Crankarms: The Long And The Short Of It

This post is about options for crankarms with lengths outside the "normal" range -- particularly those shorter than 170mm -- available in the UK.

Photo: Highpath Engineering

You may be wondering why this question even comes up. For many of you, crankarms in the most commonly available lengths (e.g. in the 170-175mm range) suit you just fine.

But -- if you: 
(a) are a woman and/or 
(b) are shorter than, say, 5'8" and/or
(c) have proportionately short femurs and/or 
(d) suffer from arthritis or other chronic conditions of the hips, knees or ankles...
then you may just find that slightly shorter cranks fit better, give you more power and efficiency and perhaps cause less pain. 


I cannot comment on whether you personally may benefit from non-standard length cranks, or advise you on what length to get. I can, however, recommend that if this is something that interests you, you should consult a qualified, experienced bike fitter and/or a physiotherapist with a special interest in cycling to guide you in exploring this. Meanwhile, you may like to read what experienced bike fitters Julian Wall and Steve Hogg have had to say (or write) on the subject, and possibly even what a fit-obsessed middle-aged female blogger with a Goldilocks Complex (sound familiar?!) says.

BUT -- and this is a BIG but -- no amount of reading can be a substitute for getting hands-on assessment and customised advice from a practitioner "in real life". 

So - who does make shorter cranks and where can you buy them?

A few years ago, I was only aware of one supplier with a wide variety of lengths: Thorn. However, with each new bicycle build, I became aware of another. 

Then last year, Shimano offered its Ultegra groupset with a 165mm option. Unfortunately, none of the other groupsets go below 170mm. Further, there's no guarantee that Shimano will continue offering the 165mm Ultegra, much less anything shorter. Also, if you buy the Ultegra groupset just to get those 165 cranks, you may not be able to customise the rest of the group so easily, for example chainrings. 

While there are more options available now than a few years ago, they are still not mainstream options. You won't find them on Wiggle or Chain Reaction Cycles' websites! I have been keeping notes on where you can get them, however, and share those with you now. 

So, assuming that you're willing and able to put together the rest of the drivetrain in a way that's compatible with your choice of cranks, let's have a look at crankarms that you can find in sizes outside the 165-175mm range. Don't panic however, thinking you will have to plan out and source every single part of your groupset from scratch. In many cases, a full crankset (including double or triple rings and spiders) is available, but you may not have a full range of choices over the chainring sizes. You will also need to check that you have (or can get) the right bottom bracket and can run the right chainline with a chainset built around your choice of shorter cranks.

Turning now to the manufacturers and retailers: 

Thorn

Thorn Cycles in Somerset probably don't need any introduction to UK cyclists who have an interest in touring bicycles. They are also renowned for their tandem bicycles. However, they also make (or commission) various components, including chainsets and crankarms. All their products are sold through their sister company, St John Street Cycles -- usually referred to simply as "SJS". 

Here are the "short option" models of cranks made by Thorn:

• Thorn Model No. XD-2-160 / SJS Cycles' Part No.: 32210
  
  These are for single or double cranksets and fit a bolt circle diameter (BCD) of 110. They only come in 160mm length. 

• Thorn / SJS Part No: 1673L140
  
  These require 110/74 BCD so will only fit a compact triple chainset and requires a 113mm bottom bracket.
  
  I have these cranks on Bridget the Cross Check, which first opened my eyes to the existence of shorter cranks. As I needed to replace the original bottom bracket in order to fit these, we took the opportunity to add an inner "granny" ring as well, turning my touring double chainset of 48/36 into a proper touring triple of 48/36/26. This has worked very well for me and turned out to be a relatively inexpensive but significant upgrade to a bicycle destined to be an all-round loaded workhorse ridden on a variety of terrains.
  
  SJS's website currently show availability only in 140mm or 145mm lengths. Mine are 160mm. It's worth phoning SJS or perhaps even Thorn directly to find out what they have in stock or in the pipeline at any time.

• Thorn Part No. ATICK0625 / SJS Part No.: 31813L150
  
  
  These are interesting for requiring a 4-hole (instead of 5-hole) spider, have a BCD of 104/64 and work with a 110mm JIS square taper bottom bracket. As ever, check your chainline. Lengths range from 150mm up to 175mm, available in 5mm increments.

Miche

Miche too are a well-established brand for bicycle components but are Italian, not English. I don't know a great deal about them and have not, to my knowledge, used any of their products. The Surly dealer who assisted me with my Pacer build in early 2012 suggested we look at their range as I had stipulated wanting 160mm length cranks but frankly, aesthetically, I found them a little "meh". They are nonetheless considered to be decent quality and quite good value and are readily available from a number of bike shops and distributors. So here are the shorter length options that I am aware of. 

• Young - Product Code No.: 19852
  
  These require a JIS square taper bottom bracket of 107mm and a BCD of 116. Available crank lengths range from 125, 145mm, 155mm or 165mm and you can build your own double chainset to match, with a choice of chainrings from 35t to 48t. 

Now we move on to the "pretty" options....!

Specialites TA

This French company grew out of the T.A. company founded just after WWII, renowned for its chainrings and for pioneering triple cranksets. Currently, there are two models in their range that come in a variety of crank lengths; the Carmina and the Vega. The full specifications for these can be viewed and compared here. 

• Carmina
  These come in an impressive range of lengths with smaller increments than other manufacturers offer: 155,  160,  162.5, 165 and 167.5, plus 'standard' lengths of 170, 172,5 and 175 and then extending the range even further to 177.5, 180 and even 185 mm.
• Vega
  
  These are available in 155, 160 and 165 as well as 'standard' lengths 170, 172.5 and beyond to 175 and 180. 

As well as the crankarm options, Specialities TA make compatible chainrings that are, in my opinion, not just functional but very attractive as well. For my custom Enigma, I originally ordered the Carmina chainrings with matching cranks, all in a lovely silver finish. Due to a last minute availability issue, I got the black Vega cranks instead. 

The UK distributor for Specialites TA has for many years been Chicken Cycles, who are unfortunately not known for the fastest service! It now appears that Specialites TA products are available from them as special order only. I suggest giving Chicken Cycles a call before you order, to double-check availability. Also get an agreed delivery time and keep track of progress. Chicken Cycles don't contact you to keep you updated on exact delivery or delays -- you will need to chase them up ("remind them" in American) yourself.

Stronglight 

Another venerable brand from the French cyclotouriste "glory days" is Stronglight. Their website has a rather amazing catalogue-search feature for cranksets -- do take a look!  Or simply browse the selection...

• Impact
  
  
  These cranks don't run as impressively short as some of the other options I've highlighted, but they do go down as short as 160mm and go up to 175mm in 5mm increments. Spa Cycles in the UK offer a huge selection to fit a wide range of BCDs etc. You can also find options on Amazon and on Ebay from time to time. 

My 1978 (Austrian, not French) mixte roadbike recently got rebuilt with a Stronglight Impact compact double (50/34) chainset. I really like the clean, classic looks. 

Alternatives

If you're wondering if the cranks you already have can simply be shortened, you may like to talk to Highpath Engineering in Wales, who specialise in this. 

Another option is to buy "adjustable length" crankarms like these from SJS -- provided of course that they are compatible with the rest of your chainset or you're willing to swap out some bits to make them fit. If any readers have tried these, I'd love to hear how they work for you!

If you're in the USA and interested in what crank length options may be available to you there, this "Short Crank Database" from 2013 may be a good starting point. 

Happy pedalling!