JSNYC

Hi folks, a question for the sizing/fitting experts. Am thinking of swapping out the stoker bullhorn bars for regular drop bars with stoker levers, just for the sake of trying something new to see if she prefers it. Question is what size bar to go with that doesn't hit my thighs? There's about 11cm from middle of saddle to the top edge of the stoker stem. She's petite (5'), and the ~45-46 bullhorn bars seem a bit big. I figure a 40 or maybe 42 bar would be about right.

Also, for stoker, is carbon fiber bar ok? Wasn't sure on that one. Figured ok for stoker on carbon bar/stem combo (will get a long stem once we dial fit in), but I'm not comfortable going carbon/carbon on stem/bar for captain. Maybe that concern is misplaced.

Opinions/experience on this one would be appreciated.

Leisesturm

There (IMO) has to be a better reason than 'just for grins/curiosity' to go through the expense, etc. of a bar swap. As for 'hitting your thigh' ... wouldn't that depend on YOUR thighs? IOW, how can we possibly know the answer to that? My DW is 5'6" and I have her on 38cm bullhorns. 45cm bullhorn is definitely huge. I have 42cm for my own drop bars which is perfect. My road bike came with 44cm and I keep threatening to put 42 on her. I am 5'10"/200lb. Even 40/42 cm is big for a 5' petite female. But that may be what is needed to clear your hips. Bottom line, if her bars overlap your tush then you have to measure said tush and get bars that can fit around said tush and Stoker has to deal. Bullhorns kind of skirt the issue because they can run low under your rump and Stoker doesn't have to be so spread out.

IPassGas

I never understood the reason for drop bars on a tandem for most riders. The stoker is in your slipstream. A more upright position takes her/his nose out of your back and is more comfortable for stoker. If the bullhorns are not used and annoying, try a swept-back or straight bar.

79pmooney

The general rule for bar width from the old days is same as the width the centers to the shoulder balls. We used to take bare bars and place them against the balls. Shoulder balls fitting exactly into the tube ends was perfect. We varied from there for better bike control (wider) or aerodynamics (narrower); both of which have little meaning to a stoker. Here there is another factor - you.

A fit trick I discovered long ago that works really well for me and might have equal use here - I find I can vary my handlebar location along a diagonal line that keeps my elbow bend the same and it affects my power and comfort very little. For me that line is defined by a "slope" of 1 cm stem spacer by 2 cm of horizontal stem length. So I can have a stem that is high and a long ways ahead of me or low and close and my back lean stays the same. Likewise elbow bend. Highish and far ahead is more comfortable for me on long hills. I can develop more power on short hills and sprints low and close but both work for me as all day rides. (Within say 4 cm horizontal and 2 "vertical" - the spacers.)

So, if your thighs are hitting at the bar location that works for your stoker, maybe lower and further back would also work for her and clear you. Perhaps opening up a better choice of bar width. But the most important issue here is what works for the stoker! I cannot help you there.

JSNYC

Thanks that's help. The bike came with 45's for bullhorns, hence the process of tinkering with better fit.

sdodd

I went through a bullhorn to drop bar change on a couple of tandems. My wife (stoker) liked the increased number of hand positions with drop bars. But, you have to be careful with both stoker and captain fit. Find something that fits the stoker and decide if the captain can live with it. In my case, we had to go a little wider than ideal because my thighs/rear didn't fit within her bars.

The other thing to keep in mind is 'getting on' the tandem. I have super short legs for my size so I'm already at a disadvantage. The drop bars tend to catch my foot when I'm climbing on the tandem, if I am not careful. It just takes more care to get on and off.

You should make whatever changes to your tandem that make you both ride more! Enjoy!

TobyGadd

This is the correct answer!

mikebian 

To address the carbon vs aluminum bar question in the original post: About 10 years ago we had a Kent Eriksen touring tandem built for us. As we were talking to Kent, he said not to put carbon bars on a bike that you will use for touring because if you drop it, especially with a load on it, the bars may break. So, we have aluminum bars on that bike and we have dropped it a couple of times with no problem. Fast forward a few years and we're riding our Calfee. We're at a coffee or lunch stop and I go to get back on the bike, swinging my leg over the front handlebars, as I do frequently, and I got distracted, my leg got caught, and me and the bike went down. I was fine. My wife's nice carbon bullhorn bars, not so much. Completely broke off one of the horns. Aluminum bends, carbon breaks.

Other than the breaking issue, I don't see any reason why carbon handlebars present a problem for the captain or stoker. Our Calfee still has carbon bars front and back and I see a lot of other tandems with carbon bars.

Yamato72

My stoker asked for drop bars because she couldn't easily tuck with bullhorns. I sized them for her shoulder width just like on her road bike. She is also short (5') and the stoker has a lot of room on our Cannondale frame. She has zero complaints and would not go back.

OP, sorry I didn't see your question sooner.

mikemelbrooks

I put some 40cm bull horn bars from AliExpress on my friends tandem they clear my backside and being carbon fiber weigh slot less the the original bars.

merlinextraligh

From an aero dynamic point of view, it’s the open space between the stoker and the captain’s back that matters.

Even if the stoker’s head is below the captains body, there’s a lot of drag in the space between the 2.

we’ve done a number of tandem time trials, and tried a number of setups. Using power meters to evaluate this, indicates that for us, with the stoker low, and helmet touching the captains back, is worth about half a mph, compared with more space between the stoker and captain.

So if the drop bar allows a position that closes the gap between captain and stoker, it’s going to be faster.

However, if you want to get the most aero position for the stoker, we found that stoker’s elbows resting on bull horn bars, and the stokers hand grabbing the captain’s seatpost lead to a very compact, fast position.

All that said, Idon’t think that any of this matters to the OP, but if you do care about aero, it’s a misnomer that the stoker’s position doesn’t matter.