Ari Bike Pignoni oversized 40-tooth and 42-tooth cogs for Shimano and SRAM cassettes

Ari Bike, an Italian maker of various aftermarket spider/chainring units and spiderless chainrings for a wide variety of crankset brands, has just thrown their hat into the oversized cog ring.

Offering three distinct models, they cover Shimano XTR M980 and XT M771 10-speed and SRAM 1030/1050/1070 10-speed cassettes. Like the others, these 40- and 42-tooth cogs sidle up next to the back of the cassette and require removal of the 17t (or 15t for some versions) cog.

Claimed weight is 70g to 73g depending on model. They come with a replacement screw for your derailleur in case a longer B-screw is needed to help the mech clear the new cog. Retail is €65, with delivery available in the US via express courier. Pics and links below…


They’re machined from ERGAL 7075T6 then hard anodized in an array of colors.


Their main website is and the direct product page in English is here.


  1. We have been finding that y his type of product is resulting in chain skip on the lower cogs. Once the b tension is adjusted to clear the 42, the upper guide pulley ends up being lower and further back on the smallest cogs. This means not enough chain wrap. Get a smaller ring up front and learn to spin.

  2. I just received one and installed it. It works great. I had a little trouble getting it on the xd1 driver. I also had trouble with the second spacer. I damaged it during install. However it is identical in size to bottom bracket spacers which I used and work perfectly. I emailed them and they gave me a paypal address to send payment. I am stoked that I don’t have to buy a whole new cassette. Why doesn’t SRAM offer replacement 42t cogs? Seems like a brand new cassette to me.

What do you think?