Monday, August 29, 2011

The Phoenix Project - TA Specialites Carmina Crankset and SKF Bottom Bracket

Background on The Phoenix Project is available here and here.

Other than important lifestyle items like straddle wire hangers and handlebar wrap, choosing a crankset has been the biggest dilemma of The Phoenix Project.

Going into this, I really, really wanted to embrace the trendy wide range compact double and actually purchased a Sugino OX801D crankset in a 46/30 combination.  But this posed some problems with my planned rear cluster of 12/27.

The first was that the lowest gear on the outer chain ring was about 46 gear inches.  This is a little more than I prefer for starting from a standing start especially when carrying a load or pulling a trailer.  Sure, it is doable, but it is nice to options for laziness, fatigue, and so forth.  So who wants to do a series of both front and rear derailleur shifts for every stop, particularly in urban riding.

The second was that the lowest gear was only going to be 30 gear inches.  Again, for a lot of bikes, this is ok, but I want the 1985 Trek 620 to be configured for pulling heavy loads where need be.

The first option to address this was to drop the 12/27 rear cluster and go with a Shimano HG61 12/36.  This would give me a low gear on the big chainring of 34.5 gear inches and a low gear on the small chainring of 22.5.  Problem solved, right?

Well, that would solve the low gear problem but it introduces a few of its own.  The Shimano HG61 is a beast of a cassette, weighing in at about a pound vice the half pound of the 12/27 Ultegra CS-6500.  This alone isn't too much of a problem - I'm not a hard core weight weenie and the Sugino OX801D is a real lightweight at 745 grams including bottom bracket.

However, there were two other issues.  To get that 12/36 spread, the HG61 has some pretty big tooth jumps.  And even worse, I wouldn't be able to use a Dura Ace long cage rear derailleur as these only accommodate a max cog of 27, although some claim this can be pushed a tooth or two.

The alternative choice would have been a Shimano T661 rear derailleur, a fine product, but as hard as I tried, I couldn't bring myself to love this unit with the same unbridled passion I have for Dura Ace rear derailleurs.  Were it any other project than this one, which is an exercise in extravagance and self-indulgence, I would have made the accommodation but in this case I put my foot down.

So, reinventing the wheel, I finally concluded that the only way to get overall wide range but with closely spaced gears on a single chainring with a 12/27 cassette was with a traditional triple.

This then presents problems as the bicycle industry is rapidly deprecating traditional triples for road bikes and even mountain bikes.  I considered such choices as the Ultegra and Dura Ace triples, but with a large BDC of 130, the minimum middle ring can only be 39 or 38.  Again, this is doable, but generally I avoid configurations that are at the limit of a piece of hardware as it eliminates flexibility in that direction.

I then briefly considered the newly reissued TA Specialites Cyclotouriste 50.4 BCD cranks (or some of their clones from Velo Orange and Electra), but, despite claims to the contrary, these still have issues with chainring flexibility and compatibility with modern sculpted outer cages on front derailleurs.  Maybe the issues aren't as bad as they were on previous editions, but they've only been mitigated, not eliminated.

Even worse, though, is the spindly, Gothic look of the things.  I've always thought that one of these:

Would be right at home on this lady's bike:

I'm sorry, it is an inescapable mental image I have of the TA Cyclotouriste cranks.  I hope that by sharing this I haven't infected any readers.

Ultimately, and again reinventing the wheel, the obvious choice is the ever flexible 110/74mm BCD triple that reigned supreme for several decades on touring, utility, and mountain bikes.

Going into the marketplace for new 110/74mm triple cranksets, I was astonished at how few are still in production.  The Sugino XD series of cranksets seems to satisfy about 90% of the remaining market for new production items.  This is a fine, economical offering but is distinctly bland and not in the spirit of flagrant, willful violations of cycling sumptuary laws wherever possible.

Velo Orange has their own branded 110/74, which is also distinctly meh and furthemore devoid of provenance or snob appeal.  Stronglight sells a 110/74 unit sometimes in Europe, but these are just rebranded Sugino XD units.

IRD and Velo Orange both now have nifty 110/74 clones of the Sugino Mighty Tour.  Here is the IRD version:

Having been a huge fan of the original Sugino Mighty Tour, I was initially pretty excited by this.  But then I discovered that the 74mm granny is mounted on a triplizer middle chainring, which is epic fail in my estimation, particularly since no one seems to sell exactly this style of triplizer ring, much less in a variety of tooth counts.

Then I got even more excited when I found out that Sugino itself had reissued the Mighty Tour and it was available in a triple version:

But I was again crestfallen to find that the granny was attached to a triplizer ring.

I then found a couple of other obscure offerings, none of which seemed satisfactory and at this point the reader is screaming, "What about the TA Specialites Carmina"?

Ha! I actually considered this from the start and it was always in play.  However, the go-to guy for these in the U.S., Peter White, claims that he can only get these with a black spider, which I find hideous.  Plus they were French, putting me at high Phony Accent risk.  And on top of that, they just aren't the easiest things to find as well as being extremely expensive.

But after doing the above research, I thought, ok, they are a sweet item and if I can find one with a silver spider, I'll cough up the dough for one of these.

Enter Bilenky Cycles, who just happened to have these on sale and claimed to have silver 110/74 BCD spiders.  For readers that are unfamiliar with the TA Carmina, the arms and spider are separate units and for a given set of arms, there are a range of spiders, from triples to singles in various BCDs that can be attached.  Sort of the tinker-toy of cranksets.

Anyhow, this is what I ended up with in 48/38/28 rings:

Pretty luscious units, they are.  The next problem was what bottom bracket?  They take a traditional square spindle, but there is a little bit of mystery surrounding the bottom brackets for these, at least according to the Peter White site.  Therein lies a complicated tale about whether or not the spider has a rough or smooth inner surface, I had a hard time following it all.  The Internet is similarly indecisive.

Bilenky, though, was reassuringly unequivocal, said use a 113mm for a road bike on the triple Carmina and you will be fine.

It turns out I already had a new 110mm SKF square taper bottom bracket in the parts locker that I was itching to try.  These are still a bit of an unknown but are starting to make a great impression.  They have roller bearings on the left side to counteract the cross product twisting customary to that side and they are giving a 10 year warranty on the units.

While they are still a minor player in the bottom bracket market, SKF is the biggest manufacturer of bearings in the world.  Turns out that they thought that would be enough to roll into the bottom bracket market but their initial attempt was less than overwhelmingly successful.  So they backed up and gave that master of bike snob PR, Jan Heine, some sort of exclusive distributorship and he seems to be working his magic.

So I figured if Bilenky is right, and my spidey senses were affirming this, that I could slip a 1.5mm spacer on the drive side and get a good chainline.  These bottom brackets are designed to have up to 5mm of this type of adjustability, so this was all according to Hoyle.

Turns out Bilenky (and me!) were right, as the 110mm bottom bracket with 1.5mm drive side spacer gave a Sheldon-perfect 45mm chainline.


Street Cred

SKF is still largely an unknown without a lot of operating history behind their cycling products.  There was some carping on forums about their original ISIS bottom brackets but I've seen nothing but praise for their current offerings.  However, their current offerings are all pretty new, it remains to be seen how happy everyone is halfway through that 10 year warranty.

TA Specialites is a legendary cycling firm and usually of very high quality products.  Their chainrings in particular are said by many to be some of the longest wearing ones available.  Even if not, they sure are shiny:

Gizmo Lust

The SKF bottom bracket has German ball bearings.  That is pretty neat.

Here is the fixing bolt for the famous detachable spider on the TA Carmina:

Looks postively surgical.  And how about the finish on the pedal mounting insets - Bilenky thoughtfully threw in some pedal washers so I wouldn't ruin this:


The circle really turns.  Back in the day, a 110/74 triple was plain as dirt.  But now one must furtively search to the ends of the world to find a few options in this regard.

Tweed Factor

While there is no data on the SKF, the Tweed Factor is pretty high on the TA Carmina.  Generally, Tweedy guys (and gals!) avoid expensive components, the largest exceptions being expensive stuff manufactured by Nitto or distributed by Peter White Cycles.

Phony Accent


As with the Berthoud Aravis saddle, one would expect a coronary inducing Phony Accent rating for a French part.  But as with the saddle, that is only for fake copies of 1950's French parts spec'ed by American guys to Taiwanese factories.

But again, this is a real French part made by a real French company staffed by real Frenchmen (and Frenchwomen).  And it doesn't look like anything made by Rene Herse or drawn by Daniel Rebour.

Just in case you couldn't read it:

Lily Gilding

This has lily gilding all over it.  It is doubtful there is much functional difference between the TA Carmina and an infinitely cheaper Sugino XD crankset.  And for the price of the SKF bottom bracket, I could have bought 4 or so cheaper bottom brackets.

Running Tally

$3730 USD

We bring forward $3628 USD.  We subtract the $484 USD price of the Sugino OX801D crankset.  The TA Carmina was $449 USD inclusive of shipping while the SKF bottom bracket was $137 USD inclusive of shifting.

The Sausage Factory

Everyone who sells the SKF bottom bracket recommends getting the Park BBT-18 tool to install this rather than attempting to install with a 1 prong locking ring wrench.  I decided to go with the herd wisdom:

It turned out that the hex nut on this thing is huge, bigger than my biggest wrench or socket or even my gorilla crescent wrench.  But then I had a brainstorm:

That is the right size.

The 110mm SKF bottom bracket is separable as shown, the red ring being the non-drive side:

Per the instructions, I first installed the drive side unit with 1.5mm spacer, this went in pretty easily and was torqued down to "lots":

When I got to the red non-drive side ring, I understood why everyone recommended the special tool, as it took a fair amount of grunt to get this fully tightened.  I'm pretty sure I would have damaged the red ring trying to do this with a single prong bottom bracket tool:

I then installed the cranks (I'm an inveterate taper greaser....), torquing to 350 inch-lbs:

I was very pleased with the 45mm chainline on the first try.


Anonymous said...

Thank you for this. I have been agonizing over this for months. I have a Comotion Americano with a broken crank arm (RaceFace Race Turbine 110/74). My solution however may be to strip all off the bike's otherwise newish componetry and sell these and the restored frame and let it be somebody else's frankenstein-bike problem. I think I can tour perfectly well on a mountain bike...

Anonymous said...

Very nice !

Do you have any problem with JIS tapering bottom bracket

I have order carmina crank,and on TA website they say is ISO tapering, and some people say it is JIS

Best Regards Roger

robatsu said...

Do you have any problem with JIS tapering bottom bracket

You know, over the years, the amount of discussion I've heard vs. the amount of trouble I've had with ISO vs. JIS bottom bracket taper must be at least 100 to 1.

Unknown said...

Excellent write-up. I was wondering where you got your torque spec for the Carmina crank arms? I have a new Carmina crank set but it did not come with any installation instructions and I couldn't find this spec on their website anywhere. I was going to go with the general torque that you find on many websites but wanted to see if TA called out anything different for the Carmina. Thank you.

robatsu said...

For the 350in/lbs torque spec, I just used a "typical" number for square tapered bottom bracket/crankset, nothing specific to the Carmina.

Unknown said...

Thanks for the super quick feedback...sounds like it worked for you so guess that is the torque I will use.

Anonymous said...

Thanks so much for this post, I've enjoyed the heck out of your site, and agree that the dearth of new elegant true 110/74 touring cranksets is sad. You mentioned the old 110/74 Sugino Mighty Tour Triple. I have one of these, and am interested in trying out SKF's bottom brackets. I wondered if you had any recommendations as far as spindle length? I'll be using it on a Hilsen with 46-36-24 rings. If not, no worries, and happy/safe riding!

robatsu said...

For a Sugino Mighty Tour Triple, it is a pretty big spindle, like 118 or so.

The problem is that the offset is really large, like 7mm or so, and most all bottom brackets these days are symmetric.

The folks on the C&V forum on may be able to give you a suggestion/recommendation.

Anonymous said...

Thank you so much for the swift response! I'll follow up over there.

Anonymous said...

I am also realizing, my Mighty Tour is a 110 triple/ no 74. But I'm sure you knew that! Thanks again.

Louis Du Brey said...

I've had a TA Carmina crank failure after two years of use and about 4000 miles. If you ride these cranks, I encourage you to check the inside of the cranks. You can't see the cracks from the front or the side. I've posted a report here:

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