Test Koga Colmaro Extreme: The travel gravel bike in the classic look of the Dutch manufacturer impresses with invisible tube transitions and surprises with a 650B wheelset. The equipment and driving characteristics are great, as is the price - and the bike can also be moved in a sporty manner.
At Koga, the traditional supplier of touring bikes and racing machines, the focus has recently been increasingly on gravel. It started with the beautiful aluminum bike Colmaro Allroad with racing bike geometry and space for 35 mm wide tires, which of course has its limits in the terrain. The Roqa announced for next year will be just as sporty, but more suitable for off-road use - a gravel racer made of carbon with 45 mm tire clearance. The Koga Colmaro Extreme, on the other hand, relates more to the company's touring bike DNA.
Koga Colmaro Extreme: elegant look typical of the brand
Of course, “extreme” is relative. First of all, the gravel bike looks rather harmonious in the typical Koga look: Dark blue metallic paint with copper decor, which goes perfectly with the Tanwall tires, covers a frame that shines in the upper area with practically invisible tube transitions. If you think the Colmaro is a carbon bike at first glance, we apologize!
The geometry isn't really extreme either. Koga offers four frame heights in which the head tube grows by 30 mm each - from 120 to 210 mm. When it comes to seat length, the smallest and largest frames are separated by just 13 mm. However, the Colmaro Extreme isn't exactly short; The sitting position is sportier than you would expect from a touring bike. So you have to be careful when choosing the size.
However, the price is extreme, namely extremely cheap. For 2.499 euros, the Dutch not only deliver the beautiful frame, but also a Shimano GRX 600/800 with 2×11 gears, as well as a high-quality DT Swiss G1800 Spline wheelset. So the overall package is right - but what does the Koga Colmaro Extreme look like in detail?
Travel gravel bike with many attachment options
In keeping with its intended purpose, the bike is equipped with all sorts of threaded holes - mudguards and carriers can be attached, as well as three bottle holders and a small top tube bag. What is striking is that at Koga, every screw is equipped with a plastic washer - a sign of the great quality awareness of the in-house assembly. Shift cables and brake lines are routed to the bottom bracket in the down tube, and the front brake line runs through the fork. The screwed BSA bottom bracket is always good when it comes to assembly, maintenance and spare parts supply.
Shimano group with top function
There are no discussions about the components: The GRX 600 is functionally equivalent to the more expensive version; Only in a direct comparison do you feel that the 800 STIs shift slightly more crisply. And the crank installed on the Koga may be a little heavier than the hollow-forged GRX FC-RX810, but it may have a more suitable gradation. At 46/30 instead of 48/31 it has a slightly shorter gear ratio, which is a good thing, especially for gravel. Together with the 11-34 crown there is a very large translation range - and then there is the matter of the development...
Koga Colmaro Extreme – Handy thanks to the 650B wheelset
A special feature of the Koga is the 650B wheelset. On the one hand, the smaller diameter of the rims ensures that the wheel feels quite manageable despite the large tire volume, but on the other hand, it reduces the rolling circumference and thus the unfolding - i.e. the distance covered per crank revolution. With the Koga, the plan works, because the aluminum Geravel bike can be steered with ease and, despite its not exactly light weight, appears extremely lively. With smaller frames, the 650B wheels also create a harmonious look.
On the other hand, due to the smaller radius, the bottom bracket is closer to the ground - compared to a 622-40 tire, around 10 mm, and with the 622-45 even 16 mm. This is something to keep in mind when riding the Koga on trails. Of course you can also ride the bike with 28-inch wheels; Then there is enough space for 45 mm wide tires, maybe even more.
Koga mounts WTB Byways in a width of 47 mm, which roll easily and smoothly with a slick tread, but do not have a very strong profile on the sides. Wet, muddy surfaces are not necessarily this tire's forte.
Unusual handlebar shape
There are smaller surprises with the add-on parts. The quick release on the seat clamp is only on the test bike, but the unusually shaped handlebars are standard: the top link is oriented slightly towards the rider and slopes towards the outside and then rises again in the upper curve. Depending on the grip position, this leads to subtle, quite pleasant changes in the position of the hands and arms. The aluminum seat post is not D-shaped like the Colmaro Allround, but round with a standard diameter of 27,2 mm. Although the bike is by no means hard, you have the option of retrofitting a comfortable carbon support.
The Koga only leaves something to be desired when it comes to weight. Including pedals, it weighs just over eleven kilos - almost one and a half kilos more than the Colmaro Allroad with SRAM Rival 1×11 and identical 28-inch wheelset. Luckily, weight isn't that important when cycling with luggage, and the bike doesn't seem a bit sluggish even when used for sport. If you look at how many gravel bikes you can get from Koga at a manageable price, it won't be difficult to decide on this bike.
