I'd suggest to report your installation difficulties back to your vendor. It is their responsibility to verify you got the correct sprocket, it is listed correctly and suggest mods (if they are actually needed?)
Their listing may be based on fitment error, let them verify, based on your info, the ultimate answer.

 

Hi everyone,

I'm hoping someone can offer some insight. I recently purchased a bike with around 8,000 miles and decided to replace the chain and sprockets due to rust on the existing chain.
I ordered a front sprocket from Sprocket Center (part number JTF512-16RB), but I'm running into clearance issues during installation. The OEM sprocket fits snugly into the channel for the retaining plate, allowing it to seat fully and rotate into position so I can install the bolts. However, the aftermarket sprocket seems to be a few millimeters too thick, preventing the retainer from fitting properly.

There’s a rubber dampener on both sides of the sprocket, one with a groove that appears designed to accommodate the retainer assuming the sprocket is installed with the correct side facing out the retainer would not fit. The strange part is that if I reverse the sprocket, the retainer would fit properly, but I would need to grind down part of the rubber on the back side to make it work. and accommodate the clip

Could this sprocket be mis manufactured, with the rubber dampeners installed incorrectly? Would it be inappropriate to grind down some of the rubber on the opposite side to make it fit in reverse? Or would it be better to slightly file the retainer and install it as is? I'm hoping to avoid any potential balance or misalignment issues, as I'm unsure whether modifying the sprocket or retainer could cause unusual side effects.
Any advice or experience with this part would be greatly appreciated!
Thanks in advance.

hi, this issue is more common than you would think simply because aftermarket parts are not to OEM spec and differ because of patent rules.
However you have several options open "all will work as this has been covered on the forum several times"

option 1. buy a new plain sprocket (without rubber cushion/rubbing strips).
option2. keep the sprocket you have "it is brand new" and modify it to fit.

to make the one you have fit simply either rub down the strip (on the back side) down on a flat surface using sand paper, until it fits flush enough to slide in the retaining clip and bolt it up, or turn the sprocket round ditch the retaining clip and replace it with a standard external spring "C" circlip the correct size to fit the groove to hold the sprocket onto the shaft, either works just fine.

FWIW, I have theses sprockets on both bikes because I like the idea of the rubber cushions, on the gen 1 I sanded down the backside and fitted the stock retaining clip. but on the gen 2, I ditched the stock retaining clip and fitted a circlip instead both methods work just fine.
also note, rubber cushioned sprockets are thicker than plain sprockets so may seem stiffer to turn when fitted, this is not a problem as 50miles down the road they will wear in a bit but still retain a snug fit on the output shaft.

 

Thanks everyone for the replies! I went ahead and modified the sprocket using a Dremel tool to better match the OEM damper. It now fits like a glove. Sprocket Center was kind enough to send a nonrubber dampened version as well, which would have worked too, but I’ll be sending it back since I chose to go the route of modifying the original.

For future reference, I’ll keep in mind that the customer rep mentioned the sprocket is designed to fit many different models, so it doesn’t account for differences between manufacturers. So if you dont wish to modify part stick with oem or non rubber sprocket.