# 29er Tandem?



## Soupboy (Jan 13, 2004)

Got the green light from the old lady to move forward on a tandem project. She likes the idea of more "family" time and hauling the kid(s) in tow with the Burley. I like the idea of simply more ride time and another bike...and I suppose that other stuff too. 

I'd love to get a full blown ill-nasty Ventana FS tandem but me thinks that would not be cost justifiable. Sooooo, I'm thinking a 29er HT with rigid fork, Turdbuster posts (that's for you Padre), Rohloff drivetrain (dual EBBs, vertical drops), KH wheelset with the fat Schwalbe slicks, and Hope 6-potters frt/rr would be a solid family "touring" bike.

Shoot me down.


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## Padre (Jan 6, 2004)

Soupboy said:


> Got the green light from the old lady to move forward on a tandem project. She likes the idea of more "family" time and hauling the kid(s) in tow with the Burley. I like the idea of simply more ride time and another bike...and I suppose that other stuff too.
> 
> I'd love to get a full blown ill-nasty Ventana FS tandem but me thinks that would not be cost justifiable. Sooooo, I'm thinking a 29er HT with rigid fork, Turdbuster posts (that's for you Padre), Rohloff drivetrain (dual EBBs, vertical drops), KH wheelset with the fat Schwalbe slicks, and Hope 6-potters frt/rr would be a solid family "touring" bike.
> 
> Shoot me down.


A tandem by definition is a hokey machine....so the thud fits right in. I'm wondering why the Rohloff though, just for cool sake?

Also, which rigid fork could accomodate this set-up? Custom I suppose. Perhaps a custom White Brothers thru-axle jobber could suffice as well...

I think the idea is fun.


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## Cloxxki (Jan 11, 2004)

Also, the Rohloff has a certain limit on smallest front ring (maximum torque?). Perhaps they don't like tandem use for it either?


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## Soupboy (Jan 13, 2004)

C&P,

Fork - custom rigid in 4130 or a WB. I just don't know if all that mass would be too much leverage for the WB single crowns. Maybe a special DC fork? I thought about the Mav, not sure how it would do either. I'm a beast and my wife is not but we'd still be >400# combined. She won't be game for much beyond paths, gravel and double track but I'd have it built susp-corrected for at least a 100mm fork should I want to do silly things with like-minded stokers (I WILL be captain of this vessel).

Rohloff - purely for fock's sake and aesthetics. You can go to www.mtbtandems.com and see them built up. Alex Nutt is a solid guy and seems to know his stuff on the tandem front.


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## DoktorNo (Nov 2, 2005)

*Vicious 29er tandem fs.*

Vicious Cycles is now building a tandem 29er with a Titus Racer X rear suspension.


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## b1umb0y (Feb 28, 2005)

Soupboy said:


> Fork - I thought about the Mav, not sure how it would do either. I'm a beast and my wife is not but we'd still be >400# combined.


Looks like Mav makes a special fork for tandems. Cool idea overall... maybe I will have to convince the uxorial unit into something like that... 

bb


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## Endomaniac (Jan 6, 2004)

Soupboy said:


> Shoot me down.


As a fairly big tandem enthusiast ill throw my 2 cents in. Rember that forces aplied to a tandem are much more than what 2 single bikes ever see. Id drop the Rohloff idea from the get go. I don't think you will get an adequate rear spacing with that hub and I'm not sure it would stand up to the abuse. Also, you need 40 spoke minimum rear wheel and that eliminated the Rohloff too. A regular drivetrain doesn't stand up to tandem abuse very well but at least they are easy and cheep to replace. Double EBB's sounds like too much stress on the rear BB shell to me. Id look at the DT tandem hub, it has a disc adepter that screws onto the drum drake mount. I think it only comes in 40 hole so you will have to see if you can get a Chris Holmes rim custom drilled. The king hubs are nice but I think the DT is beefier.

Thudbuster for the captain is going to freak out the stoker as the Captains butt is constantly moving back toward them, plus you won't have the ability to use a standard stoker stem but will need some other way to mount the stokers bar, id ditch that idea too. A rear thudbuster would be an excellent idea though. The stoker can't ever see what's coming up and if the captain doesn't call out bumps very well the stoker will suffer. Tandems are all about everything being in sync between the 2 riders, 2 suspension posts are going to be too much different movement going on.

I don't know what kind of budget you have for this but a custom as you describe is likely to be a very expensive bike. I would go strait to the more experienced tandem builders to start with but most are going to try and stray you away from 29" on a tandem for wheel strength issues. Many tandem builders' suggest 26" rims for heavy teams riding on the road. For rigid forks make sure the builder is using a tandem specific one piece steerer tube, the good ones requite a 1" star nut in a 1 1/8" steel steerer tube. That fork will need to be one strong SOB. Personally I wouldn't want to ride any suspension fork that wasn't a dual crown on a tandem.
If the goal is more family time and you want to pull a trailer you probably aren't going to go all out on nasty trails. If I where you I would look hard at the Cannonade tandems that come with disk brakes the road and mountain versions are really the same thing with the brake bosses welded on at different places. The frame will clear a 44c mutano in the rear no problem and the fork will clear a nano but barely they are a great bargain and ride very well. A few modifications and one of those could meet your needs.


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## [email protected] (Sep 14, 2005)

Endomaniac said:


> As a fairly big tandem enthusiast ill throw my 2 cents in. Rember that forces aplied to a tandem are much more than what 2 single bikes ever see. Id drop the Rohloff idea from the get go. I don't think you will get an adequate rear spacing with that hub and I'm not sure it would stand up to the abuse. Also, you need 40 spoke minimum rear wheel and that eliminated the Rohloff too. A regular drivetrain doesn't stand up to tandem abuse very well but at least they are easy and cheep to replace. Double EBB's sounds like too much stress on the rear BB shell to me. Id look at the DT tandem hub, it has a disc adepter that screws onto the drum drake mount. I think it only comes in 40 hole so you will have to see if you can get a Chris Holmes rim custom drilled. The king hubs are nice but I think the DT is beefier.
> 
> Thudbuster for the captain is going to freak out the stoker as the Captains butt is constantly moving back toward them, plus you won't have the ability to use a standard stoker stem but will need some other way to mount the stokers bar, id ditch that idea too. A rear thudbuster would be an excellent idea though. The stoker can't ever see what's coming up and if the captain doesn't call out bumps very well the stoker will suffer. Tandems are all about everything being in sync between the 2 riders, 2 suspension posts are going to be too much different movement going on.
> 
> ...


Good work Endo... you know your tandems.

If you really want a pimp ride... go for a Retrotec Tandem. He's doing 29er's with or without Ventana rear.


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## robpennell (Aug 3, 2004)

I just happened to be on the phone with these guys www.davincitandems.com when I was reading this thread so I asked them. They can build a 29er tandem no problem. Would be worth a phone call but $ could be up there.


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## Cloxxki (Jan 11, 2004)

I would see why 26"makes a stronger wheel, if ALL RIMS shared the same extrusion. However, they don't. And plenty strong 29"rims exist. The Kris Holm unicycle ones for instance (one man, one wheel, rather than 2 : 2) .
With such a rear rim I wonder if the Rohloff would still be out? 40 spokes make loads of sense though. Why save weight there if you're with twice the power?
When going with a rigid fork and also a custom frame, perhaps some 26" forks are attractive cheap candidates. Dirt jump forks and stuff like that. And I guess if you later go for a longer suspension unit, Geometry suffers less than with a single bike?


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## ~martini~ (Dec 20, 2003)

Tandem, eh Soupy? Should be a rollicking good time. I'd love to get one for the partner and I too. Someday....

Look up Bob Brown and stay local! I've talked to him about doing a 29" tandem and he's all for it. Perfect Chequamegon material there. Even rigid you'd be fine. Bob would a great source to bounce ideas off of too. I like the idea of devinchi as well. Their independant coasting thing is neato, and works quite well.

I'd ditch the Rholloff idea as well. i'm sure it'd handle it but you really DO need more spokes in the rear. Turbuster for the capitan is silly too. There's lots of absorbtion in those looooong tubes. The captains ride is startlingly smooove.

ohhh, browsing and found this: 








Retrorec tandem. sweet stylee for you and your honey!


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## SortedCycles (Mar 8, 2004)

*Rohloff hubs*

If you do go for a Rohloff hub you'll have to stick with 135mm spacing. We asked them about getting a wide spaced hub made for use on a snow bike and they came back witha definite no!


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## Soupboy (Jan 13, 2004)

Thanks for all the feedback. 

Post - makes sense to keep the captain's post rigid. Hadn't thought about my bouncing caboose. Maybe I should let my wife ride captain.

Fork - Yeah, thought maybe a Surly Instigator fork might be a good place to start. I'll look into the other susp options (WB, Mav) but out of the box think fat rims and high volume tires should provide enough cush for intended use.

Drivetrain - I'm by no means a Rohloff expert, but I thought they could handle quite severe torque loads. 

Wheels - 29ers or nathan brothers. KH should be plenty of wheel for what this bike would supposedly be subject to. Properly built 36H should be fine. I might even use my current Hope tandem front hub and track down a rear one to match.

Cost - shouldn't be too bad if kept HT. I'm specifically staying away from the FS because as much as I like them I actually want my wyf to go out for a 2nd ride.

Complete bikes - I will build a recumbant, FS, 30-spd, unicycle before I buy a Cannondale. Not sure why, but that is how I feel.


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## Hjalti (Jan 22, 2004)

Rohloff should do fine on the tandem. Alex Nutt knows his stuff. Chris Timm has been riding and racing for several years on a Rohlofff equiped tandem.

http://tandem-fahren.de/Mitglieder/Christoph_Timm/TandemTechnology.html

http://tandem-fahren.de/Mitglieder/Christoph_Timm/transalp2001.html


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## el-cid (May 21, 2004)

b1umb0y said:


> Looks like Mav makes a special fork for tandems.


I'm still liking that Risse Trixxy fork, it should be able to be spaced for a 29er, should be plenty stiff, and is fairly affordable (lotsa shouldas, but looks promising).


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## TandemNut (Mar 12, 2004)

*ON 29" tandems...*

Just my .02 on 29" tandems:

1. We have a suspension fork prototype built for 29" tandems on the way. It's built by ATC, which makes our regular T-5 tandem forks. The fork has 4" travel, uses a 20mm axle, and has an 18.5" crown-to-axle, which helps reduce one of the issues with the bigger wheels - taller standover.

2. Rohloff hubs are perfect for tandem use. While they're only 135mm spacing, the hub builds a perfectly symmetrical wheel (no dish), which is stronger in 32 spokes than a dished wheel in 36 or 40 spokes. Some doubt 135mm spacing on tandems, but we've used 135mm spacing on our Fandango brand and most of the Ventanas we sell for the last 5 years. We've had ZERO (knock wood) wheel failures. That's a function of a professional wheel builder (John Kovachi) and appropriate spokes and rims (Sun Mammoth or MTX and Sapim 13/14g spokes). Rohloff hubs are the strongest hubs we've used on tandems, and the only hub that has not failed on a tandem (yet). I wouldn't worry about the strength of the hub.

3. We're working on a 26" rear/ 29" front setup for our Fandango tandems. I believe the value of the 29" front wheel is best utilized on the front, and the hybrid concept helps us get things rolling until we finalize an entire new frame design. Most tandems need more standover in the rear than the front, so this helps in that aspect as well. The combo would work better in full suspension, but that's another design still in the testing phase...

4. Our biggest challenge for 29" tandems is wheels that are strong enough. I'm also working with another fork manufacturer to build custom front hubs that will offer more strength for a tandem front wheel, and hopefully more durability. Rear wheel strength may be somewhat of an issue as well, given the predominance of 135mm spacing on mtb tandems. Heavier/stronger rims and stronger spokes are paramount for wheel survival, and we're working on that. Some options are Suns RhinoLyteXL 29", and Sun may even run some Mammoths for us. We just have to order lots of whatver to get them made.

5. When building 29" tandems, we have to address bb height as well as standover. The best off-road 26" tandems out there, the Ventanas and the Fandangos, have high (13 - 14" static) bb heights. We ride technical terrain, and low bb's are the biggest obstacles to making things happen on a tandem off-road. Of course, if you raise the bb height, you have to adjust the standover accordingly, or you have none left because of the high bb height. Assuming adjustments made where necessary, you end up with a short (vertically) frame with a relatively high CG. You have to balance the head angles accordingly to offset the challenges of the higher CG, and it's a ticklish balance.

You don't need a suspension seatpost in the captain's position, unless you're riding some really rough stuff, with a rigid fork such as we use on our ususpended tandems (Funn fork). The ride for the captain on a hardtail tandem is better than the ride on a full suspension single bike. Really! Being suspended across a 73" wheelbase will do that. A good front fork makes a huge difference, and the Thudbuster is a great solution for the stoker. Not as good as full suspension, but definitely doable for many teams. Either way, the ride will be smoother than most single bikes.

Cannondale makes great tandems, and they're made in the good 'ole USA. However, if you ride one off-road, the bb height will be a killer. I know, I started on a Cannondale, as did very many of our customers. I've glad Cannondale's making mtb tandems; our first three tandems were Cannondales. But those who actually ride their tandems off-road need adequate bb clearance, steeper head angles than typical for tandems, and decent standover. The Cannondale gets one out of three right - the standover. If you're riding dirt roads or roads, there's not a better value than Cannondale, and I'd buy another one the minute I need a road tandem, as I think they're great values.

Just my .02. The exciting thing about 29" tandems is that we're just beginning to get manufacturers interested in offering them as options. I'm looking forward to the next year or so, when we get some of these ideas rolling and see how they hold up. In the meantime, Vicious makes a 29" frame, and as noted here, da Vinci can make one as well.

Shameless plug, but if anyone's interested, we'd be glad to help you out with the tandem.

Thanks


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## TandemNut (Mar 12, 2004)

el-cid said:


> I'm still liking that Risse Trixxy fork, it should be able to be spaced for a 29er, should be plenty stiff, and is fairly affordable (lotsa shouldas, but looks promising).


Risse, along with Maverick, are the other fork manufacturers that have agreed to build us 29" tandem forks. Mavericks are best used for lighter (<350 lbs) teams. The Trixxy is a beefier fork and is fine for heavier teams. The good thing about the risse is that the axle spacing allows a wider spoke flange on the front hub, and we're working with them to get a prototype built with just that setup. The result should be a much stronger front wheel, which gets most of the taco'ing on tandems. Tandems put huge side loads on front wheels.
Anyway, I like the Trixxy as well, but don't have the extensive time on them that I do on the ATC, which has proven bomb-proof. I'm hoping the Risse proves to be another winner.


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## sparrow (Dec 30, 2003)

*Hijack....*

Alex, ever use a Hopey Steering Damper on a tandem? I've been using one on my half bike, and just put one on our Ventana ECdM. It is magic, can't imagine riding without it. Ought to be standard equipment. You can PM or Email me off my profile if you'd like.


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## Bigwheel (Jan 12, 2004)

*We have $2300 worth of chopped liver......*



sparrow said:


> ever use a Hopey Steering Damper on a tandem?


I got one to try out on ours but haven't got a chance to mount it yet.

Sure seems like there is rad element out there riding tandems. For most couples I don't think FS is necessary, certainly wouldn't put it before a Devinci ID. I like that you can throw anyone on back and take off with confidence at both stations and you gain ground clearance with a wide range of gearing that is easy to shift due to the closer ratios.


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## sparrow (Dec 30, 2003)

*Independant pedalling...*

is worth a look, but do test drive it. We noticed far more pedal impacts with the stoker's pedals with ID than with the peadals joined up by in-phase as is "normal" tandem set up. That's in rugged singletrack riding where objects are coming up too quickly and often for the captain to call out for the stoker to miss. Less tricky riding I bet it'd be fine.


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## TandemNut (Mar 12, 2004)

sparrow said:


> Alex, ever use a Hopey Steering Damper on a tandem? I've been using one on my half bike, and just put one on our Ventana ECdM. It is magic, can't imagine riding without it. Ought to be standard equipment. You can PM or Email me off my profile if you'd like.


I've not used one, but I have customers who won't ride tandems without them. In fact, one team declined upgrading to a Maverick fork just because they couldn't use the Hopey. Must make on heckuva difference. 
Our typical riding is low speed technical stuff vs high-speed open stuff, so I'm not sure how well we'd appreciate it. Then again, it might be like 29" wheels; you don't know how much difference it makes until you try it.
I'd like to hear more about your experiences with the Hopey on your tandem. I get asked about them sometimes.
Thanks


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