Shimano Ultegra 16T Cog question
#1
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Shimano Ultegra 16T Cog question
I'm wanting to change out one my 16T cogs on an Ultegra Cassette. My original 16T cog is stamped "16A". The replacements I've found are all stamped "16B".
Can someone tell me what the difference is between one stamped 16A versus 16B?
Thanks
Can someone tell me what the difference is between one stamped 16A versus 16B?
Thanks
#2
Really Old Senior Member
Likely designed to work with adjacent cogs of a different size. Shift ramps and all that....
You "probably" wouldn't notice a diff.
I've mixed cogs on various 9 speed cassettes and didn't notice anything on my less expensive gear train.
You "probably" wouldn't notice a diff.
I've mixed cogs on various 9 speed cassettes and didn't notice anything on my less expensive gear train.
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What Bill said. Clean off your "16A" really well and hold it up next to the picture in your post, and you'll probably see differences how the teeth are formed. If you want to get really geeky, you could buy some 16Bs and grind down the wide spline so that the cog can be installed in any of the 8 possible orientations to see which ones shift the best.
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Agree with both Bill & Scott above that it may not make a difference but I have had problems a couple times in the past with mixing a cog from another cassette with different gearing and it was always a little hesitant going into that gear. Played around with grinding the wide spline and moving the cog around, checking all adjustments, new chain, slightly worn chain, etc., but some of the non-series cogs didn't work as good as the proper matching cog. Just sayin'. I say try it and it may work fine but at worst it's mostly just an annoyance. Also you can go to the Shimano site and get a part number for the original cog and do a search with that or check with your LBS who will almost certainly have to order it. Try checking the photos of other 16t cogs from Ultegra and 105 or Dura Ace even and see if you can match the shifting cutouts of your original. I believe the cogs themselves are the same thickness for 10 & 11 speed so that increases your options.
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I don’t see an issue using B for A considering both are 1t to adjacent cogs. I have found issues subbing a 1t designed cog in a 2t cassette. In those cases there was one ramp instead of two. Tried multiple clocking of cog, but didn’t help enough.
John
John
#7
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My original, which I can't find anywhere, looks like this.
I went ahead and ordered a 16B. I'll report my findings after I test it.
I went ahead and ordered a 16B. I'll report my findings after I test it.
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#9
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Thanks Scott, that helps.
Digging through some Shimano documentation it looks like 16A is used on 11-23T, 11-25T and 12-25T cassettes. The 16B is only used on the 11-32T cassette. That other chart I posted had me scratching my head because I have an 11-25T cassette.
Digging through some Shimano documentation it looks like 16A is used on 11-23T, 11-25T and 12-25T cassettes. The 16B is only used on the 11-32T cassette. That other chart I posted had me scratching my head because I have an 11-25T cassette.
Last edited by Pacelineg; 07-29-21 at 02:47 PM.
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In my experience from a prior attempt to build a custom cassette by combining cogs from two cassettes, even if the suffix of the individual cogs match, there could still be shifting issues.
Bike Forums - View Single Post - Custom 12-28 cassette
If you view your cassette from the rear and slightly to the side, as you rotate the cassette, the light hits it at a certain way when all the shift ramps are lined up, at least between the cogs with only a one tooth jump.
Bike Forums - View Single Post - Custom 12-28 cassette
If you view your cassette from the rear and slightly to the side, as you rotate the cassette, the light hits it at a certain way when all the shift ramps are lined up, at least between the cogs with only a one tooth jump.
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#11
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In my experience from a prior attempt to build a custom cassette by combining cogs from two cassettes, even if the suffix of the individual cogs match, there could still be shifting issues.
Bike Forums - View Single Post - Custom 12-28 cassette
If you view your cassette from the rear and slightly to the side, as you rotate the cassette, the light hits it at a certain way when all the shift ramps are lined up, at least between the cogs with only a one tooth jump.
Bike Forums - View Single Post - Custom 12-28 cassette
If you view your cassette from the rear and slightly to the side, as you rotate the cassette, the light hits it at a certain way when all the shift ramps are lined up, at least between the cogs with only a one tooth jump.
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Here's the "A" version if the "B" doesn't work out. 1pc Shimano Ultegra CS-R8000/6800 16T Cog for (11/12-25T 14-28T) 689228409439 | eBay The photo of the cog looks wrong but the part # matches up (Y1Y916000) so maybe wrong photo.
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#13
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Here's the "A" version if the "B" doesn't work out. 1pc Shimano Ultegra CS-R8000/6800 16T Cog for (11/12-25T 14-28T) 689228409439 | eBay The photo of the cog looks wrong but the part # matches up (Y1Y916000) so maybe wrong photo.
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#15
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I received and installed the 16B cog. I just wanted to report back that it shifts perfectly fine on my 11/25.
Thanks for all your input, it's much appreciated!
Thanks for all your input, it's much appreciated!
Last edited by Pacelineg; 08-06-21 at 01:33 PM.
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