conor

i'm planning my next build, and pretty on the line about the cranks i want. if i went with bmx cranks, i'd probably go with profiles; undecided when it comes to track.

now here are my concerns:
-fit. after reading up on them and searching the forum, i'm fairly certain they will work. (the frame will be, as of now, a soma rush.)
-weight. they're heavy, and i don't know if i wanna drop the extra cash for the lites. also, the lites would be 170 vs. the 165 of the regulars. how noticeable is the weight difference? i know the numbers (off the top of my head they're about twice as heavy as track cranks), but how does it affect riding?
-functionality. i think they look gorgeous on a fixed gear, but! i don't want to feel limited by them. of course, i could put the iros from my current bike on it, but that might be a pain in the ass. some early calculations place the bike at over $1000, which also makes me hesitant--spending big bucks on a bicycle that is potentially limiting in its use. (this goes back to the weight issue. will it become noticeable after 20, 30, 40 miles? more?) also: is there any chance of stripping the axle when skidding? i'd use a brake, but i find skidding quite fun (though i'm sure i don't do so extraordinarily much).

so that's that.

thank you in advance, y'all.

sp00ki

They will work, as long as you get the appropriate bottom bracket.
The weight difference is nominal. They're only slightly heavier than, for instance, a pair of sugino 75 cranks (which are what 90% of the fg you'll see are built with).
The 1/2 cm difference probably won't be noticeable unless you dig into turns at higher speed. Not familiar with that frame though, so i'm not sure if it'd be an issue; depends on the position of the bottombracket shell.
Keep in mind that you'll be limited to using bmx chainrings (sprockets), so you're going to have a ceiling of roughly 42t when looking at quality sprockets unless you get the profile (i think they make it) adapter, which will allow you to use 110bcd rings but will add even more weight.

ED: yeah, it's profile who makes the adapter.

Straws

You can use Rocket Rings, but of course that's a whole other issue in itself.

conor

i'd probably use the 1/8" bmx chainrings. that's the real draw, i think. they're so much more interesting than those made for track.

curiousincident

Using those cranks sounds like a big PITA to me, and I'd personally hate to be limited to using a 42t chainring. I'm kind of a fan of bigger drivetrains though. Whatever floats your boat.

djeucalyptus

FWIW, there are larger rings out there. I know profile makes a bunch of 46t, and they make one or two in a 48t. (I used to run a profile crank w/48t whippit chainring up front on one of my old bikes).

deathhare

Absolutely no way youre going to strip it by skidding.

operator

Strip a steel axle with an AL crankset? Not possible. You'll destroy the crankset only.

sp00ki

It's a steel crankset. Chromoly, specifically.
Though it still seems unlikely (but don't quote me on that).

frankstoneline

As far as the weight "will I feel em" issue, the short answer is no. Your legs are pretty powerful bits of muscle, and for practical reasons, a bit heavier crank wont make you feel any different than riding, and if it does you will get used to it in a few days, depending upon how regularly you ride. The difference in weight between those cranks and the sugino's is minimal as was mentioned before, and those suginos are mad popular. If you like the look and they work into your budget I wouldnt worry about em unless you are shooting for the lightest bike possible.

sprintcarblue

I have a set of 175's profiles with a titanium spindle, crank arm bolts, and sprocket bolt on my karate monkey. They're alright.

kjohnnytarr

Do it. I used an old disk spider with mine, which really gave me options as far as chainrings go.

deathhare

The arms are 4130 and the spindle is 4140 steel.
On a fixed gear road bike theyll literally last forever. Your frame would break in half before the cranks would fail in anyway at all.

RapeVan

^^^ Do you have a sad old BMX bike in your garage that you have been pillaging?

frankstoneline

haha, I have 2 or 3.
I should really get rid of em...

RapeVan

send em off to rainbow bridge

nelzar13

Use a set of primo hollow bites check em out i think Albes.com has em or empire has em to

frankstoneline

is that where they get to go play with unicorns?

goldenskeletons

i'd say it depends on what you want to do with your bike. you've most likely got a wider Q factor than typical track cranks, your cranks arm spider is going to have a smaller BCD, you need to find the right BB for a correct chainline and (not that its a huge deal, but) they'll weigh more.

you'll have to put in a little more energy to sprinting and general faster paced riding, and larger chainrings on smaller BCD spiders have a greater potential for warping.

but they'll probably be the last thing on the bike the break, and the chainring selection out there is pretty rad.

humancongereel

well, i believe that in norse mythology, it's also the place where you cross from the mortal realm to valhalla.

edit: rainbow bridge.

RapeVan

Ive always heard its where your dead pets wait for you to die...but either works i guess.

conor

i'd heard that it's not too difficult getting a perfect chainline because you use spacers. simple measurements should be able to get it, yes?