# New 29er Tandem



## MichiganClydesdale (Mar 24, 2004)

Just got this big fella put together. Quiring 29er tandem, XXL / XL, Rohloff Specific. Waltworks rigid 20mm TA fork. As you can see, I used standard cranks and run the timing chain on the drive side, in the middle chainring position - this opened up my options for 180mm captain cranks. Too much snow here still to hit any trails, but hoping to get it out on some roads tomorrow. Yes, the cranks are about 10% out of phase, that's intentional, specifically for it's first race next week. Thanks to Scott Q and Alex at mtbtandems for their help with this.


----------



## winbert (Sep 22, 2005)

Wow. And I mean _wow_. Nicely done :thumbsup:. Can't wait to hear your singletrack impressions once the trails clear...

winbert


----------



## jeff (Jan 13, 2004)

Now we're cookin with gas!!!!!


----------



## TandemNut (Mar 12, 2004)

That is a beautiful tandem! Looking forward to the first ride report.


----------



## donalson (Apr 13, 2004)

can we get a close up of the "timing chain" portion the back side specificly? ...

that thing looks wicked awesome... I still wonder how people can ride something like that on the trail... (i guess i picture how much room it takes my fat 29er self to get around some tight swtichbacks...) also wonder how the stoker copes with having virtualy no control other then "pedal harder dangit" lol... one day i'll try out a tandem


----------



## bbudell (Jun 10, 2005)

Sweet build!! Are you running the cranks slightly out of phase? I have found on a lot of the sandy Michigan trails that it really helps with traction on the uphills.


----------



## crackhead (Dec 27, 2006)

going to -10 or -15% timing for the stroker might be right for getting over trees and rocks. With the same timing, one pedal clears and the other doesn't at a giving speed unless you both stop pedaling.


----------



## MichiganClydesdale (Mar 24, 2004)

*good timing*



bbudell said:


> Sweet build!! Are you running the cranks slightly out of phase? I have found on a lot of the sandy Michigan trails that it really helps with traction on the uphills.


thanks KBS, and thanks for all your help early-on with this, I look forward to butting heads in the iceman again! I am running those cranks slightly out of phase, with the stoker leading, specifically for the race this weekend because my stoker is pretty strong (I'll let him start each push!). Mostly though, I'll run them slightly out of phase to my lead, and see how that works out on the sand.



donalson said:


> can we get a close up of the "timing chain" portion the back side specificly? ...
> 
> ... I still wonder how people can ride something like that on the trail...


It's a big bike, I don't know how much tight twisty stuff it'll see. Here in Michigan, we have some pretty wide open terrain, which should make this a fun bike. here's a couple shots of that timing chain. I had to space the drive ring out 2mm so the chains wouldn't touch. Part of the problem was I am using PC1 chains, which if you have used them you know the quick link pin sticks out a mm or so, and that was causing a problem. Eventually I'll move to a KMZ or even sram 8sp chain for the drive.


----------



## Speedub.Nate (Dec 31, 2003)

Hot damn, that bike is sizzling hot... in my favorite color, even! Props on the copper colored Avid Mag levers.


----------



## MABman (Oct 5, 2008)

I watched Q finish up that frame and pictures don't do that paint job any justice cause it is freaking stunning up close. Looks good built up and have fun with it!

The Q&C model that was built alongside that one is also a thing of beauty. Scott really likes to paint and it shows. http://www.quiringcycles.net/igallery/igallery.asp?d=\tandem\c%26q+29'er+tandem+steel\


----------



## teamdicky (Jan 12, 2004)

MichiganClydesdale said:


> Part of the problem was I am using PC1 chains, which if you have used them you know the quick link pin sticks out a mm or so, and that was causing a problem. Eventually I'll move to a KMZ or even sram 8sp chain for the drive.


Move the link to the other side. Had the same problem with interference with a bashguard once. Shouldn't have contact anymore.

SRAM PC-1 fan club president, 
Dicky


----------



## TandemNut (Mar 12, 2004)

I think you'd still have to shim out one of the rings. We end up shimming the same-side drive rings on Rohloff tandems all the time. The spacing on the spiders for 9-speed rings appears to be closer than older cranks. As a result, we've had some 9-speed chains rub against each other on bumpy trails, when set up similar to this one.


----------



## MichiganClydesdale (Mar 24, 2004)

*ugh*



BigNut said:


> I think you'd still have to shim out one of the rings.


Yep, I still needed to shim out the big ring (which threw off the rohloff drive line), because I couldn't shim the timing ring in any further to avoid chainstay interference. But I know what TD is saying, if you run a fat bash guard like raceface, the pc1 link knicks it, but can also solve that with a thinner spot ring.

We raced the tandem today, and the bike was phenomenal, but the drivetrain wasn't...but I suspected that. The driveline is off by a few mm's, and the timing line is off a bit too, because of the chainring spacing and the chainstay clearance issue. We dumped the timing chain 2x, and the drive chain once and it cost us. I had a great stoker too, we were motoring when things were clickin' good. Standard tandem cranks on order from Alex, which will fix most of the problems. But the length of the bike and the subsequent length of the timing chain is subject to frame flex and dumping the timing chain under power (particularly when there's a big difference in captain vs stoker power). I'm hoping that chain guide (would love to get my hands on the new paul cross keeper) will fix it.


----------

