Chain line query

Mike Howarth
Mike Howarth Posts: 75
edited February 2008 in MTB workshop & tech
Early in the week I posted regarding replacing a crank set due to a set of knackered pedal threads.

Fairly straightforward I thought, until I realised there are alot of different chainlines since I were riding a bike as a whipper snipper.

Having done some measurements I need to run a 49mm chainline, however I was wondering whether this is actually a standard size?

From reading around chainlines I've only seen 47.5mm and 50mm mentioned, for instance if I was to buy a crankset with a 47.5mm chainline I'm guessing this would sit too close to my frame and 50mm would present problems in the derailleur.

Ultimately I'm guessing 47.5mm chainlines are geared towards 9 speed bikes, am I along the right track?

Comments

  • nicklouse
    nicklouse Posts: 50,675
    chain lines go out to 52mm.

    if your current is 49 then you need to find a crankset that gives that chainline with the bb axle length that you have.


    And wrong track. it is more to do with frame design.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Drfabulous0
    Drfabulous0 Posts: 1,539
    Maybe I'm being dumb here but does 1mm difference in the chainline really make a noticeable difference on a geared bike?
  • nicklouse
    nicklouse Posts: 50,675
    yes. as it move the most used gears 1mm (ie you want the most used gears to be where the chain is straight)......
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown