# BMX Cranks



## liqwid (Jan 2, 2007)

Anyone know if you can run BMX cranks on a MTB as long as you're using a euro BB? Are the spindles that come with the BMX cranks long enough or can I just use the spindle that comes with the BB (like a FSA Euro Pro). I would just go with Deity or Atomlab but there are more lighter options in the BMX world. Any pro's/con's to this setup?


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## Demo-9 (Mar 24, 2006)

Any crank that offers a Euro BB set-up can be used. Most companies offer a spindle that will work. You just need to know what the shell width is to figure out the length of spindle that you need.


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## liqwid (Jan 2, 2007)

Demo-9 said:


> Any crank that offers a Euro BB set-up can be used. Most companies offer a spindle that will work. You just need to know what the shell width is to figure out the length of spindle that you need.


I'm looking more at a crank where they just give you the arms and spindle and placing that in a separate companies BB. It seems straight forward to me as long as the spindles are the same diameter but I was wondering if BMX spindles are long enough to put through a 73mm euro bottom bracket and have room for the arms/chainwheel. From looking at the individual spindle options on danscomp it looks like the BMX spindles should be long enough but I figured I'd ask around first.


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## sittingduck (Apr 26, 2005)

The shorter spindles work out ok if you can get the crank arms very close to the shell. It will depend on the frame, and how wide the chainstays are. Clearance with the arms near the pedals and the chainring are the issue. Smaller chainring setups will usually be able to be placed farther onto the spindle.


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## Demo-9 (Mar 24, 2006)

99% of the time a 6" spindle works with a 73mm BB. Like duck mentioned unless you are using a tough chainring size, crank length or really wide/short stays. If using a 19mm 48-spline crank, get a Profile BB.

Profile BB with a 6" spindle on a 73mm worked for me. And I run a 24t so the crank clearance was tough to get perfect. It is just getting the spacers lined up correctly.


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## liqwid (Jan 2, 2007)

Demo-9 said:


> 99% of the time a 6" spindle works with a 73mm BB. Like duck mentioned unless you are using a tough chainring size, crank length or really wide/short stays. If using a 19mm 48-spline crank, get a Profile BB.
> 
> Profile BB with a 6" spindle on a 73mm worked for me. And I run a 24t so the crank clearance was tough to get perfect. It is just getting the spacers lined up correctly.


Right on thats what I was hoping to hear, I'm doing this on a 07 STP (*DUCKS*) which as far as I can tell had the shortest chainstays of all the STP's years (15.75" as opposed to 16"). I'm for sure going to go with the smallest ring combo I could get on there without sawing off the stays with the chain.

Good suggestion on the Profile BB, the 4 bearing setup should last longer but I'm assuming is a little heaver. Anyone know if I have to use the spindle that comes with the cranks or as long as the diameter/spline count is the same then they should work just fine?


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## Dave Moore (Apr 15, 2004)

I run profiles on my 07 STP. I called in the order and had the original spindle exchanged with a 6"(profile CroMo) and it works great. I also use the profile euro BB. 
..and yes, any 19mm 48 spline _should_ work.

BTW, I use a tree splined sprocket.


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## liqwid (Jan 2, 2007)

Dave Moore said:


> I run profiles on my 07 STP. I called in the order and had the original spindle exchanged with a 6"(profile CroMo) and it works great. I also use the profile euro BB.
> ..and yes, any 19mm 48 spline _should_ work.
> 
> BTW, I use a tree splined sprocket.


Nice, thanks for the info. I've never heard of a tree splined sprocket before just now, those are crazy. How small of a front sprocket are you using (assuming you're near the 1:2 ratio)? Originally I wanted to do a 23 but I'm guessing thats too small for the wider chainstays.

(Tree sprocket pic if anyone cares)
...Nevermind pic didn't want to show up


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## Dave Moore (Apr 15, 2004)

Its a 28 tooth ring mated with either a 13 or 14 tooth cog. I'll be trying a different tooth configuration as soon as these wear out though. 

Currently it a hard setup to get the chain length right. A regular chain is doable but a half link works better with my particular setup. The stock chain tensioner will NOT work with my tooth configuration(I use a Rennen and still had to modify it some).

The post of Demo-9's with the photo of his Mob has a tree splined chainwheel.


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## the_godfather (Jan 19, 2007)

we need to see some dirt on that sexy bike of yours demo-9


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## Demo-9 (Mar 24, 2006)

the_godfather said:


> we need to see some dirt on that sexy bike of yours demo-9


You will never see dirt. I am a maticulous mofo and always clean after riding it. 

Yep love the Tree. I will never get anything else. Best chainring out there IMO. No tightspot, you can space it out on both sides if needed, stiff and light.


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## oldskoolm4 (Jan 13, 2008)

Demo-9 said:


> You will never see dirt. I am a maticulous mofo and always clean after riding it.
> 
> Yep love the Tree. I will never get anything else. Best chainring out there IMO. No tightspot, you can space it out on both sides if needed, stiff and light.


Amen to that! I run a 28t Tree on a halflink.


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## liqwid (Jan 2, 2007)

Dave Moore said:


> Its a 28 tooth ring mated with either a 13 or 14 tooth cog. I'll be trying a different tooth configuration as soon as these wear out though.
> 
> Currently it a hard setup to get the chain length right. A regular chain is doable but a half link works better with my particular setup. The stock chain tensioner will NOT work with my tooth configuration(I use a Rennen and still had to modify it some).


I'm running a 32/16 combo now with a half link. There's a tight spot but it isn't too bad and seeing as how I'm going to replace the BB and rear hub anyway I don't care if I'm killing the bearings. I bought the geared version of the stp and quickly decided I hate gears. Good to know the tree splined sprocket gets rid of the tight spot.


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## coiler8 (Aug 25, 2006)

Are there any BMX crank setups lighter than, say, a Shimano XT crankset?


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## sittingduck (Apr 26, 2005)

coiler8 said:


> Are there any BMX crank setups lighter than, say, a Shimano XT crankset?


 Yes, but they are made for litle kids.
The whole idea of going to BMX cranks is durability and simplicity. You'll sacrifice a little weight for that durability.


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## Demo-9 (Mar 24, 2006)

sittingduck said:


> Yes, but they are made for litle kids.
> The whole idea of going to BMX cranks is durability and simplicity. You'll sacrifice a little weight for that durability.


And stiffness. I gotta say after going to Profiles, I will never use MTB cranks on a DJ. If I didn't have brand new Saints and Hones for my DH and FR bikes, I would do Profiles on them as well.

Profile race cranks with euro BB, Ti spindle and Ti bolts is damn light.


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## coiler8 (Aug 25, 2006)

Nobody?


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## Demo-9 (Mar 24, 2006)

coiler8 said:


> Nobody?


Are you talking about your XT crank question above??

I am sure that there are cranks close to that weight. But any BMX crank (just about) will be far better than XT IMO.


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