Torx bolts fool, not metric!

My worry would be the bolts would start to back out a little due to vibration and then the potential exists they could sheer off or bend the cog. I think seeing this happen would be few and far between but I wonder how the frequency of incidents will stack up against the classic lockring.

i'd love to pick up a bolt on hub set-up. it'd made cog changes way easy and you wouldn't have to worry about it slipping at all.

I dig, I can't wait for these things to proliferate and be an equal option to the traditional setup. To me it just makes sense, having a screw-on cog on a system that puts pressure both ways is a design flaw, plain and simple. Granted it works just fine, but bolt ons seems more sensible if they can take the torsion. That's why i like the flanges on Levels.

One thing though... STANDARDIZE! everyone coming up with their own proprietary system gives me a blu-ray vs. hd headache. Quit being such capitalists and make things that swap, you crazy engineering/design people you :).

I like the bolt-on hubs, but the thread-on hub/cog can be managed pretty easily.

In order to tighten the shit out of the cog, all you need to do is take the chain off the cranks, let is just hang on the bb shell (you might scratch the bb shell, so put a rag in between the chain and the shell).
With the loose chain, you should pinch it around the cog (either through the top to tighten and through the bottom to loosen - the chain goes around it twice) then grab the wheel and turn it counterclock-wise to tighten and turn clockwise to loosen.

I know it's sounds a bit complicated but this method is super useful and works like a charm.

I'll try to post pictures of step-by-step approach to doing this if anyone is interested. Forget the chainwhip - it doesn't quite get the job done I find.

Word to DBR, 6 bolt disc ISO standard or nothing on these. Not sure what kind of fool would buy this proprietary shizz.

DBR... that'll never happen in the bike world. French, Italian, lock ring, bolt on, MAC, Windows, Linux... the list goes on....

hopefully the 6 bolt ISO disc brake standard will be what everyone settles on for these. lookin forward to it.

I have a friend who has a similar set up. After a few months, the bolts did loosen. He only has three screws though - definitely not enough in my mind. The screws are going to have to be beefy if it's gonna work. Anyway, most any part can break you don't do some regular maintenance.

The design is the same idea a disk brake though -(velosolo makes cogs that can be mounted on disc brake hubs - genius!) If the design can handle the torque downhill riders put on them, I'm sure it'll work for fixed drivetrains.

Anybody worried about the screws getting in the way of the chain on smaller sized cogs? Seems like a limitation to consider.

I was thinking the same thing, I run a 14t or a 12t and I dont thik either would fit. I'd defenitely prefer a disc brake standard as well.

Yeah, as of right now 15 tooth is the smallest cog possible with the 6 bolt ISO pattern. Maybe by using 4 bolts you can go smaller?

I sure like the idea!

dude on our forum made a DIY version of this a few years ago.
http://www.mplsbikelove.com/forum/viewtopic.php?f=9&t=9370&hilit=BOLT+ON+COG

Just gonna put my hand up and say this is my creation in conjunction with our hub factory in Taiwan. We chose the four bolt pattern in order to allow the fitting of smaller diameter cogs as the IS 6 bolt disc fitting would start to contact the chain when you get down to below a 16t. You'll notice in the photos that there are slots cut in the cog that locate onto machined shoulders on the hub body, this adds strength and means less torque is placed on the bolts. The bolts are loctited as on MTB disc bolts (they are the same) and use a T25 Torx to tighten them. Bearings are slick japanese numbers. At the moment we are still testing with Ted, Tom, Juliet, myself and some of the other guys at our office. Should be ready to launch at Euro Bike. Thanks.