Crank length and speed

Unicycles and Equipment
1

Hi all,
I have a 24x2.6 MUni that formerly had 170mm cranks (they bent). For the
type of riding I will be doing with this unicycle, I opted to go with
much shorter 150mm cranks. (I usually ride a long, flat trail with one
HUGE hill at the end followed by a medium steep 1/2 mile incline.) I am
hoping that despite the disadvantage for the hill climbing my overall
time on the ride will drop. What speed gain should I expect with the
shorter cranks? I’m looking for flat ground speeds. Usually I can sustain
7mph with 170s over a long distance.
Roger Davies, do you still have that foot speed/cadence spreadsheet
somewhere on the net?

Thanks,
J Tuttle

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2

In my experience, 170mm cranks are much to long for a 24x2.6 wheel. They make sense on a 24x3 wheel, because with a 3" tire, it is effectifly the same diameter as a 26x2.6 tire.

I dont know if its exactly right, but I would say that 150mm cranks on a 24" wheel are in about the same ratio as 170mm cranks on a 26" wheel.

Its all a matter of tast, though. I personally ride 170mm on a 26x2.6 (still don’t have my KH, my source for an Alex rim fell through), but many people prefer 150mm for 26".

Ben

3

Jeff,

Yes the spreadsheet is still there, I had to do a hunt myself because I had
forgotten where I had put it, it is at:
http://www.unicycle.uk.com/Cranklength.xls

Hope this helps,

Cheers

Roger

The UK’s Unicycle Source
http://www.unicycle.uk.com

----- Original Message -----
From: “jeff d tuttle” <moosebreath1@juno.com>
To: <rsu@unicycling.org>
Sent: Tuesday, January 29, 2002 10:10 PM
Subject: Crank length and speed

> Hi all,
> I have a 24x2.6 MUni that formerly had 170mm cranks (they bent). For the
> type of riding I will be doing with this unicycle, I opted to go with
> much shorter 150mm cranks. (I usually ride a long, flat trail with one
> HUGE hill at the end followed by a medium steep 1/2 mile incline.) I am
> hoping that despite the disadvantage for the hill climbing my overall
> time on the ride will drop. What speed gain should I expect with the
> shorter cranks? I’m looking for flat ground speeds. Usually I can sustain
> 7mph with 170s over a long distance.
> Roger Davies, do you still have that foot speed/cadence spreadsheet
> somewhere on the net?
>
> Thanks,
> J Tuttle
> ________________________________________________________________
> GET INTERNET ACCESS FROM JUNO!
> Juno offers FREE or PREMIUM Internet access for less!
> Join Juno today! For your FREE software, visit:
> http://dl.www.juno.com/get/web/.
>

> rec.sport.unicycling mailing list -
www.unicycling.org/mailman/listinfo/rsu

4

Roger,

Just noticed that you clocked 13 MPH on a 16" wheel- that must have looked hysterical! Did it wobble a good deal?

Christopher

5

It comes from being superhuman in my spare time :wink:

It is only theoretical and I have a feeling that the wheel diameter is
wrong, but I have lent out all of my 16" unicycles to the local unicycle
club so I can not put a tape measure on one. Having seen some of the
Chinese and Japanese on 16" unicycles racing I think that 13mph is well
within reach!

Roger

The UK’s Unicycle Source
http://www.unicycle.uk.com

----- Original Message -----
From: “rhysling” <forum.member@unicyclist.com>
Newsgroups: rec.sport.unicycling
To: <rsu@unicycling.org>
Sent: Wednesday, January 30, 2002 12:55 AM
Subject: Re: Crank length and speed

> Roger,
>
> Just noticed that you clocked 13 MPH on a 16" wheel- that
> must have looked hysterical! Did it wobble a good deal?
> Christopher
>
>
>
>
> –
> rhysling
> Posted via the Unicyclist Community - http://unicyclist.com/forums
>

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