Bad Surly Cog?
 

Hey, I bought a second-hand surly cog but I started to worry about using it after reading sheldon brown's warning that some surly cogs could strip a hub. The one I have has the small holes and "surly" etched on the side. Is there any way to tell if its one of the bad ones?


On an unrelated note, while putting in my cartridge bottom bracket today, I cracked the plastic cup just around the splines, not around the threads. Do you think its still usable or do I need to replace it?


Thanks for any info!

From what I know and have read the Surly cogs with the small holes are just fine, as they are the new ones. I got one last spring and one last summer for two different bikes, use them on both, and haven't had any problems at all. They both have the small holes and Surly written on them.

I would check out the teeth though to make sure they aren't worked over too much or "shark-finned" too greatly.

it has not been used but only a bit

the ones with the holes are definitely the new surly cogs and they are quite nice IMO

I just got one of these in 17t and I'm digging it. Seems like a solid, well made cog. Only had it on a few days, but so far so good.

I've had mine a year with no problems.

I've done the same thing. As long as you can get it threaded into the BB shell its probably OK, but check your LBS. Mine sold me a replacement cup for a few dollars.

i run one of the surly cogs with the holes and it is the bee's knees.

stupid plastic cups. Were you working on it in an unheated space?

They are easy and cheap to replace, so you might as well ask about one next time you are in the LBS. But for now, so long as it is doing its one small job (sitting like a collar around that side of the BB so that the other side is not carrying all the stress), it is fine.

jim

The plastic cups are fine. Just ignorant home mechanics who don't have access to a torque wrench overtighten and presto-snap-o.

And oh yeah, if it's cracked go get a new one.

Or overzealous Performance mechanics (who also gave you one too long).

I run surly 17ts on both my bikes and they both rule.

yeah, it takes are real mechanic (like yourself) to install a cartridge bottom bracket. i didn't realize how complicated it was. first i put it in the wrong way and stripped out all the left handed threads in the shell. so then, i had to dip the bottom bracket in some elmer's glue and use a sledge hammer to drive it into place, which is how i cracked the plastic cup.

Obviously too complicated for you to learn how to read installation instructions and do a proper job. K thx. Torque specs and installation instructions come with bottom brackets for a reason and it's not for recycling purposes.

I think BBs with plastic cups are not very high quality anyway. I only have one, it's a Shimano UN-25, and it's awful otherwise.

BTW, I don't have a torque wrench, neither does my LBS. We both manage fine regardless.

your an idiot. for one thing, the cup broke when it was still 2mm from the frame, under a normal amount of torque. the lbs gladly exchanged it for one that fit properly. second, i've bought and installed plenty of bb's and i have never had one come with installation instructions. luckily, replacing a bb rates just above inflating a tire on the scale of technical difficulty. if you think knowing how to install a bb makes you a master mechanic then I'm sure you also have trouble finding a helmet large enough to fit your big head.

For the record, name-calling is against the forum rules. And that should be "you're", not your.

Apparently installing a BB would be a master-mechanic level job for you. That's unfortunate. Tech docs are written for a reason, so people installing **** don't **** it up using the wrong procedure or incorrect specs.

I'm sorry if I came across as a master mechanic, i'm not. But I do know how to read installation instructions. With the difficulty scale you present, i'm surprised you didn't crack any tires when inflating them.

I forgive you.

how were they stripping hubs?

the old steel vs alum?

The old Surly cogs had a slightly non-standard thread pitch.


And as for the BBs (Shimano, Tange, Truvativ, Campagnolo and Sugino):
http://i120.photobucket.com/albums/o...eparts/BBs.png
These bottom brackets have two things in common. They are all square taper, and neither came with any instructions. Not saying it doesn't happen, but it never happened to me.

I've had the same experience, but honestly, its a pretty self explanitory process. You put the dealy where it fits, and you dont force it. Ding ding ding, winner.

As for the surly cog, been riding mine and loving it, seems to be a solid part.

FWIW, my UN-54 came in a recycled paper box without any instructions, and the plastic cup didn't crack until after a week of winter riding (20*F temperatures).

The cup on my road bike never cracked in the same conditions, but it was installed somewhere in Taiwan.