Quantcast

bmx cranks? help..

truth77777

Chimp
Sep 10, 2005
3
0
hey, i just got an 04 giant stp1 with an mrp chain guide.. how can i get a bmx crank on there and still be able to use the chainguide.. or would i need new bottom braket and chain guide for it to work or what??? cuz ive seen lots of dirtjump/urban bikes with bmx cranks.. and ive heard that those cranks and bottom brackets are way stronger... so would my frame not be compatible, or i think ive seen adapters or somethin.. would i need those or what??? could someone explain this stuff.. or is there a website where i can read about it or something??

thanks.
-bill
 

corey_rideDC

Turbo Monkey
Sep 1, 2004
1,369
0
DCmetro
there are different sizes of bottom brackets... your stp uses a european bb. most bmx cranks are 'american' (larger than euro). in your case, you can only use a euro bb.

i think what you're looking for isn't a bmx crankset, but a chromoly crankset. profile, poverty, azonic, deity, fsa, and many others make these

check out http://www.danscomp.com for good deals.
 

scurban

Turbo Monkey
Jul 11, 2004
1,054
0
SC
you just need a spider instead of a chainwheel, or a deity chain wheel will work. Almost all bmx cranks now come with a Euro bottom bracket option. It's pretty easy to set up.
 

corey_rideDC

Turbo Monkey
Sep 1, 2004
1,369
0
DCmetro
scottjustscott said:
I think you can get an adapter that will let you run american style crank spindles with your euro bb.
there are adapters to run Euro bbs in a frame with an american bb, but not the other way.
 

Mudpuppy

Monkey
Oct 20, 2001
448
0
Port Orchard/Not WSU
Something like this would work.

http://unrealcycles.com/item.php?view=39

Get the ones that are the length you want, and have the right bolt pattern on the spider to match your current chainring, and have an MTB bottom bracket, and things should work.

You could also go with just about any set of three piece cranks with a mtb/euro bottom bracket and run a chainwheel with bolt holes in it and forgo the spider. But you will need to make sure that the chainwheel has the proper bolt pattern for your guide.

http://unrealcycles.com/item.php?view=28

I had Planet X bmx style cranks on my last mtb with a Planet X spider and an Evil Guide and it worked great. Do you have a single front chainring? Because if you have more than one, you will have to pay attention to which spider you get since many spiders only have bolt holes for one chainring.

You could just call Ben at http://unrealcycles.com/ and tell him what's up with your setup and what you want and he should be able to just hook you up. If you aren't too sure about things, you might want to do that. He's good to deal with and runs a good shop.
 

Mudpuppy

Monkey
Oct 20, 2001
448
0
Port Orchard/Not WSU
truth77777 said:
Yes that crank/BB combo would work. Cranks are not Euro/American. Cranks only need to fit the spindle that the BB has.

If you got those cranks you would still need a spider to mount your current ring and guide to, or a chainwheel to mount your guide to. Unreal cycles has some good deals on spiders and chainwheels here: http://unrealcycles.com/item.php?view=165 Your guide is 5-110 right? 5 holes 110 mm on center. It should say somewhere on either the guide or the chainring.

Hope I helped.