What makes the Eker Grus special can be seen immediately: The frame is made of bamboo.
In addition to the large number of bicycle frames made of aluminium, carbon, steel or even titanium, a bike made of bamboo is likely to be a unique selling point on group rides. And often approached by interested people at traffic lights, as we experienced on our test rides. We travelled with the Eker Grus for several weeks. In the article you can read how the gravel bike performs on the different conditions of the gravel spectrum in addition to its visual uniqueness.
At first glance
Those of you who know Swedish will be in the know, but for everyone else, let’s check the yellow dictionary with the capital ‘L’: ‘Grus’ means gravel. So we’ve already clarified the bike’s intended use. And the Eker Grus also looks like a normal gravel bike – except that the frame is made of bamboo. The top tube, down tube and seat tube are made from whole bamboo tubes. This makes the frame triangle look as solid as a modern carbon frame. The bamboo tubes are hollow on the inside. Due to the naturally grown shape, each frame has its own individual look and is not as flat and smooth as other materials. Other off-the-peg bikes rarely have this uniqueness.
The seat stays and chain stays are made from split bamboo stems. This makes them narrower, lighter and particularly torsion-resistant. At the rear wheel mount, the bamboo stays merge into an aluminium triangle. The rear derailleur is also attached to this. All other joints of the individual tubes are connected with the bark fibre of the mutuba tree and a special resin. This mixture gives the frame its brown colour, which goes well with the lighter look of the bamboo. The natural pattern looks particularly interesting in sunlight.
Bamboo as a frame material
The material for the bicycle frames, the wood of the bamboo grass, grows in Uganda and is also processed into bicycle frames there. Bamboo grows particularly quickly and is cultivated sustainably. The trunks used are carefully selected and are not only light but also robust. The chain stays made of split, thin bamboo stems are connected with aluminium fittings and thus ensure particular torsional rigidity. Bamboo as a frame material not only weighs just as little as aluminium, but also has a higher tensile strength than steel and dampens vibrations when riding.
The individual bamboo tubes are connected with the bark fibre of the Mutuba tree. This can be harvested by hand without harming the tree. Bark can be harvested from each tree once a year for up to 40 years. A very robust connection is created at the joining points of the bamboo canes using a special wrapping technique of the strips of bark cloth and epoxy resin. The entire bamboo surface is coated with a durable varnish. This protects the frame from moisture and allows it to be cleaned normally with water.
The final assembly of the bikes takes place in Sweden. The aluminium parts used on Eker bicycles are also manufactured in Sweden. Eker offers a five-year guarantee on every frame sold. All bicycles are subjected to ISO 4210 strength tests.
The most sustainable frame material?
Bamboo not only binds carbon dioxide, but can also be grown and harvested in an environmentally friendly way. The mining of ores and the energy-intensive production of aluminium are therefore eliminated, resulting in a 93 percent reduction in net greenhouse gas emissions compared to an aluminium bicycle frame. Eker puts the net emissions of a bamboo frame at 1.9 kilograms of CO2, while an average aluminium frame releases 28.6 kilograms of carbon dioxide.
The complete life cycle analysis of an Eker bicycle can be viewed here.
Frame construction in Uganda
The raw material for the bicycle frames is sustainably cultivated in the highlands of Uganda. After the bamboo harvest, the bicycle frames are handcrafted in the capital of Uganda, Kampala. Master frame builder Bruce Ahimbisibwe is himself a passionate cyclist and ensures on site that all frames are manufactured in accordance with quality standards.
In addition to the ecological aspect, a bicycle made of bamboo also ensures social sustainability. Jobs have been created locally that provide employees with additional health insurance, a pension and school fees for themselves and their families. Five people currently work for Eker in Uganda, who are also actively involved in the products and their development.
The setup
The complete build of the Eker Grus at a glance
| Frame | Eker Grus 01 bamboo frame, BB86, 12×142 mm |
| Fork | Moquai Gravel Carbon-fork, 1 1/8″-1 1/5″, 12×100 axle, Flat Mount, internal routing |
| Drivetrain | SRAM Rival 1×11 |
| Brakes | SRAM Rival, hydraulic, 160 mm |
| Cassette | 40×11-42 |
| Wheels | DT SWISS GR 1600 Spline DB 25, 700c |
| Tyres | SCHWALBE G-One Bite, 700 x 38c |
| Stem | ZIPP Service Course 70 mm +-6° |
|
Handlebar |
ZIPP Service Course 70 XPLR 420 mm |
| Seatpost | ZIPP Service Course, 350 mm, Ø 27,2 mm, Offset 20 mm |
| Saddle | FIZIK Vento Argo R5 140 |
ON THE GRAVEL
The practical test
The first few minutes of riding show just how comfortable the Grus is. Whether on bumpy roads or cobblestones, the frame absorbs bumps very well. And shocks are also absorbed very well off the beaten track. The carbon fork and the comfortable Vento Argo saddle from Fizik also contribute to riding comfort. We tested the Grus in winter and spring 2024 in the Berlin area. The gearing, consisting of a chainring with 40 teeth at the front and a cassette with a gradation of 11 to 42 teeth, was a good fit in the rather flat region and offers a good all-round range in the gravel spectrum. If you are planning tours with heavy luggage or ride a lot of climbs, you could use a smaller chainring.
Riding position
Our tester Robert is 180 centimetres tall and rides the Eker Grus in frame size M. He often has to choose between frame sizes M or L, but the smaller version fits very well here. Thanks to the sporty riding position, Robert can comfortably grip all areas of the handlebars, bend his elbows and put plenty of power into the drivetrain. The frame is stiff and hardly twists even when pedalling out of the saddle, meaning that the bike can easily reach fast speeds.
Riding impression on different surfaces
The Eker Grus is heavier than a carbon bike, but is still very agile and stiff when pedalling. The frame absorbs a lot of shocks on uneven surfaces. The ride is extremely cushioned and comfortable. The Schwalbe G-One Bite tyres in a width of 40 millimetres are suitable for all-round use and are reliable on forest highways and, up to a certain limit, also in mud. Technical sections are also easy to master thanks to the dynamic riding position. The frame allows a maximum of 42 millimetres of tyre clearance.
Tubeless included
A big plus point: the Grus can be supplied tubeless on request. This saves non-professionals the potentially difficult task of setting up tubeless tyres and allows them to get started straight away with full riding comfort and puncture protection. Ideally, tubeless tyres not only ensure that holes in the tyre seal themselves, but also allow lower air pressures when riding. This significantly increases comfort when riding, especially off-road. In addition, the lack of friction between the inner tube and tyre ensures lower rolling resistance – so a few watts are also saved. There is audible milk in the tyre. What’s more, the tubeless system worked perfectly and hardly lost any air during the test period. And if you prefer to ride with a tube, you can mention this in the ordering process and your bike will be delivered as requested.
The Grus accelerates well on tarmac. It can even reach 40 kilometres per hour on a town sign sprint. With tyres with a lower profile, the gravel bike will also cut a fine figure on tours with a large proportion of asphalt. The acid test during the test period was a 170 kilometre tour around Berlin in winter. The riding comfort of the Grus Robert was completely convincing here.
Equipment
The SRAM Rival does a solid job and shifts reliably even on bumpy sections, but is not always very quiet. At 420 millimetres, the Zipp Service Course handlebar is of average width and rather compact with a 70 millimetre reach. A 70 millimetre stem focuses more on direct steering behaviour off the road. The handlebar tape from SRAM is positively inconspicuous, it is simply soft and yet grippy.
It is noticeable that the add-on parts are mounted on the bike with different bolt variants. This means that different Torx and hexagon socket bits are required. This is not a bad thing, but you should check whether all the variants are available on your own multitool or in your home workshop before setting off.
The Eker Grus weighs 9.8 kilograms in the tested configuration. This puts it in the same weight class as comparable gravel bikes with aluminium frames. It is unusual that a water bottle cage can only be mounted on the down tube. There are no mounting points on the seat tube. However, according to Eker, a frame model with two mounting points will soon be available. There are no mounting points on the top tube. A bikepacking fork with three mounting points is also available on request during the ordering process.
The Gravelvent calendar 2023 winning bike
During the 2023 Advent season, there were once again some great gravel bike-related items to be won in the Gravel Club Advent calendar. The big highlight was the Eker Grus, which provided the big prize on 24 December. It was won by Holger from Bavaria. He has been travelling with his Eker Grus in the foothills of the Alps, Upper Bavaria and the Allgäu region since February. He has ridden everything from wide and narrow forest roads, dirt tracks, fine cycle path gravel, coarse and fine gravel and single trails.
Here he talks about his impressions:
“The look of the Grus was something completely new to me at the beginning. I’d never seen a frame before that wasn’t made of aluminium, carbon or steel. Compared to such a slick design, the corners and edges of the bamboo frame make the whole thing visually very exciting. The grain of the bamboo in particular has something special. It’s a bit like an old sailing boat, depending on the incidence of light it is lighter or darker. This vintage look is definitely an eye-catcher on the gravel paths.
The handling is great. It feels better on gravel than the aluminium gravel bike I used to ride. The geometry is comfortable, but for me it’s more of a race bike.
The overall package just fits, the advice from Eker in advance was great and I’m really having a lot of fun with the bike! Thank you very much!”
“It’s a bit like an old sailing boat, depending on the light, it’s lighter or darker. This vintage look is definitely an eye-catcher on the gravel paths.”
HOLGER
WINNER OF THE EKER GRUS AT THE GRAVELVENT CALENDAR 2023
About Eker
Eker is a bicycle brand from Sweden that specialises in the manufacture of bicycles with bamboo frames. The founders of Eker, Stefan Krisch and Johan Mast, spent several years living and working in Uganda, where they came up with the idea of making bicycles from bamboo. This not only creates far more ecologically sustainable bicycle frames, but also socially sustainable jobs in Uganda. The portfolio includes the tested gravel bike ‘Grus’, the hardtail mountain bike ‘Stark’ and the urban bike ‘Varv’. The frames are manufactured in the company’s own factory in Uganda and finally assembled in Härnösand in Sweden.
THE RESULT
+ What we liked …
+ The thick, clear lacquer on the wood looks good and appears robust. It doesn’t seem to be very susceptible to scratches.
+ Comfortable ride.
+ Balanced geometry.
+ Agile and manoeuvrable handling.
+ High-quality add-on parts.
+ Ecologically and socially sustainable production.
+ Unique look.
+ Five-year warranty on the frame.
… And not so much:
– Only one mount for water bottle holders on the frame can be too little in summer (soon a version with two mounting points on the frame will also be available).
– Limited size range for small people.
Conclusion
The Eker Grus is a balanced all-round gravel bike that is fun on trails with its agile handling, but still comfortable on long rides. The frame dampens vibrations and is still stiff thanks to the material and the special processing of the split bamboo struts.
If you are looking for an explicitly lightweight race bike, this is probably not the bike for you. In reality, the weight has not proved to be an obstacle in sprints and on small climbs in the Berlin mountains.
This makes the Grus a good choice for anyone who values sustainability and is also looking for a customised bike, as every frame naturally looks a little different.
