Install the chainring on the outside of the spider

[Tom Clancy's eBike]

Hello,
My eBike is Giant Dirt E Pro. The spider is designed to have a chainring on the inside.
I'd like to change to a 44T chainring. But 44T hits the chainstay. So I move the chainring to the outside of the spider. There is a gap because of the opposite installation. I put a 2mm bolt washer between the gap. The bolt is 8.5mm.
The chainring is still wobbling around the spider. This is not a good sign. I want to know if anybody has a fix for the wobble.

 

[m@Robertson]

On a different spider, this wouldn't be a problem. On a generic 104 BCD spider you might reverse the chainring bolts so what was facing on the outside is now on the inside. Then do the same thing with the chainring itself. That lets your bolt inset properly into the countersink on the chainring, and so long as the bolt head clears the interior side its no harm/no foul. However, on your spider, meant for a Yamaha motor, their design doesn't allow for this. Usually a chainring spider has a smaller shelf on the outside, meant for attaching a chainring guard, but it can be put into service to mount a chainring on the outside.

You don't have one, and that means your ring mount is bolt-centric: - 100% of the forces applied to the chainring must be borne by the bolts. Definitely not my first choice and for a powerful mid drive motor, likely a bad idea.

It will also skew your chain line and probably turn the chain into a chainring saw if you try to ride on the bigger cogs thanks to the skewed chainline.

I think your options are to find out what the smallest ring is that will fit and use that instead. I am certain I could cobble together a way it would work, but it would never be able to get around the chainline and strength issues.

 

[theemartymac]

I'd have to concur with m@Robertson, and the only thing I could suggest if you really want to try a workaround is to take the chainring and spider to a fastener specialty store and see if you could assemble something with a set of centering or cone washers that might help compensate for the taper and lack of shelf. You'd probably spend at least as much on hardware and bolts as you would a new chainring however...