Adapt a tandem to take a child

[531colin]

…….
I can't remember if we've ever used crank shorteners on the kiddy cranks. …..
Jonathan

I googled Childs bike crankset replacement…. Lots of people selling Trek chainsets with 2 sets of pedal holes and apparently different chainsets for 20” and 24” wheel bikes. I think one set was 120 or 140 mm crank length!
I’ve never seen a set like that!

I’m sure shorteners for adult cranks would be almost as big as child cranks!

[SpaceCaptainTheodore]

An alternative, if you just want to get your tandem into action and get in some miles with your child getting used to things...

We put a top-tube seat on the back (kids-ride shotgun type thing) and my girl sits on the normal Stoker's saddle while using the pegs as a footrest from 3 1/2 - 5 yo. She gets the big-bike experience and it was cheap and easy to get running. With all the normal family time pressures it was by far the practical option.

The only complication I would add is putting some kind of guard over the rear wheel. We had a very low speed (thank heavens) foot entanglement when she got bored going uphill and shoved her foot against the rear wheel. It hadn't occurred to me that it could happen because of the level of contortion required. A bit of correx and some cable ties is a cheap and easy solution (and decorating the correx was a nice activity for the girls).

[BobSweet]

I would recommend a child back tandem. Buy 2nd hand, resell after and get your money back! All it costs is whatever ongoing maintenance you do.

[r6mile]

Update: apparently our design of our tandem, and where things like brake cables etc are placed, makes a bit trickier than anticipated. Long story short the bike shop have called and said it’s likely going to be around £300 to fit the kiddy crank and do all the necessary adjustments (plus the £100 I’ve already spent on some parts).

I just wanted to sense check whether others thought this was worth it? The bike shop suggested that a “beam” or basically one of those attachments to connect the kids bike to the adult one might be mor economical, but I am not convinced and to be honest they don’t look as safe. I’ve also looked on eBay and second hand child back tándems seem to be around £500-600. And obviously cargo bikes are more.

What do others think?

[Jdsk]

Thanks for the update.

£300 sounds a bit high, but of course I haven't seen the list of jobs.

Where are you?

...

At the moment we have two tandems ± kiddy cranks, a Follow-Me, and a two-child trailer. One of our adult children takes two grandchildren on a Pashley tagalong tandem trike trailer. Another has a child seat on the back of a Tern cargo eBike.

Previous discussions of alternatives:
viewtopic.php?t=99079
viewtopic.php?t=144168
viewtopic.php?p=1599992#p1599992
viewtopic.php?t=144168

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If the existing tandem is in reasonably good nick I'd go for kiddy cranks on that, then progress to crank shorteners, then remove those...

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But you need to do your own option appraisal: options along the top, features down the left, and start filling in the cells...

Jonathan

[r6mile]

Thanks, I am in London.

The bike shop will give me a detailed quote soon, so once I have it I can share it here.

I have googled the FollowMe tandem, and while the price is a bit cheaper than this quote, it looks like it only goes to bikes up to 20 inches, which my daughter’s bike is. So basically she would outgrow it as soon as she outgrew her current bike.

The bike is in pretty decent nick - just needed a bit of TLC from sitting in the garage for a long time.

Thanks for sending the list of threads, really helpful! I am intrigued by the option of a Tandem trike trailer, do you have any pics/links on how it works?

EDIT: The Pashley U Plus 2 looks like it could work great! (I have 3 kids in total though don’t necessarily expect to cycle with all of them at once) unfortunate that it’s discontinued and seems to be rare to find

[531colin]

……..
The bike shop will give me a detailed quote soon, so once I have it I can share it here.
…………

Will they agree to do some of the work and you do some of the easy stuff?

[Jdsk]

...
Thanks for sending the list of threads, really helpful! I am intrigued by the option of a Tandem trike trailer, do you have any pics/links on how it works?

EDIT: The Pashley U Plus 2 looks like it could work great! (I have 3 kids in total though don’t necessarily expect to cycle with all of them at once) unfortunate that it’s discontinued and seems to be rare to find

PS: One of my children has a Pashley tandem trailer trike tagalong which hooks onto her tourer solo bike. Excellent.

viewtopic.php?p=1799941#p1799941

And how we redesigned the coupling:
viewtopic.php?t=140246

Jonathan

[gaz]

Update: apparently our design of our tandem, and where things like brake cables etc are placed, makes a bit trickier than anticipated.

Tandem.png

I didn't have brake cables in the way, even so the fit was a bit fiddly (some of the etc was in the way). £300 seems like a lot of fiddly.

Do you have any pics of your tandem?

[r6mile]

This is the bike model:

https://www.amazon.co.uk/Barracuda-CALI ... 002GJG278/



I should get a proper breakdown of what needs to be done. As mentioned earlier I am not very mechanically confident so would rather leave all jobs to the bike shop even if it ends up adding more to the cost.

[r6mile]

I have spoken to the bike shop and I think I am leaning towards just fitting a footrest at the back, and foregoing the kiddy crank. Which obviously means she won’t be pedalling but I think that’s fine - and feels like a neater solution to a tagalong given we already have the tandem.

And then once she is a bit taller fitting the crank shorteners.

[Jdsk]

I have spoken to the bike shop and I think I am leaning towards just fitting a footrest at the back, and foregoing the kiddy crank. Which obviously means she won’t be pedalling but I think that’s fine - and feels like a neater solution to a tagalong given we already have the tandem.

And then once she is a bit taller fitting the crank shorteners.

Dimensions of crank shorteners from another thread:

...

Crank shorteners could be used to test whether shorter cranks are better. I fit them for children on the back of the tandems: one current pair give a 35 mm reduction and the other a choice of 40 or 80 mm. Continuously variable designs are available but I've never played with them.

Of course they do place the pedals slightly further outboard.

And they do come up secondhand here and elsewhere.

Jonathan

[531colin]

I have spoken to the bike shop and I think I am leaning towards just fitting a footrest at the back, and foregoing the kiddy crank. Which obviously means she won’t be pedalling but I think that’s fine - and feels like a neater solution to a tagalong given we already have the tandem. …….

I think you will be missing some fun with just a footrest.
I think you said you have 3 kids, I reckon it’s worth spending more money if more than one kid gets to benefit; although in my case it was spending time, very little money changed hands.

[r6mile]

Further update - turns out that the bike shop said that even just fitting in a footrest wouldn't work, because in any case the handlebar is about 30cm too far from the seat for a child. And also that it will be tricky to fit in a footrest somewhere that it won't interfere with the spinning of the rear cranks, even with the pedals removed.

So I've told them to just service the bike and leave it at that. However I find it hard to believe there isn't a way at all to make this work - so am going to keep trying.

Is there a way to extent the stoker's handlebars? Or replace them with handlebars that are more U-shaped?

[Mr.Benton]

From the picture above it looks like you have an extendible stoker stem which will give some adjustment.
You can fit handlebars like this model https://www.sjscycles.co.uk/handlebars/ ... eel-560mm/ which will bring the grips closer.
We used a pair of handle bars like these https://www.planetx.co.uk/products/selc ... -handlebar facing forward and up when mum was on the back, and facing back and down when daughter was on the back.

When my daughter first started to ride on the back we had to use a straight seat post with the saddle clamp upside down to reduce the seat height, it probably reduced the height by 5cm. You will need a different seat post to do this.

Just out of interest, if you set the saddle at the lowest height and sit your daughter on the bike, how much distance is there between her feet held flat and the pedals when at their lowest. If there is only a few cms then you could probably use crank shorteners, or wait for her to grow a bit.