blk

Sorry, I didn't see this when I skimmed the stickied thread -

Does tandem sizing follow one's usual road bike sizing? Would I ride my typical road bike size as captain, and would my stoker ride her typical size as well?

Thanks!

TandemGeek

Unless you're having a custom frame built, you size for the captain. Stoker compartments typically fall into one or two different sizes differentiated by seat post length, as the stoker top tubes tend to be about the same length across the entire size range of most builders.

Cannondale was a notable exception as their stoker compartments did, in fact, have proportionately longer stoker compartments on their larger models. Trek's T1000 & T2000 tandems also had slightly larger stoker compartments on their larger models.

ksisler

OP; You will likely get many opines on this topic. Having bought, sold, built and ridden a considerable number of tandem (frames or complete bikes) since the early 70's, I will offer mine;

I like to size the Captians stand-over height (SOH) about an inch smaller that on their best well fitted road/touring bike. Rationale; The captian of a tandem has the additional responsibility of steadying the bike when stopped at intersections, etc. Having a extra inch of stand over allows the captain to stand with his feet a few inches further apart and thus improves the steady position.

I rarely worry much about the stokers vertical situation as the stoker stays on the pedals throughout a ride. Rationale; As long as the stoker is well positioned to reach the pedals and has good horizontal space to not be up too close to the Captain's back, then the fit will be ok assuming the issues of the saddle, the seat post, the handle bar shape and feel, and the stem length and height are sorted out overtime. Mostly this is trial and error and I keep about a half dozen of each type to work through until the stoker is sorted out (which can take up to a year of riding).

Although there are exceptions, most times the Captian is found to be a few inches taller than the stoker but proportionally the stoker (if female) will have longer legs in relation to overall height. Generally this calls for a tandem about 1 inch smaller SOH than the Captians regular bike and then having a slightly downward sloping top tube leaving the rear SOH about 2-3 less than the front. This 'downward sloping top tube' tandem is also a very strong design, makes an attractive bike, and is one of the easiest to build...so a win-win situation.

Hope that helps
//K

Tom Spohn

Although it is true that the stoker's feet don't need to straddle the top tube, there are some stokers that find this situation intimidating--mine for example. Another factor might be how flexible the stoker is. Mine has has both hip and knee replacement surgery, and while strong as ever on the bike, she finds it difficult to swing her leg over the saddle to get on the bike. I second the motion that a sloping tube really makes mounting easier on the stoker. On our Cannondale the tube is low enough in the back she can lift her foot over the top tube to mount. This is a question that requires a lot of stoker input.

jnbrown

One thing to beware of is the position of the captains seat relative to the stokers bars.
In our case it so happens they at the same level, so my butt interferes with her hands.
I have had to tweak things by moving my saddle slightly forward and her bars slightly lower.

Dean V

Size the front as you would for your single. That is, same top tube length, and if you want to be more accurate use stack and reach dimensions.

DubT

We do not follow the Bill McCready method of starting and stopping. We do not like that method. My stoker does not stay on the seat when we start and stop. We therefore need a tandem that allows both of us to place both feet on the ground comfortably.

TandemGeek

Thank goodness Co-Motion developed the PeriScope; guess that's why it's so popular...

For those who have significant height differences with their stokers, or who have stokers that are small in stature, stokers who can't comfortably swing a leg over a top tube, or who want a lower top tube for any reason the Co-Motion PeriScope is the solution for a tandem that is still in the premium / performance class.

Co-Motion Periscope design approach


Conventional Co-Motion Speedster design approach


However, and getting back to the original point about tandem sizing, note that even the PeriScope design only addresses the seat tube / top tube height dimension, not reach, i.e., stokers who ride single road bikes are not typically able to replicate their single bike riding positions on most stock tandems unless they have a very upright riding position to begin with and/or have a short torso/arms and don't need a lot of reach.

So, let me once again note that you size a tandem for the captain: that's the starting point. You will not typically find a stock tandem for a 6' tall captain that allows a stoker who is a fit roadie to replicate their single bike riding position. If you have a stoker who will always be your stoker "until death do you part" then there are some considerations that you may need to address if your sizing is highly disproportionate, etc.

For the best outcome where you're buying a tandem to use with a specific riding partner, then yes... you'll want to have them along for any test rides on tandems so that unique fitting issues can be identified. However, if you're at a point in your life where you're still likely to ride a tandem with different stokers then all bets are off for getting a perfect fit short of a Co-Motion PeriScope or perhaps a used Erickson with their steeply sloping top tubes & long stoker compartments. Rodriguez tandems and some Bushnells will also have longer than average stoker compartments.

You are blessed by being in Eugene, Oregon, as you can find just about every model and size of Co-Motion for test ride at Co-Motion's factory / showroom in Eugene.

ksisler

I believe Tom was responding to my response so I will go from there forward;

1) "there are some stokers that find this situation intimidating";

No question this is true...in fact I am not sure I have met one who did not find it so. Being a stoker is flat out weird at best. With time and support as well as the luck of not getting spilled very many times, many stokers seem to grow into it at least enough to tolerate it and develop enough trust in their Captain and their shared vehicle to work with it. Not all can or do and some could but aren't willing to sign up deep enough to the trust aspects. It is fair to say also that some Captains never develop the ability at the helm which fully inspires the trust level. It is a very individualistic shared experience. Tom's point that "This is a question that requires a lot of stoker input." can't be stress enough. And this pretty much rules out the idea of buying a tandem on Friday and going on a tour Saturday morning. Lots of empty parking lot trials and loops around the block at low speed, etc., can be great for skills development and confident building.

2) "Another factor might be how flexible the stoker is. Mine has has both hip and knee replacement surgery, and while strong as ever on the bike, She finds it difficult to swing her leg over the saddle to get on the bike."

This is a very important consideration. For these teams, lowering the stokers top tube down another 2 inches or more can help. In severe cases, a Mixte-back design can be helpful. Even then an adaptive mounting procedure may be needed. As an example for use in the team devising their own specific solution, I will offer this boiler plate;

"Generally I have had best success in having the stoker stand facing forward about 2 feet away from the bike with the left hand on the saddle tip and the right hand on the end of the stoker's bar. The Captain does the same at that station and ensures the the timing side pedals are straight down. Then the stoker pulls the seat over, in effect laying the bike down enough to allow the stoker's left leg to be lifted over the top tube, placing the arch of the stokers left foot on the point where the distant pedal and crankshaft arm meet. The stoker then issues the command such as "Mounting Slowly" and together the team lifts the bike gradually toward vertical. As they get to about 60 degrees above horizontal and in close observation of each other, the Captain steps over the top tube and places his left foot just beyond the front down pedal (closer if he has spare ankles for later . At that point 99% of the stability of the bike is responsible to the Captain. The stoker slides the left foot into the toe clip and lightly tightens the strap and then fully seats and foots the right pedal, reaches down to right the right pedal for the right foot to slide in and straps down. At this point I would instruct the stoker command 'to the push off position' or equivalent and the stoker rotates the crank backwards to about 120 degrees (by lifting the left foot). While maintaining the steady, the captain can now insert the left foot into the now waiting left pedal clip or snap in if using SPD's or similar. Now that the Stoker is fully ready to ride off and the Captain has the left foot engaged and the pedal is ready for push off, the Captain confirms verbally that the stoker is ready by querying "ready to push??". Upon confirmation, both push off on the left pedal, the captain focuses first on steering and balance and works to get the right foot on top of the pedal and the team works in several smooth strokes to stabilize the bike or get it all the way through the intersection, etc. When appropriate and safe the Captain call "pause" with the right pedal up to secure the toe clip or with the right pedal down if he needs to push twist in to click SPD's, etc. Happy riding follows in most cases."

This is written as pretty Dick and Jane level on purpose to make the point that the process needs to be developed in exacting detail, fully agreed to, argued about, improved, studied, and then practiced and practiced until it is muscle memory. I used to have a set of flash cards with cartoon drawings of each step and commands in bubble art. If I can find it, I'll see if I can scan it in.

Hope the about helps
Kerry

ksisler

DubT; I wasn't aware that anyone had attempted to blame Santana_Bill for this method. If folks want to I am sure he will take the blame with a smile and probably a snicker also. That dude gets blamed for almost as much stuff as the W Bush. However, much like the half-step plus granny gearing, I do know that it was in common use here and in many countries at least a decade before Santana Corp USA started up. If Bill has advocated it (I haven't heard or actually read him doing so, but wouldn't be surprised), it is likely he ran into in when apprenticing (believe with the late Taylor Brothers?) in UK or in Europe. I do remember the late/great Sheldon writing on the method way back. Myself, I think it works well for most teams, especially when there is a distinct experience or skills shortfall with the stoker. But when a team is more comfortable with another method, I certainly think they should use that method. A team should have a plan for soldiering on if one of them twists an ankle or breaks an arm at mid-tour or is very pregnant; those sorts of things.

Appreciate the added dimension you have added to the discussion. Hope this helps along those same lines.

//Kerry

waynesulak

My stoker does not have the flexibility issues mentioned here yet but we plan to ride a long time so I am trying to understand the methods mentioned above.

Please let me know what would be wrong with the method as follows:

Captain straddles tandem per the "Proper Method" Claimed by Bill McCready and supporting the top tube with his inner thigh holds the bike rock steady.

Stoker standing on left of bike places left foot on pedal. Some clipless pedals with limited float would be an issue here but lets assume toe clips for now. Stoker then stands on left foot with left leg straight and with right foot dangling.

Would the stoker then have the flexibility to swing her right foot behind & over the wheel which would be fairly low in comparison to her hips? The saddle should not be an issue while standing on straight left leg? This could be much easier for a taller stoker vs a short one. Mine stoker is 5' 6" and the wheel is very low for her if standing on a pedal. She doesn't have to bend her right leg much at all as the leg can for the most part go around the rear tire.

Assuming the right leg could be moved behind the saddle and behind/over the rear wheel then she can place right foot in pedal.

Am I underestimating the problem of the stoker swinging right leg behind the rear wheel?

ksisler

Wayne; I would be remiss if I didn't say to the effect; As long as your team has a reliable procedure to safely get everyone on the bike and then to proceed safely, then all is good as long as the stoker agrees that the procedure is good. The one you describe is one I have seen rather often. If it works well for your team, then just ignore folks who desire to tell you that it is wrong..and I would not recommend soliticiting opinions on it. Just pedal on!

I have worked with a team whose stoker was a dual leg amputee with artificial legs (via a car wreck). We did a Mixte back for them and worked up a soft canvas strap so she could slip is under her left foot and lift her leg over. With another team whose stoker was born with only one leg and was perfectly happy with it. She could probably break the right crank arm off with her leg strength, but she would bunny-hop-walk so smoothly down a sidewalk in a denim skirt that you couldn't sense that she was one legged.

I should also note that as the decades roll on, changes will be needed... if the stoker moves through from bubbly tennis star teenager to a very PG spouse with a sprained knee and swollen feet...things will need to change. Just sort it out, bond, and pedal on.

hope this helps;
K