In a recent thread ( viewtopic.php?f=5&t=99509&p=927981&hilit=FEX54#p927981 ), I asked about single speed chainsets and received several responses for which I am grateful.
However, before committing to a Sturmey Archer chain set, I am puzzling over chainline. My rear wheel has a Dicta 16T freewheel on a DMR single speed disc compatible hub which gives an undished wheel. Therefore the chainline at the rear wheel is, to my mind, as follows:
Hub OLN dimension is 135mm
Freewheel tooth centre line is 11mm from inner face of the drop out
Chainline is thus (135/2)-11 = 56.5.
Assuming that this is true, then what length square taper would I need for a SA chainset with a stated chainline of 42.
I think that the answer is 127mm. Am I right?
I would be grateful for any advice.
Chainline assessment
Re: Chainline assessment
11mm seems too close to me; are you sure that is right? IIRC the RH flange should be ~28mm from the dropout and I'd expect the sprocket to be in the middle of the gap or closer to the flange than the dropout perhaps...
a 56mm chainline is huge. That is like having an MTB triple chainset and using the outer chainring position, more or less.
If the crankset you intend to use normally has a 42mm chainline you need to add on ~28mm to the 'normal' BB length. I'm not sure that will be possible in this case. If so, I'd suggest that you go with the flow and use an MTB chainset instead.
cheers
a 56mm chainline is huge. That is like having an MTB triple chainset and using the outer chainring position, more or less.
If the crankset you intend to use normally has a 42mm chainline you need to add on ~28mm to the 'normal' BB length. I'm not sure that will be possible in this case. If so, I'd suggest that you go with the flow and use an MTB chainset instead.
cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~