0

I have a 90s era Cannondale Killer V 900. I believe it has the Headshock fork with the shock directly below the headset.

I am converting the bike to an electric commuter. I have a few other bikes - just don't like to get to work sweaty.

The ebike motor kicks out so much torque that a steel fork is recommended. I am a noob on bike maintenance and it's tough to tell much info on the boards.

Based on what I have gathered I can get a 1.5 to 1 1/8 conversion piece and get a steel fork.

Can someone confirm this? I'm also not sure on if I get threadless or threaded and if any differences exist in lengths? (i.e. do I need some spacers or something else.)

7
  • If the motor puts out so much torque they recommend a steel fork then a 90's aluminum frame is not a good choice. So you have a few bikes? Does not make this a good project bike for conversion to electric.
    – paparazzo
    Mar 27, 2015 at 18:22
  • 1
    Unless the motor is on the front wheel, the comment about steel forks and torque doesn't make a lot of sense to me. Where did this advice come from? Mar 27, 2015 at 18:35
  • @FredtheMagicWonderDog Torque on the crank flexes the whole bike down to the wheels.
    – paparazzo
    Mar 27, 2015 at 18:40
  • Yes the motor is on the front wheel. As aluminum breaks - the torque on the fork can snap the wheel mount. So its just at the torque point. You can put on torque arms - but does not entirely eliminate the issue. Steel bends and it stronger. The same issues exists if I put on a rear motor (both the frame and fork are aluminum) - so if I put Mar 27, 2015 at 18:48
  • The same issues exists for a rear wheel as the frame is aluminum - you can put in some steel plates to reinforce the wheel mounts - -but in the rear there is limited room to do this - -so its much simpler to put the motor in front. Mar 27, 2015 at 18:49

1 Answer 1

1

Yes, you can use a 1 1/8" fork with a 1 1/2" frame. I did it on one of my bikes. You just have to get a special "reducer" headset. It doesn't look goofy at all - you can't even tell unless you look closely.

You'll have to get a threadless fork. Nobody makes reducer headsets for threaded forks.

Most new forks come with an un-cut steering tube - that means it's a few inches longer than most people need, and you have to cut it to the right length.

Make sure that the crown-to-axle distance is approximately the same as your old fork. If not, it'll change the bike's handling characteristics, maybe drastically.

3
  • Thx much - will check it out Mar 27, 2015 at 20:10
  • @TomMcCarthy be careful because the Cannondale HeadShok1.5" is not the same as other 1.5". There are adaptors specifically for this that either allow the frame to take a 1 1/8" headset or others that allow the existing bearings to be used. I have used both types and I think if you can use the headshok bearings you will be better off, and the cannondale kit is still in production. Search part KP058
    – Noise
    Jul 27, 2021 at 20:00
  • @TomMcCarthy qwertycycles.co.uk/products/…
    – Noise
    Jul 27, 2021 at 20:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.