# Short crankset, 140-150mm 24mm-68/73mm spindle



## kmjelle (Nov 29, 2007)

Do they exist, or will I have to modify an old crankset for a custom 26" wheel 14" carbon frameset? Its for my 9 year old son (134cm tall) I have the taps for making new pedal threads, left- and righthand 9/16, up to and incl 13mm drill bit, mini mill/drill press and mini lathe.


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## lem2 (Mar 2, 2008)

Yes they do but comes in square taper


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## kmjelle (Nov 29, 2007)

lem2 said:


> Yes they do but comes in square taper


And a square tapered bottom bracket will not fit my frame, I suppose. I have a press fit BB, probably identical with Trek BB92/95. No threads in the frame, so I would not be able to mount a BB with threads.


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## kmjelle (Nov 29, 2007)

Found a Sram NX GXP 155mm 24mm spindle crankset, off the shelf. Slightly long, but I guess they can do.https://r2-bike.com/SRAM-NX-Crank-Black-1x11-GXP-32-Teeth-X-Sync-BCD-94-155-mm


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## gtrguy2 (May 17, 2015)

There are some options- the GT Speed cranks have a 24mm hollow spindle, designed for an external threaded bottom bracket and come in sizes from 135mm on up. Only a 104mm BCD so you're limited on chain ring sizes but those should work.


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## stom_m3 (Jun 28, 2011)

I have the GT ones. They work well. Also, redline makes them too.

Here's the link to my build thread with them. I started with XT 165mm, went to GT 155mm and went a 2 steps lower to 145mm.
http://forums.mtbr.com/families-riding-kids/carbon-frame-xs-26-build-1000095.html

steven


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## kmjelle (Nov 29, 2007)

I am limited by this aerozine 24mm press fit BB on my sons 14" 26"er carbon frame. Is this the Redline crankset you suggest? This Redline microline uses a 113mm ISIS BB. It comes in lengts from 130-170mm.

My son is 129cm/4′3″ tall, inseam 58cm/23".

I am located in Norway. The GT and Redline options seem hard to come by in correct lengts outside USA. On the other hand I can order the 155mm Sram NX crank from Germany, along with other parts I need.

Is it too long?


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## stom_m3 (Jun 28, 2011)

Both GT and Redline use 24mm spindles for their 2 piece cranks. The link you have above are the wrong ones. Check out the link below. I don't see why you couldn't just order them from JR or Dan's Comp.

2-Piece Crank Kits - Cranks - BMX Parts

As for the 155mm length, you will need to judge him. My son is 4' 7" and I put him on shorter cranks to keep his cadence higher.


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## kmjelle (Nov 29, 2007)

Thanks for the links. I have sent JR and the german shop a mail. Shipping at $51 from USA. Though the Sram crankset might be so new that few or noone has it in stock. Will keep you updated.


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## goodmojo (Sep 12, 2011)

Bmx cranks come in the size of cranks you want. Not sure why a square taper bb wouldn't fit though

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## kmjelle (Nov 29, 2007)

goodmojo said:


> Bmx cranks come in the size of cranks you want. Not sure why a square taper bb wouldn't fit though


If anyone would suggest a square taper BB that is press fitted into the 41mm cups (no threads, options in short cranksets are many.


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## kmjelle (Nov 29, 2007)

The Sram NX 155mm crankset is so new that noone has them in stock. I have shortened Shimano hollowtech to about 145mm. Not super solid due to the hollow nature of these arms. I will let my son give them a try. May be they hold fine for his limited power output. Gain some experience with them, and maybe consider the Srams later in the summer.


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## Steve-XtC (Feb 7, 2016)

Are the Zee cranks hollow ??? They may not be AS light as you'd like but should be available to fit the same as the hollowtech cranks ...


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## kmjelle (Nov 29, 2007)

I used shimano xt hollowtech 2.


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## Steve-XtC (Feb 7, 2016)

Bottom brackets and headsets freak me out .... Too many stupid variations and standards but I was basically saying if you already got a hollowtech on then you should be able to get a non hollowed Zee in the same... 

It looks like the weird part is just the axle length is shorter than the normal but presumably the ends are the same or you wouldn't have got the other shimano on...? 


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## clarkrw3 (Feb 21, 2011)

Bombshell Spinnergy cranks 104 bcd too


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## kmjelle (Nov 29, 2007)

great find. Tnaks a lot. So far the Shimano Xts have held up nice at about 150mm, shortened from 175mm. Nice finish to the Spinnergy crankset.


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