SesameCrunch

I just finished converting my Downtube folding bike into a recumbent with a kit from Cruzbike.com. The kit was previously installed on my Specialized mtb, but it turned out too heavy. So, a few hours in the garage, and ta-da! A folding recumbent!

It's probably about 27 lbs, feels very light and nimble and should take the hills around here pretty well. The fold is a bit compromised right now because of the hinge in the top tube, but I'll fix that with a custom bracket eventually. Should be fun to ride!

The bike used to look like this:

Now it looks like this:

BlazingPedals

Interesting application! Report back on how much it helps the climbing to lose ten pounds.

Tom Bombadil

I've never ridden a front-wheel drive bicycle. What does that feel like?

SesameCrunch

The weight difference is immediately noticeable. This bike is also much more nimble.

I'll give a report after riding in different conditions. Only thing is, weatherman calls for rain for the next week

SesameCrunch

It's a little different since every pedal stroke can inadvertantly steer the bike. You end up pulling on the handlebars to counter the foot stroke. After a while you get used to the rythm and it becomes second nature. The ability to pull on the handlebars helps on the hills when you need to crank hard.

The more experienced fwd riders will tell you that they can ride/steer hands-free also because of the ability to steer with the legs. 'Course I'm not quite there yet.

I'm still getting used to starting on an incline on this bike, but perhaps that's common to all 'bents.

I'm pretty new to 'bents, so I still don't feel as strong and confident as when I'm on my upright, but I'm hoping to get to that point with this bike soon.

ahorner1946

Cool looking recumbent/folder bike! When you get the folding part all sorted out you might get something started!!

I have looked at the web page for the conversion kit, but I didn't notice any thing that indicated the kit would work on 20 inch bikes! So, what was involved in adapting the kit to the 20 inch folder!

I also saw your post on the folder forum, and began to wonder how the conversion might work with a geared hub like the Sturmey Archer 8 speed! Any thoughts on that?

Great job! I'm interested in knowing how this progressesfor you!!

Al

SesameCrunch

There is no difference in installation between 20" or 26" wheels. It was actually easier on my folder compared to the mtb.

I am intrigued by an internal hub version of this also (as is another poster, bobkat). It would make for a clean front end. I don't know too much about internal hubs, but I seem to recall that you need a horizontal dropout. With this kit, the dropout is "vertical".

I wonder if John Tolhurst, the designer will weigh in on that question??

atombikes

Have you measured the trail on your conversion? It is really hard to tell from the pic, but it looks like you may have a very small positive trail number, or even slightly negative. Might make for interesting riding!

Tom Traylor recommends 4" to 4-1/2" of postive trail for this type of bike:
https://traylorfwd.home.mindspring.com/geometry.html

SesameCrunch

The trail is 4". The axle length of the bike is 3/4" shorter with the new setup. Went from 42.5" to 41.75", so no big impact. The handling is very nice, a little on the "nimble" side, but I'm very comfortable with it.

PuttPutt

Nice looking conversion. Question:

The Downtube website, list the Downtube, IX model at 27 pounds. (or 25.5lbs w/o pedals, barends, fenders, rack, kickstand). https://www.downtube.com/Downtube_200...e_2006_IX.html

So, how did you manage to install a 9 pound cruzbike kit, without increasing the bike's original weight?

SesameCrunch

I took off a whole bunch of weight to lighten up the bike and to accomodate the kit. E.g.
- original seat and 500mm post - >2 lbs. Cruzbike seat is included in their 9 lbs
- folding stem - 2.5 lbs. No longer needed
- front suspension - 4 lbs. replaced with non-suspension fork at 1.4 lbs
- rack, kickstand, and misc. - >1lb . didn't need them
I also have Velocity Thracian wheels and Schwalbe Marathon tires instead of the original Quando/Kwest combo. Don't know the weight difference, but I'm sure there's some.

BlazingPedals

Wow! I think the Cruzbike seat looks good, at least; but that weight surprises me! By contrast, the traditional RANS seat is only 7 pounds and it's generally viewed as being on the heavy side. There must be some heavy foam in that baby to make it 9 pounds!

I like Velocities. They're pretty light and very smooth, but not so light as to be unreliable. Me and wimpy parts don't get along!

atombikes

[QUOTE=BlazingPedals]Wow! I think the Cruzbike seat looks good, at least; but that weight surprises me! By contrast, the traditional RANS seat is only 7 pounds and it's generally viewed as being on the heavy side. There must be some heavy foam in that baby to make it 9 pounds!QUOTE]

I think he was saying the whole KIT weighs 9 lbs. The seat must weigh 2 lbs?

I'm still not seeing 4 inches of trail though. If you flip the fork and install the FWD adapter designed for a 26" wheel on a 20" wheeled bike, that will effectively REDUCE the positive trail, won't it?

Why did you remove the disc brake when you went to the rigid fork?

I like your conversion, it's a great idea and looks like it would be fun to ride.

BlazingPedals

Ah, that would make more sense. the seat just doesn't look that heavy.

Flipping the fork backwards increases trail. The function of fork rake is normally to reduce trail to a desired amount.

atombikes

Yes, but the Cruzbike bracket moves the driven wheel forward, bringing it closer to the headtube centerline. Look at the picture, it appears (to my untrained eye) that the centerline of the headtube contacts the ground very close to the contact patch of the tire. I suppose it may be an optical illusion, but the point where the centerline of the headtube intersects the ground doesn't appear to be 4" from the tire contact patch?

It could be that the front end is swiveled to the side a little? Maybe that is what is confusing me?

SesameCrunch

Regarding the seat, Atom is right. The 9 lbs is the entire kit, including the seat.

As for trail, I measured it at 4". Perhaps I'll take a picture closer up so you can see it better.

The non-suspended fork did not have disk tabs on it, so I went with the old brakes. I wish I could have kept the disk brakes, though. I have Hope Mono Minis, they're perfect application for folders.

Oh, and I re-did the seat bracket and have a full fold on the frame now!

ciderbob

Really nice conversion. I have looked at the folders with sort of project in mind. I'd like to see it folded.
The folks a Cruzbike should really be looking at this.

Ciderbob

SesameCrunch

Ciderbob:
Sorry that it took a while, but here are some photos of the bike folded.

The recumbent seat has to come off. The folding handlebar got replace with a non-folding riser. There are two hex bolts to remove to take the riser off, which I didn't do for the photo.

And here's the latest upgrade - child seat for my 3 yr old...


Cheers,

Javier

SesameCrunch,

Wow! Those are great pictures, particularly the one of you riding the converted folding recumbent with your toddler on the child seat. So, how is the handling at slow, "normal", and high speeds?

Best regards from Northern Virginia.

Javier
Woodbridge, VA

SesameCrunch

Handling is fine, after you get used to the front wheel drive. Also, the small wheels make it a little twitchier than 26" wheels, but again, that's something you get used to. Turning radius is actually very good. No problems at low (4mph lowest) or high speeds. I'm still getting used to this bike on downhills, so I've only gone up to the mid 30s in mph (without the kid ).

There is some loss of traction in the front wheels when starting on wet roads with 7/8% grade, but never on dry pavement.

Floyd

Congratulations on a job well done. Even the little one can enjoy.

ciderbob

SesameCrunch,

Thanks for the great pictures. Again that's a very nice bent. I wonder how it could be done with Under Seat Steering?

Ciderbob in Frederick MD

SesameCrunch

Sorry Ciderbob, I have no experience with USS, so perhaps someone else can look at the pictures and offer some opinions.

Although, I must say, that USS would defeat one of the benefits of Front Wheel Drive. Supposedly, the ability to pull on the handlebars allows you to pedal with more force and efficiency. USS would eliminate that ability.

cat0020

I have a hard time imagine a front wheel drive and under seat steering recumbent.. is that something possible?

ciderbob

I was thinking of somthing like the Flevo designs. I like USS as is a very relaxed riding position. I believe you could pull on the bars just as effectivly as OSS. Just an idea

Ciderbob