Bike review: ElliptiGO SUB

Today’s review will focus on a different kind of bike: the stand-up bike or SUB. Once again I’m drawn to an unusual looking bicycle, but this one won’t draw quite as much attention as a recumbent. Unlike recumbent bikes that have you reclining on a large seat as you pedal, SUBs are essentially bikes without seats, making you stand upright. You may be surprised that I’m reviewing a bike that is so opposite to a recumbent, but what I’ve recently learned these past few months is that SUBs offer many similar health benefits as recumbents.

These bikes fit nicely in the space between running and cycling. By providing the upright position of a runner, there is less strain on the back, shoulders, and arms compared to being hunched over on a typical diamond-framed bike. At the same time, the pedaling motion is free of impact forces on the lower joints. So runners can enjoy the feeling of running without the hard impacts, and cyclists can enjoy riding without saddle soreness or any of the other aches commonly associated with regular bikes.

There are only a handful of SUB manufacturers. The most popular probably being ElliptiGO, followed by a few others: Cyclete, StreetStrider, HalfBike, and MeMover. SUBs can be distinguished mainly by their style of pedaling which includes a typical circular motion, a long-stride elliptical motion, a teardrop-shaped motion, or even a stepping motion.

The ElliptiGO SUB

Last September I had the opportunity to test ride two ElliptiGO standing bikes: the “3C” elliptical pedaling bike and the “SUB” circular pedaling bike. The elliptical bike was unique, but I found it large, heavy, and awkward to pedal. Plus I couldn’t justify the 3C’s steep price tag when the ElliptiGO SUB was a fraction of the cost and offered similar benefits. In the end, I bought a floor model matte blue ElliptiGO SUB at a local fitness shop. 

The ElliptiGO SUB has an aluminum frame and rigid steel fork. The drivetrain is a trigger-shifting 8-speed Shimano Altus rear derailleur (11-34 cassette) and 60T chainring (309%). It has 20” aluminum wheels with 1.5” Kenda Kwest tires and Shimano rim brakes. The pedals are oversized platform pedals designed to support your entire foot. The steering column is height adjustable with indexed locking. The handlebars are a medium width supplied with ergonomic grips and a kickstand comes standard. Taken together, I think these specs make an attractive package that is the lightest and most compact stand-up bike (29 lbs and 66” length).

One thing to note is that the 20” ElliptiGO SUB is no longer in production and instead ElliptiGO now offers more costly, larger wheeled versions of their circular pedaling stand-up bikes (MSUB/RSUB). I would have liked to see them continue to offer the smaller SUB as their lowest tier bike to introduce new riders to the benefits of stand-up bikes.

Fun in the SUB

While I was looking forward to the upright posture and low-impact benefits of the SUB, the sheer fun and convenience of riding it took me by complete surprise. The SUB has relegated my Azub e-MINI recumbent to the back of the garage, becoming my daily commuter for the past 4 months. This bike works well for short, brisk rides to work and around town. Unlike a recumbent bike, the SUB is very easy to hop on and off, navigate tight turns, and maneuver around obstacles. The additional 12” of height you gain on the SUB gives you a great view of the road ahead and makes you easily visible to others. Hills are conquered with relative ease with the help of your standing weight on the pedals, unlike my experience patiently spinning to slowly climb on a recumbent bike.  

Elliptigo’s claims about low impact are not exaggerated, and standing the entire time makes for an intense cardio session. For someone with chronic low back issues, the upright position combined with the pedaling motion doesn’t bother my back. Being able to rock side-to-side while pedaling adds a welcome upper-body component to the workout as well.

Limitations

Despite these benefits, the SUB does have its shortcomings. Without a seat, you likely won’t want to ride this on day-long tours. There are individuals out there doing century rides on stand-up bikes, but not this non-athlete.

Another reason these stand-up bikes make for poor touring bikes is there’s no place for a rear rack to carry panniers or trunk bags. When riding the SUB, it will just be you and what you can carry on your body such as a backpack. To transport a small amount of stuff, you could add a handlebar bag, but you’ll never get the capacity of full-sized rear panniers. I added a small Burrito handlebar bag to stash my keys and phone. Ideally, I’d like to see ElliptiGO engineer a front rack system to support a large basket or bag and front panniers to give commuters a bit more cargo space. This would expand the versatility of these bikes from just pure fitness machines to something more utilitarian.

I was surprised by the lack of bottle cage bosses on the frame, which meant buying a Topeak cage mount to attach to the steering column. I also would have liked to see mounts for full-length fenders. Unfortunately, ElliptiGO only offers a full fender set for their RSUB model and just a partial rear fender for the SUB.

Final remarks

I’ve been espousing the benefits of recumbent bicycles for so long that I never imagined enjoying such a different kind of bicycle this much. If you’re a current or former runner or a cyclist who wants to ride without the discomfort of a regular bike, then the ElliptiGO SUB (or any other stand-up bike) is worth trying. However, if you need a bike for running errands, commuting, or going on long tours, you may find yourself limited by the SUB’s lack of cargo-carrying capacity.

Bike review: Azub Origami


Since I began riding recumbents, I’ve often dreamt of traveling with one in a suitcase and unfolding it in some remote destination to tour the countryside. While the pandemic put the brakes on traveling for some time, it did allow me to search for my ideal folding recumbent. In the end, I decided to get another Azub: the Origami. Initially, I planned to replace my Azub MINI with the Origami, but the MINI has since transformed into my cushy electric pedal assist bike that I just can’t bear to let go of yet.


The build

The Origami is a short wheelbase (SWB), dual 20″ aluminum frame recumbent with over-seat steering (OSS). The frame is a streamlined monotube design that looks fast even at rest. The rear of the frame has a creatively integrated pannier rack that rotates out of the way when folding the bike. The frame lines allowed Azub to set up a simple chain line with just a couple long chain tubes and no idlers.

I ordered the Origami in the spring of 2021 with basic options (Sora 3×9, BB7 brakes) except for a carbon fiber seat upgrade. As usual, Azub offers a wide array of customization via their online configurator. Having recently converted my MINI to electric, I had a bunch of nice parts for the Origami. While the stock weight of the bike was probably around 40 lbs (still below most airline weight limits), my final build came to ~30lbs in the end— making it a fairly light travel bike as far as folding recumbents go.


Just another Azub?

At first glance, the Origami may look like a slightly (13 cm) longer Azub MINI, but there are some key differences. Namely, the Origami lacks suspension and does not accommodate under-seat steering (USS). Of course, in exchange for losing those features, the Origami gains one biggie: it folds (more on folding below).

The Origami also allows for a more reclined /aerodynamic position compared to Azub’s other bikes, and the position of the bottom bracket is slightly higher to deliver more power. Another difference is the more narrow handlebars on the Origami, presumably to help keep the bike compact when folded. It’s a minor detail, but it will limit your cockpit space for accessories more than other bikes.


The ride

I found the Origami, with its rigid frame and sporty seat positioning, to be a quick little bike. The small wheels gave it fast acceleration without any suspension sluggishness. The narrow handlebars tucking your arms/elbows in makes you feel like you’re racing. While this isn’t a racing bike, it’ll just get you across town quickly with a smile on your face.

The ride can be a bit unforgiving, and riders will benefit from the natural suspension of wider tires running at low pressure. I replaced the stock 1.5” Marathon Racers with 2.15” Big Apples and test rode on some packed dirt/gravel trails. While the Big Apples made the ride tolerable, I yearned to get back onto the cushy full-suspension MINI to protect my sensitive back from the jolts. That said, unless you have a particularly delicate back, I think most riders will find the Origami to be comfortable both on and off the road (with appropriate tires).


The fold

As you can see in this video by Azub, it takes just a minute to fold or unfold the Origami. Compared to other folding recumbents, I think this is as easy as it gets.

A few noteworthy details that aren’t so apparent in the video:

  • Azub includes a double-legged kickstand to hold the bike up for you while going through the folding/unfolding process.
  • They also include clip-on platform pedals you can take off when packing the bike.
  • The boom can be easily removed for packing since it is held in place with two quick releases.

Once folded, you can roll the bike by holding the handlebars, or you can place it in a soft carrying bag to sling it over your shoulder. For air travel, you’ll want to put it in a hard-shell suitcase, so note the folded dimensions of the bike down below. I haven’t purchased a suitcase for it yet, but I’ll be sure to write about packing it up when I do.

Folded with seat: 35x35x14 inches (LxHxW)

Folded without seat: 35x30x14 inches (LxHxW)


Other folding recumbents

There are a few other folding recumbents worth considering:

  • HPVelotechnik Grasshopper fx – full suspension, dual 20” with OSS and USS steering options.
  • Linear Limo/Roadster– LWB and SWB versions. Rigid frame with 26/20 wheels and OSS or USS steering options. Frame folds into a ski tube, but wheels and seat must be packed separately.
  • Performer Conquer– a sporty, dual 20” rigid frame SWB bike with OSS steering. The Conquer is a FWD bike, so it may be a steep learning curve for some.
  • Toxy-ZR– This German company makes several folding recumbents, but the ZR is by far the most exciting. It’s a dual 20” FWD low racer with rear suspension and OSS steering. Definitely on my wish list to try one day.
  • Trident TWIG– an entry-level 26/20 steel frame bike with OSS steering.
  • Bike Sat-R-Day– Sadly this folding recumbent is no longer manufactured by the folding bike gurus at Bike Friday, but I couldn’t leave it off the list. It’s a classic with its tiny 16” wheels and compact dimensions.
  • Lightning P-38 Voyager– Not technically a folder, but this version of the popular P-38 has S&S couplers that allow you to take the frame apart and fit the entire bike in a suit case.

Final remarks

If I were to change one thing on my Origami, it would be to do away with the rear cassette and derailleur in favor of an internally geared hub. While doing so would add a little weight to the bike, it would simplify the drive train and make it less susceptible to damage during packing and traveling.

The Origami, with its rigid frame and aerodynamic seating position, is a sportier, livelier bike compared to the MINI. You won’t win any races in the Origami, but you’ll have a trustworthy companion for all your worldly travels.

MINI revisited: It’s electric!

While e-bikes can be a divisive topic among cyclists, it’s hard to ignore their increasing popularity. Admittedly it took me some time to warm up to the idea. Do I still get a workout? Is it “cheating”? After test riding an upright e-bike, I realized my worries were unfounded and it was time to transform the MINI once again. This time into an e-recumbent bike suitable for just about any terrain.


E-assist options

Azub offers attractive e-assist builds with Shimano Steps or Brose. The electric motors are integrated into custom booms, wires run internally, and the battery is mounted on the rack. Unfortunately, Azub can’t sell an e-assist upgrade (probably licensing-related?). Thankfully there are plenty of after-market options. While they won’t look as sleek, they’ll be a fraction of the cost if you don’t mind a little DIY work.

Some e-assist kits place the motors in the rear or front wheel hubs while others place them at the cranks (i.e. mid-drives). Two popular mid-drive manufacturers are Bafang and TongSheng. Both seem like good choices, and in the end, I decided to get the TongSheng TSDZ2 motor.


TSDZ2 specs and features

The TSDZ2 has a small form factor yet puts out an impressive 500W of power and 100Nm of torque. The 8 lb motor assists at up to 28MPH and/or 100RPM (you can always go faster but the motor won’t assist you). It can be installed on any bike that has a standard 68-73mm bottom bracket.

The most attractive feature of the TSDZ2 is the torque sensor which provides a more natural pedaling feel. With a torque sensor, if you pedal gently you get a gentle assist, and if you pedal hard the motor will assist more. In contrast, without a torque sensor, a motor will give a flat level of assist as long as you are pedaling. The torque sensor obviates the need for brake sensors to cut power since the motor is quick to respond when you stop pedaling.

While the motors are widely available, I purchased a recumbent-specific kit (the ECO+) offered by Eco-Cycles. They provide cable extensions to accommodate long recumbent frames, and a boom clamp specific to your boom diameter for securely mounting the motor. Eco also offers additional upgrades, including a software upgrade (OSF upgrade) that allows for custom assist levels and higher RPM assist.

The kit I chose included a more durable PEEK plastic gear inside the motor unit, the SW102 small LCD screen, and a 42T chainring to handle moderate hills. I skipped the throttle option in favor of always having to pedal. I also passed on the custom software upgrade to keep things simple.


Installation

My local bike shop installed the motor onto the boom for me, and I installed the rest myself. I used zip ties to run three cables along the bike. One cable ran up the steering assembly to the display screen. Another cable ran to the back chainstays for a speed sensor. The third cable ran to the battery. I mounted the battery (52v 13ah Jumbo Hailong Shark; 11 lbs; 30-60 mile range) beneath the seat with the versatile T-Cycle universal battery mount.


Riding with e-assist

It’s no wonder e-bikes are so popular. With the pedal assist, I no longer have to worry about how hilly a particular route is before I go out. I still have to work to get up those hills, but I can get there faster.

I can choose from four assist levels (eco, standard, super, turbo). With the torque sensing system, at each assist level, the system will add a percentage of the power you are outputting. So if I’m putting out 100 watts while using the first assist level, the motor will add 40% (or 40 watts) to the output. That percentage keeps going up at each assist level, so you can decide how fast you want to go at the output you’re producing.

Another benefit I had not anticipated is being able to quickly clear intersections from a stop. Cars don’t have to wait for me to get up to speed, and I can spend less time worrying about them getting mad. Relatedly, I can also be more patient since slowing down or stopping for others isn’t such a big deal when I can get back up to speed easier.

It’s only been a few weeks of riding my electrified MINI, but I can safely recommend e-assist to anyone looking to enjoy more time on their bikes without fearing those hills.

The Psyclists’ first spring ride

The Princeton Psychology/Neuroscience cycling group dusted off their bikes and reconvened after a long winter.

Today’s route took us along the scenic D&R Canal towpath from Princeton to Rocky Hill. From there we crossed to the other side of the canal and looped back with a stop at PJ’s Pancake House in Kingston for some coffee and snacks.

Interesting sightings included a few dozen sunbathing turtle, some hissing geese, and a great blue heron flyby.

In total, we rode 13 miles– most of which were flat except for the steep hill along Rt 27 into Kingston.

Here’s our Garmin route for anyone interested in the ride.

Bike review: Azub MINI

A happy new bent rider picking up his bike at Jersey Bents in Hamilton NJ (the shop has since moved to Berlin NJ).

The MINI was my first recumbent, and I’ve ridden it regularly for the past four years. Now I’m riding a similar bike, the Azub Origami, that I’ll review in a future post. Be forewarned, given the significant time I’ve spent in the saddle with the MINI, this will be a detailed review.

By 2018 my back problems convinced me it was time to stop riding a regular bike and seriously consider a recumbent. After a few months of internet research (mainly on the popular BentRiderOnline forums), I decided on a bent for leisure riding and commuting: one that had full suspension to smooth out the ride, and small 20” wheels to reduce my falling distance. I (incorrectly) figured falling was inevitable having never ridden a recumbent.

Basic specs

The MINI is a short wheel base (SWB), compact dual 20″ aluminum frame recumbent with rear and optional front suspension. It’s about as long as a standard bike (165 cm) with a wheel base of 109 cm, so it can be stored in relatively small spaces. The MINI is known to be easy to ride and master, quite maneuverable, and have good acceleration due to the small wheels. These characteristics make it best suited an urban/commuting environment, but it can also handle itself off-road.

The MINI as it originally arrived with above seat steering.

I configured the bike with a few upgraded options: disc brakes (Avid BB7), air suspension (MEKS SASO front and SR SunTour rear), SRAM dual-drive drivetrain, carbon fiber seat, and above seat steering. Unfortunately, right around the time I received the bike, I was affected by ulnar nerve issues originating at my elbows and making it difficult to use the above seat steering. Thankfully the steering on Azub bikes can be easily switched, so I contacted Azub and had them send me an under seat steering (USS) system to swap in.

Comfort

The bottom bracket is positioned just slightly above the level of the seat bottom, making this a comfortable touring bike while still allowing good power transmission from the legs. The full suspension was very plush. The frame and fork allowed for wide tires, such as the 2” Big Apples to further improve comfort. I don’t know if the upgraded rear air shock absorber feels any different from the standard spring shock, but I had no complaints about it. The shock absorber even had a lock you could reach around and engage while riding up a steep incline to cut out any loss of energy from the minor bouncing “pogo” effect as you pedaled.

The hard-shell seat fit like a glove and could be reclined to around 35 degrees. When first starting, I had the seat positioned closer to 45 deg. and slowly reclined it as I became more confident. The seat’s incline and fore/aft position can be changed on the fly with convenient quick-release skewers. The Azub headrest does a decent job but is difficult to adjust without a small wrench on hand.

I should mention that the Azub SIX and Azub MAX are almost identical to the MINI. Their main difference is the wheel sizes. The MINI is 20×20, the SIX is 26×20, and the MAX is 26×26. I test rode them all, and while I was not tall enough for the MAX (I felt uneasy having just my toes reach the ground at a stop), I did consider the SIX until I realized that the larger rear wheel on the SIX prevented the seat from reclining as much as on the MINI. If you’re considering similar bikes, the SIX and MAX are worthwhile options, especially since the larger rear wheels allow those bikes to have both higher gearing and less rolling resistance over large obstacles.

Drivetrain

The SRAM DualDrive (DD) system consisted of a 9-speed cassette/derailleur along with a 3-speed rear internal gear hub (IGH). The system provided an ample 540% gear range and kept the front of the bike clear of multiple chainrings and a front derailleur. The drivetrain is controlled with one hand using a combined twist (for the 9 gears) and trigger shifter (for the 3 IGH gears) on the right side. A rider can fine-tune the gear range by swapping out the single front chainring.

As a first-time bent rider, it was easy to see why Azub offered this drivetrain option. Starting from a dead stop on a recumbent can be tricky, especially uphill. Incorporating an IGH allows the rider to shift to a lower gear while at a complete stop. So you can get out of a bind when you find yourself at a standstill and in the wrong gear.

The DD system worked reliably, but unfortunately, SRAM decided to discontinue them in 2017. Probably the biggest concern I had with this system was the fragile plastic click box that connected to the IGH via an equally fragile pull rod. Instead of the DD system, Azub now offers a nearly identical drivetrain by Sturmey Archer.

Brakes

The Avid BB7’s are popular brakes that work well without much fuss. They don’t provide much range when you want to feather the brakes, but they have plenty of stopping power.

Top-down view of the under seat steering setup where you can see both the brake and shifter cables protruding out and looping back in.

Azub mounts the brake levers on the USS handlebars in the “correct” orientation. By that, I mean when you grip the levers your pinky finger is closest to the end of the lever (as it would be on a regular bike). This provides the rider with a more natural feel when squeezing the levers, but it also means you end up with unsightly brake cables protruding out the ends of the handlebars and looping back in. In contrast, HPV orients the levers on their USS bikes the opposite way so that the brake cables follow along the handlebars as they exit the lever (yeah yeah I know I’m being picky here). As much as I like the lever orientation that Azub uses, I’d rather have less cable clutter and I did in fact change the lever orientation later for a cleaner look.

Ride stability and steering

The MINI is stable at both low and high speeds, thanks to the long wheelbase. I’m able to keep a fairly straight line even while climbing steep hills. The bike also handles itself at high speeds. My comfort level maxed out around 32 mph during some fast descents. I found its stability made it easy to learn how to ride and I never fell over. Also, being able to modify the steering ratio of the USS handlebars is a lot of fun allowing you to dial in the steering exactly how you like it.

Carrying capacity

Despite its small appearance, the MINI is rated at 275 lbs. The way the rear luggage carrier integrates into the main frame of the bike is clever. You can mount a trunk bag and a pair of pannier bags on the carrier. If you don’t need the carrier, you can slide it out of the frame and insert a plastic plug on the end of the frame. For more capacity on long tours, Azub offers additional side and bottom carriers as well.

Weight and custom upgrades

My biggest complaint about the bike was the hefty weight. Sure it wasn’t designed to be fast, but the bike weighed in at an impressive 45 lbs. I wanted to lighten up the bike, not just to help me get up those hills, but also so that I could lift the thing onto my car. So over the years I replaced many of its components with lighter counterparts.

I ended up replacing the stock wheelset with Velocity A23 wheels, the disc brakes for v-brakes (Paul Components), and the DD drivetrain with 11-speed road components (SRAM RED 11-32 cassette, rear derailleur, and bar end shifter).

For the front of the drivetrain, I was planning on a standard 34/50 double but soon realized my upper gear range would be severely limited by the small rear wheel (maxing out at 84 gear inches). Instead, I opted for a popular 2-speed front IGH, known as a Schlumpf Drive. This gave me the equivalent of 30/75 in the front (727% range; 18-125 GI).

I also replaced the front fork with a carbon fiber (CF) Bacchetta Johnson fork, and the aluminum front boom with a CF version from HPV. Since most of my riding was on the road, the loss of front suspension wasn’t too detrimental to the ride quality and the switch to CF provided significant weight savings.

Sizing up the competition

Besides the MINI, there is one other bike available stateside that is fully suspended with dual 20” wheels: the HPV Grasshopper FX. Fortunately, the only recumbent shop in NJ was a few minutes away from me at that time, and I had the opportunity to test ride both bikes and agonize for weeks trying to decide between them. They are similar bikes and either one would have been fine. One major difference is that the Grasshopper can fold up. In the end, I appreciated the design elements of the MINI and found its seat a bit more comfortable. I also liked that the Czech company has a reputation for making their bikes rugged and overbuilt for heavy world touring.

Final remarks

The same MINI after a few years of upgrades and a new paint job.

When all was said and done, my MINI ended up weighing a more manageable 30lbs and being an even more pleasurable bike to ride. Since switching to the Origami a few months ago, I’ve swapped most of the above upgrades over and returned the MINI to nearly stock form.

The MINI is currently on loan with a recumbent-curious friend. I’ve been considering selling it, but after writing this review I’m having second thoughts. Maybe I can make some space to keep it. After all, suspension recumbents with USS are a rare breed nowadays.

Thanks to the good folks at Azub and Jersey Bents for answering my non-stop questions about their bikes.

Recumbent types: Steering

Under Seat Steering (USS)

The handlebars on a recumbent may be mounted below the rider so that their arms hang in a relaxed position. Known as under seat steering (USS), this is arguably the most comfortable and least tiring steering position since you’re not reaching up to grip the handlebars. That said, it can be a bit trickier mounting/dismounting a bike with USS without practice, and you’ll be less aerodynamic when riding since you’ll have a wider profile against the wind. It’s also worth noting that USS is more mechanically complex and expensive, often requiring non-standard bike parts including a tie-rod to link the bars to the fork (known as indirect steering). There are a few USS bikes out there with direct USS steering where the handlebars connect directly to the steerer with a stem (just like a regular bike but inverted), but the handling can be a bit too twitchy with direct USS steering. In contrast, indirect steering often allows the rider to fine tune the feel of their steering by changing the placement of the tie-rod to adjust the steering ratio.

Personally I’ve found USS to be the ultimate design in recumbent comfort. My first recumbent came with above seat steering (ASS- see next section below), and I immediately had to switch it to USS because my elbows were giving me problems. Despite the comfort, USS did get annoying when I needed a good place to mount accessories like my GPS. Having USS also made it harder to walk my bike since I had to bend over it a bit to steer it, and I needed a wider space for parking or storing the bike. My elbow pain improved a few years later after a couple surgeries (cubital tunnel release and ulnar nerve transposition), and I did switch back to ASS without much of a problem mainly for the sake of convenience.

If you’re interested in USS bikes, you have a few options in the US including Azub, HP Velotechnik, Linear Recumbents, and Long Bikes. In Europe you’ll have a few more options with Challenge Bikes (Netherlands), Slyway (Italy), and Flux, Toxy, and Traix (all in Germany). Just note that the HPV Streetmachine and Toxy bikes use direct steering, and may be a bit more tricky to ride.

Above Seat Steering (ASS)

When the handlebars are mounted over the rider’s lap and they have to reach up to them, the bike is known as having above seat or over seat steering (ASS or OSS). Compared to USS, ASS is more aerodynamic and generally easier to learn. You’ll have some choices regarding the shape of the handlebars: “praying hamster bars” that keep your arms in a tight position close to your chest versus “superman bars” where you are gripping onto wide bars in what is called an “open cockpit”. The superman bars are more ergonomic since they keep your hands/wrists in a neutral position where you don’t have to rotate your wrists to hold onto the handlebars. ASS does require your arms and shoulders to be more engaged compared to USS, so your arms will tire after a while. Unlike USS, you’ll have plenty of room on the handlebars to mount accessories such as mirrors, bells, and lights, but you may also have worse visibility with the handlebars blocking your line of sight (especially if you are in an extreme horizontal position).

Pivot Steering

There is a less common type of steering out there known as pivot or center steering. On these bikes, there’s a pivot at the center of the bike, allowing you to steer the front wheel by leaning. These bikes may come with side bars to help you lean into a turn, and may have no handlebars at all! I’d love to try such a bike one day, but the only center steering bikes I’m aware of are old Flevobikes from the Netherlands.