Forum home Mountain biking forum MTB workshop & tech

Standard chainring bolt length?

CraigXXLCraigXXL Posts: 1,852
edited September 2010 in MTB workshop & tech
I've tried fitting my bashguard tonight and the bolts aren't long enough on my XT chainset. From what I can gather they are narower than standard but how long are the standard ones as I need 8-9mm?
The bashguard is the e-thirteen Turbocharger which supposed to fit with standard bolts but I don't want to order any to find they are too short too.



  • nicklousenicklouse Posts: 50,675 Lives Here
    they are the same width as standard.

    the bash should have come with the required length bolts.

    so how long are your current ones? and how short do they seem to be?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • CraigXXLCraigXXL Posts: 1,852
    The nut part is about 5mm with the bolt around 6mm. It doesn't come with bolts as they supposed to use standard bolts according to their blurb.

    On the MTBR forum a guy from E13 responds with

    Derby - The 7075 inserts refer to the custom gold sleeves that prevent overtorquing of the Turbocharger (which would lead to cracking). The TRC was also designed around "Double" size chainring bolts. There are two typical sizes...usually 6mm total length bolts on more Trail/AM cranks and 8mm total length on FR/DH cranksets. The 6mm bolts typically only barely engage threads, and the 8mm bolts are fine.

    If anyone has any other questions feel free to email me!

    philip @ e*thirteen
  • nicklousenicklouse Posts: 50,675 Lives Here
    so there is your answer. :wink:

    as there are a shed load of sizes.

    but if it does not use the standard double bolts it should have been provided with them.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • CraigXXLCraigXXL Posts: 1,852
    Cheers Nicklouse. The online retailers don't state what the bolt length is which is most unhelpful but refer to them as standard, inner and outer. As the eThirteen guy said there are two standards between AM/Trial and Freeride/DH none of which are used by the retailers.
    I will take a trip down to Evans today, if they don't have anything suitable then the bashring is going back for refund. The only reason I went for the eThirteen one because it didn't need additional bolts.
  • CraigXXLCraigXXL Posts: 1,852
    The bashguard has been returned.

    Anyone thinking of getting one of these eThirteen bashguards please note that it will not fit XT or XTR cranks without purchasing additional bolts at a further expense. I'm not sure if other Shimano cranks are affected too.
Sign In or Register to comment.