[RayB]

...how to fit a BMX sprocket to a Shimano Hollowtech2 crank??!

I'm givin' my hardtail a makeover this winter and this really caught my attention.

 

[pickuptrucker]

dang those bikes look dialed. what frames are those?

 

[WestCoastHucker]

i didn't really read the details, so i'm not totally sure this is the mod you are looking for...

http://ridemonkey.com/forums/showthread.php?t=212149

 

[RayB]

i didn't raelly read the details, so i'm not totally sure this is the mod you are looking for...

http://ridemonkey.com/forums/showthread.php?t=212149

I saw that earlier. Not quite what I'm lookin' for. Still super rad though.

 

[bikeit13]

I'm pretty sure what those people did were just use the granny ring and grind down the larger tabs. Typically a granny ring is 22 or 24t but you could prolly track down a 25 or 26t.

Hope that helps

 

[RayB]

I'm pretty sure what those people did were just use the granny ring and grind down the larger tabs. Typically a granny ring is 22 or 24t but you could prolly track down a 25 or 26t.

Hope that helps

Well yeah, that's pretty obvious.

I'm curious how they attached the sprocket to the crank itself. Does anybody have a spare Shimano crank and BMX sprocket kickin' around? Do the 4x64 BCD granny holes line up with those on the sprocket?

 

[Bikael Molton]

i think bikeit's point was that it isn't a bmx sprocket you are seeing in those photos. It's a 4-bolt XC granny bolted to the standard 4bolt granny studs in the crank arm.

 

[RayB]

i think bikeit's point was that it isn't a bmx sprocket you are seeing in those photos. It's a 4-bolt XC granny bolted to the standard 4bolt granny studs in the crank arm.

doh! Read it wrong.

That makes sense.

I think I figured out how to go about doing this....

 

[spliffy]

the xtr thread was mine that i did and that was with the older xtr cranks both those picks are just granie gears on the cranks with the outer ring tabs cut off should work fine with a single speed set up, but there is no way to put a bmx ring on the new hollowtwchs they are a pressed on spinder that will not come off without being able to go back on.

 

[sittingduck]

That might require a regular cassette hub too, a single speed hub is probably going to have a pretty bad chainline.

 

[t1maglio]

That might require a regular cassette hub too, a single speed hub is probably going to have a pretty bad chainline.

The first one definitely looks like that is the case, with how the cog is spaced out, perhaps with spacers or a Gusset setup.

 

[grom-dom]

my friend had an imperial sprocket like this. it can make the cranks snap though if i'm not mistaken

 

[pancho64]

that first bike looks so nice

 

[bballboy388]

http://bike.shimano.com/publish/content/global_cycle/en/us/index/products/bmx_bike/dxr.html

 

[BikeSATORI]

A guy on the Eastern26 team a year or so ago had a sprocket on an XT crankset... thought I had a photo somewhere but can't find it.

Keep in mind, a few years back, when it was common to have a bolt-on grind guard on your bmx sprocket, some of them had a commonly used BCD that existed in MTB, like 104X4, or the smaller granny pattern (forgot the dimensions off hand)...
Then, with the cranks, they are simply ground down to only have the granny mounts, appearing to have almost no "spider" area...

 

[BikeSATORI]

oh yeah, I found the photo. I posted up about this probably a year ago or so... not sure how you'd go about searching for it though... ?

Not a dremel job to drool over, but he got the job done. Eastern Medusa sprocket.