Fixed gear riders? Tech question…

[CruiserTrash]

I have plenty of geared bikes, so I figured I should build a fixed gear. I’m slowly accumulating parts and recently I got a track cog and lock ring. I’m running into issues however. Maybe somebody can help. Mud people are usually pretty mechanically minded, and I’m not a member of any bike forums - so here I am.

I’m using a 130mm Surly flip flop hub that I scored for cheap because the freewheel threads were trashed. I wasn’t planning on using them anyway. I bought a Miche English threaded cog and a lock ring.

I installed the cog and it overhangs the lock ring threads by a lot. I really only have 1.5-2 lock ring threads exposed. That doesn’t give me much confidence considering the lock ring needs about 40ft-lb of torque. I’m guessing either the hub or the cog is some kind of non-standard piece. I’ve built probably 30 bikes in my life but never done anything in the track/fixed gear world so I’m out of my element here.

Surly hub, cog threads are 5.5mm long

Miche track cog, about 8.5mm wide (measuring one handed in the photo so the measurement seen isn’t super accurate - it’s truly 8.5)

Maybe two threads showing with the cog fully seated. The angle of the photo makes it look more generous than it is.

The lock ring gets tight almost immediately, and you can see below the amount of unused threads on the interior of the lock ring. Tiny flathead screwdriver for scale.

So what gives? I reached out to “Retrogression” the place I bought the cog and lock ring from and they were zero help. Condescending from the get go, tried to sell me some kind of problem solver lock ring, didn’t bother answering a single question let alone the main question of “which one of these is non-standard”. I just want standard parts so I can easily change cogs in the future. I don’t really know anyone else who works on fixed gear drivetrains. My wife dailies her track bike but has always had a local shop do the work … and they’re out of business.

I’m planning on buying another cog and lock ring but I want to figure this out before I waste any more money.

 

[1FZj80]

It would be easy to machine the cog to match the thickness of the threads on the hub. Just an option if you can't find the correct gear for that hub. It would obviously move the chain inboard by the amount of material removed.

 

[CruiserTrash]

Ordered a new one, so we’ll see how that goes. I’ll post measurements for posterity sake. I just want to get to the bottom of what I have that is non-standard.

 

[1FZj80]

I'd be happy to help with machining if needed.

 

[CruiserTrash]

I'd be happy to help with machining if needed.

I appreciate that! I feel like buying a fixed cog shouldn’t require machining though. Tons of people ride fixed gear bikes on the street or at the velodrome. There’s English and Italian standards, but beyond that it doesn’t seem difficult for people to buy parts, install them, and ride. I’ll see what these new cogs look like and go for on there.

 

[1FZj80]

Agreed. But, I have had to make sleeves, spacers, bushings, axle shafts, etc. and find a little mod to make things fit is sometimes the easiest option.

 

[use2bn83]

My fixed surly 1x1 used a cog and lock ring that were threaded opposite, but the cog used was flat (no built in flange like you have) and I selected a spacer for chain alignment.

It’s now just a single speed unfortunately I don’t think I have any pics, I’ll see if I can find images of the parts.

Edit: just went and looked at my 1x1. I was wrong about the flat cog. I was mixing up my single speed setup with my fixed setup.

Good luck, I don’t remember any hiccups though other than fixies are for folks that hate their knees lol.

 

[CruiserTrash]

My fixed surly 1x1 used a cog and lock ring that were threaded opposite, but the cog used was flat (no built in flange like you have) and I selected a spacer for chain alignment.

It’s now just a single speed unfortunately I don’t think I have any pics, I’ll see if I can find images of the parts.

Edit: just went and looked at my 1x1. I was wrong about the flat cog. I was mixing up my single speed setup with my fixed setup.

Good luck, I don’t remember any hiccups though other than fixies are for folks that hate their knees lol.

Yep, my Surly hub is two opposite threaded portions like all fixed gears. The lock ring thread diameter is smaller so the cog slips past it. Both are English threaded.

No shipping notification on the new cog and lock ring yet. I bought them from a company called Profile Racing. Apparently they’ve been machining top-grade BMX racing components since the 70s and now are making track bike parts. Seems like it’s all done in house in Florida, and they appear to have a fairly sizable facility. It seemed like a cool way to support a specialized US-based business and possibly get something high quality without paying the high prices for track bike stuff. I don’t understand why all the track bike parts are so ludicrously expensive … but all of it is. there’s a premium versus similar road bike parts for whatever reason.

 

[use2bn83]

Yep, my Surly hub is two opposite threaded portions like all fixed gears. The lock ring thread diameter is smaller so the cog slips past it. Both are English threaded.

No shipping notification on the new cog and lock ring yet. I bought them from a company called Profile Racing. Apparently they’ve been machining top-grade BMX racing components since the 70s and now are making track bike parts. Seems like it’s all done in house in Florida, and they appear to have a fairly sizable facility. It seemed like a cool way to support a specialized US-based business and possibly get something high quality without paying the high prices for track bike stuff. I don’t understand why all the track bike parts are so ludicrously expensive … but all of it is. there’s a premium versus similar road bike parts for whatever reason.

Oh yea, very familiar with profile. Funny enough, when my 1x1 was a fixie it had profile crank arms on it haha. My General Lee 24” had profile crank arms and hubs as well. Great company, and making super quality gear for a long time.

Whelp better start your glucosamine supplement and add a rear brake if you don’t already have one.

Post pics when she’s rippin.

Also for the record, on my fixie commuters back in 2008 haha, we just red loctited cogs on old freewheel hubs with no lock ring and for the most part they didn’t move. So it’s possible that those 3-4 threads would have held haha.

 

[CruiserTrash]

Oh yea, very familiar with profile. Funny enough, when my 1x1 was a fixie it had profile crank arms on it haha. My General Lee 24” had profile crank arms and hubs as well. Great company, and making super quality gear for a long time.

Whelp better start your glucosamine supplement and add a rear brake if you don’t already have one.

Post pics when she’s rippin.

Also for the record, on my fixie commuters back in 2008 haha, we just red loctited cogs on old freewheel hubs with no lock ring and for the most part they didn’t move. So it’s possible that those 3-4 threads would have held haha.

I lived through the "fixie craze" of the 00s and remember how many dirtbag "conversions" were on the road. Score a cheap old steel road frame, loctite the cog on the freewheel threads, remove one chainring, and chop the drop bars so they were about 10" wide (or, alternatively, chopped into bullhorns). If you had money you got some Velocity Deep Vs in an obnoxious color. Oury grips on every one of them. I didn't participate in all that madness back then so I'm making up for it now. But I'm old enough that I value my health, hence wanting a lock ring and a front brake.

Good info on Profile. I had never heard of them, but it's nice to know they're legit.

 

[CruiserTrash]

1982? 1983? Holdsworth Mistral touring frame.

I’m building it up with 1950s British bikes in mind. It’ll get north road handlebars like a “tourist” style bike, but the fixed gear will be more like a “path racer”. The wheelset is 650B so the tires will be 38mm wide in keeping with the old British stuff. Full fenders of course and probably an old light (converted to LED). I’d like to build a second rear wheel with a Sturmey Archer hub for more of the classic “tourist” thing.

I got the bare frame a while ago and have been doing the “one piece at a time” thing as I find appropriate parts. It’s been hanging on the wall and slowly growing. Once the bars arrive it’ll have to come down. Bars, tires, grips should arrive this week. Got some MKS road pedals I can throw on for now. Then I’m just waiting on the cog & lock ring. I love Nitto stuff but I’m not sold on the stem - the old British ones had like 20mm of reach and the length of the Nitto looks odd to me for this build. I might try to eBay one from an old Raleigh or whatever.

Alright, that concludes Jim’s weird niche bike TED talk.

 

[CruiserTrash]

Ok, the Miche cog was the oddball. The Profile cog & locking showed up and it’s going to fit perfectly. Cog is ~6.5mm wide versus the Miche at 8.5mm. Cog threads are 5.5mm, so that leaves enough of the Profile cog hanging over that the lock ring won’t bottom out. So file that away in your memory banks (whoever is reading): the Miche stuff seems meant for another standard of hub.

 

[use2bn83]

Ok, the Miche cog was the oddball. The Profile cog & locking showed up and it’s going to fit perfectly. Cog is ~6.5mm wide versus the Miche at 8.5mm. Cog threads are 5.5mm, so that leaves enough of the Profile cog hanging over that the lock ring won’t bottom out. So file that away in your memory banks (whoever is reading): the Miche stuff seems meant for another standard of hub.

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Good to know! Also, the way that is configured is backwards to how most are installed, is that for chain alignment? Doesn’t the flange usually seat on the hub body?

 

[CruiserTrash]

Chainline is dead nuts on too

Good to know! Also, the way that is configured is backwards to how most are installed, is that for chain alignment? Doesn’t the flange usually seat on the hub body?

It wasn't fully tightened in this photo and I did end up turning it around. Chainline is within +/-0.5mm. Pretty bang on for what I'm doing, occasionally pleasure cruises around the neighborhood.

 

[CruiserTrash]

Small update:

Been riding the hell out of this bike. Super fun and super exhausting. I still haven’t installed a brake but I’m probably going to. I have everything except a cable, which I should really just grab from the local shop.