E-Type BB; Fits like a Glove, but will it effect chain line?

scatty76
scatty76 Posts: 23
edited April 2014 in MTB workshop & tech
Hi, I have just fitted a BB for my new MTB Build. After closer inspection of the BB packaging, it appears to be an E-type mounting BB!

Though it fits perfectly with NO gaps and WITHOUT the use of spacers, will this affect my Chainline or give me ANY other issues I should be aware of?

Is it a BIG NO-NO, using an E-Type BB with a standard "clamp around the seat tube" type Front Mech?

From what I have researched i'm looking for a 47.5mm Chainline, or is that wrong? I'm no expert on these things!

Some useful Specs:

Giant NRS 3 (Yr.2003) Frame.
Shimano ES-51 E-Type (68x113) Bottom Bracket.
Shimano LX M571 Chainset.
Shimano LX M571 Front Mech.(Standard clamp on frame-NOT E-Type Mount!)

I hope that's enough information for my question's, and thanks for your help...

Scott.

Comments

  • The Rookie
    The Rookie Posts: 27,812
    It will affect your chainline by a tiny amount (about 2mm) I wouldn't worry about it, that's probably the tolerance most square tapers fit to anyway!
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • scatty76
    scatty76 Posts: 23
    Thank-you!
    I thought I may have to get a new BB, but so long as it wont ghost-shift or mess up my indexing I will leave as is.

    ** Just a note, it is an Octalink splined axle/crank arm interface and not a Square Taper, if it makes any difference to it...
  • nicklouse
    nicklouse Posts: 50,675
    As above your chain line will be inboard by 2.5mm as will your crank. And on the other side your crank will be further out.

    Fit a spacer.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • scatty76
    scatty76 Posts: 23
    Thanks! I have one on order...

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