REGULARLY INTERMITTENT/NO ASSISTANCE – NOT SPEED DEPENDENT

NEW INSTALLATIONS: Please ensure you install your sensor the correct way up – if you do not see green LEDs in Pedal Setup Mode when pedalling forwards, try pedalling backwards – if you see green, then your sensor is upside down.

If assistance isn’t working or only comes in occasionally and silently then your sensor is probably not correctly adjusted, or in very rare cases, may be damaged. Other possibilities to check are listed near the bottom of this page – but we strongly recommend checking the below in order, until the issue is found. The Fitting Instructions are much more detailed, but we repeat the important points below, most importantly – the 3 views which show correct alignment. Re-adjustment of a sensor which was working will only be required if that sensor has been knocked out of position or is loose – we recommend that the 3 pictures below are checked carefully first before adjusting the sensor in case this is not be the problem.

If you have an earlier Cytronex kit where there is a sensor connector, you can complete a sensor reset by undoing the connector with the bottle off, reconnecting the sensor and then reconnect your bottle and follow our advice below.

Adjustment will only provide reliable assistance if the sensor is still firmly fixed and the bicycle cassette / rear wheel are correctly tightened and the rear hub bearings do not need replacing. Always check sensor is firmly fixed when adjusting – zip ties should have been pulled tight with pliers and the two screws properly tightened. Also zip tie heads must be positioned under the chain stay and not facing outwards.

Please see the 3 different views below that show correct sensor alignment. The most common issue we see is that the sprocket teeth are not centrally aligned to the end of the sensor head as shown by the photo with blue line – this can only be viewed from directly above. Please note that if you need us to check, we can only do so with the exact same 3 photo views as below and often when taking these photos, the problem will become immediately apparent and will not require our help.

Also if the problem is not resolved, we recommend moving the sensor closer – see the photo below with the yellow lines.

Correct sensor alignment:

Once adjusted as shown in these 3 photos both screws should be carefully tightened to ensure a firm fixing, taking care not to round the screw heads. To test your sensor alignment, use Pedal Setup Mode –

1. If you have the one-way button (green, blue and red LEDs) engage this by holding down the Boost Button for at least 4 seconds until the Bottle LED turns blue and then release the button.
2. If you have the two-way button (amber, blue, green, red and white LEDs) then you can enter Pedal Setup Mode by holding the left side of the Boost Button down for 4 seconds until a blue and white LED shows on the Boost Button (the Bottle LED will also go Blue) and then release the button.

When you pedal forwards in Pedal Setup Mode the bottle LED should stay green, if you have the two-way Boost Button then this should also stay green during forward pedaling. Intermittent problems are almost always caused by movement (e.g. sideways movement of the sprocket) and are best tested by riding in Pedal Setup Mode on the road because any movement due to loading / pressing hard on pedals on hills will become apparent (the bottle LED will show blue if Cytronex is not receiving a correct forward pedaling signal, as will the button if it is a 2-way button). When finished, exit Pedal Setup Mode with a single momentary press of the Boost Button.

Please note that a constant red LED when using Pedal Setup Mode shows that the pedals are being moved at a speed representing more than the maximum speed for assistance (in this case, the sensor is working however). With the two-way Boost Button even if the bottle LED goes Red for this reason, the Boost Button will show a Green LED if the sensor is correctly positioned. If you are not pedalling very fast when you see a red bottle LED in Pedal Setup Mode then please see “Assistance fades out silently at low speed”.

If sensor is correctly and firmly fixed but still does not show green reliably in Pedal Setup Mode:

Disconnect bottle then reconnect and try again in Pedal Setup Mode. If it still does not work – do not re-adjust, but leave until the next day, with the bottle disconnected. If the sensor then works in Pedal Setup Mode when reconnected the next day – contact Cytronex and confirm this is what happened, we will advise what to do. However, we recommend checking the below first:

Check gold Bottle Holder pins (in the top connector) do not retract if you push a finger carefully on the end (they can move around a little but should not move backwards). If any retract or are already shorter, contact Cytronex. Please note there are 8 pins not 9 in the Bottle Holder connector.

Check the sensor cable for nicks – if the bottle LED still does not show green when pedaling forwards in Pedal Setup Mode then most likely there is damage to the cable or a fracture where the cable joins the sensor head. If so, contact Cytronex.