Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Tandem Cycling A bicycle built for two. Want to find out more about this wonderful world of tandems? Check out this forum to talk with other tandem enthusiasts. Captains and stokers welcome!

User Tag List

Reply
 
Thread Tools Search this Thread
Old 11-29-05, 03:08 PM   #1
Speedub.Nate
fanatik
Thread Starter
 
Speedub.Nate's Avatar
 
Join Date: Mar 2005
Location: SF Bay Area, California
Bikes:
Posts: 413
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
29"er Convertible, questions...

I've been contemplating a mountain tandem for the past couple months for my wife and I. Never one to take the easy way out, I'd like to go the tandem / solo convertible route (similar to the Rodriguez 8ball hardtail http://www.rodcycle.com/eightball.html), but with 29" wheels.

I am presuming we'll use the bike mainly for fireroad and non-technical trails, but steep climbs and descents typical in Northern California. I also anticipate some road touring on this bike, but not epic distances. The key is a trunk-stowable, transportable bike that we (or I) can easily carry & store incognito, easing worries of theft when traveling on non-bike vacations, and getting my wife out on some trails she otherwise might not want to tackle solo on her own bike. Plus just a little bit of variety added to the normal routine.

Couple of roadblocks:

- Getting a 29" frame built seems to be no problem, but what about a fork? Are there any 29" compatible tandem rated suspension forks featuring an air spring or an air assist spring that will allow them to work with a solo rider (me @ 200 pounds) or with two riders? Or do I just go rigid with this setup?

- Any thought on the geometry issues involved with two different sized riders and a convertible setup? I typically ride a 19-20" frame and my wife a 15-16" frame. She would be the stroker, meaning when the bike is in the solo configuration, I'd be riding on her smaller half of the bike. I'm supposing that as long as I get the reach right, I'll just have a really low top tube with a whole bunch of seat post showing.

- I'm definitely planning on a Speedhub for this setup (making a single-sided drivetrain practical). I am confident in the proven 32 hole Speedhub standing up to off-road tandem duties in a 26" application, and touring in a 700c configuration, but any thoughts on a 32 hole 700c/29" wheel standing up to off-road abuse?

...and thinking Avid 8" discs are the way to go for ease of conversion (plus I use them on all of my other bikes and like 'em). His & hers Thudbusters (short travel & long travel) would round things out.

Thoughts?
Speedub.Nate is offline   Reply With Quote
Old 11-30-05, 04:49 PM   #2
crosswater
GiantOldGuy
 
Join Date: Oct 2004
Location: Pulaski, TN
Bikes: Merckx Mx Leader, Trek Singletrack 800, 87 Santana Elan
Posts: 29
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Check out http://www.zinncycles.com/bikes.aspx ...I also found the crank arm length article rather interesting... They seem to have the bases covered on the frames and crank arms for big guys and gals. The case they make for 29" wheels is intriguing... I thought I had bought my last bike...oh, well.
crosswater is offline   Reply With Quote
Old 12-01-05, 05:46 AM   #3
ElRey
Senior Member
 
Join Date: Aug 2005
Location: New Jersey
Bikes: Colnago C40 HP, Aegis Trident, Cannondale tandem
Posts: 491
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Stick with what's readily available at first: I'd buy a used standard Mt. Tandem and see if you really want/need those 29"ers... A custom order on one's first try at anything seems overly ambitious.
ElRey is offline   Reply With Quote
Old 12-01-05, 05:50 AM   #4
galen_52657
Banned.
 
galen_52657's Avatar
 
Join Date: Jun 2004
Location: Towson, MD
Bikes: 2001 Look KG 241, 1989 Specialized Stump Jumper Comp, 1986 Gatane Performanc
Posts: 4,020
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
For the type of riding you are describing, a standard fork would work.
galen_52657 is offline   Reply With Quote
Old 12-01-05, 09:11 AM   #5
TandemGeek
hors category
 
TandemGeek's Avatar
 
Join Date: Jan 2002
Bikes:
Posts: 7,213
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by Speedub.Nate
I've been contemplating a mountain tandem for the past couple months for my wife and I. Never one to take the easy way out, I'd like to go the tandem / solo convertible route, but with 29" wheels.
We had a similar discussion on my off-road tandem enthusiast's forum about 2 weeks ago. I'm not sure if any consensus was reached; however, I would encourage you to post your same questions to our off-road forum as I'm sure it will stir up some responses as there are several other teams who have an interest in the 29" bikes.

More information and links to the forum: http://www.thetandemlink.com/Double_Forte.html
TandemGeek is offline   Reply With Quote
Old 12-01-05, 12:06 PM   #6
Speedub.Nate
fanatik
Thread Starter
 
Speedub.Nate's Avatar
 
Join Date: Mar 2005
Location: SF Bay Area, California
Bikes:
Posts: 413
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks, everyone, for the replies.

I'm very much sold on the 29"er aspect of this project. I have been riding a 29" hardtail since fall of '02 and am sold on the workings of the larger wheels. I'll jump to a 29" solo full suspension when the right bike comes along. As it is, my thinking is that for a non-suspended tandem, the 29" wheels will provide a significant advantage in rolling smoothness (sort of "built in" suspension if you will) and if I'm forced to hit the trails on a rigid bike in the solo configuration, I'd have it no other way.

On one hand, I am slightly concerned about going "all out" with a custom build out of the gate. On the other hand, my wife and I have rented ill-equipped tandems on a few occassions and done some decent riding on them, including some choppy trails in the Marin Headlands, and we both agree this is something we want to persue. Specing a rigid fork and rebuilding the Speedhub of my 29"er into a tandem-worthy wheel will make a significant dent in initial costs.

TG, I signed up for your Yahoo! group and will check out the thread as soon as you approve my request for membership.
Speedub.Nate is offline   Reply With Quote
Old 12-01-05, 01:44 PM   #7
TandemGeek
hors category
 
TandemGeek's Avatar
 
Join Date: Jan 2002
Bikes:
Posts: 7,213
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by Speedub.Nate
TG, I signed up for your Yahoo! group and will check out the thread as soon as you approve my request for membership.
You're approved. Again you may want to repost your questions as part of an introduction note to the other forum.

The YahooGroups search engine is awful; however, the 29" discussion has been pretty recent and those posts should be easy to find. You'll also find that several of the regulars are using the Rohloff hub, to include our dealer-member Alex who specializes in off-road tandems. Sherwood Gibson (Ventana) will occasionally chime in as well.
TandemGeek is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 12:16 PM.