×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Will this bearing last? Dirt bike

Will this bearing last? Dirt bike

Will this bearing last? Dirt bike

(OP)
Hi all I’m currently in the early stages of designing an electric start system for my Dirtbike (Kawasaki KDX200) using a bendex style set up. The bendex has to be mounted the wrong way, the bendex will engage the engine via a gear attached (bolted) to the flywheel (see photos) but due to it having to be mounted the wrong way I’ll need to put a smaller gear in between the flywheel and the bendex to reverse the rotation and turn the engine in the correct direction. This small gear would be constantly spining with the engine when it’s running) I’d use a sealed bearing mounted onto a shaft. So my question is would this sealed bearing last under constant motion and spinning at the same RPM as the engine? Keep in mind the gear is very small so there would be a lot of stress on the bearing only stress from the RPM of the motor. Cheers images bellow ⬇️ (photos of are of the bendex fully extended downward to show it engaging the small gear)

RE: Will this bearing last? Dirt bike

Yes. There are lots of bearings of the same type within the engine and provided you're is not loaded during normal operations it will exceed the life of those other bearings.

Can you find a starter that does not require a support bearing?

Can you find a starter with a roller clutch so it can stay engaged with the primary gear at all times?

As a fellow dirt bike rider, e-start on a KDX? That bike will start itself with a stiff breeze on the kick starter.😉

RE: Will this bearing last? Dirt bike

(OP)
In order to remove the use of a a chain and starter sprag clutch which requires oil to use and also adds extra moving parts
. I’ve decided to use a bendex as it can be run dry. The only “load” on the bearing will be that of the engine spinning. As for the kick start yes absolutely these bikes start unbelievably easy, but I ride enduro so I cant count the amount of times I’ve had to actually get off my bike to kick start it. In this situation an E start set up would be amazing it seems like as long as the shaft is the correct size and has good tolerances. The bearing is pressed in straight and is lubed properly it will last. Thanks for the reply.

Quote (TugboatEng )

RE: Will this bearing last? Dirt bike

Didn't Kawasaki have a 2 stroke engine in the 70's that used the flywheel/stator as a motor for electric starting?
As someone with an XR250R (imagine that), I feel your need for the magic button.

RE: Will this bearing last? Dirt bike

Seems like there would be a bunch of drag with that small gear always spinning. Can't you reverse the direction of the starter somehow?

RE: Will this bearing last? Dirt bike

Quote (XR250)

Can't you reverse the direction of the starter

This is the path I'd be wanting to take.. starter motors are DC devices, it can be done. The changes needed are straightforward, how easy it is depends on the specific construction of the motor you're using.

The easiest solution would be to find a starter motor that turns the right direction. Starter motors are cheap.

RE: Will this bearing last? Dirt bike

(OP)
https://www.eng-tips.com/userinfo.cfm?member=XR250
Yes I’ve luckily found a bindex which spins the correct way so no need for that silly idle gear and bearings set up so now I can just use a starter motor and bindex. That’s all Ill need so it’ll remove the extra moving parts. This is a far better set up and should last forever.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close