Chain shifts down cassette when backpedalling

[nathanm]

So I've changed the crankset on the girlfriends anthem from raceface to a shimano slx and from a rf narrowwide 32t chainring to a 30t ebay "snail" brand.

But now when I backpedal it changes 2-3 gears down (towards centre of cassette) and tries to fall of the derailleur pulley.

I don't believe I had this issue with the rf crankset though I only tuned it in thr stand and didnt ride it.

Appears to be a chainline issue but how do I fix this with a press fit bb?

 

[moorey]

11sp Shimano? Par for the course in the low gears.

 

[Dales Cannon]

yes it does, don't worry about it.

 

[fatboyonabike]

but how do I fix this with a press fit bb?

cut it up into small pieces and cash in the aluminium, put towards a proper Non PF frame..thank me later

 

[PJO]

I'm assuming that if you used the ebay "snail" chainring that it is a standard fitment (i.e. not direct mount)
If so, you can use these spacers to successfully modify the chainline, I've bought some in varying widths and modified mine.
The guy sells them in various sizes and also has a non-ebay online store.

edit: you might need to buy slightly longer bolts for the chain rings...

 

[nathanm]

I'm assuming that if you used the ebay "snail" chainring that it is a standard fitment (i.e. not direct mount)
If so, you can use these spacers to successfully modify the chainline, I've bought some in varying widths and modified mine.
The guy sells them in various sizes and also has a non-ebay online store.

edit: you might need to buy slightly longer bolts for the chain rings...

cheers mate. yeah after a little research today I'm coming to the same conclusion that the chain line is "out" with the conversion utilising 3x cranks, not specific 1x. Will be measuring chainline and adding spacers I reckon. appreciate the link.

 

[moorey]

Where on the 3x cranks have you mounted the ring?

 

[fatboyonabike]

Where on the 3x cranks have you mounted the ring?

great question....(quickly jumps to the FW thread for response)

 

[moorey]

great question....(quickly jumps to the FW thread for response)

Belongs there solely on buying PF

 

[nathanm]

Where on the 3x cranks have you mounted the ring?

Jeez, do people really think I have that high a level of mechanical ineptitude? DONT ANSWER THAT.

at the end of the crank arm of course, pedals on one side, chain ring on the other. Had to drill out the bolt holes though for the larger pedal spline.

 

[Daniel Hale]

at the end of the crank arm of course, pedals on one side, chain ring on the other. Had to drill out the bolt holes though for the larger pedal spline.

do you have it mounted medially of the bolt holes, closer to frame, or on the outside of the bolt holes?

 

[nathanm]

do you have it mounted medically of the bolt holes, closer to frame, or on the outside of the bolt holes?

Medically?

has been bolted in the standard middle ring position.

 

[nathanm]

you know what though, it's probably the wrong way round now I think about what fuckwittery I could have committed. I've just assumed the writing would be on the outside?

 

[T-Rex]

So I've changed the crankset on the girlfriends anthem from raceface to a shimano slx and from a rf narrowwide 32t chainring to a 30t ebay "snail" brand.

But now when I backpedal it changes 2-3 gears down (towards centre of cassette) and tries to fall of the derailleur pulley.

I don't believe I had this issue with the rf crankset though I only tuned it in thr stand and didnt ride it.

Appears to be a chainline issue but how do I fix this with a press fit bb?

Why is this even a problem? Unless she is trying to get her fakies dialled?

 

[moorey]

you know what though, it's probably the wrong way round now I think about what fuckwittery I could have committed. I've just assumed the writing would be on the outside?

Meant more if you mounted where middle ring goes, or outside ring.

Also....medically, @daniel?

 

[Dales Cannon]

you know what though, it's probably the wrong way round now I think about what fuckwittery I could have committed. I've just assumed the writing would be on the outside?

Yes, that is correct. Measure your chain line but all my 11s drop off the biggun when going backwards.

 

[Dales Cannon]

Meant more if you mounted where middle ring goes, or outside ring.

Also....medically, @daniel?

He meant intimately but softened it for you sooks.

 

[moorey]

He meant intimately but softened it for you sooks.

Ok. Thanks for clearing that up.

 

[Daniel Hale]

medially, ie middle, you could mount it medically but i’m guessing ring change or extraction might be painful

 

[Dales Cannon]

medially, ie middle, you could mount it medically but i’m guessing ring change or extraction might be painful

Probably the mode too.