Rivvy Silver Chainrings
SILVER SILVER CHAINRINGS @ $1.00/tooth
By popular silence we opted for the unsung sizes that hit the hidden sweet spots between the familiar, famous sizes. In all cases, we opted for the most expensive and longest wearing aluminum (7075) and a smooth satin finish that's appropriate for any of our bikes, and certainly any others. They're not bead-blasted or matte; they're not gleamers like TA rings. They start off looking worth their price ($1/tooth, remember) and with use look as gritty and unspecial as any chainring. All rings have the super prestigious SILVER logo.
To fit the Sugino cranks we sell, but there are millions of other 110x74 cranks out there. The modern four-bolt cranks are not. The center-to-center distance between bolts on a 110mm crank is (by eyeball, not by math) 65mm. That's how you tell, if you don't know.
110 x 45t, 43t OUTER rings
We weren't just trying to be diff here. Most of us ride puffy tires, which means a 46t feels bigger than 46t, so going to 45 or 43 makes sense. The oddball sizes didn't make the decision any harder, though.
They're "ramped and pinned," to use the industry parlance, which just means the inner surfaces have the strategic cutaways and grab-pins that allow front indexing to work. We're vehemently opposed to front indexing, baffled up the wazoo that it even exists, but there it is, and making these rings compatible with front indexing doesn't make them worse in any way (just more expensive to buy). For front friction shifting, the ramps and pins probably help at the microscopic level.
The outers have a unique web between two of the pins, and on that web is the SILVER logo.
110 x 35t MIDDLE ring
Same logic: A tiny tooth smaller to account for bigger tires. No big deal, seriously.
You could use it as an outer, although we'd have to say, it's a little small for that. But what physically defines it as a middle is its lack of ramps and pins.
74 x 25
This one we purely clearly picked to be the only ones (please don't email proof that we aren't) with a 25t ring.
Get creative. You don't need to swap all at the same time. Do it as needed. Try to keep the middle-to-big gap to 10t or less, for best shifting. Like, let's say you're riding a 46-36-24 now (the standard Sugino ratios). Turn that 46 to a 43 and omygosh, the middle-to big shift will be like ghee. Even a 45 will improve it.
Starting from scratch, a 43 x 35 x 25 combo would be hard to beat. Whatever-these are all top quality American made rings, holding nothing back. Easy to remember pricing, too.
Come with a "Grub Screw" that you put behind the face of your crank arm to prevent the chain from jamming between the big ring and the inner face of the crank arm.
Many cranksets come with this anti-jam feature built in like this one on the Sugino.
That pin there keeps the chain from getting stuck between the chainring and crank arm.
Here's the screw that serves the same purpose on our Silver rings.
The red stuff is locktite. Every home shop should have locktite, so if you don't, get some. Smear it on the grub screw before you thread it onto the chainring.
Here's a neato tool to keep that chainring nut from spinning round and round.