Author Topic: changing out seat post on a rad expand 5  (Read 1862 times)

radex5owner

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changing out seat post on a rad expand 5
« on: September 16, 2022, 09:21:19 AM »
So I have the opposite problem that most rider have, I'm short (5'1") and I want to know first the diameter of the seat post to see if I can get a lay-back post where the seat is positioned back. ,  I can still reach the ground when stopped but  have a better pedal stroke for riding.  Because I have the rad basket on, I only have about an inch to work with but feel it will give me the distance for better knee expansion.

JimInPT

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Re: changing out seat post on a rad expand 5
« Reply #1 on: September 16, 2022, 01:24:25 PM »
My MiniST2's seatpost diameter is 27.2mm, which I believe is the same for all Rad bikes including yours. 

I replaced the factory unit with a Redshift suspension post, which I love and has a pretty good fore/aft range on the rails.  It's 350mm long and fits these frames very well.
Shucks Ma'am, I'm no "Hero Member", I just like to wear this cape.

handlebar

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Re: changing out seat post on a rad expand 5
« Reply #2 on: August 02, 2023, 12:48:28 PM »
So I have the opposite problem that most rider have, I'm short (5'1") and I want to know first the diameter of the seat post to see if I can get a lay-back post where the seat is positioned back. ,  I can still reach the ground when stopped but  have a better pedal stroke for riding.  Because I have the rad basket on, I only have about an inch to work with but feel it will give me the distance for better knee expansion.


Seated to pedal, I can touch the ground with one toe, but when I stop I can sit with the balls of both feet on the ground. The saddles of both my bikes tilt forward so I can easily slide forward and downward as I stop. As I ride, pressure against the bars and pedals keeps me from sliding forward. It's the old-school way to get stability when stopped and full leg extension when underway.

As a rule of thumb, when a rider sits in pedaling position with his foot on the pedal that's in front and level with the crank, the front of his knee should be over the spindle. (It can be checked with a plumb bob or, more elegantly, the plumb line of a laser level.) You may find that a layback post would not help you.
« Last Edit: August 03, 2023, 05:41:45 AM by handlebar »

John Rose

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Re: changing out seat post on a rad expand 5
« Reply #3 on: November 29, 2023, 07:33:05 PM »
So I have the opposite problem that most rider have, I'm short (5'1") and I want to know first the diameter of the seat post to see if I can get a lay-back post where the seat is positioned back. ,  I can still reach the ground when stopped but  have a better pedal stroke for riding.  Because I have the rad basket on, I only have about an inch to work with but feel it will give me the distance for better knee expansion.
Would you still be okay for the reach to the handlebars?
RadMini ST 2 / RadExpand 5

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Re: changing out seat post on a rad expand 5
« Reply #3 on: November 29, 2023, 07:33:05 PM »