Introduction

The unique selling point of the all the Batec machines, both powered and un-powered is that the user needs no external assistance to join the machine to the wheelchair. This is a major liberating factor for wheelchair users wishing to be independent. The company provide weld-on and clamp-on attachment brackets that should fit most chairs. An important aspect of the company's design is that very little effort and no lifting is required to connect the handbike to the wheelchair (See: http://cyclingotherwise.co.uk/index.php/kit-reviews/batec-add-hand-bike/)

The company offer the Batec Manual handcycle (£2,495) and the Batec Hybrid powered handcycle (£5,495) as well as power only machines. Company literature seems to imply that the Batec Manual and Hybrid machines are seen as cycling replacement tools. However there is another segment of the market that gets little attention from all the handcycle marketers; the handcycle as a walking replacement tool. In addition, if the user is getting older or feels that they are not strong enough to cope with a manual machine any more, the marketers seem to be thinking only in terms of cycling rather than walking. For example the Batec Hybrid comes with a 36v 500 watt motor, three battery options up to 14.5Ah (4kg) and weights in at 19.9kg. The specification states that the machine has a range of over 30 miles suggesting that its market positioning is similar to that of the over powered electric bicycle.

The Alternative Option

The exercise reported here is for a Batec Manual handbike that is used as a walking replacement rather than a cycling replacement. Its current and intended future use is on accessible footpaths, urban areas, country parks and so on, none of which are intended for cycling. In this context a 'good speed' would be 4-5 MPH and a typical 'outing' would be 3-5 miles. Thus the user specification is for a light, low power motor and a small low weight, reliable battery.

The choices available to the older 'walking handcycle' user are to trade-in their manual machine for one of the many powered handcyle such as the Batec Hybrid which will fail to meet their needs. The alternative is to go for a custom conversion that yields a hybrid handcycle that exactly meets what the user specifies. At this point, enter Tony Castles of Eclectic Bikes (http://www.eclecticbikes.co.uk) who has a long history of designing and building low power electric bikes including the popular Nano Brompton.

The Custom Design

The discussion with Mr Castles led to the following specification being requested:

  • Hand throttle and pedalec controls
  • Low power electric motor wheel with cassette attachment
  • Small and lightweight battery

Tony Castles converted this into:

  • Hand throttle and pedalec controls.
  • Mojo (Tongxin?) 36v 250W powered hub built into a 20” wheel.
  • S-LCD3 LCD Meter by Guangzhou Corp.
  • Custom Control box
  • Bosch 36v 4.0 Ah lion power tool battery [Part no 2 607 336 915] in bag with Brompton luggage fitting
  • Brompton luggage block power connector
  • Brake lever 'kill motor' option

The conversion has been very neat and is such that one would hardly know that the machine has been electrified. The pedalec magnets disc is close to the chain guards on the chain wheel so is nearly invisible. The user controls or ‘meter’ is mounted on a flying bracket just below the chainwheel bearing as there is nowhere else within easy reach of the user. The Brompton luggage bracket is mounted on a blanking plate a short distance above the wheel meaning that the weight of the battery adds to the traction weight of the front wheel. The control box is tucked into a cavity just above the hinge for the handcycle steering. All the wiring is out of sight either in new conduit or utilising existing conduit runs. The new wheel was almost a perfect fit for the existing dropouts and only required minor adjustments to the alignment of the brakes and chain. There is no separate torque arm and the design uses profiled nuts to lock the drive axle to the dropouts. Wiring to the motor emerges from the axle and then is ducted away to the control box. The battery sits in a small padded bag on the Brompton luggage bracket.

This design gives the user the following traction options:

  1. Un-powered normal handcycle function.
  2. Powered at level 0 – Control panel provides speed and other functions but no power to the drive.
  3. Powered at level 1 and above:
  • Non-cranking powered motion controlled by the thumb throttle.
  • Cranking with power controlled by the pedalec mechanism.

The design has more than met the specification in terms of weight:

 

 

Original Condition

Post Electrific-ation

Batec Hybrid

Basic weight

13.5kg

16.4kg

19.9kg

Battery

-

1.8kg

4.0kg

Sub-total

13.5kg

18.2kg

23.9kg

Removable Traction weights (2)

5.0kg

5.0kg

5.0kg

Total operating weight

18.5kg

23.2kg

28.9kg

The converted machine with battery fitted, but no traction weights, weighs in at 18.2kg which is slightly less than the machine in its original condition with the traction weights attached. This is a significant achievement as it means that the task of loading the machine into a vehicle is not much harder than it was before.

The User Experience

The task of attaching the converted machine to the wheelchair feels no different to what it did in its original condition. Once connected the machine can be propelled as before and feels no different as the motor hub runs freely without power and there is little difference in the weight to propel.

The user control panel allows the setting of a maximum powered speed. For this machine it was thought that an initial maximum speed of 4MPH would be appropriate. However on level ground with a good surface it is difficult to tell whether the motor is running or not since 4MPH is easily attained and exceeded.

The thumb throttle comes into its own when the user needs a rest and wish to coast. Again the quietness of the motor makes this a pleasant option. The thumb control is also very useful where the machine needs to be maneuvered in a sharp slow turn and cranking is difficult because of the acute angle of the steering.

The pedalec control comes into its own for ‘normal’ progress and especially for hill climbing. Initial trials without the traction weights suggested that loss of traction and wheel spin could be an issue on hills, especially if the surface was loose grit. As a result the traction weights have been added for all subsequent operations. In the former unpowered condition it was usual to have a wheelchair bag suspended from the handles on the chair. Although this had a tendency to reduce the traction weight, the pusher in attendance was always able to compensate with a little input when necessary. It now seems obvious that the bag should come forward and be mounted on the Brompton luggage bracket. Mr Castles is converting one of the larger Brompton luggage frames so that the battery can live in the bottom of the wheelchair bag.

User reaction to the converted machine is ‘delight’ but, for readers who like some data, three trips have been logged and monitored.

Trip 1 – This is a circular route of 3.5 miles comprising mostly moderately hilly tarmac back roads and a canal towpath in original (grass and mud) condition. Speed was mostly around 3mph as this was an accompanied walk. On some of the downhill sections speed was allowed to creep up to 4mph, but the companion had difficulty keeping up. On the uphill sections where the companion would previously provided a boosting push, none was required. On the canal bank, especially on the steep little slopes around locks the companion acted as the stabiliser and brake. The Batec machine has two brakes operating on the front wheel so in slippery conditions front wheel skidding is easily achieved. On a steep uphill tarmac road no support was required except for crossing a cattle grid.

The statistics for the route were (provided by Viewranger):

  • Distance – 3.6 miles
  • Average speed – 2.7mph
  • Height gain – 165ft
  • Time – 1hr 20m
  • Power use was measured by the amount of energy required to re-charge the battery. The monitor showed 0.07kWh

Trip 2 – This was also an accompanied circular walk around Tegg's Nose Country Park near Macclesfield, Cheshire. The route is a mixture of gravel paths, very rough stony paths, grass, and tarmac all with steep gradients. The distance around is 1.7 miles and there are three disabled accessible kissing gates to negotiate. Once again there was loss of traction on the steep gravel parts of the route and companion pushing was required to maintain progress. On the grass sections there was again a problem with wheelspin but companion pushing was used to overcome the gradient. The effort required in pushing was significantly less than when the machine was unpowered.

The statistics for the route were:

  • Distance – 1.7 miles
  • Average speed – 1.7mph
  • Height gain – 251ft
  • Time – 1hr
  • Power use was 0.03 kWh

Trip 3 – The third trip was another circuit, from the Knutsford entrance to the Courtyard of Tatton Park, Cheshire. The outward leg was a grass path with mole/rabbit potholes becoming bare earth near the house. The grass was mostly dry and the machine had little trouble maintaining traction except for the very steep bare earth section near the end. However, pusher effort at that point was significantly less than when the machine was unpowered. The return was by the tarmac road back to the gate. The first half of this was downhill and mostly braking but the climb up to the gate offered no challenge to the machine. There was some degree of challenge for the companion in keeping up.

The statistics for the route were:

  • Distance – 4.0 miles
  • Average speed – 1.9mph
  • Height gain – 251ft
  • Time – 2hr 5min
  • Power use was 0.05 kWh

Overall this gives total logged trip distance of 9.3 miles for 0.15kWh (150 Wh) which is about 16 Wh per mile. Compared to an electric bicycle this is not particularly good. However, the 36v, 4Ah Bosch battery should be good for at least 10 miles of this kind of mixed surface journey. Bearing in mind that this is meant to be a walking replacement handcycle, a single battery charge should be more than sufficient for the kind of outing it will be expected to do.

Conclusion

This conversion has more than lived up to expectations. It is light making the manhandling of the machine little different from before and the un-powered user experience is completely unchanged. The controls are very effective and reasonably intuitive. The amount of power available is easily controlled and more than enough for the job. The majority of the time the power setting is 1 only being raised to 2 or possibly 3 on hills. Battery capacity is more than adequate and replacements are readily available from eBay and elsewhere.

The tests carried out so far suggest that the machine would benefit from having its slick Schwalbe Marathon tyre replaced by one with a more 'aggressive' tread*. Similarly the moving of the wheelchair bag from the chair handles to a frame on the Brompton luggage block will improve adhesion.

We would recommend this conversion package to any user whose handcycle is a walking replacement. There are plenty of very powerful cycling replacement machines on the market, but this conversion fills an important gap that the handcycle manufacturers seem to have ignored.

Price: Approximately £925 including fitting, testing and adjusting to the user's requirements.

Supplier: Tony Castles, Harepath Farm Industrial Units, Burbage, Marlborogh, SN83BT Tel: 07974 723996

 *Subsequent advice received suggests that using a much lower tyre pressure will also help improve traction.

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