hi all - I completed the dreaded
Day run ...
(2 trips of 29.5 kms with a recharge of 9 hrs between trips) - Pedalling 90% of the time.
Bike - 11kg Urban Flat Bar (light MTB/Road Cross -no suspension) fully kitted with small front panniers (wider front profile) & a pair of tiny rear panniers with battery top bag. Bike weight fully loaded (GM kit, battery pack, weather clothing, tools, tubes, lighting etc) <34kg
Test A -
Terrain mainly a continual incline that ends in group very steep hills - the last being the steepest. 20km of the trip has no stop/starts.
Average speed 29 km/h
Throttle used in the 70-100% range
Battery cut-outs on last hill at the 28.5km mark - very little assistance available.
Controller very warm to touch - but not hot. (venting will be required)
Top speed 48.7 kms/h (down hill)
Range 29 kms - some intermittent power avail over the last 0.5kms
Top regular speed on flats about 34-37kms/h with pedal assist.
Test B -
Opposite (return trip) terrain mainly a continual decline starting with a group very steep hills. 20km of the trip has no stop/starts.
Average speed 26.16 km/h - (early battery cut-outs reduced average speed - from 30.1 km/h prior to the cut outs)
Throttle used in the 90-100% range ( was a litte over confident due to the results of Trip A & travelling mainly on declining terrain)
Battery cut outs occured at 24 kms mark - (still some hills on the last leg of the trip - bike heavily assisted by pedalling up the hills at slower speeds)
Controller warm to touch - but not overly warm.
Top speed 56.3 kms/h (down hill)
Range 24 kms - some intermittent power avail over the last 6 kms
Top regular speed on flats about 36-39kms/h with pedal assist.
Sorry - but I could not find my multi-meter to record battery status - before/after rides. (I think one of my boys has stashed it
) but will have to find it evaluate the SLA battery pack's performance.
This was a promising 1st run - however a LIFEPO4 battery back 36v/20AH is required for 30km+ ranges -if 90-100% throttle is used.
Performance for the motor was strong for about 65-70% of the distance on each trip but you begin to notice the batteries (SLA 14AH) struggling after the 20km point. As the SLA's capacity to hold charge will deteriorate with warmer weather & regular deep discharging - I would consider them suitable for 20km ranges. I would expect much higher average speeds with a LIFEPO4 battery - due to the higher AH (no cut outs), higher efficiency , less weight (-4kgs) - allowing the entire trip to be power assisted. Overall the GM kit performed well (the 24km/h to 24.5km/h squeal point aside - but seems to be isolated to my particular hub) & has identified that higher performing batteries or more moderate throttle use is required to travel 30kms with assistance.
The performance on the GM bike is very strong over 20kms when compared to my 9C road bike - however...I find that it is a hare versus the tortise scenario up to the 20km mark. With the GM being the hare..after 20kms the higher speed of the GM kit is offset by the continued performance of the tortise. So I'm off to source a LIFEPO4 pack to keep the hare happy.
Hopefully this test will assist ppl who are interested in the GM kit (non regen) as a mode of commuting in real life situations.