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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!

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Old 04-28-10, 03:33 PM   #1
stevage
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Sliced toe injury - ever happened before?

Just returned from a Europe trip that included a scheduled 9 day tandem tour of the Dordogne/Quercy region of France. On day 7, however, the stoker (long-suffering girlfriend) got her foot caught in the link chain, cutting her toe badly enough to require 14 stitches. Wondering if anyone has ever heard of this happening before? In retrospect it seems like an injury waiting to happen...

Here's what we think happened: We got to the top of the hill at the site of the famous Pech-Merle cave, and were anxious to go and buy tickets as quickly as possible. We slowed down at the approach to a car park, where there was a chain link fence blocking the entrance. While I was trying to work out how to get around it, she thought we were stopping, and said something to that effect. We were both hot and flustered though, and I didn't really hear or pay much attention. We think she then put her right foot down, just as I turned the bike left, getting her foot inside the chain. It then got dragged along as I pedalled, and crushed under the chain ring. When she yelled out, I stopped pedalling pretty quickly, but the damage was done.

Looking at the bike later, two thoughts occur:
- this can only really happen on a tandem. On a solo bike, you'd stop pedalling the instant your foot was caught - or probably earlier.
- it could easily be prevented with some sort of very simple guard behind the chainring, mounted directly from the frame.

Thoughts? Anyone ever heard of this happening?
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Old 04-28-10, 11:28 PM   #2
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Over 3 decades of tandeming and never heard of this type of incident!
However have seen shoe laces and bottoms of long pants getting caught into the chain/chainring, but nothing disasterous.
Proper voice communication and a bit less anxiety could have prevented this.
Hope all is well now . . .
Pedal on TWOgether!
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Old 04-29-10, 01:04 AM   #3
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How about wearing shoes????
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Old 04-29-10, 05:02 AM   #4
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Sorry to hear about her injury, I hope she recovers quickly. Maybe you'll look into fabricating a chain guard if she's skittish?

I never had that happen for me as my stokers rarely ever put their feet down for any stop until I do it first to get the tandem stable. For me probably the biggest exposure for chain grab is for fingers while just working on the bike.


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Old 04-29-10, 06:28 AM   #5
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Thoughts? Anyone ever heard of this happening?
Not with a foot as described, not even with little kids.

In fact, I find it a bit amazing to even consider the decisions and actions that had to come together at the same time for this to have happened:

1. Deciding to use the two-foot down tandem start & stop technique vs. stoker staying clipped in during stop & start, aka. The Proper Method (Permanent fix, no need for a chain guard)
2. Poor communication between captain & stoker, particularly in light of the two-foot down technique which requires a lot more communication (Root cause)
3. Stoker having her foot off the pedal at anything other than the lowest point of the crank circle while preparing to stop... consistent with the typical two-foot down tandem start & stop technique
4. Stoker moving their foot inboard towards the sync chain

About the only thing I can think of that would have caused 3 & 4 to happen at the same time was that your stoker attempted to put her foot back on the pedal while it was moving and somehow "missed" the pedal.
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Old 04-29-10, 07:22 AM   #6
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The injury wouldn't have happend with a belt.
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Old 04-29-10, 11:30 AM   #7
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Belt doesn't seem impervious to this, smaller toes might get crimped and isn't there a raised edge on one side of the belt wheel?
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Old 04-29-10, 11:32 AM   #8
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The belt would likely derail to the inside (or simply break)... neither of which is going to happen to a chain.
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Old 04-29-10, 04:47 PM   #9
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>Not with a foot as described, not even with little kids.

I'll tell her this, I'm sure it will cheer her up

>1. Deciding to use the two-foot down tandem start & stop technique vs. stoker staying clipped in during stop & start, aka. The Proper Method (Permanent fix, no need for a chain guard)

I assume you're referring to Sheldon Brown's method? We tried this. Didn't work. We had a Bob and rear panniers, and it was almost impossible for me to keep the bike stable with her sitting on the bike - the front wheel just wanted to lift off while the back fell over sideways.

Our normal method for stopping was for me to indicate that we were stopping, stick out a foot, and slowly lean the bike over. But...we weren't stopping.

>2. Poor communication between captain & stoker, particularly in light of the two-foot down technique which requires a lot more communication (Root cause)

Yep.

>3. Stoker having her foot off the pedal at anything other than the lowest point of the crank circle while preparing to stop... consistent with the typical two-foot down tandem start & stop technique

Not sure, it might have been the lowest point.

>4. Stoker moving their foot inboard towards the sync chain

My theory is this happened as she was trying to step off. As you step off normally, it would be natural for your other foot to rotate inwards, and possibly enter inside the chain space. On a solo bike it just doesn't matter...

The real issue in all this was that she was nervous about me crashing into the barrier, communication broke down, and in her words, "I forgot that I wasn't riding by myself" - she was nervous and wanted to slow down and get off, so that's what she tried to do.

What was frustrating was the rest of the trip we were doing so well - good communication, working together etc. Just one brief let down caused by tiredness and anxiety, and disaster. Fortunately we only lost one and a half days, but they would have had some of the big highlights.
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Old 04-29-10, 04:48 PM   #10
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How about wearing shoes????
She was wearing soft runners. The chainring sliced straight through. I'd post a photo, but it's pretty gruesome.
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Old 04-29-10, 05:39 PM   #11
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I would say it is just an unfortunate accident, that though avoidable in hindsight (like they usually are) it is more in the category of being one of those things that you write off to experience and I am sure it won't happen again.
I also wouldn't say that having the stoker clipped in during stop starts is the "proper way". That is like saying you should put your shirt on before your socks. It doesn't really matter, whatever you prefer and are most comfortable with.
How about this one.
Tandem team stops at intersection with stoker clipped in. Captain loses control of bike and it overbalances and falls over. Car drives over stoker who is now lying on the ground with the bike.
I could imagine that happening at least as easily as what happened to you.
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Old 04-29-10, 07:10 PM   #12
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She was wearing soft runners. The chainring sliced straight through. I'd post a photo, but it's pretty gruesome.
No need for pictures. That sounds ugly! It's hard to imagine that much damage through a pair of shoes, even light ones...
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Old 04-29-10, 07:11 PM   #13
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I'll tell her this, I'm sure it will cheer her up

Sorry, but this really is a new one on me.

I assume you're referring to Sheldon Brown's method?

Among others, yes. And, yes, there are situations when it may not be practical or feel "right" to teams, and a heavily loaded tandem might fit that description. However, for the vast majority of teams it simplifies the starting and stopping process. BTW, do you happen to have a photo of your tandem loaded-up for your tour that you could share?

Not sure, it might have been the lowest point.


What I was trying to describe was what typically happens with foot that is opposite (her left foot) of the one you put down (her right foot in your original post) when stopping. The REI-guy in this video demonstrates this pretty well beginning at the 00:42 mark... except that he puts his left foot down during his demo. However, the 'up' foot (right) remains in the lowest part of the pedal stroke which, again, is pretty typical.


She was wearing soft runners.

What are soft runners? Do these work with clips and straps or have a cleat that works with clipless pedals? Or, are these street shoes used with platform pedals?


Regardless, as others have noted, best wishes for your friend's complete and quick recovery and here's hoping that it doesn't diminish her interest in future tandem adventures.

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Old 04-29-10, 07:16 PM   #14
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I also wouldn't say that having the stoker clipped in during stop starts is the "proper way".
Which is true for anyone who prefers or needs to use the two-feet-down starting method...

But, I don't disagree that 'the proper method' is a rather polarizing label: consider the source.
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Old 04-29-10, 07:42 PM   #15
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Which is true for anyone who prefers or needs to use the two-feet-down starting method...

But, I don't disagree that 'the proper method' is a rather polarizing label: consider the source.
Which is why the phrase "The Proper Method" is usually either italicized or in quotes - most of us think of it as only "Proper" for the one person who so named it. For the rest of us it's short hand for a popular method, but certainly not the only method.
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Old 04-29-10, 07:44 PM   #16
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It's hard to imagine that much damage through a pair of shoes, even light ones...
I've gotten my hand caught in the timing chain working on the bike on the stand. Did a fair amount of damage.

I can definitely see a lot of damage happening under load through a soft pair of shoes.

Chains on fixed gears, and to a lesser degree timng chains on tandems can inflict a significant injury.
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Old 04-29-10, 08:05 PM   #17
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I suppose you're right, especially if it is really tight like a timing chain or FG can be.
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Old 04-29-10, 08:11 PM   #18
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Chains on fixed gears, and to a lesser degree timng chains on tandems can inflict a significant injury.
That's even an understatement.... chains and sprockets are simply one-dimensional meat grinders regardless of what they're used on. They'll take your digits clean off at the joint if they go full-cycle and there's no slack.

In fact, when the grandkids are around the bicycles and tandems are now hung high to keep their little hands and fingers from grabbing a chain and running their hands into the gear mesh by imitating granddad working on the bike. I didn't realize this phenomenon would be a problem until our first grandchild came out to visit granddad while he had a tandem in the workstand and went right for the elevated stoker cranks!!! We had a 'learning session' after that and ran some carrots through the gears to drive home why we keep our hands and fingers away from the chains and gears.
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Old 04-30-10, 12:10 AM   #19
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>Among others, yes. And, yes, there are situations when it may not be practical or feel "right" to teams, and a heavily loaded tandem might fit that description. However, for the vast majority of teams it simplifies the starting and stopping process. BTW, do you happen to have a photo of your tandem loaded-up for your tour that you could share?

Yes, but not for a while. I managed to lose the memory card that had most of the photos. Thanks to a random sequence of events involving an Icelandic volcano, there exists a backup copy on a computer in London...

I'll have to start another thread with some of the other adventures from the trip. It was, all in all, a lot of fun, and the freakish accident described here had some interesting and very pleasant consequences.

>What are soft runners? Do these work with clips and straps or have a cleat that works with clipless pedals? Or, are these street shoes used with platform pedals?

Ah, unfamiliar language? Runners = sneakers = sports shoes = non-cycling specific. Soft = well, soft So, yes, street shoes used on flat pedals. My pedals had toe clips (not cleats).

>Regardless, as others have noted, best wishes for your friend's complete and quick recovery and here's hoping that it doesn't diminish her interest in future tandem adventures.

At the moment, getting her back on any bike at all will take some coaxing. It was pretty traumatising, even if the injury itself could have been a lot worse (a few more millimetres and tendons would be in danger).
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Old 04-30-10, 12:13 AM   #20
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>That's even an understatement.... chains and sprockets are simply one-dimensional meat grinders regardless of what they're used on. They'll take your digits clean off at the joint if they go full-cycle and there's no slack.

Wow. Makes me even more surprised no one has heard of this injury. Eep.
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