azgordo

is there such a document and if so where is it available.

gerry

masiman

I don't know of a Shimano compatibility document per se. I have been able to have all my questions answered:

1) Here
2) Sheldon Brown
3) Good local mechanics
4) Buddies
5) Trial and error

Pretty much in that order for success.

Soil_Sampler

https://bike.shimano.com/publish/cont...ty_charts.html

ginsoakedboy

+1 on Sheldon Brown for this info -- maybe more reliable than Shimano itself, because not market driven.

operator

Ok, could we have at least some evidence that the shimano tech docs are wrong? An example? What possible reason could they have for lying?

masiman

I don't think they are wrong but I do think they are at least incomplete.

The majority of the compatibility questions don't revolve around is RD-xxxx compatible with CS-xxxx, but will can I get my Manfucaturers X-speed shifter/brifter work with this derailleur or cassette/freewheel.

I don't know if some of the incompatibilities can be overcome by changing spacers. Likely not worth it, but you won't find that in the Shimano literature either.

maddmaxx 

The manufacturer does not lie. They do however for liability reasons make conservative claims on what is compatable with what. Experience has taught many however that it is indeed possible to mate crankset xxx with derailleur xxx and have the two work together.

Having many sources of information is not a bad thing.

azgordo

outstanding,
thanks

Sheldon Brown

They want to sell you new stuff, not to have you use your old stuff. They also assume that you're an incompetent fool.

See: https://sheldonbrown.com/capacity

and: https://sheldonbrown.com/speeds

and: https://sheldonbrown.com/bbsize

Sheldon "Perfect Is The Enemy Of Good Enough" Brown
+-----------------------------------------------------------+
| Always listen to the experts. |
| They'll tell you what can't be done, and why. |
| Then do it. --Robert A. Heinlein |
+-----------------------------------------------------------+

Wordbiker

I wouldn't call it "lying" as much as having a margin of error. Much like overclocking a computer, there are always "hacks" that allow one to exceed the manufacturer's specs...at the risk of accelerated wear, less than optimal performance, loss of warranties and more attention paid to maintenance. I'm sure the folks at Shimano (and PC hardware manufacturers) are well aware of how their products are being implemented by savvy enthusiasts, but using their compatibility specs keeps things within a "safe" level of wear, keeps returns to a minimum, and allows almost any mechanic a reasonable chance at building a modular drivetrain that works well with a minimum of incompatibility issues. The extra capacities are built in to ensure reliability.