Crank Length...

Hi All

Some days ago, I’ve invited everyone to see my homebuilt unicycle at my
webpage. A special answer was gave by Klaas Bil. You’ve said that my
unicycle has a high Q factor, because the “S” cranks I’ve used.

After a long search in my city, I’ve found a pair of cottered cranks
absolutely straight. I’ll mount the “new” cranks (to tell the truth, the
cranks was took from an old children bike…), but I have a doubt… These
are 4 1/2" cranks and I took notice that the best majority of 20" unicycles
uses 5" cranks…

Now the question: These 1/2" each crank will be significant? What will be
the effect?

Thanks

Eduardo

Ypê Bike: http://www.ypebike.cjb.net/
Ypê Mono: http://www.ype.unicyclist.com/

Re: Crank Length…

Eduardo L P Jr wrote:
> I have a doubt… These
> are 4 1/2" cranks and I took notice that the best majority of 20" unicycles
> uses 5" cranks…

Many riders use 110mm cranks on 20" unicycles - pretty much the same as
your 4.5". Go for it, you’ll never want 5" cranks on a 20" again. :slight_smile:

Regards,
Mark.

Fujitsu Telecom Europe Ltd,| o
Solihull Parkway, | In the land of the pedestrian, /|
Birmingham Business Park, | the one-wheeled man is king. <<
Birmingham, ENGLAND. | O

5 inches roughly = 125 mm
4 1/2 inches roughly equals 112 mm.

It will be like putting 110 mm cranks on instead of 125s, more or less.

Theoretically, the uni should go about 13% faster - that’s top speed and average cruising speed. The exact figure doesn’t matter, but you will notice a small difference.

You will have around 12% less leverage, which will have a small effect on hill climbing and idling.

In practice, it won’t make any huge difference.

I ride a 20 inch with 110mm cranks, a 24 with 102s, a 26 with 150s and a 28 with 110s - all are controllable and idleable. Don’t worry, the pros and cons will more or less balance out. On the whole, I prefer shorter cranks. Not everyone does.

I think your’ll be fine with the shorter cranks, Some people prefer them as you can see, I however do not. I like longer cranks (140’s) on my 20" this is probably because I do more trails stuff than freestyle though.

Have fun with your new toy

Chex

Re: Crank Length…

Eduardo,

Have you tried your new cranks already? Did you notice less wobbling
or any other difference related to the cranks being straight?

Klaas Bil

The average person falls asleep in seven minutes.

Re: Crank Length…

Hi Bil

I don’t try the new cranks outdoors yet, but indoors, they seems to be a
good choice… Tomorrow I’ll try and tell…

[]'s Eduardo

Ypê Bike: http://www.ypebike.cjb.net/
Ypê Mono: http://www.ype.unicyclist.com/

----- Original Message -----
From: “Klaas Bil” <klaasbil_remove_the_spamkiller_@xs4all.nl>
Newsgroups: rec.sport.unicycling
To: <rsu@unicycling.org>
Sent: Saturday, November 23, 2002 10:50 PM
Subject: Re: Crank Length…

> Eduardo,
>
> Have you tried your new cranks already? Did you notice less wobbling
> or any other difference related to the cranks being straight?
>
> Klaas Bil
> –
> The average person falls asleep in seven minutes.
>
>


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