Author Topic: Crank arm reccomendations  (Read 288 times)

Offline Hamez

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Crank arm reccomendations
« on: May 16, 2020, 07:45:38 PM »
Hi, I am new to the site (51 year old) having just picked up a used KHE tantra and need advice.


It has rear pegs and current 165mm crank arms.


My feet keep hitting the back peg due to the short rear end.


Thought about getting 155 or 145 arms to put on, keeping current bottom bracket / spindal


Would this work ? Anything I need to take into account ?


Thanks in advance for comments and advice,  at 51 starting off slow but already enjoying the frustration of not being able to balance 🤣

Offline mal

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Re: Crank arm reccomendations
« Reply #1 on: May 16, 2020, 09:42:19 PM »
Assuming that its a 9t spindle on the rear hub consider getting a smaller than 25t sprocket if you decide to go with so short arms.The shorter the arms the harder it gets to pedal,and in flatland its good to be able to pedal away with ease when you finish a run. If pedaling is hard it will work against your pedaling away  because it will create a force against your flow out of the trick.
I hope i made some sense,i cant explain it very good because english is not my first language..!
« Last Edit: May 16, 2020, 09:52:05 PM by mal »

Offline nosubsteve

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Re: Crank arm reccomendations
« Reply #2 on: May 16, 2020, 10:15:55 PM »
english is not my first language..!
Don't worry about it, mostly Americans on this forum.

Offline Hamez

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Re: Crank arm reccomendations
« Reply #3 on: May 16, 2020, 11:30:40 PM »
Thanks for the advice and it makes perfect sense (didn’t think about the effect of harder peddling).  I will have a look at arms and smaller chain ring (have 9t on rear)) - thanks again for the reply, great to be part of the community 👍😀

Offline rideflat43

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Re: Crank arm reccomendations
« Reply #4 on: May 17, 2020, 01:32:57 AM »

Back in the day it was 175MM was the thing and then it was 170MM
and now it is like 165MM and yeah it gets a little harder to pedal but
you have to remember..two long cranks in flatland and you got the speed.
I am not like pedaling everywhere and just get my bike out of my truck
and then two quick cranks and I got enough speed.


When it comes to spocket size//there are a few factors as explained and it
is really the speed and style of your riding for that. I use a 24T/10 ratio
myself  and it works.

Offline mal

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Re: Crank arm reccomendations
« Reply #5 on: May 17, 2020, 09:16:02 AM »

but
you have to remember..two long cranks in flatland and you got the speed.
I am not like pedaling everywhere and just get my bike out of my truck
and then two quick cranks and I got enough speed.



This too.Thats why i won't go below 165/160. I have 170 now and looking to get some 165/160 ones because with a 13'' chainstay and my big feet the pedal is too close to the peg

Offline DaddyCool

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Re: Crank arm reccomendations
« Reply #6 on: May 17, 2020, 11:34:25 AM »
Hello Hamez,
could you please post a picture of your crank? If it is a 19 mm 48 T spindle you have options... As they others said less than 160 mm is not common, but of course you can do that. Some riders use 140 mm but this is special. Maybe 150 mm could do it. But there are not many cranks in this size. If it is 48 T, maybe Profile is the only option. First you need to find out what spindle you have...

Offline rideflat43

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Re: Crank arm reccomendations
« Reply #7 on: May 17, 2020, 08:53:50 PM »

I would not recommend below 165MM and 160 is a little short and
you will start having ussies..170mm is good if you do not have a vehicle
and have to pedal to your spot.170MM would be the top length and then
165MM would be a good crank length if you do not have to pedal somewhere.


160MM is the very bottom of that length and there are some frames you can
use the 160MM length cranks and you have to remember it is going to be harder
to pedal at 160MM, so maybe a third pedal to get speed is needed.You are also
going to have to go to a reasonable gear ratio also ,,,20-25 front spocket and 10-
12 real time gearing.


I would not recommend going below 160MM and I see some of the Profiles cranks
arms go down to 145MM and that is a bit crazy to say the least and that are for those

setups for kids or the rollers type flatlanders!There are none I now that use 140MM
but I know of some rolling flatlanders who use 145MM and they are a crazy too!
« Last Edit: May 17, 2020, 08:56:24 PM by rideflat43 »

Offline rideflat43

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Re: Crank arm reccomendations
« Reply #8 on: May 17, 2020, 08:58:35 PM »

You can always go 6 pegs
Adam Pintek style riding and yeah
lol

Offline Hamez

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Re: Crank arm reccomendations
« Reply #9 on: May 17, 2020, 09:49:11 PM »
Thanks for the replies and advice, something simple seems to be a lot more complicated a bit like how simple I thought balancing on a bike would be... reality sucks - I will post picture tomorrow perhaps I can cut my toes to shorten my feet 🤣

Offline Flatism®

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Re: Crank arm reccomendations
« Reply #10 on: May 18, 2020, 10:10:06 AM »
im on a 12.5 cs (ilike) also with 165 arms - and yes my heels catch stlll too.
Think the only way forward is to go to shorter cranks 155/ 160 -  especially if 1 has big hooves ;)
Flat-ism

Offline out~riding

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Re: Crank arm reccomendations
« Reply #11 on: May 18, 2020, 02:02:44 PM »
The Tantra has really short chainstays, only 12"... infact, that frame was Wolfgang Sauter's signature frame and he didn't even ride with cranks...
The Tantra was also available as a complete bike and it came with 152mm cranks.
So yes, a 145-150mm crank arm would be much better for you.

https://www.youtube.com/watch?v=g9GxrOoBdNk


Offline Hamez

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Re: Crank arm reccomendations
« Reply #12 on: May 19, 2020, 05:31:00 PM »
Thanks again for all the feedback and comments I have learnt a lot from my post
  • I should have done more research and perhaps not brought the first flatland bike I saw!
  • I should wear smaller shoes or cut my toes off
  • I will keep the cranks for the time being (my spots are close by)
  • If I come across a pair of cheap shorter arms I may buy them to see if they help
  • Worse case I can sell the bike and look for something different or perhaps use my daily rider (85 Skyway Streetbeat) for flatland
Again massive thank you, I didn't expect so my comments

Offline rideflat43

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Re: Crank arm reccomendations
« Reply #13 on: May 19, 2020, 08:43:28 PM »

Hamez..I am now 59 years old and still ride..going back into the early 1980's
with the Curb Dogs and then with the Flatland Fugitives..becoming a Fugitive
back then.The bit with being short is good for flatland riding and I do know a
few tall riders like my friend Trevor(Meyers) and fellow Fugitive Nate Dawg
Hansen.I am talking about leg and foot length here and dealing with hitting the
back of your foot with longer cranks and then the problems of having too short
of cranks..it is harder to pedal.


This has been a  problem for many and continues to be at times..my point is to
start out with what you have now..your spot is nearby,so no problem pedaling
there to ride..You have 165mm crank arms which is a good length for your cranks
and finally..adjust your feet on the pedal so you do not have that problem and
just learn to ride in doing pedaling, gliding into tricks different and pedal tricks.
If you still have a problem with foot room and hitting of your foot in certain
tricks..maybe down the line got to 160mm cranks.Save up for it and see how
you like it. I mean your close to your spot so a little harder pedal to the spot will
not be too bad and as I have said..two pedals and you got speed for most linkts.