SRAM Omniums
11-18-18, 09:37 PM
#1
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SRAM Omniums
Are SRAM Omniums 825g for the crank and bb together, or is that just the crankset? I have seen postings that sell Omniums with and without the.bb, and both websites had the same weight oddly enough! Anybody weigh their Omniums?
11-18-18, 11:51 PM
#2
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Were they used? I was under the assumption that they were sold as crankset with bb from SRAM... I could be wrong though?
Do you have the link to just the arms?
Do you have the link to just the arms?
11-19-18, 09:32 PM
#3
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https://www.thebikesmiths.com/products/sram-omnium?variant=6898288099362&utm_medium=cpc&utm_source=google&utm_campaign=Google%20Shopping&gclid=C j0KCQiA28nfBRCDARIsANc5BFCL2zM4Zs0CcTn7oE94iOetaHLoZki5-N6LHglPVGROdNLU4SXkfWsaAvZCEALw_wcB
If that is the case, Omniums are not an upgrade for me in terms of weight. Currently using Sugino VP130s (converted double road crank with a single chainring and shorter chainring bolts). That weighs in at 705g, and if I remember, the Tange BB i'm using is pretty heavy. If I do change the crank, I would like it to be lower weight.. Not sure if I would honestly notice any difference in stiffness, though I do feel some difference between the Shimano 105 5700 crankset (external BB system) and the VP130s.. I feel like the 105 crank transmits better.. Maybe that translates to more stiffness.. or just placebo effect lol.
Dave
Dave
11-19-18, 09:45 PM
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Velodrome Shop and Retrogression both list it as 825g including bottom bracket.
https://www.retro-gression.com/produ...mnium-crankset
https://www.velodrome.shop/track-cha...rack-chainset/
https://www.retro-gression.com/produ...mnium-crankset
https://www.velodrome.shop/track-cha...rack-chainset/
11-19-18, 10:39 PM
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The vendors I found earlier were listing their Omniums as new.. Can't recall which website. Found a site this morning, that says the crank itself is 825g, and the bb is 106g:
https://www.thebikesmiths.com/produc...saAvZCEALw_wcB
If that is the case, Omniums are not an upgrade for me in terms of weight. Currently using Sugino VP130s (converted double road crank with a single chainring and shorter chainring bolts). That weighs in at 705g, and if I remember, the Tange BB i'm using is pretty heavy. If I do change the crank, I would like it to be lower weight.. Not sure if I would honestly notice any difference in stiffness, though I do feel some difference between the Shimano 105 5700 crankset (external BB system) and the VP130s.. I feel like the 105 crank transmits better.. Maybe that translates to more stiffness.. or just placebo effect lol.
Dave
Dave
https://www.thebikesmiths.com/produc...saAvZCEALw_wcB
If that is the case, Omniums are not an upgrade for me in terms of weight. Currently using Sugino VP130s (converted double road crank with a single chainring and shorter chainring bolts). That weighs in at 705g, and if I remember, the Tange BB i'm using is pretty heavy. If I do change the crank, I would like it to be lower weight.. Not sure if I would honestly notice any difference in stiffness, though I do feel some difference between the Shimano 105 5700 crankset (external BB system) and the VP130s.. I feel like the 105 crank transmits better.. Maybe that translates to more stiffness.. or just placebo effect lol.
Dave
Dave
Last edited by mouse; 11-19-18 at 10:49 PM.
11-19-18, 11:09 PM
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To be honest... and I know I’m probably going to stir a big can of worms here... but from a machinists standpoint... someone who works with metals, and a lot of aluminum day in and day out I think the stiffness argument is just a selling point. Yes I will not argue that 7075 IS indeed a stiffer material than 6061. Especially on paper. But the amount of force needed to display the difference is quite huge. To the point that idk if it would be noticeable. I believe it is a superior alloy absolutely, but both are T6 and imho I think it’s more of a genius marketing ploy to get more $ for essentially the same product. Just my .02 cents. Anywhoo! Omniums are a great crankset regardless, and I would say that small amount of weight difference won’t be noticeable either. That’s just me though
11-19-18, 11:36 PM
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i'd agree to an extent. The bike industry pushes stiffness a lot as a marketing strategy, and what gets lost in the fray is the fact that if a is stiff enough for the rider's needs, it doesn't matter if b is stiffer. Frames, wheels, and handlebars all flex more than cranks in most cases anyway. The omnium crank is a great product -- easy to install, well designed and well made, durable, reliable. Only functional downsides are some inconsistencies in frame compatibility and some reported issues with the stock bb (though i've had no problems with mine). And it's pretty economical compared to the other performance oriented track cranks out there.
11-19-18, 11:54 PM
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There was a huge difference when my Bianchi was upgraded from stock FSA cranks/bottom bracket to Dura Ace.
I could tell the moment I first pushed on the pedal.
Whether the stiffness was from the BB, cranks or both, I don't know. My guess is that the bottom bracket had a lot to do with it.
-Tim-
I could tell the moment I first pushed on the pedal.
Whether the stiffness was from the BB, cranks or both, I don't know. My guess is that the bottom bracket had a lot to do with it.
-Tim-
11-20-18, 12:06 AM
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There was a huge difference when my Bianchi was upgraded from stock FSA cranks/bottom bracket to Dura Ace.
I could tell the moment I first pushed on the pedal.
Whether the stiffness was from the BB, cranks or both, I don't know. My guess is that the bottom bracket had a lot to do with it.
-Tim-
I could tell the moment I first pushed on the pedal.
Whether the stiffness was from the BB, cranks or both, I don't know. My guess is that the bottom bracket had a lot to do with it.
-Tim-
11-20-18, 02:44 AM
#10
aire díthrub
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‘Stiffness’ at the crank is going to be a combined product of the bottom bracket and the design of the crank, not simply the cranks material. I agree with the poster above about the difference (or realworld lacktherof) between 6061 and 7075. An external bearing, large spindle crank will be stiffer than a square taper. A wider crank, say like a dura ace 9100, will be stiffer than a slimmer crank, like a dura ace 7400. And these things will create extra stiffness well beyond what any difference between Al alloys may give you. If a crank is stiff but your bb isn’t, or your crank isn’t but your bb is, it’s a wash. I’ve never ridden ominums, but in my opinion, worrying about a minuscule amount of weight is a pointless endeavour, as you could gain or lose more than a minuscule amount of weight if you cycle after a heavy meal. I dont know how stiff ominums are, but stiffness is more important than weight for a crankset, if performance is what you’re concerned with. your current cranks are square taper, so I have no doubt that ominums will give you much better performance and you won’t notice at all, that minuscule weight. I say this as a person who uses a DA 7400 crankset and 7400 square taper bb.
Last edited by seamuis; 11-20-18 at 02:49 AM.
11-20-18, 04:21 AM
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‘Stiffness’ at the crank is going to be a combined product of the bottom bracket and the design of the crank, not simply the cranks material. I agree with the poster above about the difference (or realworld lacktherof) between 6061 and 7075. An external bearing, large spindle crank will be stiffer than a square taper. A wider crank, say like a dura ace 9100, will be stiffer than a slimmer crank, like a dura ace 7400. And these things will create extra stiffness well beyond what any difference between Al alloys may give you. If a crank is stiff but your bb isn’t, or your crank isn’t but your bb is, it’s a wash. I’ve never ridden ominums, but in my opinion, worrying about a minuscule amount of weight is a pointless endeavour, as you could gain or lose more than a minuscule amount of weight if you cycle after a heavy meal. I dont know how stiff ominums are, but stiffness is more important than weight for a crankset, if performance is what you’re concerned with. your current cranks are square taper, so I have no doubt that ominums will give you much better performance and you won’t notice at all, that minuscule weight. I say this as a person who uses a DA 7400 crankset and 7400 square taper bb.
11-20-18, 08:31 AM
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Nobody is worried about anything and @bonsai171 isn't talking about a minuscule amount of weight.
Just standing on the side of the trail Dave and I were able to point to several pounds of extra weight on his bike - 400 gram tires, heavy tubes, boat anchor seatpost and bottom bracket, etc. Cranks are just part of that, that's all.
He is a thin, athletic guy and will benefit from a lighter bike.
His old cranks are converted road cranks anyway and worth upgrading for looks alone.
-Tim-
Just standing on the side of the trail Dave and I were able to point to several pounds of extra weight on his bike - 400 gram tires, heavy tubes, boat anchor seatpost and bottom bracket, etc. Cranks are just part of that, that's all.
He is a thin, athletic guy and will benefit from a lighter bike.
His old cranks are converted road cranks anyway and worth upgrading for looks alone.
-Tim-
11-20-18, 09:13 AM
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Nobody is worried about anything and @bonsai171 isn't talking about a minuscule amount of weight.
Just standing on the side of the trail Dave and I were able to point to several pounds of extra weight on his bike - 400 gram tires, heavy tubes, boat anchor seatpost and bottom bracket, etc. Cranks are just part of that, that's all.
He is a thin, athletic guy and will benefit from a lighter bike.
His old cranks are converted road cranks anyway and worth upgrading for looks alone.
-Tim-
Just standing on the side of the trail Dave and I were able to point to several pounds of extra weight on his bike - 400 gram tires, heavy tubes, boat anchor seatpost and bottom bracket, etc. Cranks are just part of that, that's all.
He is a thin, athletic guy and will benefit from a lighter bike.
His old cranks are converted road cranks anyway and worth upgrading for looks alone.
-Tim-
11-20-18, 11:12 AM
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SRAM website lists it as 825g . It doesn't mention anything about BB but I'd assume that's weight for cranks only.
I also agree with the comments about stiffness of the gxp BB and external in general making a big difference.
I also agree with the comments about stiffness of the gxp BB and external in general making a big difference.
11-20-18, 05:06 PM
#15
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Nobody is worried about anything and @bonsai171 isn't talking about a minuscule amount of weight.
Just standing on the side of the trail Dave and I were able to point to several pounds of extra weight on his bike - 400 gram tires, heavy tubes, boat anchor seatpost and bottom bracket, etc. Cranks are just part of that, that's all.
He is a thin, athletic guy and will benefit from a lighter bike.
His old cranks are converted road cranks anyway and worth upgrading for looks alone.
-Tim-
Just standing on the side of the trail Dave and I were able to point to several pounds of extra weight on his bike - 400 gram tires, heavy tubes, boat anchor seatpost and bottom bracket, etc. Cranks are just part of that, that's all.
He is a thin, athletic guy and will benefit from a lighter bike.
His old cranks are converted road cranks anyway and worth upgrading for looks alone.
-Tim-
IIRC the tange bb i'm currently using was 540g by itself. Even if the SRAM Omnium is 826g by itself and the bb is 106g, adding up the weights-Sugino VP130 + BB = 1245g
Omnium + BB = 932g
The difference between these setups is almost 3/4 of a pound! I guess my mind is made up
Probably worth an email to SRAM for clarification-although I don't see a way to do that on their site.The Omniums will take any 144bcd chainring too, right? Seen some information on sram having a proprietary chainring thickness (5mm) and possible compatibility issues.. Maybe someone has experience with this?
Maybe if I can stop eating cookies I can loose 5-10 lbs too ha.
Dave
Last edited by bonsai171; 11-20-18 at 05:15 PM.
11-20-18, 05:20 PM
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I switch back and forth between the stock ring and a 49t FSA ring depending on what gearing I want. No issues whatsoever.
11-20-18, 07:59 PM
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Clark W. Griswold
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If you are concerned with stiffness try Viagra. To everyone else just buy yourself a nice crankset/chainwheel and enjoy life!
