Tandem wobble

[DaveP]

Went for a short ride on Sunday. Quite enjoyed ourselves - managed a couple of hill starts - progress!
However, at one point we had to negotiate a dogleg crossing of the A5 and bottled it, as I dont think we are quite nimble enough yet to be happy waiting in the middle of such fast road in order to nip through a gap.
So, I decided to ride it solo while the wife walked across.
To my surprise, I could hardly handle it, the steering was twitching from side to side really severely, and at one point I nearly fell off. Unpleasant.
The bike handled ok once we were both on board, and it tracks normally when pushed, so I'm a bit perplexed by the episode.
Could it be something as simple as me not having time to adapt to the change in loading and repeatedly over reacting to normal steering movements? or could it be a sign of a developing mechanical problem?
I know my position on the bike isnt quite right yet, but this hasnt happened before.
Anyone else had it?

[Si]

Worry ye not - wobble/strange handling is not at all uncommon when the stoker is not on the back, your tandem is fine.

we had to negotiate a dogleg crossing of the A5

Shenstone -> Heart of the Country?

[531colin]

Its just another set of conditioned reflexes to aquire....you already have riding your bike(s), riding the tandem 2 up, then theres riding the tandem "solo", riding a solo with a kid in a seat, riding a tandem with kids of varying weights stoking.........I still have to look for the keys on this thing, though...and I get them wrong a lot!
Thought about a recumbent?

[Vorpal]

It's the weight distribution...

A bicycle needs a reasonable proportion of the weight on the back axle to handle well. A tandem with no stoker shifts the weight distribution forward. It's a bit like trying to ride your solo bike whilst sitting on the front handlebars

Our childback tandem isn't too bad that way. Maybe the smaller stoker section puts my weight sufficiently back on the tandem that it isn't as badly affected? Anyway, I've gotten used to riding it back from the school run with only me on it.

[speedsixdave]

For a while speedsixkate & I tandemed to work - I dropped her off after a bit and carried on to work solo. And I never really got used to it! However I found lower gears and spinning caused less wobble than pushing bigger gears. Mebbe you will have to modify your riding style a bit. As the others point out, it is quite normal.

[reohn2]

welcome to tandem solo!

[AndyB]

I suspect it's the difference you notice - I've never had any problem riding our tandem solo, but then the stoker only weighs 17kg to start with. You just need to watch it when using the rear brake!

[thirdcrank]

When I saw the thread subject, I was expecting to see a a post from a certain skipper about the unbalancing effect of passing shoe shops (Names withheld under the Human Rights Act )

As a teenager, I was daft enough for a while to go training on our ancient, heavy tandem. I don't ever remember it wobbling, although my legs were sometimes a bit shaky. I've probably posted before that I once had a female stoker abandon ship (near Bishopthorpe, when it was a lot more rural than it is today) and after a search I had to ride home and announce I had lost her. A sort of "man Overboard!" in the nautical language of tandems. I don't remember the tandem wobbling, but I felt a bit shaky shill she turned up again.

[Robert]

I find riding a tandem solo whilst pulling a loaded trailer impossible. I have tried - it didn't work.

[Vorpal]

I find riding a tandem solo whilst pulling a loaded trailer impossible. I have tried - it didn't work.

I do that regulalrly. We have a two-wheeled trailer that hooks onto the rear axle, and I find it makes the tandem more stable rather than less. My stoker is only 4 (almost 5) and tends to get tired at more than about 20 miles for the day. When she gets tired (or when the weather is miserable) she rides in the trailer with her little brother.

My trailer loaded with kids & accessories is an extra 5 or 6 stone. Most of that is supported by the trailer axle, but some (maybe 1/4?) is supported by the rear axle of the tandem, so it is better than unloaded, but not as good as with my daughter in the stoker's seat.

It's hard work to pull the loaded trailer, riding a tandem solo, but doable. And I've ridden as much as 15 miles like that. I don't think I'd want to tackle any real hills, but we don't have any most places we go.

[Robert]

Probably the difference between a one and two wheel trailer.

[DaveP]

Thanks All - thats enormously reassuring!
I'll put in some solo practice and keep my fingers crossed

[horizon]

It's the weight distribution...

A bicycle needs a reasonable proportion of the weight on the back axle to handle well. A tandem with no stoker shifts the weight distribution forward. It's a bit like trying to ride your solo bike whilst sitting on the front handlebars

Our childback tandem isn't too bad that way. Maybe the smaller stoker section puts my weight sufficiently back on the tandem that it isn't as badly affected? Anyway, I've gotten used to riding it back from the school run with only me on it.

vorpal: this is what I was going to post, but I am not sure now that it is correct:

I spent some time this year trying to reduce the upper body effort involved in handling our Galaxy Twin (this was just to make it less effort to ride.) I brought the handlebars up and back which helped but I also moved the rear panniers as forward as possible and put heavy objects in the forward part of the panniers. The aim was generally to move weight forward - the opposite of what you suggest. My explanation for the instability of the tandem is that weight at the back creates a levering effect that is hard for the Captain to counter (this is much the same as another thread about the whipping effect on a heavily loaded single bike). Once the stoker is on the bike, the weight is partly forward again and distributed away from the rear wheel. It may be however that the stoker either or also provides a damping effect - the bike cannot wobble because there is too much weight on it. This also explains why it is easier to ride with a small child on the back rather than an adult. However it doesn't explain then why it should wobble when there is no stoker at all. The worst wobble I have experienced is a non-stokered tandem with panniers in place, worse than just the bike with no stoker.

My conclusion is that we are talking about two different factors, but I am not at all clear about this.

[goatwarden]

When we got our first tandem I found that it wobbled when I rode it solo. Also when I got back on a solo it would wobble initially, until I reaclimatised. I don't notice wobbling on solos or tandem without ballast now. I think, as someone said above, it's just a matter of getting used to it and developing appropriate reflexes.

[LollyKat]

Maybe it depends too on the tandem design? When I used to pilot a Dawes Horizon Twin with my daughter, I never noticed any wobble when I rode it solo. It was a marathon design, with the diagonal extended through the rear seat tube to the rear drop-out.

I used to take her to her various Saturday dancing, drama etc. lessons on the tandem, dropping her off, riding home, then going back for her later.