shorter cranks
Sue Reinert
Eric Daume
If I were to install shorter cranks on my 2018 Pocket Llama what other adjustments would I need to make? Current cranks are size 170 and I am getting shorter as I age. The Llama frame is small (top tube 48 cm).
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John S. Allen
On Sep 18, 2025, at 10:43 AM, Eric Daume <eric...@gmail.com> wrote:
If your body is staying the same, shorter cranks need a taller seat height to get the same leg extension. Then you might need a taller bar height to keep the seat to bar relationship the same.
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John S. Allen
On Sep 18, 2025, at 11:40 AM, John S. Allen <jsa...@bikexprt.com> wrote:
I am getting shorter too, and the change is in my spine, not my legs. My trousers still fit. The main adjustment that I think you may want to make is to get the handlebar closer.
John Thurston
To answer your specific question, I'll echo and amplify what others have said.
If you shorten the crank, you'll want to raise your seat by the difference to maintain your leg extension. If you want to maintain the same height relationship between your saddle and bar, you'll also want to raise your bars by the same amount. So if you replace your 170mm crank with a 165mm, you'll want to raise both the saddle and bar by 5mm.
Raising the seat should be simple. Raising the bars may be more difficult. How difficult depends on what style riser, stem, and bar you have.
Shortening the crank won't change the gear-inch range you have on the bike, but it will reduce the leverage you can supply. You'll have less torque (so climbing in the gears you have may be harder), but (with a little practice) will be able to spin more quickly.
From here on, I'm providing unsolicited observations and
suggestions. Take them, or leave them, as you like.
As I have aged, I've changed the configuration my Llama (from the
90s) several times. My legs haven't changed their length much, but
I'm a whole lot less flexible than I used to be! I'm still running
170mm cranks (though not the original), but I've had three
different stem risers made for it as I've changed. I've also
changed my saddle, as my riding position has changed.
Think hard about your body and pedaling needs before you simply
swap cranks and expect an significant change in the bike fit.
Think about bar height and reach, with respect to your saddle
position. Then, if that needs to change, talk to Bike Friday.
There was a time when they'd send you a fully adjustable
riser/stem for your bike. You'd make changes to it until you had
the bars just where you wanted them, and then you'd send it back
to Bike Friday. They'd then make a custom riser which put the bars
exactly where you wanted them.
-- John Thurston Juneau, Alaska
Sue Reinert
Phil Hammerslough
On Sep 18, 2025, at 10:12 AM, Sue Reinert <reine...@gmail.com> wrote:
If I were to install shorter cranks on my 2018 Pocket Llama what other adjustments would I need to make? Current cranks are size 170 and I am getting shorter as I age. The Llama frame is small (top tube 48 cm).
