BBSHD PEEK and/or Metal Gear Wanted

[whitebsw]

Hello everyone. Trying to complete my first ebike build and am in need of either a PEEK Gear or metal gear for the BBSHD. This is a "souped-up" build w/ the BAC 855 controller and pretty large battery pack. From what I've gathered the nylon gear just isn't going to hold up for the riding I plan to do. Seems like Luna never has either of these in stock and I worry they may never again. Tired of waiting. Figured I'd reach out to see if anyone had either laying around they wanted to get rid of. Willing to pay for shipping and whatever reasonable price you ask. Appreciate any assistance you can provide.

 

[Chalo]

Keep the motor spinning in an efficient RPM range, and torque in the reduction gear will be moderate. Leave it in top gear and beat on it like you're trying to break it, and it will oblige you.

Switching steel-on-polymer gears to steel-on-steel risks tearing up both the metal gears, because the design didn't accommodate that. A steel gear intended to run on nylon doesn't have to be hardened or generously lubricated like a steel gear pair. Substituting a second steel gear for nylon would be like getting a tungsten carbide crown on a bum tooth. Yeah, sure it will keep that tooth from wearing, but it will trash the natural tooth that bites against it.

 

[tomjasz]

The steel gears are not around because they were a failure. those peanut butter gear stories are from those that don’t control temperatures. Or ride a BBS01-02 like it’s a BBSHD.

 

[whitebsw]

Appreciate the feedback. Will experiment with the nylon gear and see how it holds up taking into consideration both motor temp control and keeping torque within reasonable ranges. Will likely upgrade grease here soon and see how that helps things.

 

[tdiz]

Since this was the first search result I came up with for BBSHD Peanut Butter Gear, I thought I'd offer some real world experience to future people worried about proactively replacing this weak link.

I have 1800 miles on my BBSHD with the original peanut butter gear, and it's still going strong.

I load up the drive system fairly aggressively, sometimes riding at low PAS settings, and putting a lot of my weight on it, and sometimes I just want to have fun so it's throttle time and motorcycle style riding.

There are lots of hills here, and I ride on some dirt but mostly, mostly gravel, grass, and pavement.

I ordered one of the replacement gears from luna a while back, but figured I'd just keep that in my parts box until I need it.

So my advice is the same as my advice for all internet news/opinion - don't worry too much about the fear mongering. Try it and see. It may not be an issue at all in the long run.

And I weigh 350 pounds, and ride a heavy bike with clydesdale wheels, a big battery, and saddlebags sometimes full of groceries.

 

[Mongo]

For those looking for a PEEK plastic replacement BBSHD gear, Luna is now offering a carbon composite mixed with the PEEK plastic version:


HV (High Voltage) is also offering a PEEK plastic version now:



I've got Luna's original PEEK gear version in my BBSHD motors, and they're very quiet. As already written, treat the drive correctly and the nylon gear will probably hold up fine.

I did have a stock nylon version fail once, but not from the gear teeth melting/deforming. Instead, I suspect the one-way clutch was slipping and heated up, melting the nylon to clutch junction:

 

[harrisonpatm]

For those looking for a PEEK plastic replacement BBSHD gear, Luna is now offering a carbon composite mixed with the PEEK plastic version:

Carbon composite plastic gear? My thinking is that this will create the same issue that @Chalo was discussing earlier: carbon composites can sometimes be abrasive enough to wear down the steel gear that it's meshing with. Alternatively, an all-nylon or all-PEEK gear has a degree of flexibility to increase toughness. Adding carbon would make it stiffer and could make it easier for the teeth to crack and chip.

Am I wrong? I like 3d-printing with carbon fiber composites for lots of things, but this seems like a not great application.

 

[Chalo]

Carbon composite plastic gear? My thinking is that this will create the same issue that @Chalo was discussing earlier: carbon composites can sometimes be abrasive enough to wear down the steel gear that it's meshing with.

Sure, maybe? If the resin matrix serves as a kind of solid lube, then the carbon filler might be more polish than abrasive. Still I think if the part was engineered for nylon, the farthest I'd want to wander from that would be something like Hydlar ZM (basically nylon filled with kevlar fiber and moly disulfide). That would make the part stronger, more heat resistant, more wear resistant, and self-lubricating.