Chris_W

Shimano are about to release a new set of tandem cranksets that use external-bearing bottom brackets (i.e., two-piece crank design). Shimano's previous tandem cranks used Octalink bottom brackets, so this should be a major step forward in terms of weight and stiffness. EDIT: Official weight now given as a total of 1772 grams for both sets of cranks (170mm), bottom brackets, and chainrings.

I haven't seen an official announcement about this, I just accidently found the tech' doc's while looking for something else on the Shimano website. The product numbers are R603 for the stoker and R601 for the captain. I've since found an official description of them at the website of the UK's Shimano importer, Madison (see here and here). Still no photos yet, but there are some line drawings to look at in the PDF tech docs here and here. A few web-stores even have product pages for them (although no stock yet), and they are listed as having an RRP of about 500 UK pounds for the stoker cranks and 225 UKP for the captain's. It will be interesting to see how these prices translate to other currencies - the UK pound is currently doing quite poorly.

This will finally allow consumers and manufacturers to have a decent alternative to the FSA Gossamer cranks that most decent-quality road tandems are currently sold with. There are several reasons why I believe the Shimano model will be better than the FSA Gossamer. First, the Shimano cranks will be hollow instead of solid (which should mean that the Shimanos are lighter and/or stiffer). Second, Shimano chainrings nearly always shift better and last longer than FSA's. Third, Shimano will offer 170mm captain cranks (I know most people don't care, but the 172.5mm FSA captain cranks that we have really do bug me because they feel too long); it looks like both captain's and stoker's cranks will come in both 170mm and 175mm versions.

It's not all positive though, the biggest problem being that Shimano are using the 30-39-52 chainrings that come on the 6703 Ultegra triple crankset. All three rings are of a special design and are difficult to change to custom rings. The outer ring has built-in threads for the chainring bolts that are hidden on the inside, and the ring is shaped to follow the lines of the spider - use a different ring and you'll need new chainring bolts and the external shaping will look quite wrong, but at least the BCD is the standard 130mm (timing cranks also have 130mm BCD, the stock timing rings have 40 teeth). A bigger issue is that the inner ring does not mount to it's own mounting points on the spider (which would normally have a 74mm BCD), but instead bolts onto a special middle ring using a unique 92mm BCD - so to use a smaller inner ring you would also need to change the middle ring to a "Triplizer" model (I believe Stronglight and TA both still make them, but this makes changing the inner ring an expensive and complicated ordeal).

With the 2-piece crank design, it is hard to adjust chainline very much. I haven't found any info yet on what the chainline is on either the drive-side or timing-side cranks, but this is likely to be important information for anyone considering an upgrade to these cranks to know how compatible they would be for the current setup. The tech doc for the stoker's cranks lists shims of various sizes that can be used under the left-hand crank to alter it's position (see item #5 here), but the equivalent is not shown for the captain's crank (see here). EDIT: drive-side chainline is officially 45mm, timing-side chainline is 49.9mm (compared to 53mm on FSA's cranks).

BTW, as well as these new Shimano cranks and the FSA Gossamers mentioned above, other 2-piece, external-bearing tandem road cranksets are the FSA SL-K, Truvativ Elita, and Lightning. These are all included in my table of triple cranksets in this thread, I'll be adding the new Shimano cranks to that table soon.

jnbrown

Although I had to hold my nose and close my eyes when I ordered the Gossamer crankset, it has turned out to be trouble free and I was able easily change the gearing to 50/39/28. I did replace the front with a Shimano Ultegra crankset (170mm) installed backwards with helicoils to reverse the pedal threads because I didn't like the large Q factor of the FSA crankset. Also I have noticed the newest generation of Shimano cranksets are quite noisy when using the large chainring.

justcrankn

Here in the states, QBP is expecting them 8-19-11. Dealer cost is $10 more than the SL-K. They currently have the captain listed at 175 and the stoker at 170 and 175.

Chris_W

I've got a few more details on these cranks from the 2012 Shimano dealer catalogue that I picked up at Eurobike this week. I still can't find a product page for them on Shimano's website, so here's the info:

Weight: 1772 grams inclg. BBs (FSA's SLK tandem cranks are listed as 1787g, Gossamers are 1972g).
Lengths: 170 or 175 for captain and stoker (although the above post suggests that some importers may unfortunately not offer the 170mm captain cranks).
Chainline: Drive-side = 45mm, Timing-side = 49.9mm (FSA uses 53mm on the timing side).
Colour: Dark grey like the new 2012 Ultegra group. The styling and finish is just like that of the new Ultegra, but instead of having the Ultegra logo, it just says "Shimano" on each crank.
Chainring BCD: Confrimed as 130mm for non-drive and 130mm for drive-side, with a special middle ring that the inner ring attaches to with a BCD of 92mm.

They are also appearing on more retailers websites, with Chain Reaction in the UK listing the captain's cranks for 175 UKP and the stoker's for about 400 UKP. However, they don't expect to receive any stock until December. They are showing 170mm captain cranks as one of the options.

waynesulak

I hope that many avoid these cranks if they in fact use nonstandard BCDs. Sadly they will most likely find there way into the OEM market and new tandem riders will find themselves with little options when they need or want to change rings.

I will continue to pay more for Davinci cranks that allow for stokers and captains to choose their crank length and BCD. They weigh no more than the proposed tandem crankset and give the option of purchasing bottom brackets that will outlast any FSA or Shimano BB.

The tandem manufacturers do a great job designing tandem frames for stokers in the 5 foot height range but then puts the same 170mm cranks optimized for much taller riders.

twocicle

I just received my set today so I have these in hand and not via a sales rep.

If my digital food scale (zeroed) is corrrect, here is the weight info I recorded for the Ultegra Tandem set:

2012 Ultegra Tandem set:
R601 - Captains cranks (175mm) incl timing: 665gm
1- BB6700 (bottom bracket included in the set) : 95gm

R603 - Stoker triple cranks 52/39/30 (170mm) incl timing: 1005gm
1- BB6700 (bottom bracket included in the set) : 95gm
1-spacer bag incl crankarm bolt: 30gm

TOTAL SET: 1890gm *

* That puts this Ultegra set squarely between the FSA SL-K and the heavier Gossamer MegaExo set, per the FSA website specs.

====

FWIW, here's a brief of all the tandem sets from the FSA website:

SL-K LIGHT TANDEM Crankset
https://www.fullspeedahead.com/produc...ANDEM-Crankset
BB30: 1350 g (Set)
MegaExo: 1571 g (Set)

* not sure if these weights include the BBs (ie: 108g * 2 = 216)

---

SL-K MegaExo Tandem
https://www.fullspeedahead.com/produc...MegaExo-Tandem
1571 g (Frond and Rear Crankset)
MegaExo BB 108g * 2 = 216
Total 1787g

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Gossamer MegaExo Tandem Crankset
https://www.fullspeedahead.com/produc...andem-Crankset
1756 g (Front and Rear Crankset)
Mega Exo BB 108g * 2 = 216
Total 1972g

JSNYC

That's actually very helpful to know.

Any idea what a Da Vinci crankset weighs?

DubT

I installed the Shimano Ultegra cranks a few months ago and my weights are a little different, here is what I recorded:


The total weight of both cranks along with the bottom brackets, spacers, fixing bolts etc. was (according to my scale) 1866 grams 749/1117 the FSA cranks that I took off weighed 1956 860/1096.*

I am using the 175 cranks front and rear, I replaced a set of FSA cranks, SLK in the rear and Gossamer in the front.

I am extremely happy with the cranks and especially the shifting, I am also happy with the 52/42/30 rings.

Wayne

JSNYC

I heard the 6700 shifting is great, irrespective of weight. Just got one for my regular road bike so will find out for myself.

TandemGeek

1,311 grams with Race Face 53/42/30 chain rings & daVinci's 34t timing rings

1,637 grams total with Middleburn self-extracting crank bolts & two Phil Wood Mag/Ti BB's with alloy adjusting cups: 68x108 & 68x111

Note: This is also what our 1st daVinci crankset weighed back in 1998.

twocicle

Throw me a bone... what did you end up sourcing for the 42t on this crank?

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Ok, I screwed up on the weight despite measuring it 3 times earlier. Initially I had it correct, then when breaking out the components for individual weights I did something wrong and used that value. Doh!

Well, this is what I have with my cheapo digial food scale: 1890gm.
That is including all the nuts & washer-spacers, everything except the plastic tester (3gm).

I don't know how I'm getting 30gm more than your gear since our stoker cranks are only 170mm. Sigh. Guess my scale is bad. Time for another of the endless upgrades.

Anyway, while I'm not jumping up in glee (or angst) over the weight, I am very happy to know we have some of the stiffest cranks & BBs available for mainstream tandems, and that the pedal thread inserts will not go take a vacation (pertaining to FSA).

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Other: checkout this really nice chart by Chris_W... https://www.bikeforums.net/showthread...sets-Chainsets

dvs cycles

[QUOTE=twocicle;14032739]I just received my set today so I have these in hand and not via a sales rep.]
What make of Tandem are these going on?

DubT

I was wrong, for some reason I thought the rings were 52/42/30, I just went out and counted the teeth on the middle ring - 39 teeth, not 42. Sorry about that.

Wayne

DubT

Here is a location that has pictures of the Shimano cranks on our Calfee.

https://www.bikeforums.net/showthread...nks?highlight=

twocicle

Our 1st Calfee. It's a new, unused 07 frame w/AlphaQ fork. We saved a few bucks by getting a dusty frame. We didn't start looking for this but ended up there. My wife found it, so it's "her" 7lb baby now

Maybe I should start a "My Build" thread?

twocicle

Yes. We referred to those photos as fuel for ours

akexpress 

I have our set and will be installing with the Gates belt drive on our Calfee this weekend. 170/170 crank arm length to replace our Calfee carbon cranks

waynesulak

Why are you replacing the Calfee carbon cranks?

Chris_W

You can use a TA Tripleizer 42 tooth chainring. I tried it out as an exercise at work with the regular Ultegra triple 6703 single bike cranks, and it was entirely compatible, although I did not mount it on a bike. Using that, you could then change the inner ring to a 28 (or even 26). The TA is not as stiff and probably won't shift quite as well as the Ultegra, but if you want these cranks and still want chainring options then it is your only option.

akexpress 

We have had a hard time keeping the spiders true. They were very out of true when they were delivered and were somewhat better after Calfee worked on them. They no longer sell/make(or outsources them in reality)them. It has been a problem both on the drive side and the timing side. It at times made front shifting very inconsistent. An interesting aside even with this problem we have had zero issues with our Gates belt drive tracking and working as designed.

twocicle

Word of caution regarding delivery of the Shimano Ultegra R603 (stoker) crankset. The way this is boxed by Shimano can lead to the axle end puncturing the underlying inner box that contains the timing crank w/spider.

Apparently this is a deficiency of the way Shimano packs the crank as they do not put a packing boot over the end of the axle and just leave it bare and hanging down inside the box.

The original set that came to me had marring/gouges on the timing spider - having this replaced by the retailer.

Sprout97 

As a reference point, does anyone know the weight for the 6503 crankset & 6500 bb? I'm trying to decide if an upgrade to the R601/603 is cost-effective.

CaptainHaddock

So I'm just not seeing the Shimano cranks anywhere on their U.S. website. Are they not offering them in the U.S.?

twocicle

I never did find these listed on Shimano's website either. However, QBP (Quality Bike Products) has the R601 (front) and R603 (rear) cranks in their catalog, so any dealer can order these from QBP. Online, you will find a few dealers listing them: PrecisionTandem, TandemsEast, eBikeStop, Jensenusa, etc.

QBP incorrectly listed them in the catalog as not including the bottom brackets, but they are indeed included as part of the set.

Chris_W

I don't believe the cranks are in Shimano's product listings, but if you search hard enough you can find the pdfs of the exploded tech drawings on Shimano's site - R601 and R603 are the key terms. As mentioned, local Shimano importers are now listing the cranks, and some online stores also have them.

BTW, it's a good thing that the cranks don't have MegaExo BBs, those would be for FSA cranks, Shimano's external bearing BBs are denoted as Hollowtech II; the two are VERY similar designs and sizes, but mixing and matching between the brands doesn't always work.