What Effect Does Total System Weight Have on eBike Range?

Pete headed into the Highlands for an explore of the Cairngorm’s finest to see what effect total system weight has on battery range.

With the assistance of H+I Adventures’ head guide, Mr Chris Gibbs and their trusty Yeti 160e T1 ebikes (review to come), Pete headed into the mountains proper to see how total system weight affects how far you can go on an ebike.

Photos by Pete Scullion.

The concept behind this ride was pretty simple. Take two people who are very much not alike in build, give them the same bikes, give them the same route and see who’s got the most battery left at the end of the day.

I’ll start by saying this was not a controlled experiment and isn’t the be all end all of range experiments for ebike batteries. The idea was to go and try to rinse the tank to see just how much total system weight affects range.

With that in mind, you have Chris ‘The Bear’ Gibbs. You don’t get a nickname like that by being troubled by stiff breezes. Chris guides H+I’s Coast to Coast pretty much weekly in British Summer Time, and has acquired a considerable diesel engine as a result. Think locomotive diesel to my 1.3 TDI.

It’s no exaggeration to say that Chris is the same weight as myself plus a 48.5lb (22kg) ebike. I am 9 stone (58kg), so 12.5 stone total with the Yeti ebike. Chris tips the scales 12.5 stone (80kg), so pushes the overall weight just over 15 stone 10 (100kg) with the ebike. Both of us have hefty bags too, Chris with his guiding pack and me with my full camera setup.

So… The ride. We’d start at the Hayfields car park in Glenmore, summit Ben Macdui then make our way back to Glenmore via an… interesting route that might not actually work unless you get the magical mixture of ebike power and ground that has been dry for some time. I’d suspect this would be what some people call ‘Type 2 fun’ otherwise. Namely, not fun in the slightest for anyone who actually enjoys the riding of bicycles.

Without actually discussing it prior, we both decided that the Shimano EP8’s Trail mode was the best option for anything vaguely technical thanks to getting the full power of the motor with a slightly less over enthusiastic delivery that Boost offers.

Chris was down one bar of battery some 3.7 miles in. Doesn’t sound like much, but that opening stint saw us climb 1400ft from our start elevation of 1000. Plenty of power moves to keep the bike moving over the rocks that litter the hill.

It wouldn’t be another two miles and an extra 1300ft of climbing before I’d drop my first blip of battery atop the Cairngorm plateau proper, mountains now stretching out in all directions as far as the eye could see.

It wouldn’t be long before that where Chris would see his second bar of battery go some 6.3 miles into the day with an extra 150ft elevation on the clock, to just before we made the punchy climb to the summit of the UK’s second highest peak.

Believe it or not, we’d enjoy a considerable quantity of descent from this point, from the sublime to the ridiculous, both good and bad. The sun was very much starting to make itself felt and we were both glad of the generous helping of sun cream we’d set out with.

It wouldn’t be until the 13 mile mark before either of us would lose another bar, and not unsurprisingly, it wasn’t me this time. With 3500ft of up and 2250ft descent at that point, it wasn’t a ride for the faint-hearted either. Down three with my fourth bar holding on strong.

So I thought, anyway. An extra mile and 100ft of climbing later, and I’d have lost my second bar. The last big climb of the day remained and then we’d be on the home stretch. As the final kick approached, there was no chance I was leaving the mode selector alone, and I opted to use Boost to get me over the crest of the last climb. I didn’t fancy pushing a 22kg bike at this stage in the proceedings. The clock had just run past 4.30pm and we’d been out since 9.30am.

Total ride distance was a smidge over 21 miles, with 4000ft of up and down. The bikes hadn’t skipped a beat al… Oh, yeah, my mech almost ripped itself off at the furthest point out after taking a ding from a rock somewhere higher on the mountain. Chris showed his skills and had it swapped out in minutes. No bother.

It seems pretty obvious that increased weight, some 25% higher, will lead to a drastic reduction in range on comparable ebikes. Chris had lost two bars almost at the same distance I had lost my first. From thereon in, there was a sizeable descent and you’d likely need Alpine-sized climbs or a much earlier start than we had available to really test the true range of these batteries. Or you could just jam it in Boost the whole way and see what happens. That doesn’t seem like the best option to me.

There’s certainly plenty of ways you could eek out more from the battery too. We stuck with the stock modes and made no use of the E-Tube app that allows you to customise the outputs of the modes. Also, it seems very apparent that to get the best from the EP8 motor, cadence is everything. Churning hard gears tends to give you very little back by way of assistance, what effect that has on range, I’m not entirely sure.

Keep your eyes peeled for a full review of the Yeti 160e T1 on our Bike Reviews page real soon.

Check out what adventures H+I can take you on over on their website here.

You can read Pete’s review of the Shimano EP8 motor from the official launch here.