|   What to look for in rear cogs | wolfereeno
Jan 12, 2004 7:12 PM | | I'm going to swap my rear 16 tooth gear with either a 17 or 18. Its currently an 81" gear and I want to go to something 72-76"
I was looking on Excelsports site and they have a couple of different cogs. Some indicate shimano compatibility - don't know if I need that. And another's listed as a BMX cog that can be used for fixed gears. I have no idea what kind of cog I need. The bike's a Bianchi Pista.
I may also buy a 44 front ring for a different combination I want to try. Any suggestions?
Also, I guess I need a bottom bracket wrench to take off the lock ring, correct?
Thanks
-Bill |
| Quality......... {NM} | gspot
Jan 12, 2004 7:36 PM | | |
| re: What to look for in rear cogs | trout_bum
Jan 12, 2004 7:38 PM | | You want to use a track cog on a Pista. I believe the newer ones are 3/32" pitch. Mine is a 2003 and is 3/32. You can use Surly track cogs from excel or go to www.harriscyclery.com - they sell Dura Ace track cogs for $21.95. D/A is what comes stock on the pista, so you know these will fit perfectly.
The pista has a flipflop hub so you can mount a BMX freewheel on the other side of rear wheel - but not recommended to do without a brake(s)
As for the lockring a Park HCW-5 works well.
For the front you want 130T 3/32 rings
Good luck! |
| re: What to look for in rear cogs | wolfereeno
Jan 12, 2004 7:57 PM | | Ok, so to utilize the flip flop on occasion, I'd need two different types of cogs. One that's BMX thread on. And another for the fixed side that's Shimano compatible? Yes?
What's 130T 3/32 mean for the front? I want a 44 tooth ring with 5 holes.
Pardon my ignorance.
Thanks! |
| re: What to look for in rear cogs | gspot
Jan 12, 2004 8:27 PM | | a BMX freewheel as mentioned before is a single speed freewheel. this allows you to coast, like on a geared bike. you can mount this on the other side of the hub, but its not a good idea without front and rear brakes.
you can buy 2 track cogs and put a larger one on one side and a smaller one on the other side, thus giving you 2 gearing combinations.
130 is the BCD of your crank arms. This is the size of the ring. Buy this size to insure it will fit with your current crank arms.
3/32 is the pitch of the chain, as some track chains are 1/8 pitch., but not your pista. (I think)
sorry for my unhelpful post above... :D) |
| re: What to look for in rear cogs | wolfereeno
Jan 12, 2004 8:38 PM | | Sorry to be so dense
>>you can buy 2 track cogs and put a larger one on one side and a smaller one on the other side<<
So are they two different types of cogs? One for freewheeling one for fixed?
Thanks
-Bill |
| re: What to look for in rear cogs | gspot
Jan 13, 2004 12:03 PM | | sort of... there are track cogs, and there are bmx freewheels. bmx freewheels are used on single speed bikes, (not fixed gears) like bmx bikes. hence the name bmx freewheel.
a bmx freewheel allows you to ability to coast, while a track cog will not let you coast. They both will fit on to your hub. Do not use a bmx freewheel without front and rear brakes. It is dangerous.
this is a a track cog looks like.
I got this from :
http://harriscyclery.net/site/page.cfm?PageID=49&SKU=FW6880
this is like the one you need, only in a bigger size. |
| re: What to look for in rear cogs | gspot
Jan 13, 2004 12:07 PM | | a bmx freewheel looks like this. there are bearings inside to allow you to coast.
no worries on your knowledge, i'm here to help. ask any more questions you may have. |
| Ok, I get it! | wolfereeno
Jan 13, 2004 2:32 PM | | I just assumed that the freewheel cogs relied on the freewheel being in the hub. Didn't realize they have bearings of their own.
Thanks |
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