one!
  • cooldadcooldad Posts: 32,599
    Read Parktools link below first. Info on everything.
    The end cap you refer to is actually to pre load the bearings, like a headset topcap.
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  • Corners R UsCorners R Us Posts: 214
    cooldad wrote:
    Read Parktools link below first. Info on everything.
    The end cap you refer to is actually to pre load the bearings, like a headset topcap.

    Cheers for pointers. I watched a YouTube video last night so have an idea as to whats what. Looks simple enough if you remember to remove the tab in the split in the cranks! My terminology might be a bit off as all this tech is relatively new to me! Looks like the cap is only hand tight anyways and as you say just to pre load the external (correct?) bearings.

    I'll have a read of the Park Tools link and bookmark it for future reference.

    Thanks again. Corners
  • The RookieThe Rookie Posts: 27,804
    You don't need to remove the cranks to fit a bash, can all be done in situ......allen key in the front, screwdriver (if needed at all) across the frame into the back.
    Current steed - Whyte T129, 2013 frame, mongrel Revelations, Giant dropper, Stans S1 wheelset. 12, Magura Trail Sport brakes, 1x11. 12.8Kg
  • Corners R UsCorners R Us Posts: 214
    You don't need to remove the cranks to fit a bash, can all be done in situ......allen key in the front, screwdriver (if needed at all) across the frame into the back.

    Thanks for confirming, I thought as much but it was a bit late last night to break out the tools in the murk in the garage! I have a chainring bolt screwdriver already in the tool kit to do the job justice! Now to order a loverly red Hope bash gaurd for a splash of colour and protection!!

    Corners
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