46/32 Cranks

Shimano is launching Metrea Cranks with a 46/32 ratio. I think it is a cool looking design and I'm reaaly liking the ratio.

http://www.roadbikereview.com/reviews/shimano-launches-new-sora-r3000-and-metrea-u5000/2

FSA is also coming out with lower ratio cranks. They'll have some using a weird 4 bolt 94 bcd pattern that can do ratios like 48/32, and also an inexpensive 110/74 bcd double in 46/30 like the Sugino OX601Ds.

SRAM offers a 48/32 double in their Via groups for commuters. The Via GT is about $150 from European retailers.

drwelby wrote:FSA is also coming out with lower ratio cranks. They'll have some using a weird 4 bolt 94 bcd pattern that can do ratios like 48/32, and also an inexpensive 110/74 bcd double in 46/30 like the Sugino OX601Ds.

SRAM offers a 48/32 double in their Via groups for commuters. The Via GT is about $150 from European retailers.

Glad to read that FSA has a 110/74 crankset. Such a good standard for giving a really wide range of options.

I found a set of small Sram rings (46t/38t) for my Gossamer crankset which I plan in using for a hilly 100 mi. gravel race. I may also see if it works to mix & match with what I have and use a 46t/34t combo.

I am running White Industries VBC cranks with 44/30 rings. Very nice in my hilly terrain.

drwelby wrote:FSA is also coming out with lower ratio cranks. They'll have some using a weird 4 bolt 94 bcd pattern that can do ratios like 48/32, and also an inexpensive 110/74 bcd double in 46/30 like the Sugino OX601Ds.

When?

Hard to say. They showed it at the Taipei show so it's intended for 2017 model year bikes. That would imply production starts late summer 2016. But that assumes they had enough interest in it from the OEMs. It may not go to production, or it could be OEM only and not sold as an aftermarket item.

My $.02 on this topic --- just a few thoughts:
- Always trying to balance various design goals in my drive train: gear range, shifting efficiency, mechanical efficiency, and to some extent, weight and cost.
- To solve many of these issues, at least on paved roads, the main manufacturers Shimano, SRAM, FSA, Campy have opted for some version of 11 speed 2x, with the compact 50/34 being the go-to for lower gearings, with usually an 11-28 in back. IMHO this is a poor design for several reasons. While this arrangement gives you a wide gear range, there is not enough overlap between the chain rings which requires frequent double shifts -- or even worse frequent cross chaining. 
- While on paper, everything looks great, mechanically, a chain and cog system losses mechanical efficiency as the number of teeth engaged - especially on the cog end - decreases. This loss isn't too important, unless the number of cog teeth is fewer than 14. At 11 and 12 teeth there is a measurable and noticeable loss in mechanical efficiency of the drive train, That's the reason you'll see many TT bikes set-up with 56 chainrings. Not so much to get a higher gear, but rather to be able to run 56-15 or 56-14 for better mechanical efficiency and as a bonus, a straighter chain line.
- In short, IMHO, "compact" road set-ups suck; and are virtually useless for gravel grinding.
- In the bad old days of 7-8 speed cogsets, the solution to all of this, was the road triple crank. And it was a very good solution, which sadly has been abandoned by the major manufacturers. Yes -- you can still get triple cranksets, especially in mountain bike configurations, but it is very hard to get these to work with brake shifters common to GG bikes.
I don't know, but maybe the best solution- short of going to a flat bar mountain bike front end- is to regress to an old fashioned 8 or 9 speed brifter triple setup similar to the one I'm using on my road tandem --- 52-42-32 in front, 12-36 in back?
PS: I have similar concerns and issues with 1x setups-- but that is another topic.
PPS: Currently running 11 speed 105 group on my Haanjo Comp GG bike with a medium cage 105 rear der. Switched to a 11-36 Sram cassette though. By screwing in the b-screw, the 105 med. cage der. handles the 11-36. The 36 is a little noisy --- but works. A Wolftooth hanger may fix the noise. So far, I've been able to get up some fairly  steep short dirt road climbs; but I suspect I may have to get some lower gearing for some longer steep climbs, or rougher roads. Probably a Wolftooth hanger with an 11x40 rear cluster? 

 

This may not be applicable for GG bikes, but for my road bike, I recently went from '96 Campy Record  53/42/32 x 9 to '15 Chorus compact 50/34 x 11.  Shifting is much better and my bike is about 1.5 lbs lighter.  Would less weight cancel out any drivetrain inefficiencies?

BWV 211 wrote:This may not be applicable for GG bikes, but for my road bike, I recently went from '96 Campy Record  53/42/32 x 9 to '15 Chorus compact 50/34 x 11.  Shifting is much better and my bike is about 1.5 lbs lighter.  Would less weight cancel out any drivetrain inefficiencies?

I can't really say. 1.5 pounds sounds like a lot; but really has little overall effect. For that matter, loses in mechanical drive chain efficiency are also small, and for most riding situations, unimportant. So, it really boils down to the type of rinding and terrain you ride. And of course, personal preferences. When you updated your old drive train, you also probably updated many other components of the system, besides the crankset. And went from an older technology to a much improved new technologies. These all may account for your smoother shifting etc. Unfortunately, the major players in the industry haven't applied the same interest to road triples. My main gripe with the standard 50/34 compact road setup is the big gap between the rings that always require a lot of double shifting and also a lot of cross chaining while riding on rolling terrain. 

I've just built at a new FSA Gossamer 386 on a Specialized Sequoia Elite, (48,32).

It's four bolt, 100bcd by my rough measurement (70mm between bolts). 

The "adventure" gear-sets from FSA has 90bcd, the one from Praxis has a 110 but only works with their cranks with some special bolt hookup. This metra groupset is just another quiver in the ever increasing options we are getting now. I hope that its built to ultegra standards and not sora standards.

It's rumored that Shimano has a road clutch derailleur and a supercompact road crank slated for the 105 level for 2018 bikes.

thomasha wrote:I've just built at a new FSA Gossamer 386 on a Specialized Sequoia Elite, (48,32).

It's four bolt, roughly 100bcd by my rough measurement (70mm between bolts). 

Having a closer look, the large chain ring on the Gossamer says 110bcd. That seems unlikely, as it has the bolts at 77mm apart. I doubt I measured that poorly, so I'll have a closer look some time soon.

I'm looking for a 46/30 crankset for my Masi CXGR equipped with Shimano 105 11 speed, BB30 I believe. I've heard FSA is coming out with one, but can't find anywhere yet. Does anyone know of anything available now that would be compatible and provide me with 46/30, or even 44/28 up front? I changed to 11-36 cassette last year, can't really go bigger in back without changing out derailleur too. I think going smaller in front would give me the gearing I'm looking for on the steep gravel roads of upstate NY. Thoughts or recommendations? I don't really want to go back to square taper bottom bracket, which seems to be the only current choice.

I ordered the Rotor 46/30 Spidering set this week.  It's a PITA to find.  Got out of the UK from:

http://www.velotechservices.co.uk/shop/vclose2.asp?prd=224549&cat=373

They have one left now I see.  Supposed to be at my door (US) Monday.  

Had already purchased a Rotor crank used, just for this.

Compass also has some interesting crank designs - if you don't mind going retro on your BB: https://www.compasscycle.com/product-category/components/cranks/

I also find the crank lengths a bit odd 171, 177 mm. I spoke to the folks at Compass about the non-standard lengths. The explanation, as I understand it, is that they use forged cranks and don't want to machine them down to standard lengths which they claim other manufacturers do, because this weakens the crank arm. You also have to use a retro square taper BB with a threaded BB shell. Love the variety of chainring alternative from 24 to 52 teeth. I also asked about 11 speed compatibility - they said they were planning on doing some tests and would let me know. They also argue that there is no real practical difference between 171 and 172.5, and ditto for 177 vs 175. I run 175's and have some heel clearance issues with my size 47 bike shoes. The 177's may not fit my big feet. 

Are there smaller chain rings that would fit my current FSA 110mm BCD crankset? As far as I know, the current 50/34 is the smallest I can go. Am I wrong? And if so, please tell me what is available and where it can be found!

Cmtgravel wrote:I'm looking for a 46/30 crankset for my Masi CXGR equipped with Shimano 105 11 speed, BB30 I believe. I've heard FSA is coming out with one, but can't find anywhere yet. Does anyone know of anything available now that would be compatible and provide me with 46/30, or even 44/28 up front? I changed to 11-36 cassette last year, can't really go bigger in back without changing out derailleur too. I think going smaller in front would give me the gearing I'm looking for on the steep gravel roads of upstate NY. Thoughts or recommendations? I don't really want to go back to square taper bottom bracket, which seems to be the only current choice.

Thats from germany https://www.bike-components.de/de/FSA/SL-K-Modular-Adventure-BB386EVO-Carbon-Kurbelgarnitur-Modell-2017-p55184/ , only in 175mm in the moment.