Is racing an e-MTB easier? - Racing the Cannondale Moterra SL e-bike at Ard Rock

We teamed up with Cannondale to answer that question.

@JWDT.media

Ty Rutherford

Sep 3 2024

Racing an e-bike is easier right? E-bikes make riding and therefore racing, more accessible to a wider range of people. We got together with Cannondale and Ard Rock to find out what e-bike racing is like aboard the recently released Moterra SL to explore the nuances of racing an e-bike at one of the UK’s largest events.

The race: Ard Rock

Now in its 11^th year, Ard Rock is a staple of the UK mountain biking calendar. Although racing is very much at the heart of the event, it could be likened more to a mountain biking festival aimed at the whole family. With over 150 brands in attendance, the trade village has plenty of sights to see with the latest and greatest tech on show. Food and drink are aplenty in the street food area where you can grab anything ranging from a wood-fired pizza to a Greek salad and some top-notch coffee. Even if you’re not racing there is plenty of entertainment on tap throughout the three days for the whole family including live music, a pump track, a jump area with airbag landings, kids skills coaching, and many opportunities to win prizes. Demo bikes are on offer which can be tested on a dedicated loop with two practice stages.

The racing is split into the full-length enduro and shorter sprint on Saturday along with the fun sport and intro race on Sunday. E-bikes are reserved for the Sunday race too on the full-length enduro loop and that was the race for me.

The main loop racks up 45km and 1,500m of climbing over seven stages. If you don’t fancy the full loop, Saturday also hosts the shorter Sprint Enduro which races three stages still clocking 30km and 1,000m of climbing.

The trails are a mixture of open moorland featuring rock, dirt, ruts, and grass sections with some rooty wooded sections for good measure. Nothing overly steep but plenty of gradients to keep things fun – Ard Rock's organisers call these alpine-style trails.

For the event, we partnered with Cannondale to race the Sunday e-bike enduro race aboard the recently released Moterra SL.

The bike – Cannondale Moterra SL

E-bikes usually fall into two distinct categories, lightweight and full-fat. The full-fat standard offerings provide 85-90Nm with a battery of around 750Wh, the price you pay is that the bikes usually weigh around 55lbs (25kg) or more. Hence the need for a lightweight option which could be as light as 40lbs (18kg). However, to shave all this weight the motors are smaller and less powerful (35-50Nm) and the batteries are around 350Wh.

Cannondale released the Moterra SL back in February to offer the power of a full-fat e-bike but in a lightweight package. Headline numbers for the Moterra SL show the new Shimano EP801 motor with 85Nm of torque, a custom 601Wh battery and a claimed weight hovering around the 44lbs (20kg) mark.

The Moterra SL rolls on a mixed wheel mullet set-up with 150mm rear travel paired with a 160mm fork. However, the suspension layout looks like a typical Horst link design at first glance the lack of bearings in the chain stay is a departure from the normal, instead relying on the carbon to flex. Flex stays are nothing new and present a couple of advantages allowing engineers to tune some compliance into the rear end and save a little weight through the omission of bearings and associated hardware.

Flip chips in the top of the seatstay allow the conversion to a 29-inch rear wheel but all models come from Cannondale in the 27.5-inch set-up. Adjustability is also available in the headset cup which can be rotated 180 degrees to affect the angle by 1.2 degrees.

Headset cable routing is an option however it is not enforced on the Moterra SL – my bike had the brake hose, dropper cable, and gear cable entering the frame through the head but did have the motor control wires through the headset.

The new Shimano EP801 motor is the lightest full-power e-bike motor on the current market offering 85Nm of torque. Cannondale has specified four custom modes to manage the assistance ranging from eco, trail, trail two, and boost. Cannondale also has a custom 601Wh battery which is claimed to weigh 6.8lbs (3.1kg) – this is one of the lightest watts per kilo batteries on the market. A point to note is the lack of a range extender so the 601Wh is your lot and with the frame design, swapping out batteries isn’t an option either.

Claimed weights, depending on the spec, range from 19.5 – 20.6kg (43 – 45.4lbs).

The experience of racing an e-bike

Racing is fatiguing – obviously – but it’s not just the race that depletes performance. You’ve had a tough working week, physically and/or mentally tough, which takes its toll by the time you hit the weekend. You’ve then got to travel to the race, perhaps late one evening after work, which, at least for me, was a six-hour ordeal, followed by some very questionable sleep in a tent or van.

So before you even swing a leg over the bike you’re not running at 100% - peak performance is nowhere to be seen. In this situation, particularly on the 250m elevation climb up to stage one, I was thankful to have some electrical assistance.

Any e-biker will know battery anxiety is a real thing, no one wants to be left out on a course with a dead battery and a heavy bike to pedal. After boosting my way up the first climb and feeling quite smug until I noticed I’d already dropped a bar of battery – that’s 20% gone!

Some quick mental maths knowing the loop has 1,500m of climbing means I’m going to run out long before the finish – the battery anxiety started 15 minutes into the race and suddenly I realised this wasn’t going to be quite the jolly I had initially thought it would be. My new strategy involved conserving power with eco on the transitions and little tasters of the trail setting for short nasty sections only. During the race runs I had it set in trail for assistance but not too much shove.

Speaking of race runs and descending brings me neatly to my next realisation. The motor cut-out at 15.5mph (25 km/h) happens sooner than expected in a race run. Off the start line the boost up to speed is welcomed but once you hit that speed limit the bike becomes a heavier than normal heft to pedal and, depending on the motor, there is also some extra resistance in the pedalling as well.

The stages at Ard Rock require a lot of out-of-the-saddle sprinting to make good time and by the bottom of the stages, I was nearly hyperventilating trying to catch my breath back. Now this isn’t to say I wouldn’t be breathing just as hard on the analogue bike but although there's some assistance, riding an e-mountain bike still requires a lot of physical exertion, to my surprise.

That said, where the e-bike's assistance really came in handy is the janky awkward flat sections that are slow and technical, the extra boost from the motor here really helps pick up speed across these sections. So an e-mountain bike can be a little more forgiving, especially after a mistake.

Of course, the e-bike does allow for a more leisurely transition to the stages where, even in eco, there is plenty of assistance to get me up the hills. This was a massive help for me to feel a little fresher at the top of the stage and feel like I didn’t need to preserve my own energy to get around the rest of the loop. Knowing I had the electrical assistance to get around the course meant I could push harder during the stages. The assistance also got me around the course quicker and without having to push the bike up hills.

As an example, my moving time for the race was three hours whereas friends of similar fitness on analogue bikes took four and a half hours to complete the same loop.

Depending on the event you may have the chance to practice the stages on the day before the race. A sighting lap to suss out the course is super handy and helps figure out how best to use the battery. However, you’re going to need to make sure you start the race day with a fully charged battery. Options are to bring a second battery if you’re lucky enough to have one and have a bike that can easily swap out batteries – not all of them can.

You could bring some kind of power station or generator to charge the bike in the evening but again there’s an investment cost to doing this. Some events, such as Ard Rock, offer battery charging, perhaps for a small charge but they’ll usually want you to leave the battery with them (again, an issue if your bike doesn’t feature an easily removable battery). This strategy also has your race day very much relying on someone else to ensure you’re battery is fully charged and that feels risky to me.

Racing e-bikes certainly comes with its own set of challenges. You gain the assistance to complete the course without it being so draining, keeping you fresh for the race runs but also have the added consideration of battery management throughout the race.

Although the Moterra SL is one of the lightest e-MTBs around, the extra weight of the e-bike carries speed well on course and tracks the ground better but over 15.5mph you’re pedalling a heavy bike with no assistance. The charging of the bike needs thinking about if you plan to use it for more than one day over the race weekend however having that electrical assistance is welcomed when you’re tired from a busy working week and travelling to the race. No doubt there are pros and cons to this kind of racing but, for me personally, I enjoy all types of racing. The e-bike is a tool to get it done and making allowances to get the best out of the bike is part of the skill and experience of racing them.