Singlespeed & Fixed Gear - Soma Cogs + Phil Hubs = (almost) BAD NEWS

My Soma cog (from Nashbar) had been slipping on my brand spanking new blue Phil hub on the commute into work. I thought at first it was in my head as the lockring was very tight. Turns out, the lockring was bottoming out on the hub and not even touching the ~too narrow~ Soma cog.

I felt the slipping on the ride into work. Then I read about bad Soma cog compatibility and stripped hubs this morning on the forum (and Brent's post on the issue). I almost ***** myself thinking about my purdy new hub all f'ed up. I nervously rode home at lunch without backpedaling, hoping, praying, that I hadn't stripped the hub.

Turns our the threads were OK. I caught it in time. Lessons learned = Soma cogs are too narrow for Phil (and potentially other hubs). Time for a EAI cog.

I thought Soma fixed that problem and has made their newer ones wider.

I thought Soma fixed that problem and has made their newer ones wider.

Well, nobody told Bike Nashbar. They are still selling the narrow ones and calling them "Quite possibly the finest fixed cog ever created"

When I built my new wheels I just bought a phil cog for the hub. Figured they should go together, and I was already spending enough money on the wheels. Sort of like my camera equipment, why buy inferior lenes for my really high quality body.

i was very relieved when i found that even after experiencing some pretty disconcerting slippage, my threads weren't stripped when my cog worked its way loose.

phew.

When I built my new wheels I just bought a phil cog for the hub. Figured they should go together, and I was already spending enough money on the wheels. Sort of like my camera equipment, why buy inferior lenes for my really high quality body.

+1

I just spoke to Soma, and the guy I talked to felt that either Nashbar was selling old cogs or the one I got was defective (stamped too hard). He said that when Nashbar will go to Soma with the returned cog I sent back, that Soma will make sure they aren't selling anymore old cogs, and if Nashbar doesn't take the return he will get me a new cog direct from Soma.

Thanks Soma.

(I still think I will run the EAI and/or get one from Brent)

stamped too hard? my soma cog said "cnc machined" on it...

stamped too hard? my soma cog said "cnc machined" on it...

Yea, that's what mine said too. Maybe they stamp the, oh who knows... (me trying to think and type and the same time)

I just spoke to Soma, and the guy I talked to felt that either Nashbar was selling old cogs or the one I got was defective (stamped too hard). He said that when Nashbar will go to Soma with the returned cog I sent back, that Soma will make sure they aren't selling anymore old cogs, and if Nashbar doesn't take the return he will get me a new cog direct from Soma.
Wow, good on Soma. Let's just hope Nashbar follows through with their leg of the transaction, so the whole issue actually gets sorted out.

so, wait, how do you know if it's the cog that's slipping? (thinking that maybe his cog has been slipping...)

so, wait, how do you know if it's the cog that's slipping? (thinking that maybe his cog has been slipping...)

I could feel it slipping when I skipped or skidded. Slipped back maybe a 1/16 of a rotation, but enough to feel. Then it would slip forward when I stood up to mash.

did it make a creaking sound when slipping?

hm. methinks I should make a trip to the lbs.

I know they're expensive, but I would never use anything but a Phil cog on my Phil hubs.

(I still think I will run the EAI and/or get one from Brent)

If I were to get a company to back me up like that I would at least be willing to try the replacement part out. Anybody willing to stand behind their product like that deserves a shot in my book.

If I were to get a company to back me up like that I would at least be willing to try the replacement part out. Anybody willing to stand behind their product like that deserves a shot in my book.

Yes, that's a good point, but Brent at Phil Wood has said directly not to use Soma or Surly cogs on Phil hubs. I'd prefer not to have a non-warranteed Phil hub because I used a cog that the manfuacturer says not to use.

... you can always just use bottom bracket spacers on the hub so that the cog doesn't bottom out.

Spacers are just washers, and introduce one more place in the stack for slippage to occur. This is why washers are used between bolt heads and whatever a bolt is clamping against. I would not recommend adding a spacer or washer into a fixed gear setup for this reason.

Surly and Soma are both known for having cogs narrow enough to be incompatable with some hubs. Both companies have apparently corrected the problem. I'm riding on a newer Surly cog, and it is definitely wide enough for my Formula hub.

Spacers are just washers, and introduce one more place in the stack for slippage to occur. This is why washers are used between bolt heads and whatever a bolt is clamping against. I would not recommend adding a spacer or washer into a fixed gear setup for this reason.

Surly and Soma are both known for having cogs narrow enough to be incompatable with some hubs. Both companies have apparently corrected the problem. I'm riding on a newer Surly cog, and it is definitely wide enough for my Formula hub.how new is the surly cog you're using? i have the same combination and want to make sure this isn't cause for concern...

I tohught phil hubs required campy/phil cogs? Dont they have slightly different threads?

The lockring threads, yes.

atleast your SOMA cog threaded on to your Phil Hub

incompetent south of mission *******s!

The lockring threads, yes.

cog threads as well (http://www.bikeforums.net/showthread.php?p=2338710#post2338710)

^thought so, just couldnt find that post.

ah CRAP! :D

Yea, that's what mine said too. Maybe they stamp the, oh who knows... (me trying to think and type and the same time)

They probably stamp the cog as a frisbee and then CNC the teeth.

Also, whoever said don't put BB spacers in there, think about it. We use spacers/washers on all kinds of crap that we want to slip until it gets tight, and then stay f****** put for good once it's snugged. Axles, for example.