These are high quality Japanese replacement chainrings made of dur-aluminum by either Sugino or SR (Sakae Ringyo).
They are made of 3.0mm aluminum plate stock that is stamp cut to shape and then turned on a lathe to cut the tooth area to width and produce the precision tapered teeth on both sides. Each of them also has the fixing mounting holes redrilled to recess the fixing bolt screw head or nut. After machining, they are anodized to prevent oxidizing. The outer chainrings do not have an anti-jam pin.
Mountain bike sizes are available in Silver or Black, (Black costs a bit more). Road racing sizes are available only in Silver. Mountain bike bolt patterns are 74mm for the inner, 110mm for the middle and outer chainring.
Road racing doubles use 130mm for both chainrings. Weights for each of the sizes are listed in the accompanying table. Available as mountain bike or road bike replacements. $ Price and Sizes Available in Catalog
It's just possible that you think shift gates, steel rivets, and added steel teeth are either unnecessary, or that the exchange rate has made the Japanese models too expensive. Perhaps you have just reached your limit as to how much money should be shoveled to the Orient, and want an American made alternative. Remember, chainrings are the only measurably consumable part of your cranks, and they will wear out and have to be replaced.
These chainrings are made in Southern California from 1/8" (3.175mm) 7075-T6 aluminum plate. Each piece and each tooth is CNC machine cut with the teeth tapered in thickness by lathe. The inners have a 58mm bolt center diameter, the middle and outers use a 94mm BCD. They are anodized in Blue, Black, Lavender or Silver. Functional, not fancy. Specifics are available in the table. $ Price and Sizes Available in Catalog
Action Tec is one of two firms selling Titanium chainrings. No one can say Titanium is inexpensive, but it's generally means that it's the last time you will ever have to buy that time again.
The Titanium used for these chainrings is an alloy of Titanium, with 6% aluminum, 4% Vanadium, and inertly, some Iron, Oxygen, Carbon, Nitrogen and Yttrium. This produces a Titanium alloy that is half as dense, (density is described as grams per cubic centimeter), or having half the weight of the same sized amount of steel, yet the Titanium has twice the strength, on a per weight basis as 21-6-9 aircraft steel.
Recapping half as much by weight, with nearly twice the strength, (for strength comparison 21-6-9 steel fails at 64,000 psi, while Titanium 3AL 2.5V fails at 115,000 psi), so in the same volumetric amount the Titanium is almost four times stronger than steel. For comparison sake, the best aluminum, 6061 treated to T6 fails at 40,000 psi.
Most chainrings are made from considerably softer 2014 aluminum, and a comparison to the softer aluminum isn't even available, because you would generally not use Titanium in place of 2014. All this is to give you a sense of how durable these chainrings are and to infer how long there useful life is. Truthfully, we haven't heard of one wearing out, the chain on a bike is softer.
The reason that these chainrings don't, by weight, appear to be appreciably lighter than the aluminum variety, is the aluminum ones are, and have to be made considerably thicker than the Titanium one to achieve the strength needed to stand against the steel drive chain. Titanium is a much more rigid metal and not subject to the same flex and distortion that soft aluminum is under load.
The Action Tec chainrings are cut from a piece of Titanium plate that approximately 2.0mm thick. The teeth are then ground for the tapered points. The final stage has the fixing bolt holes re-drilled, just slightly, for the bolt to fit flush.
Action Tec chainrings are available in Mountain bike fixing bolt patterns only, with 24, 34, 36, 48 or 50 teeth. Mountain bike bolt patterns are 74mm for the inner, 110mm for the middle and outer chainring and their is a 20 or 22 tooth inner Micro Drive/Hyper-C chainring using an oval hole that acommodates both 56mm and 58mm patterns. Weights for each of the sizes are listed in the accompanying table. $ Price and Sizes Available in Catalog
These are special heat-treated stainless steel chainrings that will not bend, nick, chip, or wear out nearly as fast as aluminum chain rings. Since Stainless steel is so much stronger than aluminum, Onza was able to make these rings thinner, which in turn cuts down on the dreaded chain suck. Naturally steel is heavier than aluminum, so these weigh a little more. Onza incorporates into these it's "Sweet Tooth," which is a tooth near the top and the bottom of the pedal stroke that cut shorter in height.
The Sweet Tooth, with it's shorter height, permits the chain to move onto and engage faster in a front shift. The spacing of these teeth is designed to minimize the chain engagement time. Buzz Saw chainrings begin as 2.0mm stainless steel plate stock that is die cut to shape, then turned on a lathe to cut it to the thickness for the chain and taper the point on the teeth.
Buzz Saw chainrings come with special width aluminum spacers to adapt and fit all mountain bike cranksets, and are made only in the 74mm and 110mm fixing bolt pattern. Available in a 24 or 26 tooth inner, and 34 or 36 tooth middle. Weights for each of the sizes are listed in the accompanying table. Made in Taiwan. $ OnZa Prices and Sizes that are still Available in Catalog
And now for something completely different. A Marin County, California company called Paragon Machine Works makes in small batches special chainrings for a group of riders on Mount Tamilpias that ride down the roadway on this mountain at the fastest speed they have the nerve to control. These "Downhill" riders to go even faster wanted chainrings with more teeth so that one crank revolution would turn the rear wheel several rather than a few times.
The 60 tooth downhill chainring is for these riders. It is totally machined from 5mm thick aluminum plate stock. All the excess aluminum has been milled away with precision cut teeth. This ring is a behemoth, and is painstakingly made to withstand monstrous stress. It is made of 7075 aluminum that is anodized to a titanium grey color. The 60 tooth ring is made only in the 110mm bolt circle diameter so it will fit on all mountain bike cranksets.
Remember no front derailleur will work with this, it's too big for the cage to accommodate. This gear is for flat, cajones out speed. The Paragon 60 tooth chainring weighs 173 grams. For the Few, it may seem expensive, but that's the way Marin County is!! $ Price and Sizes Available in Catalog
Profile Racing of St Petersburg, Florida makes machined from aluminum plate stock replacement chainrings. In each case the rings are milled out of plate with a CNC milling machine. The chainrings are cut from 3.5mm thick plate then turned to reduce the thickness in the area of the teeth equally from both sides making the teeth 2.0mm thick.
The chainrings are anodized in Blue, Black, Green, Lavender, or Silver. The inners have a 74mm bolt pattern, the middle and outers have a 110mm pattern. The inner positions are available in 24, 26, or 28 teeth. The mids are made in 36 or 38 teeth and the outers are made in 46, or 48 teeth. Although these don't have all the riveted on steel parts some of the Japanese chainrings have, they are easily affordable and made in the States. $ Price and Sizes Available in Catalog
Shimano has a version of chainrings called Superglide, which is the predecessor to the SG-X chainrings and evolved from a design Shimano called Uniglide. The Uniglide and Superglide concept for the front chainrings, has teeth that have been cut shorter in height than most of the others on the chainring. These cut down or "w-cut" teeth provided a portal for the chain to pass smoothly through, then drop squarely on the chainring.
The Superglide chainring puts these cut down teeth at two designated positions on the crank revolution. One of them is at 11:30 in the rotation, the other is at 5:30. The altered teeth at these areas, where the pedal pressure is the lightest, provide designated spots for the chain to be released and picked-up. Because the pickup and release points on the chainrings are carefully positioned in relation to each other, the chain moves quickly and directly from one chainwheel to the other. Dropped chains, grinding, and late engagements are pretty much eliminated. The Superglide concept is available in Round chainrings for Road cranks only. $ Price and Sizes Available in Catalog
Shimano has added further distinction to their aluminum mountain chainrings beyond merely cut down teeth. The SG-X is their newest design to facilitate quick shifting. The SG-X chainrings were first seen on the XTR cranks.
The outer chainring has four cut notches in the back side, with a 3.5mm diameter steel rivet at their base. A second 6mm diameter rivet occurs 25mm behind the 3.5mm rivet. These two rivets are to lift the chain's outer link plate, during revolution, to the top of the teeth so it doesn't rely just on being shoved by the front derailleur.
The outer chainrings are machined from 4mm thick plate. The middle chainring has four steel "shift gates" riveted to it. The gates are paired with a 44mm on center distance. The gates have a small protruding tooth that grips the outer link plate to lift the chain. To help the chain's journey, the die-cut 2.59mm plate is stamped to make ramp on the back of the chainring that holds the chain in place as the steel tooth hooks the chain. SG-X chainrings come in both 58mm, 74mm, 94mm, and 110mm bolt center diameters. Weights are listed in the accompanying table. $ Price and Sizes Available in Catalog