gkelley

How can it be less powerful?

cc700

power isn't the right word, efficient. it requires more force. the crank is a lever. you can apply more torque with a longer lever.

gkelley

oh yeah of course, i thought you were implying that you can't exert as much force with omniums, which is absurd since essentially when it comes down to it a crank is a crank

cc700

i just think the stiffness difference in length with these materials is so small it's not worth it. and you're gonna have to put more torque on a shorter length so it will bend more anyway.

sp00ki

it's not nearly that simple. longer is fine for rapidly increasing torque (or applying constant force against substantial resistance, ie while climbing a mountain), but what you gain in leverage you lose in spin which is more important when you've reached top speed and are sprinting.
remember, track cyclists aren't climbing, and there are no events where you start the race at a sprint. you're usually sprinting from the top of a bank or a higher speed, so stiffness is far more important than leverage to the track disciplines.

andre nickatina

Kilos baby.

Match sprint too, if you're kiloing your opponent though that's not common at all at my track unless it's known that that's his main weakness and you're trying to exploit it...

Other than that I agree with your post. 167.5 is a good balance of spin and torque for crank length I believe... though I can't really tell the difference of 2.5mm either way at that point.

backlyt

I got these cranks on my FTP, look great, super easy to assemble.
The q factor does bother me a little since I'm kinda duck-footed and hate hitting my new cranks with my heels.
I'm used to 170s and now I have the 165s.
it's nice having that little big of security when cornering, and it is easier to spin.

bikeman68

can any of you Urban fixie guys tell me why you spend so much $$ on track cranksets when you arent racing for Natl team status? You can get Truvativ Touro cranks, or other more affordable taper cranks with the chainline options via bb spindle lengths, and you'll move just as fast on the streets. My fixed grear trainer bike has old '93 Campy Athena cranks, and with same crank length as the Road bike, and it does well with Miche Primato Chainrings.No pedal strike either, on an old road frameset with 175mm cranks, and up to 135 or 140 rpm.I save the track bike for the track race.
And the Omnium cranks have a too tight chainline of 41mm, with no room for adjustment with a longer bb spindle.Remember you still have to power your bike with your legs and A and AT power.
The oversize connections give an edge to racers, but for Urban Fixies, why worry about that?

cc700

street cred.

why buy a ferrari if you never race it?

doesn't mean people don't want it anyway.

200 dollars is NOT a lot of money to some people.

I don't think anyone in this thread is saying they're better for urban riding.

i'm hoping to buy a set of s300's soon for my commuter.

Enxu

I've been riding the SRAM s300's since April. No problems so far.

Yo!

I'm selling or trading my NIB 165mm/48t Omniums for some Sugino 75's in 165mm; I couldn't get the chainline right with the Omniums on my frame and the spider hit the chainstay. Not to mention I think a steel lugged NJS looks better with Sq. taper anyway.

Hit me up if anyone is interested.

idiq

I'm curious what you mean by the "too tight chainline" - if you have a track frame and a track wheel, the chainline should be straight. Why would you need to adjust with a longer BB spindle - the spindle is on the drive-side crankarm. Adding a longer spindle would throw off your chainline.

bikeman68

Idig
what I mean is the chainline of 41mm falls a little short of the track standard of 42 or 42.5mm, and this cannot be adjusted at the crank, which can be trouble.If you do have this Omnium crank I suppose you can adjust the rear cog chainline by seeking the German made EAI cog, with its thinner inside spacer that would compensate for the chainring being 1mm closer to the chainstay. Anyhow, now you know what to expect if you get the Omniums.

cc700

1mm spacer on the drive side... that would fix it... no?

idiq

If the issue is that the crank sits further toward the frame than the cog, then a spacer on the bottom bracket cup (two are provided) should correct it.

If the issue is that the cog sits further toward the frame than the crank, then you must switch cogs as a spacer would only push the chainline further apart.

The only time I had an issue is when I experienced the latter situation, and this was corrected by moving from a Miche Cog / DA Hub to a DA Cog / DA Hub. I could have actually used a shorter chainline from the Omnium cranks. My chainline is now straight (on a T1).

Fugazi Dave

I like these cranks, but unless something happens to my ($55 <3) DA cranks that is catastrophic I don't see myself veering away from square taper any time soon for street riding. We can talk performance all day, but for the vast majority of us street riders (including the monsters in the crowd) will never see a real world difference in our riding. What most of us have is working just fine, and I think it's important to keep that in mind when talking about technical improvements to stiffness, etc.

Brig

Finally rode mine this weekend. Gotta say, coming from the stock Kilo Touro's they "feel" so much better. I know, I know, I'm gonna get reamed for saying that....but they're butter smooth and holy cow, a ton quieter than the touro's. Also, had the bike on the car for a weekend road trip and everybody was freaking out because you can see right through them.... Also, for all the haters who think they are too expensive.....$165 shipped from bikeisland is far from too expensive.

That is all.

Astronomical

steveymcdubs

asthman is unbanned!

mattchambers

Are Shimano and Campy 144mm BCD track chain rings compatible with the Truvativ Omnium?

I called SRAM tech support and stayed on the phone for about ten minutes while someone tried
to provide the answer. I was told "I'll research this further and get back to you" he took my
phone# and I have not heard back. I made the call early last week.

Seems like it should work, but I figured I'd ask.

Yo!

Seriously?

The people at Sram were confused by this question?

Any 5 bolt 144bcd ring will work on a 5 bolt, 144bcd crank.

idiq

Yeah, either of those rings will work fine. As said, any 144bcd ring will work. The only thing is you'll likely need to buy some new chainring bolts.

The Omnium bolts can accompany the Truvativ chainring fine (it's 5mm thick) but when using a thinner dura-ace ring, you'll have some play. The best thing I think to just buy new chainring bolts (the cheap Sun Lite ones work fine) instead of playing around with spacers, although you could do either.

On my setup, the thinner D/A chainring doesn't throw off the chainline. The play is very slight.

evotion

I love my Omniums. I upgraded from Messengers, which is still a great crankset, but I love my Omniums.