Chainline Issue on mid drive Specialized Hardrock

[Biggsy66]

I just installed a 48V 1000W Mid drive motor on my Specialized Hardrock and the chain line is no good from the largest rear cog. Anyone know if I can move the cassette closer to the derailleur to bring the chain away from the wheel and straighten up it's line? It is a shimano 8 speed.

 

[WilliamT]

Depends on what mid drive motor you purchased. If you have a BBS02 or HD, then you can purchase chainrings with different offsets.

 

[Lindenwood]

Probably the simplest option would be to rearrange the cassette. Bassically, take out a couple smaller cogs and stick them (with their respective spacers) on the inside of the cassette closest to the wheel. Then, adjust the shifter to "lock out" those last couple of gears.

Now, without spending any money, you have fixed your chainline issue without losing total gear range. Unfortunately, the downside is that you end up with maybe a 6-speed shift range with larger jumps between gears.

If I end up going with a BBSHD on my 120mm BB fat bike, the resulting chainline will require me to pare my 10-speed shifter down to 7 cogs, for the same reasons.

Good luck!

 

[Biggsy66]

OK thanks guys. I ended up locking out the top gear which in my case is 8 but it's no bother really because the BBSHD has so much power i didn't need it anyway. I'm actually pretty happy with the setup although the gear shifter is ordinary so I'm thinking about changing the lot, gears, shifter, cable, derailleur etc. The current setup is a Shimano CS-HG31-8 Cassette paired with a Shimano Altus derailleur and Altus SL-M310 shifter that's seen better days. Any suggestions would be appreciated. Oh I also upgraded to a Lekkie 46T chainring. I would like more top end but not sure how much more I can get out of it. It only reaches around 45kph on the flat with a top end 52V 14AH Panasonic battery. It could be my 85kg's that's slowing it down but I was hoping for maybe 60km/h. Anyway it's still a great thing, I'm loving it.