NRissy

Bought a Santana Encore; was given the crank-set for a child stoker kit (missing chain and bottom sprocket) Thought everything was going to be great. Then I realized that the child stoker kit was for a smaller size seat tube so it wouldn't work. Instead of buying a kit for $250 I decided to see how low I could make the seat go. I think with my shorter crank arms this is going to work(might need some peddle blocks as well) but..... how should I attach the seat without scratching the paint but still make sure the seat doesn't fall off?

I will be buying a child seat instead of the adult seat; but otherwise I think this is going to work!




How would you attach the seat?

Ross200

Have you thought about ordering/making the proper size shim for the kiddie bottom bracket? Many kits come with shims for all three seat tube sizes.

It doesn't look CLOSE from here. I have the feeling some young person could soon be very unhappy.

Darth Lefty 

That looks miserable.

I put a kid stoker set on mine but it wasn’t trivial. In addition to the kit, I needed to replace the stoker crankset. The one I had was 130 bcd and the kid crank was 36t. The crank was 5in arms so really not good til the kid is big enough for a 20 in bike.

My kids aren’t interested, anyhow. The seat is now way up in the air. I wish I had a Periscope or a small Jefe or Fandango

NRissy

We already ride all the time; I have a wee ride co-pilot that he is frustrated with because he knows he is free-wheeling. he wants to peddle.

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I dropped the seat almost three full inches. If I put 2x4 wood blocks on the peddles; I will gain another two inches.
I am getting a set of child crank arms that my local bike store has. I guess after buying one child crank set and it not fitting; I am trying to get creative and save myself $250. If my son doesn't like it or their is issues; I will spend the money on a child stoker kit; I have three boys; I will have a stoker for some time because my boys are ages 5 yrs, 2 yrs, and negative one month(baby due May 3rd!).

Alcanbrad

If the kiddie stoker crank shown has a mating clamp for the other side and the bolts clear the existing seat tube and all you have to contend with is the difference in diameters shown it should be almost trivial to 3D print a pair of radius adapter shims and with longer bolts you are in business. There are a lot of 3D printing hobbiests that would do it for cheap

bwebel

I think you need to just bite the bullet and get a bottom bracket assembly that will fit the bike...you don't need to spend $250 on a full setup, just the bottom bracket mount. From the pics, the child's feet are really only at the crank center, you'd need pedal blocks that are the full length of the crank arms. I can not imagine this is going to work well.

I think I"d also look at getting another stem that will get the bars closer to the stoker, maybe one with an adjustable pivot? If you want your kids to want to ride with you, the fit has make them comfortable.

jccaclimber

This seems like a decent job for a 3d print if it holds up, but even a hand made block of wood or filed down aluminum would probably do the trick.
I agree that replacing just the BB assembly should not be hard. I wouldn't be surprised if one of the tandem builders was willing to sell just the BB block seeing as you already have the rest of the pieces, they like making it easier for people to use their bikes.

The shim on the tube side doesn't need to be the perfect diameter, a simple 90° V with the tube touching the flats would probably hold reasonably well. Certainly better than if the adapter was accidentally made to a slightly too large diameter.

Alcanbrad

while this is true, I would be very careful if going this route. The simple V will contact the seat tube in only 4 places each being a very narrow line. Since you don’t know the tube wall thickness and you don’t know and can’t really control the clamping force you run the risk of deforming/damaging the seat tube.

spreading the clamping force evenly over the largest area possible will minimize the chance of damage.

be sure and let us know how you make out.

jccaclimber

This is an excellent point. I tend to assume that everyone else has a good feel for “This doesn’t look right, maybe I should stop”, but if you don’t you could easily crumple a tube in an unfortunate and permanent sort of way.

A block of hardwood would be a much safer solution in that regard. You could even get it close by putting some sand paper around the tube to form the block. Just be sure to use a wrap of tape on final install. This will both account for the thickness of the sandpaper as well as protect the paint on the tube.

PDub62

Personally, I wouldn’t risk my kid’s safety or my tandem’s frame with any cobbled solution. It’s worth the investment to have a solution that is designed for the job especially since you have three kids who would be using it. Keep in mind that if the crank arms are too long you risk injury to your kiddo (or possibly just a miserable ride). My daughter is now 10 and has been riding with me for 5 years. I used a child stoker kit and changed cranks every year or two in order to keep the arm length at approximately 10% of her height. That way she’s able to spin at my cadence with no issues at all.

NRissy

Thank you all for the imput. I took my bike down to a bike shop I trust and had a nice talk with them. We looked at blocks and other ideas and ultimately decided to go with a child stoker kit because we want my son to love riding on the tandem. Not just simply to put up with a system that works; but isn't as comfortable as riding a bike should be. Luckily my Local bike shop knew of two or three people who have had a child stoker kit and I have one that I am picking up whenever the two of us can meet up as we both live out of town from the bike shop in opposite directions.

NRissy

Alright. Here is what the final product is! My boys are so happy. Happy Father's day to me!!!!