teachndad

Hi,

I wanted to share my new experiences into tandeming. I recently bought a used tandem to help my 13 year old who has balance issues and cannot ride a bicycle on his own.

Out of craigslist, I found a Northwoods mtb style tandem. It looked trashed having sat out, but I saw through the dirt and baked paint. 125 bucks later, an hour of lubing and cleaning and it was ready to go. The SIS Shimano shifting worked without any adjustments.

We have had ssssooooooo much fun on this tandem. It got my boys outside and they have found new enthusiasm for riding. We used to just grab the bikes and ride a mile to the nearest 7/11 and have Slurpies and then return.

Now, with the tandem, we have been riding two miles to the local Blockbuster, but better yet, we have taken the tandem offroad. We did some single track with some short climbs a few days ago, and then did some fire roading just yesterday. We are not covering more than a mile or two, but it's a beginning. "Dad, go faster..."

I might add, we are doing this with an Adams Trail A Bike added on. We ride as a threesome. I have 4 boys, ages 13,9,8, and just turned 4. The Trail A Bike was chiefly for the 4 year old. He loves it. , but yesterday,on the fire road, I took, the 9 year old as stoker, and the 8 year old was on the Trail A Bike. We are a fun sight to anyone who sees us. We get lot's a smiles, and "Hey did you see that?".

You can't beat the tandem for togetherness, as you all know already.

Here are two pix of us on the tandem.




(In this image, my 8 year old is in the stoker position. He can't reach the pedals, but he doesn't care. He just taps the tops of the pedals as they rotate)

I had a few questions. The only thing missing on the tandem when I bought it was the chain idler, or chain tensioner. I am not sure what you call it. I am not sure where to find one. I found one on Amazon.com made by Pyramid. https://www.amazon.com/Chain-Tension-...9368889&sr=1-5 I figured that might work. Where else can I find these?

When I bought the tandem, I noticed that it was gone, but figured I would see if we could ride it. It's fine down to 7/11 or Blockbuster, but yesterday we had some problems with the drive chain getting slipping off onto the teeth of the second crankset. I attribute that to the chain slack. This especially happened when the cranks weren't parellel. The chain became very taught, and I had worked out a fix to get the chain back on to both the front and rear crankset. The tandem has a crossover drivetrain.

How should I set up the cranks. Should they be parallel, or should they be offset by 90 degrees. I thought they should be parallel, especially with the kids on it, so we don't drag a pedal on a turn.

Despite the no name brand tandem, it has been working fine for us. It was made in Indonesia, and the lable indicates Performance Bikes - Sold in Performance Bike shops? The SIS shifting works very well. The cranks are cheap, with plastic pedals, but I don't notice flex in the cranks, even under hard pedaling.
It needs two new seats and two new tires, and the chain idler.

It's brought back my enjoyment of biking. I used to bike tour during the late 70s in my late teens, and an overuse injury to my knees stopped that cold. At 46, it feels like a rebirth.

Cheers.

Rod Wylie

johnlyons53

Rod,

The vast majority of tandemistas ride with the pedals 'in phase' (front and back the same). Timing chain tensioning is usually accomplished by way of an eccentric mounting of the front crank axle. Typically there is a clamp or setscrew arrangement that needs to be loosened and then the eccentric is tuned with a pin spanner and that adjusts chain tension. Google 'Harris Cyclery' and check out the tandem maintenance articles by Sheldon Brown to get a better idea of what's going on. Welcome to the club

moleman76

Rod,
I'd guess that the idler you found would do the job -- since your bike (at it's original sales price point) probably doesn't have an eccentric for the captain's bottom bracket. You do have some sort of bracket welded on to the bottom tube to mount it on, right?
- Joel N.

masiman

It was something like 20 deg this morning here. I know it is colder elsewhere but I wish I could comfortably wear short sleeves right now.

You may already know about blocks, crank arm shorteners and kidback/stokids to help fit kids into the stoker position. If not, you can search them here or through google.

Congrats on the ride.

teachndad

Hi Joel,

Yes, there is a bracket welded on the bottom cross tube on the frame to place an idler as pictured.

Thanks!



Masiman,

I have been learning and saw the "kid pack" crankset for adding children. Cool stuff, but pricey. This project was done with limited funds. If we get into this, then maybe some newer stuff - time will tell. I like the blocks idea, though. That I can work with.

Thanks!

Rod Wylie

moleman76

Rod,

Crank shortners can be seen here:
https://www.tandemseast.com/parts/cranks.html

If you have any aerospace machinist friends, you might be able to put together some of your own.

Or, maybe find some shorter cranks so their legs don't have to stretch as far when the crank is down.

Blocks on the pedals, or extra-thick pedals (effectively raising pedal surface up toward the stoker is probably a simpler way to go.

Might be time to locate the nearby "Mr. Fixit" bike repair shops and check out their parts bins.

Your kids look to be having a great time. Better start looking for a quad, so you can have 3 stokers plus the trail-a-bike!
- Joel N.

kevbo

An alternative to the idler is a "ghost" chain ring: A chain ring a bit larger than the ones on your sync chain, that floats at mid-chain engaging both the top and bottom chain runs. It may take some experimentation, but as a first cut, spread the two runs apart, and measure the verticle distance to the outside of the chain, then look for a chain ring that measures about that diameter. You can also use two slightly smaller ghost rings if that is what you find. There is virtually no stress on the ghost rings, and minimal chain engagement, so worn out (for normal use) rings will probably work fine and you might get these cheap or free at a bike shop.