making non boost crank compatible with boost?

serviceguy

Well-Known Member
Shimano's own instructions dont show the same amount of spacers on each side...
View attachment 108113

That has nothing to do with boost, is just the way you adapt different BB shell width to match the correct width of the standard crank. The 5mm difference between the 68mm and 73mm BB shell is equally split on both sides.

Boost is dead. Super Boost is the now!!

Anyway, there's no point to this conversation, what @jimvreeland said!
 

Patrick

Overthinking the draft from the basement already
Staff member
If they made the crank arms and chain stays thinner, they could make super mega boost.

who are they? certainly not the peasants.
 

stb222

Love Drunk
Jerk Squad
That has nothing to do with boost, is just the way you adapt different BB shell width to match the correct width of the standard crank. The 5mm difference between the 68mm and 73mm BB shell is equally split on both sides.



Anyway, there's no point to this conversation, what @jimvreeland said!
lol, boost shimano has a wider spindle, so just need more spacers. I have 500 hours on it with uneven spacers
 

serviceguy

Well-Known Member
lol, boost shimano has a wider spindle, so just need more spacers. I have 500 hours on it with uneven spacers

Uhm, I was under the impression they had a flatter spider for boost cranks. I must have been wrong, what would I know, I have super boost plus.
 

stb222

Love Drunk
Jerk Squad
Uhm, I was under the impression they had a flatter spider for boost cranks. I must have been wrong, what would I know, I have super boost plus.
Nope, the difference is in the spindle lengths, hence where there is only one model chainring for each level (SLX/XT/XTR). You may see different offsets fro after market manufactures that are designed for shimano's 12 speed chains.
 

serviceguy

Well-Known Member
fc-m7000.jpg


FC-M7000-11-1 (standard) and FC-M7000-11-B1 (boost), same Q-Factor, same chainring (notice the boost has less range, no 34T) , different chainline. I guess the 3mm are factored in the crank/spider only. Same goes for XT.
 

Santapez

Well-Known Member
Team MTBNJ Halter's
Shimano SLX 170mm cranksets have been impossible to get. REI ended up with stock and by that time I forgot to check to make sure it was boost. It wasn't...

Before I put them on I did a quick googling of how much the crankset will not work on my boost bike...this thread was at the top.

I can say no issues in the parking lot test. If anything it does seem to work slightly better in the larger gears. If I had some spacers laying around I'd probably try to push it out a mm or a few mm. Only ones I have are the regular ~3mm spacers and didn't want to mess with BB.

Seems to be A-OK.
 
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