Is a Boosted rear free hub needed for boosted Crank set

[FattyMcFat]

Hello,


I recently bought a Shimano M627- B(oost) to replace my old non- boost one.
My question is:
Do I need to replace the rear hub as well?

If yes, then I have another question, bellow.
Right now I have a FH- M618, but according to the compatibility document from Shimano, the Casette I have CS-HG81-10. doesn't appear to have the FH M618, let alone the M618- B in the compatibility table.
In the idea that I have to replace it, I would choose another SLX, the FH-M7010-B (compatible according to the document from Shimano) .

My question:
Do I have to replace the whole hub on the rim itself, or just the internals will do?


Thank you for your time!

 

[on any sunday]

A boost hub does not fit in your frame, if it is not boost. Try the crank. Problem? Buy a normal one.

 

[---]

I recently bought a Shimano M627- B(oost) to replace my old non- boost one.

Why?

 

[FattyMcFat]

A boost hub does not fit in your frame, if it is not boost. Try the crank. Problem? Buy a normal one.

Hello,


Why not?

I checked the part list for the M618 and the 618-B and they use the same Axle and sleeve (same length) . The only difference is the boost bushing. Wouldn't it make sense to buy the boosted Hub and just change the bushing?

https://resources.chainbox.io/2/cyk...5-e2dd-4d36-937b-b9b034586f3c/Y39F98010_B.pdf

Why?

Because of economical and availability reasons.

MfG

 

[on any sunday]

Because Boost is 148 mm and the normal FH- M618 is 142 mm.

 

[FattyMcFat]

Because Boost is 148 mm and the normal FH- M618 is 142 mm.

Hello,

Noob question:

Is there a possibility to convert the boosted FC to non- boosted, or is determined by the length of the Axel of the FC that goes through the Bottom Bracket?


Thanks

 

[der-gute]

Its not the axle.

Boost is not defined by axle lengh.

Boost cranksets do have the chainring mounted more towards outside, so the chainline is bigger.

In SRAM cranksets its defined by the chainring, in Shimano cranksets its defined by the crankset.

Boost spacing 148 mm hubs are completely different to older 142/135 mm spacing hubs. A boost hub is not convertibl to 142/135 mm, but 142/135 mm hubs can be adapted to a boost rear end.

 

[FattyMcFat]

Its not the axle.

Boost is not defined by axle lengh.

Boost cranksets do have the chainring mounted more towards outside, so the chainline is bigger.

In SRAM cranksets its defined by the chainring, in Shimano cranksets its defined by the crankset.

Boost spacing 148 mm hubs are completely different to older 142/135 mm spacing hubs. A boost hub is not convertibl to 142/135 mm, but 142/135 mm hubs can be adapted to a boost rear end.

So it's not possible for me to transplant the sprockets and pedal arms on the old non boosted one?

 

[der-gute]

This way (boost cranksets on non-boost frame) can be possible.

But nobody can tell you either it works with your frame and gearing or not.

 

[FattyMcFat]

This way (boost cranksets on non-boost frame) can be possible.

But nobody can tell you either it works with your frame and gearing or not.

It doesn't. The chainline is weird (extremely bent/ torsioned) and I can't make the chain jump on the biggest cog of the FC.
That's why I asked if I can transplant the cogs from the boost onto the non- boost. But unfortunately my Torx broke into the screws of the cogs of the old sprocket, so good luck with that.

 

[der-gute]

If the diameter between the four screws is the same, it can fit.

In Shimano cranksets the chainline (boost or everything else) is made by the crankarm, not by the sprocket.