[Theorist]

Thank you. Did you use it with a 45 tooth rear sprocket and a new 106 link chain? If not, do you believe to would fit?

I did some calculations and work on the sprocket cover clearance but won't know until it arrives and I install it.

Geometric calculations indicate the 16 tooth sprocket needs 5.015 mm more radial space than the 14 tooth sprocket. I measured a 5mm thickness of pages from a magazine headed for recycling. After cutting a strip of these pages about 2cm wide, I was able to place it around the chain on the 14 tooth front sprocket and then_barely_ fit the front sprocket cover on over it. I used the splatter marks of the grime flung from the chain to the sprocket cover to mark, score, the relevant areas on the sprocket cover. Using a Dremel I removed 1-2mm of aluminum from the inside of the cover. Then I used some play do to 'see' under the cover. I pressed the play do on the inside cover, pressed the cover into place over the sprocket and chain to create a mould I could measure. Moving around, I couldn't find any place with less than 6-7 mm of clearance. I removed another 1mm of aluminum where there wasn't at least 7 mm of clearance around the chain and 14 tooth sprocket, so hopefully at least 2mm clearance around the chain and 16 tooth sprocket.

When the 16 tooth sprocket arrives I'll try to mount the modified sprocket cover over it and listen carefully for any new noises as I ride. I'll also look for any marks suggesting any contact been the chain and sprockets cover the next few times I clean and lube the chain. I'm most concerned about grinding debris between the chain and sprockets cover, so I'll be looking for and signs of that.