TW Bents

[Kungfuguy]

Hi, I'm new to bents! I'd love to have one. I love the design of the Cruzbike. I think it is the right compromise of form and function. Many bents are too extreme in design. Too low or high. Too long. Poor visibility. Etc..... At first glance the CB looks like a conventional bike and that's what drew me here.

I'm rather fond of the TW Bents Cobra. It's has a FWD and folds. The chain bends at a 90 degree angle. Can John explain what purpose this serves?

Sadly TW Bents is closed! There are very few vidoes of the Cobra on youtube. Not sure if it went to market?

 

[Kungfuguy]

http://www.twbents.com.tw/HTM

http://www.twbents.com.tw/HTM/cobra.htm

 

[Eric Winn]

FWD with fixed bottom bracket

FWD with fixed bottom bracket (FBB) achieved by allowing the chain to twist. Chain routing is controlled by idlers.

Cruzbike includes the bottom bracket in with the steering triangle of fork, boom, and chainstays resulting in a moving bottom bracket (MBB) FWD. No chain twist, much shorter chain, standard upright bike bits, e.g. no idlers and such but you do have to learn to ride the MBB aspect but it is mucho fun.

Here is an example of the RaptoBike Mid Racer where you can see how the chain twists a little as the front wheel is turned.

-Eric

 

[Ivan]

Yes to Eric's comments. Thus,

Yes to Eric's comments. Thus, the Cobra has front wheel drive without pedal induced steering that MBB has. I researched the Cobra when I was learning about recumbents, especially cos I was looking at folding capability since I am a Brompton rider and someone had made the Cobra available in Singapore (so yes it went to market). However, I felt the Cruzbike design made more sense and considered Quest, Silvio and Vendetta purchase. Those idlers would sap energy! If you are telling me TW Bents stopped producing then I am glad I didn't buy that!

I now have Silvio 2.0 on order, and decided I only need one bike that folds!

 

[Eric Winn]

Yep, I have a folder too but

Yep, I have a folder too but unlike Charles' Cruzigami, it doesn't lend itself to being converted to a Cruzbike.

This is a Mobiky Genius with 12 inch wheels and a 3 speed Sturmey Archer hub. Disc brake in front with a band break or some such in the IGH rear. I used to do 20+ mile rides regularly with it. Folds very, very quickly and pretty small if you fold it all the way.

Unfolded.
alt="Mobiky Genius unfolded"

Folded with the Topeak DynaPack hanging from the front hook.
alt="Mobiky Genius folded with DynaPack hanging from front hook"

-Eric

 

[Eric Winn]

One thing I meant to mention

One thing I meant to mention about Arnold's Raptobike Mid Racer is that the main tube has a sliding joint under the seat. NOTE: His Low Racer uses a sliding front boom and doesn't share these advantages.

Two advantages over other FWD stick twisters (say that 3 times really fast, go on, I dare you!):

• You don't have to muck with resizing the chain to fit a different sized rider. Other FWD stick twisters have a sliding boom so if you change the rider size you generally have to lengthen or shorten the chain to match whtever you did with the boom - slide it out to make it longer for taller riders or in for shorter riders.
• The joint can be pulled apart making the bike sort of <i>fold in half</i> making it much easier to tranport inside a vehicle. Of course you will either fiddle with the rear brake cable and/or housing or fit some sort of quick release coupler.

These are fast, fun bikes although you have to watch out for Rapto bite - where your clothes or worse, your leg <i>gets bitten </i>by getting caught in that large top idler and chain.

I came very, very close to buying the Mid Racer until I stumbled across the Cruzbike site and decided these made more sense. PLUS, Jim, and John, Maria, etc will respond quickly to inquires and emails.

Arnold tends to have trouble with responding to queries. I never did get any responses to the emails I sent asking some questions. That said, Arnold makes cool bikes and I still think they woud be fun to own and ride.

-Eric