bikex10

I am having a hard time finding some black tandem cranks for our mountain tandem without breaking the bank. I have been kicking around the idea of just buying 2 single cranks and converting to same side chain configuration. I can buy 2 single cranks cheaper than what I have been finding tandem's for. Is there any thing that I need to be aware of before I spend the money? Was going to go with 104/64 BCD and a 44/36/24 ring setup.
Any thoughts as to why this might be a bad idea, or is there a better idea out there?
How is the preformance affected or is it?
With a 36 tooth ring we would be able to run in the lower 20's when the conditions allow, and when we could go faster it would probably be down hill and could coast then anyway, so I don't see a need for the large ring which would be the timing ring.
Any input is appreciated.
Thanks

mrfish

Yes you can do single sided gearing, but you may be surprised to find that the spread of gears people use on a tandem is much larger than on a single so restricting yourself to 2 chainrings may not be such a good idea as you would miss out on some big grins.

We regularly use the granny ring and wide range cassette on the tandem for steep hills (up to 25% near us), which on a single bike you can soldier up in 39x23 if reasonably fit and strong. Theoretically you can do this on the tandem as well, but it's much more difficult than on a single - I suspect it has something to do with the fact that we have the gears and we are supposed to be out for a fun ride together not to beat other people up a hill.

Then down the hill we get payback for the uphills and increasingly regularly get the 53x11 spinning. Sometimes on the flat with tailwind this happens too 2 nights ago we literally blew past 3 single bikers grinding up a local hill, still riding in the big ring at minimum 20mph faster than they were. Stoker did threaten to kill me afterwards for making her ride harder than intended, but as I said afterwards I never managed to ride up that hill spinning the big ring all the way up and over the top on my own, so it was worth it.

oldacura

Harriscylery.com had some tandem cranks. Don't know if they're black though.

rmac

Don't know what your budget is but did you look at the DaVinci cranks?

https://www.davincitandems.com/comp.html#cranks

With rings they are $550. For about $100 more they will black anodize them.

Another option is to get single bike cranks and have a helicoil installed so you can put them on the other side for the sync chain. This may be the less expensive option. Installing a helicoil is about $35.

sharoldsen

chucksbikes.com had some black Truvativ Firex tandem MTB cranksets for $150. If you search for tandem in their site's search box, they come up, but they don't seem to be listed under the cranksets link. You might want to contact them to check if they are still carrying them.

stevetone

It's my understanding that, with the correct chainring bolts, you can mount a fourth chainring on the outside of your triple in back. This extra chainring would be for your timing chain.

A good write-up can be found here.

Steve