JAJ0404

I currently have 172.5mm cranks on my road bike. I've always meant to see what I "should" be using, and I finally found a couple of sites and supposedly I should be using something around 158/159. So, I started looking for some cheap 160mm cranks, just to see if it made a difference (planning on buying a new bike next year, wanted to make sure I get it right then). I'm having trouble finding 160MM cranks/crankset for a 130mm bcd. Any ideas?

Al Criner

You can settle for 165s which you can definitely get, or get your cranks modified. There are people who will modify your cranks to shorten them.

Wilfred Laurier

just curious

how tall are you that 160mm is the reccomended length

also

i recall a test in a bike mag years ago
that had all riders improve speed with longer cranks
i dont recall if it was a properly conducted scientific study
but it certainly suggests that very short cranks
are rare for a reason

also
regardless of what a formula says
or doesnt say
your comfort is the most important
so ignore everything between
just curious
and the second also

FBinNY 

I had a bunch of NOS SunTour Sprint 130/160mm cranksets. I sld most to Harris Cycles some years back, and they may still have a few. Otherwise, I might still have one or two tucked away someplace.

I don't know how tall you are, but unless you're shorter than 5'6" or so, or have a low BB, or limited front wheel clearance, odds are you don't need 160mm cranks.

There's lots of "science" about crank length, but bikes have been around for over a century, and the 170mm "standard" is the result of many years of evolution. Consider also that it evolved when the average height was far shorter than today. In fact many argue that the increase in height argues for longer cranks.

I you've been riding 172.5 cranks and don't find the low/high positions straining you or giving you the "knee is in my gut" feeling, you're probably fine staying with them.

joejack951

These Stronglight cranks are most likely a 110mm BCD but come in a 155mm length: https://www.probikeshop.com/stronglig...ver/66755.html

Specialties TA likely makes exactly what you want but it won't be cheap. Their website is being weird at the moment though.

As Al noted, 165mm cranks are fairly common. The problem with shortening is that you'd need the existing pedal hole far enough away from the new location in order to not lose significant strength. You would need at least 180mm cranks (probably longer) in order to safely modify them to 160mm. Good luck finding those too.

JAJ0404

Thanks guys - - I'm a hair under 5'10", but my inseam is only about 28.5", that's how I get the small crank measurement. I just wanted to test it to see if it was more comfortable before I bought my next bike, especially since I keep a bike for at least 10 years usually. I do get that 'knee in the gut' feeling if I'm in the drops, but I'll probably just wait until next year and try a 165MM. If the difference is noticeable, I'll ask about 160MM.

HillRider

Are you using the correct inseam measurement? Your cycling inseam is not the same as your pants inseam measurement.

ThermionicScott 

I bet that the 165mm cranks would do the job if you don't have any major problems with the 172.5's. Don't forget to bump the saddle up by about 7.5mm when you make the change.

fietsbob

better luck in having a 110 bcd in a short arm . as the niche is youth BMX , and so they offer from 140.

https://www.origin-8.com/product-desc...model_uid=1006

TallRider

at 5'10" I'd be really surprised if you are "supposed to" have 160mm cranks. Unless you should have been 6'5" but broke the growth plates in your knees at age 8.

I would strongly suggest you stick with the normal 170mm cranks, unless you have REALLY proportionally-short legs and long torso. Even then, 165 is the lowest you should go, and that's a fairly common, easy-to-find size. 160 and below get into rare territory.
There's also some personal-preference variation that has some relation to pedaling style. If you like to spin a high cadence, shorter crankarms make that easier. Longer crankarms are better for stomping at lower rpms.

ezbikin

Lots of recumbent riders use shorter cranks, to encourage spinning on hills, as we can't stand and use our body weight to climb. I use 155mm and I'm 5'8". Some sources: PBW bikes has a 155mm crankset in 130/74 BCD that comes with 30-42-52 rings (about 95 bucks). Origin 8 makes a 130/74BCD crankset without rings, available on Amazon for about 35 bucks, and Mark Stonich of Bikesmith Design shortens cranks as well as having already shortened sets for sale. My wife has a crankset on her recumbent in 28-38-48 160mm crankarms. I bought the crankset for $7.99 new, removed from a youth bike. It's not elegant, but it does the job.

Garthr

If you can swing 110 BCD, Sugino XD2 in a 152mm with 24/36/50 rings is about hundred bucks. You can take off the 24 of course, either way use a 107mm BB.

As far as length, it's all subjective. I have a 36" inseam and size 15 feet,. I use to ride 185's. I thought I "had to" ... lol ! Well, I changed to a mid foot pedal position and decided to try shorter cranks. First 175's then 170, nahh. Then the 152 Sugino. Bingo !! Sweet spot !!! I get all the leverage I did with the 185's AND I get a speedy circle to spin. It's indescribably awe-some !!! You won't find this method in book, or an online article, It just arose in me to do it.

36/50 rings are more than enough for especially if you are using an 11t or 12t cog. I'm fine with even a 13t.

Shimagnolo

Also, the Sugino XD600: https://www.universalcycles.com/shopp...ls.php?id=9824

I put a 152mm XD600 on the ex-GF's bike, but she was only 5'3".

hamster

I think that you should remeasure your inseam. The ratio you're reporting is very unusual. At your height I expect inseam in 31-33" range. I'm 5'6" with inseam of 29.5".

160 cranks are virtually nonexistent. Major manufacturers only go down to 165 and even then 165's are hard to find because most stores only stock 170 and 175.

I have a used triple crank that was custom shortened to 155 mm and I no longer use, if you're interested.

Bill Kapaun

I'm 5'11 with somewhat limited range in motion in my R knee.
I've experimented with-
175 Chronic knee pain 60 RPM
170 Some knee pain 80 RPM
165 No knee pain 85 RPM
160 NO knee pain 82 RPM and they DID feel too short.

I really feel you'd be happier with 165 than 160.