JSNYC

New to the tandem scene, am wanting to learn about parts & how things work & so forth.

Apart from wheels (which I'll have built to tandem-spec), what else is there that is very tandem-specific that I should look out for?

Can anyone recommend a good website to look for that is comprehensive in terms of offering tandem-specific parts?

Thank you.

WebsterBikeMan

Well, of course there's the frame.

Seriously, the list, just off the top of my head, would be
- the fork
- the eccentric bottom bracket
- crank set (captain's has chain ring on left, stoker's has extra chain ring on left).
- stoker's stem
- stoker's bars (sometimes) - and stoker pegs (sometimes)
- suspension seatpost on a road bike (for stoker)
- tandem length cables or cable splitters attached to double single-length cables

This is all assuming you want a traditional machine with a timing chain on the left.

Google Tandem Links, and wander around in that. You'll get pointers to a number of Tandem shops from there. Ones that immediately come to mind are:

TandemsEast
GearToGo
PrecisionTandems
TandemsLimited

Also Harris and Peter White have some tandem-specific stuff (PW in particular makes tandem-specific wheels).

JSNYC

thanks a bunch.

holy smokes there's quite a few xtra things to think about...like a lotta xtra chainrings!

i've never been a fan of fsa cranks on road bikes (have known a few people who had 'em implode), but are they the de facto standard on tandem rigs?

i had planned on using ultegra sl group that i have available, but from the looks of it, all i'm going to be able to salvage will be shifters, derailleurs and front brake (assuming i have a disc on the rear). or maybe i'll just use both calipers. majority of terrain we'll be riding on doesn't likely warrant a disc. and so much for the 53x39 crank....i'll be needin' a triple in all likelihood.

well, this is good stuff and food for thought. thank you very much for the tips & hints.

here's one other perhaps stupid question--i'm seeing that stoker stems mount on captain seatpost. would you recommend an aluminum captain post as a consequence of the loads put on it? or is carbon fiber ok? the likely diameter of the seat tube of the frame i'm getting will be 27.2 (if that matters in terms of post strength).

merlinextraligh

^ You can use your ultegra SL group. You'll just need to add a timing chain and two tandem specific cranksets, (and an eccentric)

You'll need a new brifter though if yours is not a triple if you want a triple. Then you'll also need a new RD. Oh well, I guess you won't be using much of that group after all.

merlinextraligh

There are other tandem crankset options. But FSA offers two alternatives that are pretty popular. The FSA Gossamer tandem crankset is a pretty good value, and the FSA SLK Tandem cranksets is about the cheapest tandem specific carbon crank available.

If you don't have to have external bearing cranksets (i.e. square taper or ISIS) your options open up a lot.

I also don't have a high opinion of FSA cranks (although through a combination of circumstances I've ended up owning several)

That said, we've had good luck with the FSA Gossamer Tandem crankset, after we upgraded the BB bearings to ceramic.

merlinextraligh

Co-Motion uses CF seatposts on their high end tandems. Our Robusta has Alpha Q carbon seatposts, and we've had no problems. You just want to make sure that you do not over torque the stoker's stem.

I would not hesitate to use the Alpha Q seatpost spec'd by Co-Motion, given their track record with them. If you use another CF seatpost for the Captain, you might want to check with the manufacturer, or other tandem teams that have used the particular seatpost.

JSNYC

thanks a bunch for all the replies.

i've been checking out co-motion website and using their parts specs on certain bikes as a guide for what parts to use.

have also been reading a lot of the threads on here, lots of good stuff, all of it.

kinda of excited about having a project like this to think through...i enjoy this sort of thing.

jnbrown

I did extensive research into tandem cranksets while preparing to build our new tandem.
I wanted to stay with external bearings vs the old square taper BB. The options were FSA, FSA..... Lightning.
The Lightning cranks are crazy light but cost $1500 for a pair.
I even considered using Shimano for the front, reversing the cranks and getting helicoils installed so the pedals would thread on the correct direction.
There no way to use Shimano on the rear, so I would have Shimano front and FSA rear resulting in a chain line mismatch which would preclude ever using a Gates belt drive.
So I ended up with FSA SLK on the front and FSA Gossamer on the rear. This was the only way I could 170 cranks on front and 165 on the rear.
FSA just recently got in some front SLK 170s after being out of them for several years. I carefully installed the cranks following FSAs instructions and a torque wrench.
I am happy to say the cranks have been working fine with no problems whatsoever, so I wouldn't worry too much about the reported implosions.
I used a Thomson seatpost on the front. Its about as light as any carbon post and I don't think a carbon post would do much in terms of shock located at the center of bike.

JSNYC

wow, that's something i hadn't thought of....

i hate the feeling of not knowing what i don't know....

thanks.

yes i saw the lightning on another tandem, but that's waaaaay out of budget. i was considering getting the new shimano 5700 or 6700 triple group, but then i realized....ummm....what cranks do i put on the front and how does that whole setup work? does shimano even make that sort of thing? i was drawing a whole lotta blanks with that question...

speaking of parts, do i need to get any sort of special rear derail. cage length depending on the cassette ratios, assuming i'm running a triple? in other words, will a regular short cage derail. be fine for running a triple with a 12-25 cassette, or so i need to get a medium or long cage?

sorry for asking all these rookie questions. i'm adept mechanically and do all my own maintenance (and building), but like i said, not knowing things i don't know, with such things being critical, will drive me bonkers when it comes time to put all of the components together....

i'm sure i'll be asking more questions...and i appreciate everyone's patience.

Ritterview

If you were looking for new tandems, you could get one that the manufacturer already equips, and just go with what they offer. For example, Co-Motion sells the Machiatto with a standard build, go with that, and you are all set.

If you want do something different than what is generally offered, and choose each component individually, then that can become a (fun) project in of itself. It also may be somewhat of a necessity should you choose a Calfee, which will build you a frame and wish you luck. I started out with mine a year ago with this thread asking about tandem cranksets. From Calfee I got a spreadsheet of a typical build, and modified the spreadsheet to add more detail and links, ultimately this.

I think spreadsheets are key to understanding your tandem. It lists all the components, and you can add weight and price for each and tally the result. Then you can with this or that component, and see how it affects price and weight. When you finally get the bike, there are all the components that you knew first from the spreadsheet. It is neat to see the spreadsheet come to life as it were.


There are other cranksets, as discussed on this thread, but these generally are not the outboard bearing cranks which now predominate on road bikes. The more recent option is the Lightning, which is discussed in detail here. I really like my Lightning crank, it has been performed well so far, and it weighs 1.25 lbs. less than an FSA. That is probably a bigger difference in weight than between an aluminum and carbon frame, and is probably one of the cheapest ways to lighten your tandem on a $/gram basis.

Triples generally require at least a medium cage RD. I have Campy 11-speed on mine, and with 11-speed there is only one size cage RD for all cassettes. I was suprised to find with my triple that the 11-speed RD actually shifts great (the triple is still balky, but that isn't the fault of the RD).

jnbrown

A medium cage derailleur would be best like a standard road triple. I am using a Shimano 6700-GS. Since your cassette is only 12-25 you don't need a long cage unless plan to go to a larger cassette. I have an 11-28 and the GS works fine.
I have been working on bikes for 30 years and have built a number of them from scratch. I have owned 3 tandems but I will say that building this last one was quite a challenge and I ran into a number of problems I did not expect.
So unless you really want to do it yourself and feel up to the challenge there is a lot to be said about buying one already put together at the factory be people who have done it hundreds of times.
I did find this forum to be a great resource and always had an answer for every problem, question and decision I had to make.
I do have a spreadsheet of all the parts on my tandem, if you want to PM me with your email I would be glad to send it to you.
You should also study this web site:

https://www.thetandemlink.com/calfee_tandem.html

WheresWaldo

I just want to correct one item here, cage length has noting to do with tooth capacity on rear clusters. Looks at all the Shimano specs and all rear derailleurs whether long or short cage have the same tooth capacity. Where the length of the cage is important is for taking up the slack in a chain when you are using a triple front.

JSNYC

next question....handlebar width: does tandem require wider bar than used on a road bike, or same? i currently ride a 40.

thanks for the tips.

Ritterview

I'd like to believe this W2, but while a triple definitely is an indication for a longer cage length, so too is the size of the cassette.

Campy, however, which used to require a medium cage RD for its 13-29 cassette, has rigged its new 11-speed RD to be capable of handling cassettes all the way from 11-23 to 12-29.

WheresWaldo

That's why I said to look at the spec sheet. Maximum sprocket capacity on all Shimano road groups that have GS and SS versions is 27T although it can shift a larger sprocket on the road, minimum sprocket is 11T. The capacity change is in the maximum chainring difference with SS spec'ed at 16T and GS at 22T. Campy might be different.

All mountain groups that have a GS and SGS versions allow 34T max. 11T min. sprockets.

The difference is usually listed as total capacity which is the size difference between the largest and smallest chainrings, and the size difference between the largest and smallest sprockets on the cogset added together. Shimano lists total capacity as Road Short=29T, MTB Short (Medium)=33T, Road Long=37T, MTB long=43T, so as long as you don't exceed 14T difference in the crankset you can use the largest 10sp cogset Shimano makes with any size cage. if you go to a triple where typically Shimano supplies a 52-39-30 you have to switch to a GS because you have exceeded chainring capacity difference, the rear cluster capacity does not change.

WebsterBikeMan

For the captain, it's not uncommon to err on the wide side. So, if you measure at 41, you'd definitely ride 42, rather than 40. A little extra is nice for steadying the bike when holding it whilst the stoker gets on/off. In my case I'm on 46s, on both the single and the tandem, and anything wider is hard to find. It works well enough. I wouldn't go more than 2cm wider on the tandem.

For the stoker, it gets more complicated. The simple answer is you don't want the bars or stoker pegs, if any, to interfere with the captain's legs/hips. What that means depends on whether the bars are drops or cowhorns; and how long the stoker compartment of the frame is, which affects how long the stoker stem will be; and how high on the captain's seatpost the stem is mounted, which depends on the relative sizes of the riders. You may need wider bars than the stoker might otherwise ride, but you might not either.

merlinextraligh

I would recommend staying with what fits you well on the single. Our first tandem had wider bars than my single, with the thought process being that the bike would be more stable that way.

Our current tandem has the same width bars as both my single road bikes, and it handles just fine, and feels like a good fit.

JSNYC

Here’s a few other component-related questions that come to mind. Some of these my builder will address (as well as DaVinci for their crank/BB questions), but I’d still very much appreciate your experienced inputs as well. I’ll leave wheel questions out of this thread, since there are already many others dedicated to that topic, and I’ll ask there instead.

1) Cranks/BB: will FSA tandem cranks (Gossamer or SLK) run with Shimano Ultegra or DA hologram BB’s? I don’t know if the spindles are quirky like SRAM, with one end a slightly different diameter than the other. The ratio of horror stories to positive experiences with FSA tandem cranks I’ve picked up thus far is not positive (seemingly driven often by bas FSA BB’s), but it seems like they’re the only more “affordable” game in town unless I go with Da Vinci, or do something homegrown….which leads to next questions…

2) Cranks: if I picked up an Ultegra or DA 7803 triple crank, what are my ready-made options for captain front cranks and stoker non-driveside crank arm? I got excited about finding a 7803 crank online (I happen to love the 7800-series hollowgram design), but then the wind got taken out of the sails when I realized what else I’d be needing. And I don’t particularly want to be dealing with custom machining (helicoil inserts and so forth).

3) BB: Assuming my frame’s BB’s are 68mm, how do I determine spindle length on the captain & stoker BB if I get the DaVinci cranks and square taper BB setup?

4) BB: I presume spindle length variance w/DaVinci is their way of addressing chainline differences vs. FSA providing shims?

5) Cranks/chainring: For the timing chain cranks (what are those called, technically?), what is the preferable tooth count on the chainrings? DaVinci specs 34t 1-piece spider/chainring, whereas the FSA’s seem to come with 42.

6) Chain: is there anything particular about drive chain length (I’m assuming that’s what the chain is called that goes from stoker crank to cassette/derail.?) that I should be aware of, i.e., do I set it up with tension similar to single road bike? In terms of length, I presume 1 chain will suffice?

7) Chain: for the timing chain, is there anything special I need to get in terms of chain type/brand, or will any narrow profile chain do? And in terms of length, what can I expect to need, 1 ½ chains?

8) Derailleur cables: is it best (in terms of performance) to run one long one (assuming the OEM Shimano lengths work) or run them with splitters? Also, on a related topic, is there any performance (or convenience) difference between frame-mounted barrel adjusters vs. housing-based adjusters (e.g., Jagwire) given how long the cable can be?

9) Brake cables: same question--is it best to run one long one (assuming the OEM Shimano lengths work) or run them with splitters?

10) Cables & housing: any meaningful difference by running aftermarket housing & cables vs. Shimano OEM? On my road bikes, I’ve ran both Shimano and Yokozuna Reaction cables & housing, and there’s no perceptible difference (unlike my experience with that combo on my former SRAM Red-equipped bike, where the Yokozuna cables & housing made a big performance improvement, esp. since that housing is ridiculously stiff).

11) Stoker stem: I’m guessing that an adjustable stoker stem would be the best way to go for getting my wife’s position dialed in over time, but I don’t know how those types of stems work with rise & reach. Her current reach is ~61cm with ~3cm of drop. Am I better off just getting a stem that matches that reach profile, and slide it up or down on the captain seatpost to accommodate drop changes as time & fitness evolve?

12) Headset: anything special I should be aware of in that regard, particularly with respect to load/durability? Any brand preference? I usually leave headset decision up to the builder due to various geometry issues surrounding stack height. (De facto, I’ve been running Chris King HS on my road bikes).

13) Brakes: assuming I run regular F&R calipers in lieu of discs, are tandem forks—unless specifically designed—set up to run “normal” short reach calipers?

That’s it for now…

Many thanks in advance for your patience & thoughtful replies.

bikeriderdave

I'll second merlinextraligh's suggestion to stick with what works on your single. Steering a tandem is much more about balance and finesse than strength. I'm relatively small and have always used 40s on my singles. In close to 20 seasons of captaining a tandem, I have never felt the need to go wider on any of our two-fers or triples. IMO, you should start your tandem experience with a position as close to that on your single as possible, and then make small changes as they make sense. Over the years, I have decided that my 'bars can be a bit (~13 mm) higher on a tandem, but I haven't consciously changed anything else. [A pox on crank and tandem product managers who think that 172.5 or 175 mm cranks are "good enough" for all captains. Those benighted folk must all be taller than average. Three of my family's four tandems have mis-matched cranks as a result.]

Regards,
Dave

WebsterBikeMan

Trimmed a bunch of questions that you already said DaVinci will address..
34 is common, and lighter. 42 puts slightly less stress on the chain, but then the timing chain tends to outlast the drive chain by a considerable multiple.
One chain. Triples are common on tandems, which makes for a longer drive chain, but it's still just one chain. Set up is similar to a road bike or a mountain bike. Gearing is (typically) similar to a mountain bike, but the setup is basically the same.
Common to use 8 speed or even less for the timing chain. This chain is under considerably less stress, as it never has to shift, and is always aligned. Something more than 1 and less than 2 normal chains.
I find splitters to be an advantage; I have couplers, so there wasn't really a choice. Advantages with splitters include ease of finding replacement cables - don't need tandem specific cables, and if you want to change only the portion downstream of the splitter you don't need to fish it through the brifter interface (or whatever you have at the shifting end). The additional weight is trivial. The additional cost, compared to the bike, is also trivial.

You want to minimize friction between cable and housing as shifting can be more finicky with the long cable runs. I have no direct experience with various housings, though.
Usual practice is to use an adjustable stem. Height adjusts by changing position on seatpost, reach adjusts by changing stem length (telescoping). Weight weenies, once they know the exact position, have been known to replace the adjustable with a lightweight stem that matches the geometry. Bear in mind that the right position on the tandem may be a little different than that on the single.
Yes, you want something strong. Chris King is a good option. There are a few others. Others may chime in here, as I left that to my builder.
Generally.

TandemGeek

1) Cranks/BB: will FSA tandem cranks (Gossamer or SLK) run with Shimano Ultegra or DA hologram BB’. Gossamer yes, SLK sort-of; it requires the use of some shims and/or a wave spacer. There are also BB options from Chris King and Phil Wood that work with the MegaExo Gossamer and, perhaps, the SLK.

2) Cranks: If you plan to mix and match non-tandem specific cross-over cranksets, cross-cutting thread or the use of Helicoils or Time-Serts is a fact of life... and they work just fine so long as the person doing the machine work knows what they are doing... and even then it ain't that complicated.

3) BB: Assuming my frame’s BB’s are 68mm, Depends on your rear drop-out spacing as well as the size and shape of your rear stays. I've used 108mm - 118mm BB's on daVinci cranks with 145mm rear spaced tandems. Your builder should make a recommendation as for any minimum dimensions. Typically, 113 - 118 work for most 145mm rear spaced tandems.

4) BB: I presume spindle length variance w/DaVinci is their way of addressing chainline differences vs. FSA providing shims? As well as preferences for tread width / Q-factor. Phil Wood BB's also allow for 5mm of left-to-right offset which is another way of adjusting chain line independent of total crank spindle length.

5) Cranks/chainring: Timing rings... it doesn't really matter so long as the tooth count front & rear is the same. All the sync chain does is transmit the captain's power to the rear crank vis-a-via the timing rings. daVinci is at the low-end of the conventional tooth count with it's 34t CNC'd, hard-anno timing rings and they work just fine. 39t or 42t work as well; they distribute the chain loading a bit more efficiently and weigh a bit more... all of which are really nits.

6) Drive Chain: Drive chain is sized the same as a single road bike.

7) Sync (aka timing) Chain: As to how many links, it will depend on how long you spec the boom tube / stoker compartment (they typically are the same length with parallel seat tubes) and what size timing rings you use. 1.5 is about average and, again, any chain will work for a sync chain: it's a direct drive so no side loads, etc... to deal with. The only other consideration with a sync chain is spare parts compatibility with your drive chain and/or carrying spare parts for both.

8) Derailleur cables: Doesn't really matter, although it's a bit easier to find standard length in a pinch so there's always that benefit to using cable splitters. As for in-line adjusters, just make sure what ever you buy is a durable product. See related thread on "finally fixed my shifting problems".

9) Brake cables: same question.. Same answer; doesn't really matter.

10) Cables & housing: any meaningful difference by running aftermarket housing & cables vs. Shimano OEM? Jagwire, Campy, Shimano, etc... all work fine so long as you do a good job of keeping the housing short, cutting and finishing the terminations with ferrules, etc... The weakest link will always be the cable and cable stretch relative to shifting precision and when you get a little stretch you twist the adjuster a little bit. Shimano's Di2 (and future Di3) is about the only thing that will eliminate that weak link.

11) Stoker stem: Your frame builder should be figuring this out for you by comparing the frame geometry to you and your stoker's single bike riding positions and then making a recommendation. If you have a short stoker compartment you'll have a different set of options (threadless stems typically work) vs. a longer stoker compartment where an adjustable boom will be required assuming you're both of normal proportions.

12) Headset: Chris King or equivalent quality / durability.

13) Brakes: Depends on which fork you're using. Most of the carbon road forks for tandems are designed around short-reach calipers. Trek was about the only builder offering a carbon or steel fork that were designed for standard reach calipers and those are far and few between. Most others use cantilever bosses for V-brakes.

jnbrown

At some point I heard that tandems should have wider handlebars for "control".
After many years of riding 42cm bars and being uncomfortable, I switched to my normal 40 and that was much better.
Mavic SSC brakes are a great option for tandem caliper brakes. They can be a bit difficult to find though. Also they don't have a release mechanism so it may be difficult to get the wheels off unless you have Campy shifters which have the release built into the brake lever, Shimano does not.

zonatandem

JSNYC

Here's a couple ideas that we have incorporated on several of our custom tandems:
Adjustable stoker stem with a braze-on for mini-garage door opener.
Braze-on for 2 spare tandem spokes under the boob tube.
Pump braze-on where-ever you like it (ours is on top of boobtube).
Custom bottle mount on stem for stoker . . . yes, she likes her water bottle in front of her with a flexible tube/straw so she can sip without having to yank out a bottle.
Also have cable guides on fork for our hardwired computer.
If you're hgaving a tandem built to specs, might as well get what you like/want.
Pedal on TWOgether!
Rudy and Kay/zonatandem

pathdoc

It sure is cheaper to buy one, preferably a nice used one.

steve53mg

Handlebars: I use 42 on the front (same as my single), and 44 on the back. Don't forget that the captains butt has to fit in between and leave room for the stokers hands!