Singlespeed & Fixed Gear - EAI vs DuraAce vs Soma

first of all.. EAI does stand for euro-asia imports...like the one bensbike sells...correct?

second...is it really the best? its only a few bucks more than soma and dura ace doesnt come in the size i want

thanks
MAX

I've got a 15 tooth dura ace cog and an 18 tooth eai cog on the same wheel, and i haven't noticed any functional difference in them at all.

Sorry, no experience with the soma cogs.

I just recently got a Soma cog, and have been runnning a DA for over a year. The DA is great. Excellent quality, excellent wear, nice black finish.

The Soma I got is runnning fine, but I do question the quality. The finish seems iffy, and the teeth are razor sharp. As well, Brent from Phil Wood just issued some stern words of warning about the Soma cogs, so I may try to replace it with a DA.

I haven't tried the EAI, but I hear they're awesome.

i have a DA now....but for my new baby i ant 18t so...i think EAI it is

I've heard EAI and Dura-Ace are the same thing....

But I have no idea how much truth is in that.

My 17t Soma seems to be running just fine.

I think the EAIs are better than Dura-ace as they're a little more durable (IMHO). But either one is a pretty damn fine cog.

No experience with SOMA cogs

i picked EAI because its wider and gave me better chainline

soma makes two types of cogs, the shot-peened ones, are the less expensive ones, and they also make a super high-polished cog which is comparably priced to the DAs.

similar quality to the DAs. i haven't used a Euro-Asia cog yet, and i probably won't. I had an old QBP cog that lasted quite a long time (i finally caved and replaced my cog and 'ring after nearly six years). I replaced it with a DA cog. i didn't really notice a difference in ride quality. i mean, it's a cog. your chain rolls over it and it drives your bicycle. as long as it's the right shape, has the right number of teeth, and the threads aren't complete sh*t, it's going to work.

i'll probably used one of the shot-peened somas next time around.

they'll all give a slightly different chainline i think yah?

EAI cogs are money!

however,

http://www.businesscycles.com/graphics/tcog-phil_proto.jpg

I have an EAI, DA and Soma cog, and the EAI looks like they took more care in manufacturing it, and it gives me a better chain line on my Bianchi Pista.

I put a soma on my IRO hub, and had to pt a spacer on there because the cog wasn't wide enough to make contact with the lock ring. I'm not buying anymore of those unless i need ninja stars. Does Phil Wood make ninja stars?

they'll all give a slightly different chainline i think yah?

yes, i think surly and soma had the thinnest...

sheldon had a page with all the measurements but i can no longer find it

The most critical issue is the threading. EAI, Dura Ace and Phil use BSC, while nearly everyone else uses ISO. These are almost identical, but not quite, and you increase the odds of stripping threads by cross threading ISO onto a BSC hub. If you're using an ISO hub then don't worry about an ISO hub, of course.

The second issue is whether the cog is tight behind the lockring. As mentioned elsewhere, this varies a bit, mostly with the cog dimensions. So get a few bottom bracket spacer rings and use them. That solves that problem. If you have a little bit of looseness in the cog behind the lockring, you can actually increase your odds a lot of a stripped hub. That kills your hub.

On the lockring on the track issue ... I've ridden both ways over the years. There's a lot of funky legend about it. The most basic issue is that nothing holds a cog on hard enough except a lockring. When I rode fixie wheels built on old BSC threaded freewheel hubs, a hard kick on the pedal was all it took to dislodge the cog. Here are a few things to think about, pro and con:

1. It takes several wheel revolutions before the cog comes off the hub (as many as there are threads on the hub, in fact), so you don't have instant calamity. And chain tension doesn't change until the cog comes off, although chain alignment may be a problem before then, depending on the hub.
2. Locktite isn't much of a solution. It either doesn't hold well enough for an emergency or it holds so well it damages the hub when you remove the cog. Either way, if/when it releases, it does so unexpectedly. That's a bad thing.
3. If you take a crash on the track, there isn't any knee-trashing event that doesn't happen with a freewheel. The downside pedal gets grabbed by the track surface any way you look at it and ends up very fast on the trailing end of whatever direction you're sliding. And your legs get jerked around to that position. So what? Happens with a freewheel too. I don't think there's anything about a lockring-equipped crash that's more damaging than anything else.
4. On the track, trackies tend to be surprisingly negligent about mechanical stuff. Tires aren't glued like you'd really expect (y'all notice Tournant and Dajka in their big mixup at the World's?), lockrings are left off, etc. For pursuit, kilo, etc. there's essentially no reason for a lockring because you're in your own space on the track and have no need to deal with a lockring. For sprints, if you are going to pop a cog loose it tends to happen not at speed but in a trackstand or a slow steep descent from the banking (or when you come off the track into the warm-up circle). It's in the massed-start and keirin events where the real risk is actually highest -- where you can't necessarily steer around a problem and simply have to stop. And that's the typical road fixie situation as well, right?

Can anyone say where Suntour fits in the pantheon of cogs?

The most critical issue is the threading. EAI, Dura Ace and Phil use BSC, while nearly everyone else uses ISO. These are almost identical, but not quite, and you increase the odds of stripping threads by cross threading ISO onto a BSC hub. If you're using an ISO hub then don't worry about an ISO hub, of course.

Woa, how do I find out what my threading is? I have the suzue jr.

thanks.

Woa, how do I find out what my threading is? I have the suzue jr.


The Junior is pre-stripped for our enjoyment.


......I've used a DA cog on my Jr with no problems.