Tern GSD S00
- Fantastically versatile
- Huge range from the twin batteries
- High quality build
- Enviolo’s CVT hub not for everyone
Tern’s GSD has already featured on ebiketips, and so far is the only bike to have picked up a five-star rating. This is the more expensive GSD S00 build with a more powerful motor, uprated stand and Enviolo continuously variable hub.
Buy the Tern GSD S00 here
All that adds a thousand pounds to the price, and our bike also came with extras: a second battery (£699), two rear seat pads (£50 each) and Sidekick lower deck (£50) bringing the total to £5,849... a lot of money then! But if you’re looking for a bike that’ll work, and last, with plenty of power for the biggest loads and the steepest hills, then you can’t go far wrong here.
If you’ve not seen the GSD before then it’s a long-tail, small wheeled cargo bike with a lot of neat features. The 20” wheels and the compact riding position combine to mean that you get masses of load space in a package that isn’t any longer than a standard city bike. The long tail features two giant panniers, that have enough capacity for some serious loads; you can also sit up to two passengers on the back bench using the optional padded cushions and foot runners, that our bike came supplied with. Two Yepp child seats will fit on the rack too. The panniers are supplied as standard on this more expensive build. Other upgrades are the motor – a 75Nm Bosch Performance Line CX unit, instead of the standard 63Nm Performance Line – and an Abus wheel lock that’s key-matched to the batteries, so you just need the one key for all the locks on the bike.
The transmission is probably the most expensive upgrade over the standard spec. The GSD00 gets Enviolo’s cargo-spec CVT hub. It has a range of 380%, and no discrete gears: you just twist it one way to make it easier, and the other to go faster. The cargo-spec unit is beefed up internally to cope with bigger loads and a long service life. It uses a Boost thru-axle for better stiffness at the back.
Other aspects of the GSD remain the same here. It’s cleverly designed such that it won’t take up any more space than a standard bike in your shed, even with its extensive carrying capacity. If you don’t have even that much space then you can also fold the handlebars down and drop the seat, and the rear rack has four feet on the back so you can stand the bike on its end if you’re really tight on storage. The seatpost and handlebars are easily adjustable via quick release clamps; the GSD will fit a huge range of riders with just a few tweaks.
We’ve given the GSD S00 to three riders over the last month or so, to see how it copes with being used for a variety of different tasks. And here are our findings...
Elies Dekoninck says: This is the first time that I have tested a more purpose-built cargo bike. I have tested various other heavy-duty city and hybrid bikes, always loading them up with panniers at the rear and sometimes even front panniers to add carrying capacity. One of the great joys of having an e-bike in a steep hilly and traffic-congested city like ours is being able to run a lot of errands for the family quickly and efficiently. The Tern GSD steps this whole capability up to another level. In addition to grocery shops, the Tern has enabled us to use the bike as a lift-sharing taxi. This has cut out a massive number of short car journeys for us. For example, I’ve been able to take my 12-year-old son to music lessons with his bass guitar and cricket matches with his entire cricket kit. My husband and I have even been out to the cinema on it together.
The rigidity of the frame together with the powerful motor, make this possible is. The weight of the bike with such loads must be using a lot of battery, but as a user you do not really notice this too much; it seems to have similar recharge requirements due to the doubling up of the batteries. The weight, centre of gravity and sturdiness of the frame make the bike very rideable with these extremely heavy loads on the back. The seat cushions and the optional metal runners for the passengers’ feet make this a real ‘hop on - hop off’ experience.
Important features that make this an exceptionally useful bike for errands are: the bags, the stand, the spring which lines up the front wheel and the ‘quick lock’. The bags have an extremely large carrying capacity. I was using them with two bag-for-life carrier bags in each pannier; this is enough for our main weekly shop. When the bags are loaded, the pannier has two additional straps on the inside to stabilise the bag and pull the shopping towards the frame. The pannier ‘lids’ then simply hook over the top to close the bag off. The simple closures - which use hooks and loops - look like they will last for a very long time. When you are not using the panniers, they fold up neatly to reveal the metal runners for your passengers; you don’t have to remove them.
The stand and the spring which line up the front wheel, enables you to load and unload the bike with no awkward or unstable moments. This is really different from more conventional e-bikes which I have attempted to load with a similar amount of weight. The two stand legs seem to operate semi-independently which takes into account any unevenness of the surface that you are parking on. They definitely work very well. One thing I struggled with was getting the bike off the stand. Once it’s heavily loaded it requires quite a big pull force to bring it forward off its stand.
This version of the turn GSD has a continuously variable transmission gear system. This means you do not have a distinctive set of gears but rather a gear range which you operate using a twist grip. I really like the principle of this. I definitely have a comfortable cadence, which I was able to tune the twist grip to, no matter what my road condition, steepness and power assist level were. After a few days, I was used to the approximate wrist twist that I would need to accommodate the gear shift prior to hill starts, traffic lights or traffic jams. On hills, this continuously variable system allows you to very finely tune to the optimum gear - and therefore cadence - of a particular climb. At the higher end of the gear system, the twist grip mechanism itself was a bit ‘sticky’ and required a little bit more push, so the twist action wasn’t completely smooth through the full range. Altogether, I much preferred this system to the auto-shifting system, which I have experienced on a different E bike.
This an extremely shareable bike within a family. The handlebar clamps are quick release and allow you to position the handlebars exactly where you want them within seconds. The markers included on the seat post were also used in our family to quickly change riders, even in the middle of a ride. Our family already ride bikes in all seasons and all weathers and the Tern was also tested in wet and windy days. The mudguards and pedals worked well.
Overall, I’d say that we have all enjoyed riding the Tern a lot during this test and it reduced the number of car journeys in our family significantly. We’ve even started conversations about replacing the car with a bike like this.
Jez Ash says: I think maybe the best thing about the GSD is the care and thought that's gone into how it all operates and how the accessories fit together. The quick pull-tab release of the seat pads is a good example: simple, well-engineered and really satisfying. The adjustable stem is a simple and really effective thing too - how many other e-bikes could so easily adapt for me and my (much shorter) mother in law to use comfortably?
It's definitely best suited for urban use - the small wheels, lack of suspension, stoutly-built frame and upright position mean that longer out-of-town rides are a little less comfortable. I’d probably swap the saddle out for one that I got on better with if I was regularly using it for longer rides. It’s incredibly versatile as a city bike: I’ve ridden with my daughter in a child seat, with the dog in one of the panniers, I’ve made my wife give me a lift up the hill and my mother-in-law has used it to join us on family rides. There’s not many bikes that would be capable of such a wide range of use.
I don't like the Enviolo gears. I just don't buy the argument that having 11 discrete ratios is a problem needing a solution on a bike, and if they were a zero cost option I'd still opt for a derailleur, so for me it’s not extra money worth spending. Turning the twist grip to a higher gear is quite stiff, and after 2 rides it was making my hand sore; if the shifter was better, I might not dislike the gears so much. When you realise you need to change gear, rather than a click and a defined change in ratios, you need to think about "how much gear do I want to change" and then convert that into hand motion.
In this build the Tern feels sluggish on the hills, more than any other CX-engined e-bike I've ridden (including box bikes). It's heavy, sure, but not the heaviest e-bike I've tested. The Enviolo hub gear uses a tilting ball drive, and these generally have an efficiency of 70-90% Assuming the Enviolo is in the middle of that range it’s significantly less efficient than a derailleur setup, which is generally over 90% efficient, which to some extent cancels out the extra power of the motor. It never feels like you can't get up the hill, but you do find yourself going really pretty slowly; I did wonder whether this is to some extent a subjective consequence of the speedo being in miles per hour though!
Dave Atkinson says: The original GSD – that build is now called the GSD S10 – remains my favourite e-bike ever. It’s such a well-designed and versatile machine that it’s hard not to fall in love with it. You can get all kinds of things done, and when you’re finished you can sling it in the shed like a normal bike. It’s great.
The GSD S00 is great too. It adds some things the S10 misses as standard; you’re definitely going to need the excellent pannier bags, for a start, and it certainly makes sense to have a wheel lock so you can nip into shops while the bike is outside: you’d have to be a pretty committed thief to carry it very far. Passenger options are still extra on top; not everyone thinks they’ll need the option to cart people about on the back. In reality that’s one of the joys of the GSD, just being able to give people a lift without a thought: living with the GSD is so easy. Our review bike had the twin battery which extends the range considerably, but even without it the S00 would have plenty of capacity in a 500Wh single battery to easily cope with most people’s daily use. The bike is heavy and the hub gear isn’t as efficient as a derailleur, so it doesn’t have the biggest range for the capacity, but it’s still more than enough unless you’re using the bike all day as a company vehicle, or attempting a long-distance ride with a big load.
The panniers are brilliantly designed: you can fold them away entirely, and when you open them up they’ll swallow enormous loads easily. The stabilising straps hold things in place and mean that the mouths of the bags don’t gape; the simple fixings make them easy to close. If you have even bigger loads to carry then a big flatbed tray can replace the seats on the rear, and you can add a porteur rack at the front as well, both of which will hold a plastic crate. Or of course you can click two child seats on the back, or use the Clubhouse rack that fits two older kids. Pretty much anything is possible, and that’s the big draw. It’s a bike that can adapt and grow with your needs. It’s brilliantly thought out.
The frame is massively overbuilt in order to cope with the loads it’s designed to carry, so you need the big air chambers of the Schwalbe tyres to smooth out some of the bumps along the way. I didn’t find the GSD an uncomfortable bike to ride, although I mostly confined my riding to urban duties and it’s a reasonably firm ride. One of the best things about this bike is the fact that it’s just so easy to ride. There’s really no learning curve like there is with a box bike: it just feels entirely normal, and the reasonably low stepover means it’s simple to get on and off.
Is the S00 build worth the extra £1,000 over the S10? My ideal build of the bike is, I think, not either of the ones that Tern currently offer. I’d happily pay extra for the more powerful motor and the wheel lock, but if it was my money I wouldn’t go for the Enviolo cargo hub. I’ve used the Enviolo city hub on a number of bikes and I’ve really liked it, but the cargo hub just feels a bit agricultural to me. The shifter is stiff, and you need to back off the power when you’re going uphill to shift to an easier ratio. Personally I’d stick with the derailleur gears if it was my money. If you’re doing serious miles then the enclosed, cargo-grade internals may well appeal.
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Actually check out the tern website. They have plenty of 'sidekick' accessories that will do the job. The "clubhouse" looks great for older kids.
There are some neat folding pegs (near the drive chain) for use by passengers feet and Google "Tern GSD Sidekick Handlebar". This would seem to be an accessory you can buy for a passenger to hold onto. They are fixed handlebars that clamp to the seat post.
Thank you for the review. Where does an older child (age 5+) put their feet when siting behind the front rider, plus, there appears to be nowhere for them to hold onto with their hands. I am thinking tandem style.