Crank Shortening FAQs

Cost?
$45 + $8 S&H if you send me the bare arms
or
$50 + $10 S&H if you send me the arms with the chainrings attached.

Will you leave the original hole so I can use either length?
No!

Gearing
Your “comfortable and natural” spin rate will increase slightly. If you are getting spun out in high gear now, the shorter arms may fix this. If you currently use low gear more often than high gear, you will want to use smaller chainrings or a bigger cassette.
About 1/3 of the 105/Ultegra owners have me install 24-39-48 FSA ramped and pinned rings for $80.75.

Which arms can be safely shortened?
"Safely" is a relative term. They will be weakened somewhat, as there will be less aluminum around the pedal hole than before. So, I only recommend using shortened cranks on recumbents.

Back in the '70s and early '80s road cranks were often smaller around the pedal eye than is common today. Failures were rare, but not unheard of. I will shorten a good quality forged crank if it will have about the same amount of material around the pedal as those older cranks. If the crank is the cheaper, so called "Melt Forged" then I want to be able to leave about 25% more metal around the pedal.

The cranks that I believe have enough material to shorten are as follows;
(There may be others I'm not aware of. I'm always trying to find more)

I'm working on an expanded list of cranks that I will or won't shorten. I hope to post it here soon.

110/74 BCD
Suntour 175mm XC-Compe 110/74 Bolt Circle Diameter
I have a few sets of these that I will be shortening. Price with chainrings will be $15 higher than Doteks with the same rings. See Doteks for typical prices. These are finished much better than the Doteks and have an 18mm lower Q Factor (About like 105s) They take a 110mm square spindle. Click HERE for a photo.

Easy Racers branded Sugino 110/74 BCD

Older, fat Shimano 110/74 BCD MTB cranks
FC-MT60, FC-M452 LX, FC-M450 Exage

130 - 130/74 BCD
Dotek YF PRO6 130BCD Double

Shimano Ultegra FC-6503 130/74 BCD Triple
Shimano Ultegra FC-6500 130 BCD Double
Shimano 105 FC-5504 130/74 BCD Triple
Shimano 105 FC-5501 130 BCD Double
Shimano 105 FC-5505 130/74 BCD Triple
Shimano 105 FC-5502 130 BCD Double

I will NOT shorten
Shimano 105 FC-5503 130/74 BCD Triple
Shimano 105 FC-5500 130 BCD Double
These are a cheaper Non-HollowTech variety that are narrower and therefore may not have sufficient metal around the new eye.

What if my cranks aren't on your list?
In order to determine if I can shorten your cranks I need a few measurements, and some photos. I need the width and thickness 19mm (3/4") below the pedal eye - See See http://bikesmithdesign.com/Short_Cranks/measure.jpg

A close up, front view of the pedal end of the arm, with the pedal removed, would be a big help. With it I can use PhotoShop to copy the pedal eye to the potential new location. See http://bikesmithdesign.com/Short_Cranks/RD7000_170_148.jpg

A couple of other photos will give me an idea what the cross sectional shape is like at the new location. It helps to put a piece of contrasting tape. or a small rubber band on the arm (also at about 3/4") to make the shape more visible.
See http://bikesmithdesign.com/Short_Cranks/contour.jpg   In the example, the width and thickness would have been adequate with a more rectangular shape, but the large bevels reduced the amount of metal available.

If there is a recess on the back of the arms, I'll need to know the depth of the recess at a point 24mm below the pedal eye. A photo would also be useful.

Any model numbers on the back of the crankarms will help me identify them.
For instance Shimano Ultegra 6400 series can't be shortened, but Shimano Ultegra 6500 series can.

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