[Solved] Help removing Bosch lockring without the sprocket installed

[alg26]

I hope someone has a creative solution to my problem.

I did something stupid on my Trek Super Commuter 8s. I was tired after sizing my new chain and mistakenly threaded the lockring without a sprocket installed (changed the cassette +4T, pulleys and front sprocket -2T to make hills easier with the motor off). The sprocket splines spin clockwise with the lockring and left pedal but free spins from the left pedal when it’s pedaled backwards so there’s nothing to torque against to remove the lockring.

Any ideas less destructive than just cutting the lockring completely off?
The Bosch lockring design is PITA btw. So easy to slip out and scratch up the lockring.

[Edited sprocket spec and wording]

 

[fooferdoggie]

Zip tie the crank arm to a part of your bike so you have leverage. use a strong one. or get someone to hold the other crank arm either will work.

 

[alg26]

Did I mention the lockring is reverse threaded?
When I turn the lockring clockwise (pedal forward direction), the left pedal doesn’t move. Not that it matters but I just connected the right pedal and saw the same thing.

Basically, when turning clockwise (pedaling forwards direction) the pedals will spin the sprocket but the front sprocket does not turn the pedals, which is my problem. I need the chain (using the back brake) to hold the sprocket/lockring.

 

[fooferdoggie]

Did I mention the lockring is reverse threaded?
When I turn the lockring clockwise (pedal forward direction), the left pedal doesn’t move. Not that it matters but I just connected the right pedal and saw the same thing.

Basically, when turning clockwise (pedaling forwards direction) the pedals will spin the sprocket but the front sprocket does not turn the pedals, which is my problem. I need the chain (using the back brake) to hold the sprocket/lockring.

oops ya I see what you mean its been awhile since I did it. not sure what's left if it is tight. I have one if you need another one.

 

[TOOSLOW]

Cut it off, soft aluminum and fairly inexpensive.
There really is no other way to hold the other side without damage to the crank splines.
Cheaper to buy the lock ring than damage the motor.

 

[alg26]

I'm going to try cutting the old front sprocket with a Dremel in half so that I can use cassette pliers or the new chain on the bike to hold the sprocket splines in place.

 

[fooferdoggie]

I'm going to try cutting the old front sprocket with a Dremel in half so that I can use cassette pliers or the new chain on the bike to hold the sprocket splines in place.

need another one? have a spare.

 

[alg26]

Thanks. I'm good. I have a brand new SRAM 18T front sprocket I'm anxious to try. Gonna need it since I haven't ridden in a while.

 

[fooferdoggie]

Thanks. I'm good. I have a brand new SRAM 18T front sprocket I'm anxious to try. Gonna need it since I haven't ridden in a while.

I mean the lock ring do you need one? or maybe thats what you man. I am tried today. this is what I use keep the chain on and looks cool. I use share and have a 18' a bit noisy compared to the 22t that came with the bike but now my bike climbs like a goat.
https://www.amazon.com/gp/product/B01N5A610D/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[alg26]

Split front sprocket worked. Bike is back together.
Put the bike on the ground and held the wheel while I cranked on the lockring. Using the cassette pliers didn’t work.