Shimano chainrings different thicknesses - please mike your rings

[DMF]

Apparently the following isn't boilerplate to keep you using Shimano parts:

Be sure to use only the FC-xxxx chainrings. If any other type of chainrings are used, the distance between the chainrings will be incorrect...

And the part numbers are different for what is apparently the same part:

Y16T 9A420 - FC-6503 42T
Y16X 98010 - FC-5504 42T

Hmmm. I wonder why? Could it be the finish?

It's more than that — Shimano chainrings are different thicknesses. I just miked two 42T rings: one is 1.13mm, the other is 0.80mm. That's quite a difference! The thickness of the ring determines where it is in relation to the other rings, so a thinner middle ring on a spider cut for a thicker one will be closer to the big ring and farther from the small, affecting shifting. A spacer corrects that, which is why some cranksets have spacers. Unfortunately, spacers are not available.

The thing is, there is no indication on the ring as to what crankset it fits! If you're buying a replacement ring, you have no way to tell whether you've gotten the right part.

--------------------------------------------------------------

So I'd like to start a mini-project here on the BF Bicycle Mechanics forum. Let's find out what thicknesses Shimano uses for what cranksets. We'll put the results in a sticky, Mods willing. Please answer these questions:

What is the original crankset or ring part number? E.g. FC-6503 or Y16T 9A420. If you're not sure, supply what info you can.

What is the type/tooth count? E.g. A-42T. The type should be marked on the part, for instance "A-52-42-30".

What is the date code? The date code is a small, two-letter (not number) code stamped near the other markings. For instance, "CF" (June 2004) or "YJ" (Oct 2000).

What is the ring mounting thickness? E.g. 0.08mm. You may have to remove the ring to get this. Measure at the surface around the bolt hole. Inches or millimeters is okay.

Is there a spacer between the ring and the spider? How thick?

Does the ring have a counter-bore for the bolt or retainer shoulder?

Describe the finish of the ring. That is, the color and texture of the surface. For instance, the 6503 ring is a nickel color, and textured. The 5500 ring is a silver (redder than the nickel) and smooth.

Tell the BCD. Just to keep things straight. Here is how to measure.

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Oh, and if you have a source for chainring spacers, please PM me.

[nerobro]

And for those who are weight obessive.. the thinner ones are lighter.

[Treefox]

Would this be the whole Type-A vs. Type-B thing?

[DMF]

And for those who are weight obessive.. the thinner ones are lighter.

Maybe. Depends on the material.

[DMF]

Would this be the whole Type-A vs. Type-B thing?

If you mean that A is thinner than B or vice versa, then no, it has nothing to do with that — that's about the ramp/pin setups. All I can tell this far is that thickness tracks the crankset model number.

[DMF]

Here are some chain ring spacers, though they are too thick for my particular need. Nice to see that Branford is back!

Here are spacers and an application chart. They sell only to dealers.

[DMF]

Here's the accumulated results:

model     BCD   type     code     date   thick mm   spacer  c/bore?     finish
--------------------------------------------------------------------------
Dura-Ace
FC-7900   130   A-53               interchangeable with FC-6700
          130   B-53
          130   B-52
          130   ?-42
          130   ?-39
FC-7950   130   ?-50
          130   ?-34
FC-7800   130   A-53   1F3 98040
          130   A-54   1F3 98250
          130   A-55   1F3 98260
          130   A-42   1F3 42000
FC-7800   130   B-50   1F3 98010
          130   B-52   1F3 98020
          130   B-53   1F3 98030
          130   B-39   1F3 39000
FC-7800   130   E-56   1F3 98270
          130   E-44   1F3 44000

FC-7803   130   D-52   1G5 98140   interchangeable with FC-6603,4
          130   D-39   1G5 98130
           92   D-30   1G5 30000

FC-7701   130   A-53   16P 9A530
          130   A-42   16P 42000
FC-7701   130   B-53   16P 9B530    CH      1.55*       N       Y     matte nickel
          130   B-41   16P 41000
          130   B-39   16P 39000    CG      1.33*       N       Y     matte nickel
FC-7701 Triathlon
          130   ?-54   16P 98030
          130   ?-55   16P 98040
          130   ?-56   16P 98050
          130   ?-42   16P 42020
          130   ?-44   16P 44000
          130   ?-45   16P 45000

FC-7703   130   D-53   1EL 98030    CH      1.55*       N       Y     matte nickel
          130   D-39   1EL 98020    BL      2.10*       N       Y     matte nickel
           74   D-30   1EL 30000    BI      1.10      1.185     N     matte nickel
Ultegra
FC-6700   130   B-53              flagged interchangeable with FC-7900   
          130   B-52   
          130   B-39   
FC-6703   130   ?-52   
          130   ?-39   
           92   ?-30   
FC-6750   110   F-50   1LL 98010
          110   ?-34   1LL 34000
FC-6600   130   B-53   1G3 98040
          130   B-52   1G3 98030
          130   B-39   1G3 39000
FC-6601
FC-6603   130   D-52   1G4 98030  flagged interchangeable with FC-7803
          130   ?-39   1G4 98020
           74   ?-30   1G4 30000
FC-6604   130   D-52   1JP 98010  flagged interchangeable with FC-6603
          130   ?-39   1JP 98020
           74   ?-30   1JP 30000
FC-6650   110   ?-50   1JR 98010  flagged interchangeable with FC-5650, FC-R600
          110   ?-34   1JR 34000  flagged interchangeable with FC-R600
FC-6500   130   A-53   16T 98030
          130   A-42   16T 42000

FC-6500   130   B-53   16T 98020    ZL      1.625       N       Y     textured nickel
          130   B-53                AG      1.625       N       Y     textured nickel
          130   B-52   16T 98010
          130   B-39   16T 39000    ZK      1.125       N       Y     textured nickel
          130   B-39                AH      1.125       N       Y     textured nickel

FC-6503   130   A-52   16T 9A420    CH      1.625       N       Y     textured nickel
          130   A-42   16T 9A420    CF      1.125       N       Y     textured nickel
           74   A-30   16U 30000    CH      1.125       N       Y     textured nickel

105
FC-5600   130   B-53
          130   B-52
          130   B-50
          130   ?-39
FC-5603   130   D-50
          130   ?-39
           74   ?-30
FC-5650   110   F-50   1JL 98020    GD      2.87        N       N     black anodized? painted?
          110   F-34   1JL 34010    GE      2.86        N       N     black anodized? painted?
FC-5500   130   
FC-5501   130   A-53
          130   A-42
FC-5501   130   B-53   1DG 98030    BD      2.84        N       Y     black anodized
          130   B-52
          130   B-50
          130   B-39   16V 39100    BC      2.00        N       N     black anodized
FC-5502   130   same gearing      flagged interchangeable 'B' with FC-5500, FC-5501
FC-5503   
FC-5504   130   ?-52
          130   ?-42
           74   ?-30
FC-5505         same gearing      flagged interchangeable 'B' with FC-5503, FC-5504

Tiagra
FC-4503   130   D-50   1HJ 98030    GA/FJ   2.70**      N       N     flat silver grey (alum material)
          130   D-39   1HJ 98020    GA/FJ   2.90        N       Y     flat aluminum    (alum material)
           74   D-30   1HJ 30000    FF2/FI  1.80        N       N     matte/gloss steel? (steel)
                                  interchangeable w/ Sora FC-3403
Sora 
FC-3403                           flagged interchangeable 'B','B','A' w/ Tiagra FC-4503

2200
FC-2200
FC-2203

A050
FC-A050

Non-Series
FC-R700   110   ?-50   1H0 98050
          110   ?-34   1H0 34000
FC-R600   110   F-50   1HS 98020    EJ      4.67        N       Y     brushed alum
          110   F-34   1HA 34000    EK      2.86        N       Y     brushed alum
                                  34T (only) flagged interchangeable 'A' w/ FC-4550
FC-R550   130   B-53   1HZ 98030
          130   B-52   1HZ 98020
          130   B-50   1HZ 98010
          130   ?-39   1HZ 39000
FC-R553   130   D-50   1J0 98020
          130   ?-39   1J0 98010
           74   ?-30   1J0 30000
FC-R450   130   B-52   1JH 98020
          130   ?-39   1DM 39100
FC-R453   130   D-50   1H9 98020    
          130   ?-39   1H9 98010    
           74   ?-30   1H7 30000    
FC-4550   110   F-50   1HA 98040
          110   ?-34   1HA 34000

unknown 
"Shimano 9-spd SG"
          130   A-42                YJ      0.80        -       N     smooth silver
SLX
MC-660    104   AA-44  1KF 98060    ?/GB    2.90**      N       N     matte/semi black (alum material)
          104   AA-32  1KF 98040   FL1/GA1  1.90***     N       Y     nickel silver steel, matte black plastic front, shiny black plastic back
           64   AA-22  1KF 22000    GA/GC   1.90        N       N     semi black  (steel)
                                   flagged interchangeable with FC-M770,FC-M970
                                   32,22 also w/ FC-T661, 22 w/ FC-M810-2,FC-M815-2
RX-100
FC-A550  but all rings probably replacements
  Tracer   130   A-53               --      1.185       N       Y     brushed alum
  Tracer   130   A-39               --      1.185****   N       N     brushed alum
  Shimano   74   A-30               CF      1.125       N       Y     textured nickel

unknown tandem left side
           110   38               QH/H0?    3.55        N       Y     polished alu

* Measurements made on assembled crank.
** Teeth are offset outboard
*** "teeth centered on about 2.00mm" =? offset inboard
**** Teeth are offset 0.25mm inboard

[halfspeed]

Here are some chain ring spacers, though they are too thick for my particular need. Nice to see that Branford is back!

Here are spacers and an application chart. They sell only to dealers.

As always, loose screws has this kind of thing:
http://www.loosescrews.com/index.cgi...d=668929319232

[DMF]

Dura-Ace added to chart.

[DMF]

Surely someone has calipers and a few spare moments.

[operator]

Surely someone has calipers and a few spare moments.

I work in a shop - which other rings do you want thicknesses for?

[urbanknight]

Did you measure the thickness where they are bolted or under the teeth? Many chainrings have recesses which may affect your calculations as to where the ring will sit.

[joejack951]

Can you post a picture of where you are taking your measurements from? I don't have any Shimano-brand chainrings to check but the chainrings I have measured seem to be much thicker than what you've measured. They all seem to taper down in thickness near the teeth and the teeth measurements I have taken range from 1.9 to 2mm.

[San Rensho]

Why would a difference in thickness make any difference? I have an 80s vintage Sugino crankset that shifts perfectly with a 105 brifter and front der.

[DMF]

I work in a shop - which other rings do you want thicknesses for?

I'd like 9-speed 105 and Tiagra, and at least one of the low-end road cranks. Might as well get 10-speed DA and Ultegra, too. I was surprised at the differences between the double and triple DA rings.

[DMF]

Did you measure the thickness where they are bolted or under the teeth? Many chainrings have recesses which may affect your calculations as to where the ring will sit.

I measure them across the bolt holes. Measure 3-4 of those flanges and do a rough average in my head. Hundredth of a mm is more than precise enough.

It is possible that the teeth might be offset, but we don't have the gear to measure that accurately so we'll have to assume that the teeth are centered.

It's more important to get the caliper square to the surface than to worry about jaw orientation (something you don't have to worry about if you use a micrometer).

[DMF]

Why would a difference in thickness make any difference?

The thickness of the ring determines where it is in relation to the other rings, so a thinner middle ring on a spider cut for a thicker one will be closer to the big ring and farther from the small, affecting shifting

....

[also] there is no indication on the ring as to what crankset it fits! If you're buying a replacement ring, you have no way to tell whether you've gotten the right part.

Likewise if you're trying to ID a loose one.

I have an 80s vintage Sugino crankset that shifts perfectly with a 105 brifter and front der.

Uhhh... That's nice.

[operator]

Likewise if you're trying to ID a loose one.

Uhhh... That's nice.

Probably better to assume he meant the original chainrings on that crankset as otherwise it's meaningless.

[Kommisar89]

Surely someone has calipers and a few spare moments.

Yes and yes but no Shimano rings. Sorry

[DMF]

Well, I just started with Shimano, but no reason we can't expand the project. (No point in including proprietary mounting systems like an asymmetrical spider or weird BCD.)

Waddya got?

[DMF]

Something else occurs to me. It would be nice to know if rings are interchangeable between different "speed" versions of the same group. For instance, are Ultegra triple rings interchangeable between 6503 and 6603? The type codes are the same (A).

[nania]

I'd like a definitive reply on this issue too. It would be helpful to know if these Ultegra family chainrings are interchangeable.

[oldster]

Is a 7400 DA double from the 80's something you want???
Bud

[DMF]

I Want Everything!

PLEASE


Look at it this way. I probably won't try to use a 7400 ring on my 7700. But some poor sod with a 7400 might like to know if he can use an (available) 7700 ring when his wears out.

I'm frankly surprised that no one has done this investigation before.

Don't worry if your input data isn't complete. Every little bit helps.

[DMF]

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