TransAmMan
Active member
Hey Everybody
Shimano finally released a set of 160mm E-Bike cranks (** note: for the EP8 motor .. keep reading)
Background (why I wanted shorter cranks)
I have a 2019 Decoy Pro race, and decided to finally install a 2.6 rear tire .. BUT .. did NOT want to run the flip chip in high position ( I like low BB's and I cannot lie)
The reasoning : The 2.6 tire lowers the rear end of the bike by 5 mm overall diameter, that equates to an additional 2.5mm BB drop (1/2 the height difference or diameter of wheel .. actually slightly less than 2.5 considering geo is like a teeter totter .. but lets go with 2.5 for this example). The HIGH BB setting (via flip chip) elevates the BB by 7 mm. So by running the flip chip in the HIGH position, using the 2.6 wheel, the BB is RAISED by 4.5 mm (7-2.5).
SO the ultimate decision is : Change to a 2.6 rear tire and accept a 2.5 mm BB drop (with more pedal strikes) OR flip the chip and accept a BB that is 4.5 mm higher ?? After trying the high setting with the 2.8, I was not sold.
So I bought a set of the newly released 160 mm cranks from Shimano and wanted to share some info with all of you in the event you decide to do the same thing.
The New Shimano 160 mm crankset I installed was released for the EP8 motor can be viewed at :
FC-EM900
The Existing Shimano 165 crankset for the E8000 motor can be found at:
FC-M8050
Now here is what you NEED TO KNOW before going out and purchasing a set of 160mm cranks (from Shimano) and expecting a "bolt on" solution to your pedal strikes
****** The 160mm cranks designed for the EP8 motor have the SAME bottom bracket spindle specs BUT are approximately 4.5 mm shallower in WIDTH (see pics). PS I used the 2mm stock spacer from behind the cranks to achieve a more accurate width measurement in the pics below.
The E8000 motor crankset has a 2 mm spacer behind the cranks. When installing the NEW EP8 160mm cranks, the result is the cranks slide onto the spindle TOO FAR.
As a result, I have to install a new spacer behind the cranks. I know a machinist who made me a few spacers to try out. Finally settled on a 5mm spacer on both sides (to get the same end Q factor and alignment of crank serration interface with spindle)
?SAFETY NOTE ?: ***One thing to be aware of. That plastic TAB that clips down (AKA Crank arm safety plate .. pic below) on the 160mm EP8 crankset spindle WILL NOT align with the hole in the E8000 spindle. You will have to REMOVE IT. I replaced the plastic preload cap with an aluminum thread on cap as a result ... gold cap in pic above (because if the cranks ever came loose, I would not want to rely on a plastic cap the keep them on the spindle .. with the loss of the safety tab feature)
So end of story. The cranks did WORK (with some modifications), but I needed to replace the 2 mm spacers behind the cranks with 5 mm spacers AND needed to remove the safety tab above from each crank.
If anybody is thinking for buying these 160mm cranks designed around the EP8 motor, and installing on your Decoy with E8000 motor, you may find this post informative.
In the end I was able to gain almost 3mm of pedal clearance and still run the desired low BB position.
Cheers
Shimano finally released a set of 160mm E-Bike cranks (** note: for the EP8 motor .. keep reading)
Background (why I wanted shorter cranks)
I have a 2019 Decoy Pro race, and decided to finally install a 2.6 rear tire .. BUT .. did NOT want to run the flip chip in high position ( I like low BB's and I cannot lie)
The reasoning : The 2.6 tire lowers the rear end of the bike by 5 mm overall diameter, that equates to an additional 2.5mm BB drop (1/2 the height difference or diameter of wheel .. actually slightly less than 2.5 considering geo is like a teeter totter .. but lets go with 2.5 for this example). The HIGH BB setting (via flip chip) elevates the BB by 7 mm. So by running the flip chip in the HIGH position, using the 2.6 wheel, the BB is RAISED by 4.5 mm (7-2.5).
SO the ultimate decision is : Change to a 2.6 rear tire and accept a 2.5 mm BB drop (with more pedal strikes) OR flip the chip and accept a BB that is 4.5 mm higher ?? After trying the high setting with the 2.8, I was not sold.
So I bought a set of the newly released 160 mm cranks from Shimano and wanted to share some info with all of you in the event you decide to do the same thing.
The New Shimano 160 mm crankset I installed was released for the EP8 motor can be viewed at :
FC-EM900
The Existing Shimano 165 crankset for the E8000 motor can be found at:
FC-M8050
Now here is what you NEED TO KNOW before going out and purchasing a set of 160mm cranks (from Shimano) and expecting a "bolt on" solution to your pedal strikes
****** The 160mm cranks designed for the EP8 motor have the SAME bottom bracket spindle specs BUT are approximately 4.5 mm shallower in WIDTH (see pics). PS I used the 2mm stock spacer from behind the cranks to achieve a more accurate width measurement in the pics below.
The E8000 motor crankset has a 2 mm spacer behind the cranks. When installing the NEW EP8 160mm cranks, the result is the cranks slide onto the spindle TOO FAR.
As a result, I have to install a new spacer behind the cranks. I know a machinist who made me a few spacers to try out. Finally settled on a 5mm spacer on both sides (to get the same end Q factor and alignment of crank serration interface with spindle)
?SAFETY NOTE ?: ***One thing to be aware of. That plastic TAB that clips down (AKA Crank arm safety plate .. pic below) on the 160mm EP8 crankset spindle WILL NOT align with the hole in the E8000 spindle. You will have to REMOVE IT. I replaced the plastic preload cap with an aluminum thread on cap as a result ... gold cap in pic above (because if the cranks ever came loose, I would not want to rely on a plastic cap the keep them on the spindle .. with the loss of the safety tab feature)
So end of story. The cranks did WORK (with some modifications), but I needed to replace the 2 mm spacers behind the cranks with 5 mm spacers AND needed to remove the safety tab above from each crank.
If anybody is thinking for buying these 160mm cranks designed around the EP8 motor, and installing on your Decoy with E8000 motor, you may find this post informative.
In the end I was able to gain almost 3mm of pedal clearance and still run the desired low BB position.
Cheers
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