cplager

Hi,

Got bored so I did it again.





This started as a folding tandem

and I added a full Cruzbike kit up front and a seat from a second Cruzbike kit in the back. (I had brought this to this years Tour de Bronx, but due to a bad tire, we only rode a few miles).

Because it is so long, it rides really smoothly. But at the same time, it feels like any other Cruzbike (with a slightly more cramped cockpit for me). On it's maiden voyage, I accidentally found myself riding with no hands.

Because it folds, it fits nicely inside my minivan. I'm quite pleased so far.

downtube

Nice!!!

Thanks
Yan

jur

How do you change gears on the rear?

cplager

The stoker has a twist shifter (that I'll probably replace with a lever). Both of my kids have folding 16" bikes with gears, so they're (kind of) used to them now.

So I choose my gear and they choose theirs.

blakcloud

That is impressive.

cat0020

Looks like fun, very neat conversion.

For the life of me, I cannot get used to the front drive-train connected the steering, seems to me that every pedal stroke affect steering input... and climbing hills... well..

cplager

It turns out that what starts out as a weakness becomes a strength. Because of this linkage, they are a bit weird to learn how to ride. But once used to them, these bikes are the easiest to ride no-handed of any bicycle I've ever ridden (when taking this out for it's maiden test drive, I suddenly realized that I was riding with no hands without thinking about it).

And they allow you to "put your back into it" when climbing (like DFs do but not most recumbents).

cat0020

After riding bicycles for nearly three decades, I have no problem riding no-handed on bikes that donnot have steering input affected by each pedal stroke, even on a set of rollers.

Most recumbents have low-back support on seat that allow rider to "put your back into it", unlike DF bicycles that do not offer any low-back support.
Imagine a seating squat machine, that's similar to most recumbent riding position.

cplager

Bad choice of phrase on my part.

You can very much use your arms with MBB (moving bottom bracket) bikes (like you can on DF bikes). But, yes, "regular" recumbent bikes let you brace your back against the seat and really push (which you can't easily do on a DF).

invisiblehand

Sweet! The independent gears/coasting is a nice feature for riding with kids.

cat0020

I saw this interesting gem:
Comments below are not mine, but from the article I found.

"Hey Folks. I've ridden the new tandem enough to commit to the powder coaters.
I'm convinced the 2WD system is better for us than a linked timing-chain RWD like our previous tandems.
Bron, the stoker, is much happier being in control of her cadence and I don't feel like I'm pulling her legs around.
The jiggling from out-of-synch pedaling is novel but not a problem. It will get better as we pedal smoother.

I have not noticed any pedal-steering tendencies & the bike is quite manageable even in granny-gear (19 gear-inches).
FWD bikes draw some criticism for their potential to lose control when the front wheel slips (on gravel for instance).
Under our 140kg weight I don't think it will be a problem and seems to be an advantage when piloting solo.

The limits of steering due to the twist-chain FWD set up are not an issue when riding, even in a U-turn.
It is a small pain when we use a tight rail-crossing chicane on our commute.
The short sections of chain-tube are crucial when using a mudguard & or fat tires.
The chain will rub OK on a bare tire, but it snags on the edge of the mudguard.
The tubes make this a non-issue although they do lay against the mudguard when using the inner-most cassette rings.
Under this condition some chain-noise is transmitted to the mudguard.

Despite the stronger frame and more efficient drive-train the bike is not order-of-magnitude faster like I hoped.
It is noticeably easier to push but we don't seem to go much faster yet, maybe we'll get fitter with the resumption of our regular commuting.
The stiffer frame makes the bike noticeably steadier going fast downhill.
I think I did a better job with the steering geometry on this bike; it's lighter to steer, maybe the offset in the forks contributes here.
I didn't calculate rake and trail, there doesn't really seem to be hard & fast rules as far as I can see.

The SRAM dual drive hubs are great, 27 gears each & all under our right hands.
They are great for the 20" wheels, I'd have to use big (expensive) chain-rings if I used a regular front derailleur set-up.
The just-as-expensive Dual Drives look neater and are nicer to use and maintain.
The other big improvement is the BB7 disc brakes, they are amazing especially compared to the V-brakes we had on the previous tandem.
I went for the 203mm discs in case we decide to tour with this bike.