Introducing the Cruzigami Mantis

[Charles.Plager]

Hello,

I'd like to introduce you to the World's first Cruzigami Mantis - full suspension, (hopefully) packable, and with gearing between 18.5 and 111 gear inches (the standard Sofrider is geared between 26 and 107 gear inches).:



The two halves of the seat are attached by wing nuts, so I can take them apart by hand and fold the bike. More details (including many more pictures and a video tour) available in my blog.

Cheers,
Charles

 

[thebean]

Beauty!  I want to see pics

Beauty! I want to see pics of it folded!!!

 

[rodread]

Looks Great Charles, I see

Looks Great Charles, I see your sping is a little late also. I am still waiting to take my first ride on my Silvio.

Rod

 

[Charles.Plager]

I just arrived back in

I just arrived back in Connecticut (from my inlaws in Vermont). No snow here.

I've updated my blog post to show the bike folded in the back of my mini-van (with more pictures available there including Brian's 90 second time-lapse video showing how to do a Cruzbike conversion):

 

[chrisblessing]

Great work...

How nice Charles. I'm impressed with the flat fold, with the seat bottom. Like you, I'll be attempting to squeeze mine into a suitcase shortly.

I look forward to your ride reports.

Chris

 

[thebean]

I am really excited to see

I am really excited to see what you both develop! Can't wait to see them in a suitcase!

 

[Charles.Plager]

I went out for a short 11

I went out for a short 11 mile ride today on the Mantis. It feels very similar to my Cruzbike Sofrider (I can ride the new bike without hands as well).

I'm very pleased so far although I killed a brake cable (with the front triangle - I recommend those with Sofriders/Quests/Conversions to take a look to see what I did wrong) and had a tire fail. More details and pictures/video here (and you can find the original description here)

 

[Charles.Plager]

Here's an update after 100

Here's an update after 100 miles including:

* Lower seat angle
* (Sometimes Seat post rack allowing panniers
* The Mantis is faster than my Sofrider (so much so, I'm trying to figure out why my Sofrider is so slow).

When I built it, I tried to build a bike that also happened to fold and was packable. I'm happy to say that I've succeeded. For more details, see my latest blog entry.

 

[billyk]

possible reason for speed difference Mantis/Sofrider?

Tire pressure???

That is the most important speed control variable for me. I find, for the same tires, at least a 10% speed difference between slightly underinflated and fully inflated. And if you have different tires on the two bikes that could also contribute. Are the wheels the same size? Maybe switch em between bikes ...

BK

 

[Charles.Plager]

Hi BK,
I run the Sofrider at

Hi BK,

I run the Sofrider at 95 PSI and the Mantis at 85 PSI. The wheels aren't the same, but the Sofrider wheels rotate well (at least, unloaded). I can't easily switch the tires as the Sofrider tires (26") won't fit on folder and while I can get the 20" tires on the Sofrider, I won't have any brakes...

I do have tire liners in the Sofrider tires (which I know hurts, but I wouldn't think it hurts this much). I'm probably going to upgrade the Sofrider tires to Marathon Kojaks and see what kind of difference that makes.

The seat angle makes a difference, too, but the Sofrider feels slower right off the bat and air resistance isn't a big deal until at speed.

So, I'm officially guessing tires. Hopefully I'll have more later.

Cheers,
Charles

 

[Charles.Plager]

Now that the weather's

Now that the weather's finally above freezing in the morning, I've started commuting to work on the Mantis[. The bike has been showing it's a great all around bike.

I found it interesting how much the feel of the steering changes when I'm sitting up straight instead of lying down on the seat. With my mass forward, the steering feels much twitchier.

 

[baov]

Hey Charles, did you figure

Hey Charles, did you figure out what makes it so much faster than the sofrider yet?
I'm toying with the idea of a 20" conversion after converting a 24" bike for my mom and it still being too tall for her.
The price of your frame is really good, too bad they don't ship to Canada.

Sorry for the thread necromancy revive.

 

[Charles.Plager]

Hi,
Mostly the tires on my

Hi,

Mostly the tires on my Sofrider. I changed them from 100 PSI Maxxis Detonators with anti-puncture tire liners to 95 PSI Schwalbe Kojaks without and I gained 1.5 MPH average speed on my Sofrider. It's now pretty much a toss-up as to which bike is faster (I probably have faster tires on the Sofrider and that might be enough to give it the nudge).

I will point out that my seat height on my Mantis is almost identical to that of the Sofrider. What type of 24" frame did you try for your mom?

Cheers,
Charles

 

[baov]

My mom's bike is a sloped

My mom's bike is a sloped tube lady bike. It isn't ideal but that's what we had laying around, and a pretty good deal considering the 20$ we paid for it. Then again, a Y frame 24" wouldn't be much better as they all come with front suspension which further rises it.
Before i throw any more money at the problem i wanted to round up my options.

If speed is nearly identical now, and height is the same i think i'll just go with a sofrider as it could probably have more cargo capacity.

 

[chrisblessing]

Cargo on a folding 20"...

I'm with Charles on cargo - I have a mounted rack and a small set of panniers on mine, and, with the addition of under-seat panniers I'd be able to carry as much as my skinny legs can push.

 

[Charles.Plager]

If speed is nearly identical

If speed is nearly identical now, and height is the same i think i'll just go with a sofrider as it could probably have more cargo capacity.

The Sofrider is a good choice, but I'll just point out (because I like being pedantic ) that I could probably get as much cargo on my Mantis as the Sofrider. I chose not to install a permanent (non-seat post) rack on the Mantis, but I could. And on both the Sofrider and the Mantis, I could imagine installing under seat panniers (a la David Byrne), so either way, you can turn these into cargo carrying beasts.