Singlespeed & Fixed Gear - Omnium chainring swap question....

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Leukybear
10-10-10, 07:56 PM
So today I went to swap out the stock 48T chainring that came stock with my new omniums with a 46T sugino zen from my parts bin; just to find the stock chaining bolts are too long and the chainring sits loosely on the crank.
Doing some homework online, I realized I need to use different chaining bolts; can anyone confirm that these in the link below would work for this combo?
http://www.treefortbikes.com/cat/0/324/Chainring-Bolts.html#navbar=pro___333222346839___479
carleton
10-10-10, 08:56 PM
Actually...
Those won't work well. There will not be much thread gripping. Maybe 1 or 2 turns.
Here's the solution I came up with:
- Buy two sets of steel chainring bolts. One set of singles (as in the link above) and one set of doubles. Doubles are used by mountain bikers. Easily found in any shop that caters to that crowd.
- Use the backs from the singles and insert them into the crank arm and use the fronts from the doubles. They will stick through the back about 1-2mm, but they won't touch your chainstays.
- This way you get full thread engagement instead of 1 or 2 threads engaged. I use this system on my race bike.
Squirrelli
10-10-10, 09:01 PM
Incidentally, that's the same system I use.
Found them bolts at the bike co-op. :D
carleton
10-10-10, 09:02 PM
incidentally, that's the same system i use.
gmta!
Squirrelli
10-10-10, 09:08 PM
http://www.concentratedawesome.net/wp-content/uploads/2008/12/gorilla_shark_nice_high_five.jpg
http://image63.webshots.com/163/3/21/58/494332158cBRUNf_fs.jpg
Iv run SS chainring bolts on every one of my single speeds with out a single issue. Have not broke one yet nor had one come loose.
Do any of them have omnium cranks? They are having lots of problems with the proprietary bolts.
Leukybear
10-10-10, 09:38 PM
Actually...
Those won't work well. There will not be much thread gripping. Maybe 1 or 2 turns.
Here's the solution I came up with:
- Buy two sets of steel chainring bolts. One set of singles (as in the link above) and one set of doubles. Doubles are used by mountain bikers. Easily found in any shop that caters to that crowd.
- Use the backs from the singles and insert them into the crank arm and use the fronts from the doubles. They will stick through the back about 1-2mm, but they won't touch your chainstays.
- This way you get full thread engagement instead of 1 or 2 threads engaged. I use this system on my race bike.
Great stuff! :D
Seriously going to consider this.
carleton
10-10-10, 09:43 PM
Iv run SS chainring bolts on every one of my single speeds with out a single issue. Have not broke one yet nor had one come loose.
Yeah, I've run single chainring bolts on Dura Ace, Campagnolo Record, and SRM cranks. The problem is that with the SRAM Omniums, both the crank arm spider AND the chainring are so thick (TWSS) that they require double chainring bolts. But if you go to a standard chainring, you have to improvise as Vixtor and I did.
Do any of them have omnium cranks? They are having lots of problems with the proprietary bolts.
Exactly
Yeah, I've run single chainring bolts on Dura Ace, Campagnolo Record, and SRM cranks. The problem is that with the SRAM Omniums, both the crank arm spider AND the chainring are so thick (TWSS) that they require double chainring bolts. But if you go to a standard chainring, you have to improvise as Vixtor and I did.
I ran a Sugino messenger chainring on the ominum crank with standard ss chainring bolts.
bentchamber
10-11-10, 02:45 PM
Isnt the messenger chainring 130 BCD?
vs Omniums are 144 BCD?
Leukybear
10-11-10, 03:39 PM
Isnt the messenger chainring 130 BCD?
vs Omniums are 144 BCD?
He must've meant the zen messenger chainrings.
you can put the chainring on backwards till the new bolts arrive, should fix the to long bolt issue
He must've meant the zen messenger chainrings.
Indeed.
Anyway, to the OP, Do as the others have said. Just cause I didnt have and issue doesnt mean it was safe.
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