I know the subject of shortening the length of crank arms has been beaten to death. Fortunately, that’s not what this post is about.
It appears that there is nothing available commercially, either through FSA, Shimano, or Sram under 165mm. Therefore, if one wishes to ride a shorter crank arm, he/she must figure out where to get 'em.
However, upon searching myself, I’ve found BMX cranks, square taper cranks, and a company that can possibly modify your old cranks… Some of us (myself included) do not know if a square taper crank or a bmx crank, even if it’s 110 or 130 will fit a modern tri bike. All of these are readily available, but I don’t know if they’d work.
Therefore, I believe if we could simplify the search and maybe even detail what would work and what wouldn’t for crank arms below 165mm down to 140mm. Let’s get to some specifics of what will and what will not work… and why.
As long as you are ok with 110BCD and have the option traditional BB then I can’t see why these shouldn’t work.
Here’s where it gets confusing for me (taken from that website):
Top Features of the Miche Young Chainset
For use with 107mm ISO Square Taper b/bracket
8, 9 and 10 speed chain compatable
One piece light-weight forged alloy crank
155mm or 165mm length
36/46t alloy rings
Anodised silver
Weight: 530g
BCD: 116
AboutChainsets
Your chainset must fit onto your bottom bracket! There are currently four chainset/bottom bracket interfaces that you’re likely to come across. If your bottom bracket is made by Shimano and it has splines, then you need an Octalink chainset. If your b/b is NOT made by Shimano and it has splines, it’s almost certainly ISIS. There are a very few non-Shimano chainsets with Shimano Octalink interfaces so, to be sure, count the splines - ISIS has 9, Octalink has (surprise, surprise) 8. No matter which brand of b/b you have, if it has a square interface, it will require a traditional square taper chainset. If you have one of the new Hollowtech II systems, you will need to choose the exact chainset that matches your bottom bracket. Most MTB chainsets are now 9-speed compatible but these will work with an 8-speed system.
BCD is 116 for these, and we are referencing 8 and 9 splined Bottom Brackets. Do all Shimano and Sram Bottom Brackets 8 splines? If so, the Octalink would work?
Sweet. Thanks for the help. I think the biggest limiter in my understanding this concept was the bottom bracket itself. I’ve never been able to research them much, and since there’s a few variables, I was concerned I’d make a mistake.
It looks like this eBay seller has both the crank arms and BB I need.
The BB has different threading (english or italian) 99% of all bikes made in the last 10 years are english. Lastly, a bike has a BB shell width 68 or 70. Most road bikes/tri bikes are 68mm. You can measure the BB shell on your bike to confirm but it’s likely 68mm.
BCD isnt related to the BB. Its bolt circle diameter of the cranks. This tells you what bolt pattern can be used. Standard road bikes/tri bikes are 130bcd. 110 has recently entered the world of road biking as “compact” cranks. If you hear of chainrings in 50/34 those are 110bcd cranks.
First, I would recommend Lightning carbon cranks set. Crank arms to 160mm in length. Second, TA Specialites makes the Carmina crank arm to 155mm. I paired a set of crank arms with a Phil Wood BB that spins amazingly. Both these crank sets are also compatible with Quarq for the future.