Preparing your Thys 222 CVT for a maiden voyage

How to make your Thys 222 CVT (178 mm Snek) Rowing bike ready to ride

  • Mount the Bow sprit onto the frame at the steering fork. Take care that an eventual filling plate is mounted at the correct side.
  • Take care that all shift cables and brake cables are in correct position.
  • Put the steering bar in straight position.
  • Put in the wheels and make sure the cables of the brakes are mounted properly.
  • Once the rear wheel is in the frame, completely unroll the propulsion cable from the Snek, lay it on the floor without any loops. To undo loops rotate the end of the propulsion cable around it’s axis.
  • The CVT cable is a rotation poor cable so it can not be turned around its axis very much! Now lead the front end of the propulsion cable through the clamping device at the foot slider from rear to front side. Make sure the Bowden cable that goes from steering bar to the clamping device is on the outside of the propulsion cable. ( take the cable through the black shifting cable divider, rear wedge pusher, wedge housing front wedge pusher and front nylon part) You can push the 3 mm rod that is in it now out to the front with the cable when you push the clutch button (right thumb lever) all the way.
  • Leave the foot slider in rear position, Pulll the cable around 2,5 meter through the clamp so that the front end of the cable, when taken over the front lower bower pulley and back to the rear wheel would just reach the Snek again.
  • Make sure your rowingbike is standing on both wheels before you start the next step.
  • Now you have a lot of cable laying on the floor. While keeping tension on the cable roll the Snek counterclockwise so that the cable is rolled on the Snek all the way.
  • At the end there should be tension between Snek and foot slider.
  • Now you can take the cable off the bow pulley, get the cable end through the hole in the end of the groove on Snek and behind the M5 screw on the rear of the Snek and mount the end nipple on the utmost end of the CVT cable.
  • Now pull the cable end out of the Snek . Now to get the Cable on its proper place and to get tension on it you have to pull the downward bow pulley backward to lay the propulsion cable over it; take Care there is a lot of tension on the bungee! watch your fingers.

Adjust the rowing bike to your body length

You can adjust the height of the steering bar, it should be as low as possible so that you leave aprox 20 mm between you knees and the steering bar.
More important is the length of the armstroke cable (the cable that goes from top of the steeringbar to the footslider), you can adjust it in the cleat at the foot bench. When you are clicked in with your feet lying down in the chair with your feet in end of the stroke position your elbow should be in an angle of 90 degrees. If you have a left mount uipper bow pulley you have a wedge system adjuster for the armstroke cable. Push in the wedges from the front side to adjust the cable.

Important: before you start riding your rowing bike

  • Check if your shoe plates are compatible with your click pedals, get used to click in and out your feet, make sure you can always get out of the pedals, they are adjustable.
  • Always use your arms symmetrically, if you do not do that you are in fact steering.
  • Only take one hand (or two once you are used to the bike) away from the steering bar when you are freewheeling , with legs in straight position.
  • Practice this one hand steering on low speeds first!
  • Have a good look at the Snek system and check how changing gears works before riding.
  • When shifting, right thumb button is pushed all the way (like the clutch of your car or motorbike) and thereby two things happen: the Snek is locked, it can no longer turn around its axis and the propulsion cable is unlocked from the foot slider. So when this shifting button is pushed making (a small part of) a stroke is shifting down, making a (part of) a recovery stroke is shifting up.

Correct use: push the shifting button all the way, or not at all!

Notice that when you are in a low gear you will have to shift almost a full stroke before you notice difference in gear (as one circumference of the Snek at large diameter is perhaps 45 cm whereas the perimeter at smallest part is only 13 cm). When you are already in a heavy gear you perhaps only have to shift a few cm to feel a difference.

TRICKY points

The tricky point of this shifting system is that there is not a mechanical stop that prevents you from shifting too low or too high. So you always have to pay attention that you do not shift to far up or down. It can be helpful to mark the propulsion cable with a black marker to show till where you can shift. This marker will fade. You can mark it again every now and then!

Another tricky point is that you always have to ride with tension on the armstroke cable (the cable that goes from top of the steering bar to the footslider). Once you are experienced rowingbike rider you always have tension on the armstroke cable

For right mount upper bow pulley when you loose the tension it can happen that your armstroke cable rolls over the other bow pulley of the propulsion cable, you get a bit of a cable jam, You can correct that again by lifting the propulsion cable off the bow pulley. Watch your fingers again!


Always drive with two feet clicked in. when you start to ride with one leg only use very little force, you can put enormous asymmetrical forces on the foot slider and bow sprit when driving with one leg.
Once you have two feet on the pedals you can go full force!! (For disabled people with one leg we build special reinforced foot sliders with more bearings)

Ride safe

You have bought a fast and low bike. Always assume that other traffic users might not see you as you are lower and faster as they expect. Take no risks; It is not worth it!


  • Always keep your propulsion cable and Snek far away from greasy products, just clean it with water every now and then.
  • The chromium rails of the bowsprit and the ball bearings of the foot slider and the attachment point of the armstrokecable on the steering bar need a bit of Vaseline or other grease on a regular base, these parts should never be without grease!
  • The CVT propulsion cable should be replaced after about 1500 to 5000 km depending on how much you shift and on your weight and force. The more different gears you use the longer the lifetime of the cable. When you shift really very much (every 500 meters or so) this will bring lifetime down again. A heavier guy will have shorter lifetimes than a light person.
  • We advise to check all cable for damage and fatigue brakes before each ride. The rejection standard is when there are more than 10 fatigue brakes per 10 mm cable length.
  • The ball bearings of the foot bench are mounted with eccentric parts. You can adjust these with a thin (3mm) 11mm and 14 mm end wrench after loosening the centre bolt with an Allen key. Always leave some space between bearings and bow sprit so that it runs without resistance and dirt and sand can not cause a jam.
  • When foot slider bearings become noisy oil them or replace them (usually after 10.000 to 20000 km)

Good to know

The steering damper between mainframe and front fork is mounted with a black eccentric part, in this way you can adjust the neutral steering angle. The rubber steering damper should be mounted in such way that the front wheel is in straight position when the bike is hold upright.

Technical matters for CVT owners
Lubricating the bearings

Lubricate footslider bearings and the bow sprit at a regular basis, especially after riding in the rain. As long as the bow sprit and the chrome coating is permanently lubricated, the lifespan is very long.
As soon as the outer bearing rings start to corrode, microscopic crater rims are present on the surface, which increases the wear and tear of the chrome on the bow sprit extremely. Because of sand and normal usage, micro holes show up in the chrome. As long as the bow sprit is permanently lubricated nothing will corrode and all is fine. But when the bow sprit is without any grease and for example is parked wet after a ride through salty, brine water, the steel under the chrome will rust and small rust blisters will form under the chrome layer. You will probably be able to continue for tens of thousands kilometres, but it will be noisy and will not run and look very nice…

Problems with tension of the bungee (elastic shock cord in the bow sprit)

Whilst using the rowingbike, it has come clear that the bungee in the bow sprit weakens rather much after some time. At a certain moment, for example after a year, the tension of the propulsion cable is so little that it looses all tension momentarily. This happens especially when making the Recovery stroke and manifests easiest in a high gear. This may result in a skidlike feeling when making the next stroke. The cable first slips a little along the Snek before regaining its tension again and starts propelling the rear wheel. In the worst case the cable may derail from the groove and from the Snek. Minimizing problems of the tension of the elastic is best accomplished by parking or storing the rowingbike in the lowest gear, thus getting the lowest possible tension in the bungee. When not using the rowingbike for a longer period, for example during the winter, it’s best to completely untighten the shock cord.

Increasing the tension in the bungee

If the tension in the elastic is too low, it’s easy to tighten the elastic again. Pull the loose end of the two Dyneema®  cords, close to the head set on the left side, out of the bow sprit tube, and attach a thin piece of rope or iron wire to them, so you’ll be able to put them back again afterwards. Let the two knots in the Dyneema®  cord slide into the bowsprit and take the two ends of the Bungee out at the front of the bow sprit. Lay an extra knot in each Dyneema®  cord. This results in more tension on the elastic. This way of increasing the tension can be done at least one time. It may be necessary to replace the whole piece of elastic after a year or so.

Tuning the commander cable to cable clamp (the wedge housing at the footslider)

Tuning the cable to the cable clamp and making sure it runs smooth is very important. The inner cable and its casing should be replaced regularly, for example every year. When you notice that pushing the clutch button is hard, this may well be because of rust of the outer casing which grates along the cable inside it. Apart from heavy gear changing the opposite is also happening: the wedges need to practise a lot of force on the commandercable to be able to return to a fully locked situation. The wedges may not lock completely and the propulsion cable can be damaged. The wedges than do clamp the outer strands of the cable, but do not clamp the core of the cable sufficiently. The outer strands will then be pulled over the core strands and you can get deformation of the cable. In the worst case the cable starts slipping completely. This is something you don’t want, it means replacing both cable and wedges.