The SILVER crank is cold forged from 7075 T6 aluminum. That doesn't make it the world record crank, but it's not a shortcut.
There are different serieses of aluminum, differentiated by their own series and listed in thousands and whew—1000 (raw pure unalloyed), 2000, 3000, 4000, 5000, 6000, 7000. A series is defined by the main alloying elements, and overall properties of that series. Like, 7005 and 7075 are both in the 7000 series, but... as a matter of memory...they're both really strong for aluminum, but 7005 is easier to weld, and 7075 is better for forging. The most famous alloy is 6061 T6---the T refers to it being a heat-treated aluminum, and the 6 is the degree of heat treatment. It's also a forge-able alloy, and many cranks are made of it, although it's not as strong as 7075 T6 <---also heat treated. A lot of rims and handlebars are made of 5000 series aluminum. Handlebars at least--like, 5083, as I remember. Maybe 5083 T4. The best aluminum for handlebars is 2014 T6--that's what NITTO uses, and it has the best combo of strength and ductility. It's strong and not brittle. Rims are 5000-something, or 6061 T6.
For more authoritative info, cut and past this, because I don't know how to make it a link. I'll learn next week:
http://www.aluminum.org/resources/industry-standards/aluminum-alloys-101
Way off track, but most of that is close to the mark, and as a matter of fact, the SILVER crank is 7075 T6, which is about 25 percent stronger than the Sugino XD's 6061 T-something. But the SUGINO cranks simply don't break unless they're attacked by something super foreign, and so here's a case where a stronger metal may be better on paper but not in real life.
But the SILVER crank passes the toughest Mtn EN tests, which means you probably won’t break it, and if you do, it'll be in an accident so dramatic that you won't survive it to squawk. Our crank maker recommended 7075 because we wanted it to pass this test.
It has a fairly low-by-modern standards Q-Factor of 157mm to 160mm, depending on what bottom brack you use. And with a Shimano or Tange 110mm bb, the left and right crank stick out the same amount. Do you know how unusual that is?
It’s compatible with JIS taper bottom brackets, which are most of them, and the chainline is about 147 with a 110mm Shimano BB, and 150mm with a 113.
It is 100 percent fungible with a Sugino XD crank, our standard for years. If you use a mountain front derailer, get the 113mm BB; if you use a sub-mountain (like Shimano Claris or CX-70 or SORA), use the 110mm.
Basic comparison SILVER vs SUGINO XD. Two really good cranks. Our two favorite, actually.
Sugino has a softer finish that's overally slightly better, but don't go home yet... We're told the 7000 series aluminum on the SILVER is harder to get a perfect finish on, than Sugino's 6000 series alum. Maybe SUGINO’s finish department is just better. There’s nothing crappy about the SILVER finish, but the SUGINO's finish is slightly more even, or maybe the duller finish hides things better. Whatever—they're both nicely finished, but the Sugino wins that one.
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Emblem: SILVER is engraved, SUGINO is screened. Silver wins that one, but like the finish, it's a superficial thing.
Arm weight: SILVER weighs about 1/3 oz less. Neither wins, they both win. The hollow Shimano cranks are lighter, but Shimano doesn't make a lowish Q crank with the 110/74 bolt pattern (see below), so...they're not in the running here.
Lengths: SILVER: 170-173-178-184; SUGINO 165 -170-175 (also no picture). No winner here. It's probably better to have more length options than fewer, but we like the Silver jumps better. Lots of riders can ride either 170 or 175, which is why 172.5s are still sometimes made. Sugino quit making them, so we did the 173 only because it seems nuts to care about 0.5mm on a crank, and there's no reason to play into the "history" of 172.5.
Modern cranks go up to 220mm or so. Those aren't normal cranks, but there's some merit to longer legs riding longer cranks. Problems flare when you put those cranks on a bike not designed with them in mind. The pedals come too close to the ground. We're conservative-rational about crank length. I assume it jibes with what I wrote in Just Ride, because I've had no epiphanies since that.
165mm --- short legs
170mm -- normal to longish normal
173mm -- normal to long (there's a lot of overlap with 170...b/c 3mm is nothing)
175mm--the standard "long" crank for most brands
178mm -- our standard long. the extra 3mm is indetectable, but if you're looking at 175s, be extra cool and go to 178.
184mm -- LOOONG-legged riders on fat-tire bikes, which jack up the bike's bottom bracket enough to warrant a longy. Shimano's longest crank is 185mm. This is practically the same.
Back to SUGINO / SILVER comparison.
Chainring compatibility: both are 110 x 74 pattern—it used to be the most common, but it's still super common, and eliminates all worries about not being able to get chainrings. Those numbers refer to the diameters of the centers of the chainring bolts if you were to connect them. Like this:
All110/74 mm cranks, fit inner between 24t and 32t, middle rings and outer rings from 34t on up. A standard road crank has a 130mm diameter crank bolt circle, which limits you to a 38t inner ring. That's why they're for flat roads and racing.
Chainrings they come with: SILVER 44x34x24 triple, or 38x24 double (with guard); SUGINO 46x36x24 triple, or 40x26 double with guard.
Both are good, but when you're rolling around on 700x38mm tires and bigger, smaller chainrings make a hair more sense. The 11t or 12t rear cogs still let you go fast when you have to.
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Design for service: SILVER has 5-arm spider, separate inner ring washer, and uses no wafer-thin chainring spacers. SUGINO has 4-arm+hidden 5th spider, permanent spacers, and wafer-thin chainring washers.
THAT IS SERIOUSLY HUGE. Changing chainrings on the SUGINO is a PITA, and on the SILVER, it's 5x faster. Don't be bummed if you're riding around on a SUGINO crank, for crying out loud. For all-around riding, it's the second best crank in the world!Chainring guard note on double: The SILVER guard has cutouts, no big deal, but it looks slightly better; but the main thing is, the SILVER guard sits closer to the chainring, so it totally prevents the chain from jamming between the outer ring and itself. The SUGINO guard sometimes allows a chain-jam.
and this is why it may matter just a little, if you don't keep your front derailer adjusted correctly, as you should:
Don't see the 8.1mm Sugino gap as a design flaw. It seems nuts, but only faintly nuts to make the gap big enough for a chain to drop into, but if you're not sloppy iwith the front derailer adjustment, it'll probably never shift there. And if it does, it doesn't fall deep and is easy to extract. Still, the 4.7 gap on the Silver seems like the way to go.
The guards:
There's another small point, and it's how the inner chainring mounts. On the SUGINO it mounts onto a forged-on/unremovable shoulder. It's clean and easy and no big deal unless you remove the inner ring and want to tuck the crank in closer with a shorter spindle. The unremovable shoulder can hit the chainstay. Not the end of the world, just ride a longer spindle.
But on the SILVER, the inner ring mounts onto a conveniently removable spacer, so you can take off the ring and spacer and use a shorter spindle.
Why ride a shorter spindle? To get a lower Q-Factor (distance between the outside of the crank arms), and slightly more cornering clearance. TINY THING.
----------- SILVER CRANKS ARE IN, cost $225, but we don't have enough to try hard to sell them, and we're saving some for complete builds. Want to know how many we have? OK:
We got the same qty of 44x34x24 triples and 38 x24 doubles:
170: 20 (each)
173: 15
178: 10
184: 10
We have 20 chainguards. They're $20 each and mount on 110mm bolt circles.
NEW APPALOOSA PIX
It also comes in dark green. Both good.
Roman's pix will be better, but this one gives you the idea. It'll take a bigger tire with no fender, and you could ride as small as 32mm tires on it. But we'd say stick with 38mm+. No reason to go skinny on a bike like this.
Yeah, the top of the crown has these neat rack mounts. Lots of racks can fit there. Tubus REAR racks work as fronts on it.
Another view.
With fat fenders you have to grind some plastic away to make it fit. No biggie, easier. Mark used a Sharpie to mark it, side cutters for major removal, Dremel for smoothing out. When we assemble your bike, we do this. It's easy at home, tho.
I always thought it was pathetic for bike makers to show the rear derailer, as though it's a buying point. It isn't. Nobody makes a bad one, and Shimano's Deorge here is totally appropriate. What we're showing here is the 36T cassette. Combo'd with a 24t front, that's quite the low gear. More practically, tho--you can ride the 34t middle ring with it and have a less than 1:1 ratio. Might not have to drop into the granny quite so soon.
SILVER brand Chrome-molybdenum (CrMo) tubing is our own design. I/Grant think it's as well-designed as any, and better than 99 percent. No details here, I'm tired of talking about it, but the point is, it's really good. In a tubing decal first, we list the elements in the steel and its bike-frame significant mechanical properties.