SRAM Omnium crankset

Hoy is still running his 2008 7710s so that might tell you something about the stiffness of those.

You'll pay for that stiffness though.

I've not ridden Omnomnoms but I have ridden Ultegra HT2s fixed and nothing else I've ridden has come close for stiffness. I didn't take Chris's bike for a spin so can't comment on how the 7710s compare either but I do know that I paid around £75 for my Ultegra HT2s with bb and another £30 or so for a very stiff BETD ring. They are of course the very unhip 130mm bcd (I know how these things matter to you Rusty ;P ) and on my Flyer I'm having to run the c/ring on the inside of the spider for correct chainline but on a combination of price and stiffness I think they'll give your three options a good run for their money.

I dunno how the Omnoms fit together but my favourite thing about the HT2s is that they feel like you could fit and remove them a thousand times and they'd be just as tight and stiff as when new whereas I feel that square taper (and possibly Octalink) cranks have a bit of a lifespan in this regard.

In other words, this

In that case, you want Shimano FC-5600/5700 and a USE chainring. Comes out roughly the same price as your other options, as stiff as the Omniums but lighter, as light as S75 but stiffer.

CRC have 170mm silver ones on clearance at £70!

on of the cups has a plastic shim, is that missing?

those Shimano cranks are ugly tho, not that the Omniums are that much prettier.

Ideally I'd like 144BCD because it gives quite a few more used chainring options on eBay. 130BCD would mean me buying new, lower priced, chainrings. Also I'd rather be buying 165mm cranks.

I'll have a think about it though.

does the shimano 105 come with bb cups?
if its for track Id go for the Omniums, 175euros from a few German stockists. the 48t chairing is decent too.
fyi I use Omniums on the track and they are perfect, had 7710 cranks but sold them on before I used them, only reason Id change from Omniums would be for cranks with power reading ,which I cant afford anyway

Also I'd rather be buying 165mm cranks.

FC-5600/5700 are available in 165, you might have to search a bit to find a great price on them but everyday price is about £110-115

Obviously it would be nice if there were a decent chainring to fit road cranks and give a track chainline without spending £100 on the USE one, but unless you're some kind of super elite pursuit star, I'm not sure why you think owning more than one chainring is essential.

When all is said and done, though, Omniums are as stiff as HT2 road cranks, they just achieve it by using solid cranks ¼lb heavier than hollow road ones, which probably doesn't matter given that it's easy to build a track race bike that's too light to race almost by accident.

FC-5600/5700 are available in 165, you might have to search a bit to find a great price on them but everyday price is about £110-115

Obviously it would be nice if there were a decent chainring to fit road cranks and give a track chainline without spending £100 on the USE one, but unless you're some kind of super elite pursuit star, I'm not sure why you think owning more than one chainring is essential.

When all is said and done, though, Omniums are as stiff as HT2 road cranks, they just achieve it by using solid cranks ¼lb heavier than hollow road ones, which probably doesn't matter given that it's easy to build a track race bike that's too light to race almost by accident.

it is essential for track, usually 3-4 chainrings in a 1tooth step sequence

Omniums are kind of hollow, the front view is deceptive.
theres more material with the extra length in the spider arms

whats the USE chainring?
a 130-144bcd adaptor would be easy to get made anyway

it is essential for track, usually 3-4 chainrings in a 1tooth step sequence

Chainrings or cogs? Surely having 12-15t cogs sequentially are all the gears you will need

easier and quicker to change the chainring though.

easier and quicker to change the chainring though.

Eh?

5 fiddly chainring bolts versus one sprocket?

Think it's more to do with the steps in gearing. 1tooh at the front makes much less difference to gearing than 1 at the back.

With regards to BCD though, my track bike has DA 7600s, 144bcd. Iv been looking for rings and a new BETD ring (available in at BCD you want) is cheaper than most used rings I've found. Certainly cheaper than all the used DA rings I've seen.

it is essential for track, usually 3-4 chainrings in a 1tooth step sequence

And yet some people seem to manage a whole season of track league without changing either chainring or sprocket once. As with my comments on frames, I'm pretty sure you should have stopped paying for your own equipment by the time you need that kind of refinement.

And yet some people seem to manage a whole season of track league without changing either chainring or sprocket once. As with my comments on frames, I'm pretty sure you should have stopped paying for your own equipment by the time you need that kind of refinement.

it depends how serious you are about winning.

I've always run out of talent long before any marginal gains would have made the difference between winning or losing, or, more importantly, before they would have made my otherwise hidden potential obvious to a putative sponsor.

Just got myself some omniums, my frame was already faced but I faced it again anyway so that I could be sure of a snug fit. Fitted the cranks but the chain line is way off, I have Miche fixed/fixed hub on the rear which after measuring is giving a chain line of just over 40mm whereas the Omnoms are giving a chain line of pretty much bang on 42mm. I've read that Miche are meant to give a 42mm chain line but clearly mine aren't, was too tired to go back to the workshop yesterday to check the dishing/spacing of the wheel but could that be a cause? Has anyone else had problems with omniums with Miche fixed/fixed hubs? Need to get this sorted asap as I can't face riding my bike at the minute, so much friction and noise from the gash chain line!

Get a 2mm spacer between the hub and the cog and you're sorted.

Get a 2mm spacer between the hub and the cog and you're sorted.

Will give it a go, got some more spacers on order, couldn't find one last night so had to endure horrific ride home. How secure are the sprockets with a spacer, it's not going to come loose from locking up provided locking/sprocket are installed correctly?

was too tired to go back to the workshop yesterday to check the dishing/spacing of the wheel but could that be a cause?

The hub (cog/lockring threads) stays in the same position, the rim is dished depending on spacing of hub, so shouldn't effect the chainline. If the hubs been respaced, then maybe theres issues.

I don't have experience of miche hubs and not tried hovis' trick mentioned above, but as long as the cog is sat on enough thread, i should think it'll be fine. just might need to keep an eye on the cog and that its not slipping.

A spacer on the BB should sort it as well, they normally come with the GXP BB, so quite common and might be less to think about maintaining*

*assuming a gxp bb will last longer than any potential movement of the cog ;)

I've got a goldtec hub that gives a 40mm chainline and have put in a spacer. Ridden it that way for 10,000 miles and not been a problem. As long as the threads are long enough it will be fine. If you're really worried, post a picture of the cog on the hub once you've put a spacer behind it we can have a look.

A spacer on the BB should sort it as well, they normally come with the GXP BB, so quite common and might be less to think about maintaining*

GXP BBs aren't really adjustable. You might be able to pop a spacer on the NDS, inbetween the BB cup and BB shell, to pull the DS arm inboard, but it depends if there's any spare axle between the DS crank arm and BB cup. This may result in the crank arms being off center or other weirdness like the arms fouling the chainstays.

That was in my mind, but not actually tried it. Yeah, could be problematic.
So, the spacers are primarily just for road/mtb cranks then?

I believe so. For road, spacers on the NDS pull the DS inboard. You can't push the driveside outboard without messing up the preload on the NDS bearing.

If you have a lot of axle showing on the DS you could pop an extra spacer in to take up the 'slop'. This won't affect chainline or alignment, but it might stop the DS axle 'walking' the DS bearing sleeve out of the bearing.

I've added 2x 1 mm spacers and the chain line is better but still not perfect and with my KMC z510 HX chain it's still noisy/rumbling. Checked the chainring bolts which are all tight, crank is torqued up nicely and I've faced my BB shell which was pretty much bang on 68mm once faced. Going to try another wheel to see if that has an effect, not stoked! Has anyone found Miche hubs to be way under a 42mm chain line which they state?

Through the process of elimination I have managed to temporarily solve my chain line issues, Miche hubs have a 40mm chain line on one side but not both it would appear on their fixed/fixed rear hubs. I have a surly 17 tooth sprocket with two 1mm spacers and the chain line seems pretty good, still a little rumbly through the crank though so may invest in a new sprocket which is unworn.

Can anyone recommend rear hubs which offer a 42mm chain line to match the Omniums, going to build something lighter than the current one so may swell get something compatible without the need for spacers.