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Sturmey Archer Gearing on a BMX.........I'm not crazy BTW!!

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moley:
I've been thinking about getting some gears on a BMX for next spring.

Not for racing............just for getting to work and back............up hill down dale.    Instead of using a MTB for some steep hill work..........use a 20" with gears, where a standard 44/16 would never get up.   I can only just get up it on my lowest MTB 27 Speed Gear.   And for long flat/downhill stretches then I can crank it up in a high gear and get some speed up.  Singlespeed is okay for the track, skatepark and ride down the road to the offy but if my BMX had a few gears then I'd use it for some epic rides instead of my MTB and I have the perfect donor frame and forks for it too.

A browning or a 2 speed freewheel job might be a laugh but I've been thinking about my old Chopper and thought........why the hell not.   I had my chopper for about 2-3 years and never had a problem with the gears.   

My mates kid has a 16 inch with sturmey archer type gears on it so a BMX can't be impossible.

From what I've researched Sturmey Archer do a 5 speed Freewheel hub with 111mm (old spec) 113.5mm (new spec) over locknut dimension.  I presume thats the cone locknut to cone locknut so the frame has to have a 111/113.5mm gap which seems about right for a BMX.     

Gear ratio

Gear 1 - 62.5% (-)37.5%
Gear 2 - 75%    (-)25%       (Gear 1 +20%)
Gear 3 - 100% Direct Drive (Gear 2 +33%) 
Gear 4 - 133%  (+)33.3%    (Gear 3 +33%)
Gear 5 - 160%  (+)60%       (Gear 4 +20%)

Has anybody tried sturmey archer gears on a BMX (or is this sacrilegious) or has anybody sturmey archer experience?   ???

I expect some witty replies!!!!  :D

dan-dare:
forget the ratios ian, up creek and down to keswick on this weapon of lakeland destruction. :-*

  :daumenhoch: :daumenhoch: :daumenhoch:

kingkeef:
Go hang your head in shame

HEYWOOD BMX:
 :) Blasphemer! Aren``t most BMX hubs now 110mm? Sure Diggler has a spreader you could borrow.. :daumenhoch:

bof:
http://www.kinetics.org.uk/html/rohloff1.shtml

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