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UK-based Estarli was founded back in 2020 and their production facility in Berkhamsted has since brought a steady stream of new iterations of e-bikes. Its two full-size models, the E28.X (rated highly in our original review and ranking among our electric bikes of the year for 2024/25) and the E28.9, are pretty hot off the production line, complementing the brand's range of folders and its Longtail e-cargo bike (which we also loved). But what are the differences between the two models and which one would be right for you?

At a cursory glance the E28.X and the E28.9 look fairly similar. They're very sleekly conceived electric hybrids with rear hub motors and removable in-frame batteries smoothly incorporated into the design. Neither immediately screams 'e-bike'. 

Despite this, our test riding showed they are quite distinct in performance terms and which one you might steer a course for will depend very much on the intended use.
 

Two-speed belt drive or 9-speed derailleur - the specs

One of the main headline differences between the two models is the transmission. The 28.X employs a carbon belt drive for ultra low maintenance and long life. 

The 28.9 goes for the more efficient chain drive. Our test bike featured Shimano Alivio gearing, but this has since been upgraded to nine-speed Cues - which has a great reputation for performance and reliability.   

The reason for the different drive trains is revealed when we take a look at motor specs. Belt drives are limited to single speeds or hub gears and the E28.X uses Bafang H700 rear hub that cleverly combines a hub motor and an automatic two speed gear system. 

Its quoted weight is 3.2kg and quoted torque is 40Nm. That's impressive given that they fit it all into a fairly conventional hub motor space.

The E28.9 uses a Mivice M080 rear hub motor with torque sensor, offering claimed torque of up to 50Nm. It's noticeably beefier than the Mivice M070 we have seen used by some other brands but it still hides discreetly behind the gear sprocket and rear disc brake. It has a reputation as a smooth, powerful and sophisticated rear hub motor. 

Elsewhere the bikes look all but identical. The single size frame comes in both crossbar and step-through options with nicely hidden internally routed cable runs, lovely smooth welds, Tektro hydraulic disc brakes and a neat handlebar mounted high definition LCD colour display. 

Both bikes feature the same 360Wh batteries that pop out of the side of the frame very easily and they are specced with Samsung cells. 

It's good to see the bikes come with a two-year guarantee that covers all components, including the battery, and it's worth stressing again this is a UK-based company with a UK dealer network.

Both bikes are available with various optional add-ons. My test bikes not only had very different hub motors and transmissions but were also equipped differently to really enhance the relative merits of each drive system.

The E28.X came with a nicely integrated rear rack and super solid alloy mudguards with lovely thick stays (none of the all too common mudguard rattle here). This is deal for its brief as a low-maintenance, high quality town runaround. 

The E28.9 came with front suspension forks and a Redshift suspension seatpost, but no mudguards or racks (I added my own clip-on clip-off rear mudguard as the test ride took in a few muddy tracks).    

Despite the extra rack and mudguards, the E28.X weighed just 19.4kg. Suspension components meant the E28.9 was a kilo heavier at 20.4kg. If you are lifting the bikes on car racks you will be pleased to learn that removing the batteries takes a further 2kg off the weight. 

If you want the lightest options possible then Estarli quotes 'naked' weights of 18.9kg and 18.6kg respectively (including around 2kg of battery which is easily removed for carrying).  

As specced, prices would be £1,940 for the E28.X and vs £2,199 for the E28.9. Yes, the suspension options add a few hundred pounds, but our test riding found them a fantastic addition as soon as the riding gets even a little bit rough. 

Without any optional extras, respective prices are £1,895 for the E28.X and £1,850 for the E28.9.
 

Two-speed belt drive or 9-speed derailleur with suspension - the test ride  

I took both test bikes out for a 20-mile spin that mixed city centre riding in Leeds with moderately testing tracks and hills out at the nearby Temple Newsam country park. 

I discovered that, as specced, the bikes present a very distinct choice in performance terms and which you might want will depend on where and how you typically ride. 

 
City centres are busy places and you need your wits about you to ride as safely as possible, even if they have excellent brand spanking new cycle lanes, like they have in Leeds centre. I found the 'just get on and ride' nature of the E28.X superb in this respect. 

There's no faffing with gear changing and as there were no hills to speak of here, the bike could just be left in the bottom power level. With both bikes, the display was bright and crisp and proved easy to keep an eye on without being overly distracting from the road ahead. 

By contrast the E28.9 needed attention to gear changing - as with any derailleur geared e-bike. There should also be a long-term pay-off if you choose the E28.X as drivetrain maintenance should be minimal. Just keep an eye on belt drive tension and alignment and give it a slosh down with water if it gets overly mucky. Otherwise it should be good for tens of thousands of miles, unlike chain driven systems which will need fairly regular oiling, cleaning and indexing.

Venturing off-road however, I found the suspension and extra motor power on the E28.9 really came into its own - as did the immediacy of derailleur shifting, allowing you to shift up and down the gears as required with sudden changes in the terrain. 

The drivetrain was both snappy and reliable on the country park trails I tried it on. Even if you opt for the E28.X with suspension seatpost and forks, it's likely it wouldn't feel as lively or as easy to handle on the trail.

I was really impressed with both suspension components. While both bikes have fast but grippy Schwalbe G-One tyres, a comfy saddle and plush Ergotech grips with a comfortable ride position, the suspension components of the E28.9 took it to the next level and made it very trail capable.

All right, you won't want to be doing massive drop-offs or ploughing through deep mud, as you might on a full-on e-MTB, but I found it great great fun on the beginner/moderate type trails typical of family friendly country parks. Nor would it be out place on the forest access roads beloved of gravel riders. 

Of course, the point of gears, as well as making for comfy pedalling at a range of speeds, is to climb hills - so I took both bikes to my regular ultra-steep hill test, a vertiginous bike path with a gradient in excess of 20% right in the middle. 

Much to my surprise, the E28.X made it to the top - albeit with a fair bit of standing hard on the pedals in the middle and in a very comparatively slow time. Still, it was way easier than on any single-speeds I've tried up here (most of which have in fact failed to get up). 

By contrast the E.28.9 made it up in relatively good time and with much less effort. I guess the real-world lesson of this would be if you are going to encounter super steep hills regularly, the E28.9 - as you would expect - would be a clear preference.

In conclusion, both the E28.X and E28.9 are a clear step-up in quality and sophistication from previous Estarli electric 'hybrid' style offerings and represent extremely solid value from money from a UK-based company with a respectably lengthy track record of e-bike production. Whilst each excels in its own environment, both also demonstrate just how far the once humble hub motor has developed in recent times.