The SRAM Eagle has landed!!

As most of you probably know, SRAM's latest 1x12, Eagle drivetrain has been introduced.  In a previous posting I wrote, I talked about a little bit about Gear Range and Gears and Gear Inches and I thought it might be a good idea to re-visit the topic again now that SRAM has come out with its 1x12 system.

SRAM_Eagle_Vs_Rohloff

In the above picture, I'm comparing a Rohloff Speedhub 36T/16T to SRAM Eagle 32T / 10-50T setup.  I purposely picked 32T as that matches the 36T/16T well and probably a typical setup someone looking at the Eagle would pick. 

The data can be found here and you can try different combinations.

So to start, SRAM is touting the benefit of a 500% gear range which is all well and good except Rohloff has a 525% gear range and have always had this gear range right from the get go, 20 years ago.  I think at this point, there is no denying that riders like not having to fuss with a front derailleur/extra shifter and enjoy the simplicity of a single chain ring but Rohloff knew that sooner ;) 

Rohloff having 14 gears offers a consistent ~13.5% in each gear increase/decrease.  If you look at the chart above for the SRAM Eagle system, the gear step is low as 13% and as high as 20% so what that means is that some gear changes feel larger while others feel more incremental.  The gear range for the Rohloff is 70.4 vs SRAM's 67.4.  So larger gear range with more gears vs lower gear range and 2 less gears.  Which system do you think will give you a higher chance of finding that 'right' gear?  Don't forget most riders are not Enduro riders where most of the course is downhill.  Finding that right gear is important.  And let's get that elephant in the room out of the way, the SRAM Eagle is lighter and cheaper initially (although not by much) and I would argue would end up costing a lot more which I'll explain below.  

SRAM_pricing

The drivetrain for the Rohloff hub is inside a hub shell and protected from sand and grit and for the most part everything out there.  The SRAM Eagle like any other derailleur system has everything exposed so the gears will wear, that's just a fact of life.  The derailleur will wear and the cassette will wear.  I know many people that have ridden all over the world with Rohloffs and have only had to do oil changes along the way and replace the seals and maybe bearings for a cost of $150-$200.  And that's 10s of thousands of kilometers.  The SRAM Eagle cassette and derailleur will set you back $580 US every time you need to replace it.  Not to mention the extra cost of the chain ring and chain compared to Rohloff that uses standard narrow wide chain rings and standard 8 spd chain for $40.  So we must think about lifetime cost and not just purchase cost.  Unless of course we're sponsored by SRAM, then obviously that doesn't matter.  Then we'd get our own mechanic and maintenance wouldn't matter either.  But of course we don't live in a perfect world with our own personal mechanic cleaning our drivetrain after every ride. 

Let's then talk about the durability of the overall system.  The SRAM Eagle wheel requires it to be dished, that's just the reality of a derailleur system.  The spokes are not tensioned equally on each side of the wheel.  A Rohloff wheel has no dish, the spokes are equal length on each side, and hence equal tension on both sides.  An equally dished wheel compared to a dished wheel all things being equal means a stronger wheel.  That's just physics.  The SRAM wheel may be lighter but it'll be weaker and because the gears and derailleur is exposed to the elements will not be as durable. 

At the end of the day, the SRAM Eagle as great as SRAM touts it to be is really only lighter.  It's not cheaper (see above), offer more gears or gear range, stronger or more durable and requires more maintenance.   So there you have it, a comparison between the SRAM 1x12 Eagle and the Rohloff 500/14 Speedhub.  Eventually when SRAM and Shimano offers their 1x14 drivetrain, I'll have to do this again.  Although I can't imagine how thin the chain and each cassette cog would have to be and how much dish the wheel would be to accommodate that many gears. 

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Rohloff and Post Mount

There has always been a desire to mount Rohloff hubs on frames with post mount rather than IS mount.  For frame with IS mount, it's always been easy as there are IS to Post Mount adapters and with the use of the Monkey Bone, the Rohloff Speedbone is even eliminated only needing the OEM2 axle plate.  By using the OEM2 axle plate along with either the Speedbone or Monkey bone, the setup is much cleaner and no more need to use the standard axle plate that bolts onto the chainstay.  For some frames such as the Surly Troll, there is even a dedicated spot to attach the OEM2 axle plate to.  I truly feel Surly is one of the most innovative bike companies today and understands their customer base like no other.  Post mount frames however has always been tricky for Rohloff and there just wasn't a clean way to mount it. 

New for 2016, that has all changed.  Rohloff has introduced their PM bone along with 2 different axle plates.  A CC to PM axle plate as well as an A12 to PM axle plate is now available to be used in conjunction with the PM bone.

Csm_pmbone_4638a8eb35

The PM Bone enables a SPEEDHUB, fitted with a PM axleplate, to anchor its output torque to a frame equipped with Postmount direct brake mount. This torque anchoring system can only be used on 135mm, 142mm, 170mm and 177mm spaced frames with a direct mount for 160mm or 180mm brake rotors.

The PM axleplates which grip onto this PM Bone are available for both CC and A12 axle styles:

  • Axleplate CC PM = for Rohloff SPEEDHUBs with a hollow quick release axle. These can be pre-fitted to new hubs or purchased separately to convert existing hubs.
  • Axleplate A12 PM = for Rohloff SPEEDHUBs with an internally tapped axle for mounting in 12mm thru-axle frames.

These can be pre-fitted to new hubs or purchased separately to convert existing hubs.

The PM Bone is mounted between the brake caliper and the frame itself. As such, the PM Bone acts as a +20mm adapter and thus will require a 20mm larger brake rotor.  So what that means is that a 160mm rotor before will require a 180mm rotor after and 180mm will need the 203mm Rohloff rotor.  Generally this isn't a problem for most people.  People generally don't complain with more braking power.  However some frames are speced to use a maximum sized rotor like 160mm so be sure to double check. 

Now a lot of frames are still being made with IS mounts and we suspect that will be the case for many years to come.  However if you happen to purchase a frame with post mount disc brake mounts, now there is a way to use a Rohloff hub with that frame too! 

More options for 2016 and that is never a bad thing.  Next time you look for a frame, chances are it'll be compatible with Rohloff.  If not sure, drop us a line and we'll do our best to check for you!

Spokewrench


SRAM Modified Rival22 Brifters

We have modified SRAM Rival22 Brifters in stock for anyone looking at the Gebla solution for dropbars.  By far the best solution we've seen for road bars. 

Sram_rival_22_doubletapr_mechanical_shifters

Easy to install and setup and almost no learning curve as everyone is already familiar with brifters.  The only thing is that one side shifts up and the other side shifts down.  We typically setup the right shifter to shift up and the left shifter to shift down but can easily be the other way around.  The Brifters are also compatible with both cantilever and cable disc brakes such as the Avid BB7s.   

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Gebla

We have Gebla shifter boxes in stock!  And photos of it on a bike can be seen below.  The first shifter box available that allows normal drop bar shifters to be used!  With some minor modifications to either SRAM Rival22 or Force22 shifters, you can now shift your Rohloff on your road bike!  One side shifts up and other other side shifts down.

This is probably one of the most sought after aftermarket item for Rohloff hubs.  There have been many other ways that other companies have tried to allow Rohloff compatible shifters on drop bars and this is one I really like.  Riders are very familiar with SRAM shifters and know how they operate so no need to relearn anything.  The SRAM shifters are readily available and reasonably priced.  The modification is relatively straight forward and we can certainly do that for you.

For SRAM, the models that have Zero Loss Technology on the right and left side are best. For cable actuated brakes these are the shifters of Red, Red22, Force22, Rival22 and for the hydro shifters these are Red22, Force22, Rival22 and S700.  Also shifters without Zero Loss can be modified, but it is a little more work and you canĀ“t go back.

For riders that like trigger shifters instead of the standard Rohloff gripshift,  SRAM Triggers Series X9, X7 and X5 all work well.   So lots of options for all riders!

P3060210
P3060210

We have the shifter boxes in stock and can modify the shifters for anyone interested.  Email us for more information.

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Input Ratio

During the Toronto Bike Show, I had some customers come and ask what the Input Ratio limit was for the Rohloff hub and the minimum is 1.9.  What this means is that as long as the front ring ratio to the rear sprocket is greater than 1.9, the rider will not apply too much torque to the hub.  The amount of torque a cyclist can generate is quite substantial.  There is however no high limit so technically, you can install as large a ring as you like for the front. 

What does this mean for the average rider?  Generally not a lot but what this means when you are thinking about gear range for the Rohloff hub is that this provides you with a lot of flexibility.  Personally, I like my gear inch increments to be small much like road bikes with very tight cassettes to find that right cadence but as I mentioned in the posting below, this would also be applicable to mountain biking.  For loaded touring having a min input ratio of 1.9 means that a very low 14.6 gear inches can be achieved with a 32/16T combination.  You can probably ride up any mountain with 14.6 gear inches.  A Shimano 24/36 small ring, large cog in comparison would give a gear inch of 17 so the low input ratio of the Rohloff really gives the rider a lot of flexibility to adjust the gear range they need. 

I had installed a Rohloff hub on a Moots Cinco a number of years back and looking back now I realize I didn't fully understand how to take advantage of flexibility the hub afforded me.  It was setup with gears that were way too high and I'd never use.  But back then, there was never the number of single speed chain rings like today and I simply used the outer ring of my XTR crankset.  If I were to do it again, it'd be a much tighter gear range, maybe not as low as what a 32/16T  would give me but similar to the Seven Rohloff that I posted earlier.

32_16T

The table above gives the different gear inches for a low 32/16T combination.  A gear range of 62 and evenly spaced gears throughout the range. 

If you have any Rohloff related questions, feel free to email us at info@spokewrench.com.

Spokewrench


Grear Range and Gears

So I was at the Toronto Bike Show and talking to various people and tell them about the Speedhub and many were asking about how many gears on the True North Fatbike and I of course tell them 14 speed, all internal, evenly spaced, etc and some told me "Oh, I don't need that many gears, I only use like 4 gears".  And in some ways that is also true of the mountain bike industry in general.  A lot of riders kept saying, I never use my large chain ring so Shimano and SRAM went from 3x9 to 2x10 and effectively removed "7 gears".  But what really happened was the gear range remained the same but all the repeat gears were removed so for the rider, they felt like they are using less gears when in fact it's the same, just less steps.  The 2x10 setup is actually quite nice, 17-91 gear range, technically no repeat gears but in order for a rider to shift in a linear fashion, the rider would have to shift back and forth between the front and rear chain ring / cassette combination.  No one does that. 

Going back to the people I've been talking to and to me it almost seems like a badge of honour to say "Oh, I only use 4 gears" when in fact they should be saying "For the trails I ride, I found instead of shifting back and forth between the 2 front chain rings and cassette to find the right gear, I compromise and end up only using a very narrow gear range and with the drive train on my bike that equates to about 4-5 gears".  No one does that. 

So instead of talking about number of gears, we should all be thinking of gear ranges.  For the Seven Sola Rohloff project, I purposely selected a 34T/16T combination and I'll explain why a little later. (Click on chart to enlarge)

SRAM1x11

In the chart above, I've selected a common 1x11 setup and the gear range goes from 19 to 79 gear inches for a range of 415% or ratio of 4.15.  And of course being only 11 speed, the gear inches increase with each gear change the way normal humans expect.  So what SRAM and Shimano has to come realize is that riders are humans that like their bicycles to behave in a similar fashion to their cars and because humans are quite adaptable they are quite happy to make do with less if it means less things to manipulate, ie shifting back and forth to achieve an increasing high gear inch or gear.  In this case, the gear range is quite narrow, 19-79 so likely for some trails, not low enough and other trails not high enough.  And throughout the range, the incremental step sizes are quite large which makes sense because you only have 11 gears to divide into  62.  So from a mountain biking perspective, finding that right gear becomes more difficult because for some sections, it's either too high or too low.  That's why Shimano and SRAM went to more gears in the first place but wait I thought riders wanted less gears...this is getting confusing. 

So getting back to the Sola.  I wanted it to have a mountain bike gear range so quite large but I didn't need it to be able to ride the Rockies and the flats of the Prairies on the same ride.  And I think this fits for a majority of riders.  BUT I also want to be able to find the "right" gear when traversing technical sections so that would mean I need MORE gears, not less that people seem to think.  If I got a dollar for everyone that came to me that said I converted my bike to single speed because I thought that's all I needed and it was cool but I've come to realize I need more gears. 

Rohloff34_16

Rohloff36_16

So the above charts are 2 ranges that I thought would do nicely.   The 34/16 combination has a gear range of  about 66 gear inches and the 36/16 has a gear range of about 70, both are 525% or 5.25 so larger than the SRAM 1x11 of 415% or 4.15.  In both cases, I have 1 gear lower and 1 gear higher than the 1x11 so better at the steeper hills (weaker legs :)) or faster at the flats (catching up :)).  Plus also just as important, I have more gears in between to find that "right" gear that will allow me to keep my momentum and or clear that section instead of stalling and dabbing.  I ended up choosing the 34/16 combination because I felt the gear range of 15.5/81.2, 66 gear inches is suitable for the trails where I would ride this bike and also the gear steps would also be smaller because that range is divided then by 14 to help finding that "right" gear.  So once I try it in the trails, I may find that the 36/16 is more suitable and I can easily do that by simply swapping out the front ring or maybe tweak it by swapping out the rear sprocket which is both easier and cheaper than swapping out a 11 speed cassette. 

So there you have it.  That's why I choose 34/16T combination for the Seven Sola Rohloff.  So think about your trails and what gear range you need and I would argue more gears in perhaps a tighter gear range is always better than less gears in the same range.  Often times we ride with whatever is speced on the bike from brand XYZ but how can they possibly know where we ride and what we need?  They don't so we end up using 4 gears....

Spokewrench


Gear Inches and You

From Wikipedia, the definition reads "Gear Inches is one of several relative measures of bicycle gearing, giving an indication of the mechanical advantage of different gears. Values for 'gear inches' typically range from 20 (very low gearing) via 70 (medium gearing) to 125 (very high gearing); as in a car, low gearing is for going up hills and high gearing is for going fast."  So far so good but why does it matter?

For the longest time the trend in the bicycling industry is to increase the number of gears and that makes sense so that riders can find just that right gear to maintain cadence and maximize efficiency.  You don't have to look further than road cycling where the Dura Ace 11 spd 11-23 cassette increases 1 tooth at a time for each cog till the very last 2 cogs.  Mountain bikes too have gone this route going with 3x7, 3x8, 3x9, 3x10.  30 gears!  But of course everyone knows that some of those gears are repeated and there are really only 17 'distinct' gears, yikes almost half are useless!  So this didn't make much sense so let's go to 2x10 and see where that gets us.  First of all, the overall range is reduced since the large chain ring is the ring that people use the least and now there are less repeat gears but also less 'distinct' gears.  There are now 12 instead of 17 for a 24/38 x 11-34 10 spd cassette on a 650b bike.  So SRAM said why not just eliminate duplicate gears all together and go 1x11?  Brilliant!  But what does that mean?  Well, first of all the dish of the wheel has to keep increasing to accommodate the additional cog so the difference in tension of both sides of the wheel increases and given all things equal, a 11 spd wheel is weaker than a 10 spd wheel is weaker than a 1 speed wheel with equal spoke tension on both sides.  That's just physics and the way it works.  But no more repeat gears so hooray!  What about the range?  We have 11 distinct gears now compared to the 2x10 setup.  For a 30 x 10-42 setup, the range is less and more importantly I think is that the gear increases are not consistent within the range; not that the 2x10 is much better.  So that means when navigating over the trails, the gear changes won't feel the same, some shifts will make less difference than others.  For the 1x11 cassette, the increments range from 8.7% to 20%. 

Personally, I think the odds of finding the 'right' gear is higher on a 2x10 setup than a 1x11 setup.  There are simply more gears and wider range and more in between gears than a 1x11.  Because SRAM has to accomodate the lower range first without sacrificing the higher range, there is only so much it can do with gear selection.  But the gear increments for the 2x10 is also kind of all over the map.  So the problem really for the 2x10 is not that the gear selection isn't good, it's that it's not increasing in a linear fashion that humans tend to favour.  For the 2x10 to be linear, I'd have to shift the first 4 gears in the small chain ring, move to the 'large' for one gear, back to the small for the next, then back up, then back down, then up and back and forth until the last four gears where I stay in the top ring.  So much for finding that right gear. 

It's funny how the industry sometimes takes the long way around to come to the same conclusion that others have touted for years and years.  Repeat gears are not useful and linear increase is good.  Enter the Rohloff 14 Speedhub.  A 40/16T setup will give you 14 distinct gears with gear inches comparable to the 1x11 SRAM setup with a wider range and some gears in between the 1x11 gears and consistent ~13.5% increases in each gear step.  Completely weather sealed, maintenance free, stronger thicker chain and builds a much stronger wheel but admittedly weighs more than a 1x11 setup.  But let's not forget frame builders invented replaceable derailleur hangers for a reason and why it's on every mountain bike frame available today.  That ultra light weight 1x11 derailleur with titanium bits is >$200 to replace. 

One thing to note is that the 1x11 setup came about a lot due to the Enduro movement where most of the course is downhill so finding that 'right' gear isn't the most important thing so it is very good and a 2x10 setup would be overkill.  But I'm guessing most riders are not Enduro racers and finding that gear to clear the section is important and not everything is pointed downhill. 

So before you spend your hard earn dollars on that fancy 1x11 setup, decide whether or not it has the range and gears you need for the trails you do.  Maybe all you really need is a 1x10 but you'll definitely run out of gears at the high end very quickly.  Or maybe you'll come to the same conclusion that the people at Rohloff did so many years ago.  Cyclist need the range AND the overall number of gears for trail riding and they like it to increase in a linear fashion.   Rohloff of course isn't for everyone nor will it fit many modern moutain bike frames with the 12x142mm rear spacing but where it does fit, it makes a lot of sense for a lot of the right reasons. 

And this is why gear inches matter.

Spokewrench