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Discussion Starter · #1 ·
haven't searched here yet so I don't know if this is old news or not but...

I am converting my Rocky Mountain Hammer 29er into a single speed so I have been cobbing together parts and buying a few choice pieces too. My old middle chainring was sharktoothed so i needed a new one: Blackspire DH 32t will suit me fine thank you. Grabbed a kmc z510 chain from the lbs for cheap....nice. The kmc 410 on my single speed park/commuter bike has served me well now for more than 5 years so the 510 should work well...though I am probably due for a new one.

Now for the cobbed parts: I hate the idea of buying spacers from someone. They are 35 (ish) mm plastic or aluminum washers for crying out loud. So I broke apart an ancient cassette to get at the plastic spacers in there when I took a look at another ancient cassette and notice that beefy aluminum piece that the 32-18 gears are pinned to. I grabbed the dremel and cut off all the cogs. Then grabbed an old steel 18t single speed cog I used for about a year (no visible wear) and jb welded it to the spacer. I lubed up the freehub body of an old wheel, placed the spacer on it, slathered jb weld over the spacer. Then placed the 18t cog down on top of the spacer.

When it is cured I will paint the backside of the cog and spacer black and ..viola! a "free" single speed cog that spreads the load out well over the freehub body and "free" plastic spacers to get the chainline right. Hope it works well, I love cheap stuff that works well.

g
 

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Out spokin'
In cog? Neato!
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Ganze said:
haven't searched here yet so I don't know if this is old news or not but...

I am converting my Rocky Mountain Hammer 29er into a single speed so I have been cobbing together parts and buying a few choice pieces too. My old middle chainring was sharktoothed so i needed a new one: Blackspire DH 32t will suit me fine thank you. Grabbed a kmc z510 chain from the lbs for cheap....nice. The kmc 410 on my single speed park/commuter bike has served me well now for more than 5 years so the 510 should work well...though I am probably due for a new one.

Now for the cobbed parts: I hate the idea of buying spacers from someone. They are 35 (ish) mm plastic or aluminum washers for crying out loud. So I broke apart an ancient cassette to get at the plastic spacers in there when I took a look at another ancient cassette and notice that beefy aluminum piece that the 32-18 gears are pinned to. I grabbed the dremel and cut off all the cogs. Then grabbed an old steel 18t single speed cog I used for about a year (no visible wear) and jb welded it to the spacer. I lubed up the freehub body of an old wheel, placed the spacer on it, slathered jb weld over the spacer. Then placed the 18t cog down on top of the spacer.

When it is cured I will paint the backside of the cog and spacer black and ..viola! a "free" single speed cog that spreads the load out well over the freehub body and "free" plastic spacers to get the chainline right. Hope it works well, I love cheap stuff that works well.

g
Picture = 1000 words.

--sParty
 

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Discussion Starter · #3 ·
will get pics this afternoon/evening. Came off the hub fine and I hit it with the flat black enamel. Put it under a 200 watt light to harden it all up today.

My only issue is if the jb weld won't hold as hard as it says it will b/c of anomolies in the surfaces or grease that got caught in there. we'll see.
 

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Discussion Starter · #5 · (Edited)


Here's a few pics. Cog got barely off so I had to clean it and try again. This time I used quickset epoxy to tack it. After it cures I will apply generous amounts of jb weld to seam on back of cog.
 

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That won't hold once you apply some decent torque to it and then you're no better off than with a sprocket and some normal spacers.
Too much messing around for no return, in my opinion.
 

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Discussion Starter · #13 ·


Got the jb weld on it. It'll hold: 1) JB weld is strong stuff. 2)there's not that much torque between the cog and space since they both connect to the freehub body at the same points of pressure. It's not like the cog is not connected.

I'll hit it with black epoxy enamel and it'll look decent enough to use. Not exactly show worthy but it was free.

None of this is really necessary. The cog I used is fairly wide to begin with, although it did mildly score my old set of wheels after a couple of years of commuting. And yes, a new one is merely $30 or so. From time to time I just like to figure something out and save a little cash. It's a good way to chill out and solve a problem that is actually solvable.
 

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That will never hold.

JB weld does not have much shear strength. Golf club epoxy MIGHT work better, but I still think it will fail.

Now, drill and tap about 8 holes with 10-32 bolts/screws, you might be on to something...
 

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It won't matter if it holds or not, because the cog is splined. The next time you need some cheap spacers, a short stick of PVC is probably cheaper than the JB Weld was.
 

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Ganze said:
I have spacers from old cassettes. Just an experiment with old parts and epoxy. Middle of the night engineering to clear the head.
You've taken a lot of flak and held up well. I respect that. Sometimes it's just fun go head out to the workshop and create something. Period. Even if it's not the ultimate new widget... it's still a good thing to do.

Besides, it's your bike. Personally I like being master of my universe. I say good on ya.

--sParty
 

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A steel cog from j&b is like $12 with a wide footprint.
hopefully the spraypaint doesn't cloud ur head much more..
when I need to create something late at night it's usually a turkey sandwich..
 

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Ummm, turkey sandwich. I was I'm that creative in the middle of the night. The only thing I usually create around that time is a big dump in the toilet...
Ganze, the last pic made your creation look like the whole piece is made totally out of JB Weld. I hope it actually works when you get it out on the trails to really test it. It I had spent all that time on it and have it last a couple of minutes. it might just end up stuck to the drywall of my garage after I threw it like a chinese throwing star.
 
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