Ghost Cog?
 

I ran across this.. never heard anyone do this before. Kind of a cool idea:

http://www.dirtragmag.com/forums//at...1&d=1189540866

Now that's HIP

Used quite often on tallbikes, dangerous when combined with a fixed wheel... or so I hear.

Worked fine for me. This is an old trick. And it's called ghost ring.

yep! adjustable tensioner.

wow, i have never seen this. so this is actually a reliable way to run ss on a bike with vertical dropouts?

A sprung tensioner (such as a Single-ator) is a bad idea for fixed gears, braking would eliminate it from your bike. The ghost should work the same forward as it does backward. It's just a cog on an axle, mounted on the chainstay.

it's not mounted to anything. at least i don't think it is.

With a name like wroomwroomoops, you can't be wrong.

I just went out in my garage to see if it works. It does. However, it takes only the slightest nudge to make it fall off. Did it ever fall off while riding. If so, what happened?

it's not mounted to anything. it just floats in there. if it falls out, then it needs to be bigger.

i've got one on a tallbike, cos the distance between the two frames/chainring and hub isn't adjustable. works like a dream. altho, it's hard to ride behind someone rocking one of these, cos it's like magic or something, and it's hard to not stare into the thing. it seems like it should fall out, or creep forward or backwards, but it works.

Works for me. I've got a tallbike with 40x17 gear ratio, and a 40 ghost ring. Just barely fits in there without touching the cog or seat stay. Has never fallen out. I should mention that's it's a freewheel setup. I've ridden fixed setups with a ghost ring, and while safe (if done right), the play and the noise can be kind of annoying. Basically it's not the proper way to do things, but it will get you on the road.

Wait... its seriously not mounted to anything? That seems baffling. I may have to self experiment. Wheres my chainsaw?

Get a larger one, or push the one you have closer to the rear hub a few links. You gotta jam it in real good, if you know what I mean.

If someone ever feels like being a dick and taking it out of the bike, you probably won't be able to ride until you find another one.

(And as someone who has had QR's flipped, and taillight brackets stolen, and brakes loosened, I know that some people really do feel like being dicks)

By the way, experimenting with a ghostring on a tight chain is a good way to have a finger or two severed, because you have twice the "engagement points", or should I call them "traps". Use caution, keep your fingers out.

I used one for a while, too (as an attempt to tighten the chain on my vertical drop frame, and for laughs)... Sadly, it kept falling out. You need lotsa space within the chainstays so that you can jam in a large enough cog... and you also need a large enough cog, about 24-26t, preferably 1/8 if you run a 1/8 chain.

You have to jam it in real hard, as close to the cog as possible.

BTW, if someone steals it (unlikely) or it falls out and you don't put it back (more likely) you're not stranded. You just risk dropping your chain.


Edit: damn you, guys, now I'm thinking of mounting one again... only now i run a bigger cog so I probably can't:( (ghost ring would hit the chainstay)

It's a fairly common pratice with tallbikers. It does look cool, but definitely has drawbacks at times :p .

East Hill

I've done this many times on SS tallbikes. Works quite well for this application. I've also done it on a fixed gear once just so I could ride home on a bike with vertical dropouts. It worked but I wouldn't recommend it as a permanent solution on a fixed gear, but SS works just fine.

EDIT... the weirdest looking thing ever is to use a biopace as a ghost ring FREAKY!!!

I'd run into a parked car staring at that thing

fascinating

Why not put that cog on a little axle, and mount the axle to a clamp on the chainstay? You wouldn't have to worry about it falling out, and you could adjust tension by sliding the clamp forwards and backwards.

Cuz d00d... then it wouldn't be ghetto. I mean... why not just buy a chain tensioner? Or run gears? there... I said it.

I wouldn't want anything clamped to any modern thin-tubed chainstay.... especially if it is getting torqued.

As you move forward, the pressure would torque down on the chainstay and as you brake, it would torque up. I could see this destroying a bike very quickly.

A chain tensioner wouldn't work with FG.

i managed to destroy 2 chainrings on my tallbike by putting them in as ghost rings.

Man I wish I had thought of this before selling that spare vertical dropout frame I had.

As for "jamming in the cog real tight" on vert dropout setups, why not remove the wheel, place the ghost cog in the chain and then squeeze the wheel back in the dropouts? (Or is that how ya'll do it now...)