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Gravel BikesTests

Wide tire gravel bike for racing cyclists: Rondo Ratt – testing a brand new gravel bike

25 May 2022 by Caspar Gebel

Test Rondo Ratt: The Gdansk's new gravel bike combines a typical racing bike geometry with extra-wide 27,5-inch tires, which should bring sporty riding characteristics on any surface and surface. Does the bill add up? First rides are promising, and large wheels can also be mounted.

Tired of asphalt? At Rondo in Gdansk, everyone understands that. The company specializes entirely in gravel bikes, ranging from cyclocross-style Ruut X (click here for the Velomotion test) to the bikepacking steel bike Bogan, which can be ridden with two inch wide twenty-niner wheels. The Rondo HVRT comes closest to the racing bike in the aero trim, which rolls on 30 mm tires - at least if you ride 28 inch wheels, because 47 mm wide 650B tires are also possible.

650B road bike with wide tires

This may have been a compromise with the HVRT, but the new Ratt ticks differently. As a kind of mid-season novelty, the Poles are presenting a bike with this model that sees itself as a racing machine - but as one that doesn't stop at any surface, because 650B wheels are standard on the Ratt.



What it's all about? 650B or 27,5 inches, as it is called in mountain bikes, is known to be a wheel size that is the best way to go on MTBs between 26 and 28 inches (or 29 inches, as 28-inch wheels are called on MTBs - all right?) is applicable. With the gravel bike, the advantage of the slightly smaller rims is that you have more tire volume with the same outer diameter. The former is responsible for handling, the latter, of course, for comfort and traction. In theory, you get steering behavior typical of racing bikes, combined with more shock and vibration absorption as well as full road grip.

650x47B: The smaller rim diameter makes it possible to realize more tire volume with the same wheel circumference.
The frame leaves plenty of room for 28-inch wheels and tires.


Rondo Ratt with sporty geometry

And that's exactly what Rondo wants to achieve with the Ratt. Racing bike feeling on any surface is the motto, and as soon as you sit on it you think that the promise can be fulfilled. The seat geometry is more geared towards racing bikes than current bikepacking gravel bikes; So you sit rather stretched out and with a noticeable elevation. However, the stem is also responsible for this, which is exactly horizontal and thus positions the handlebars a little further down than a conventional, slightly upward-pointing stem.

The low front, horizontal stem and large support extension ensure a sporty sitting position.

If you then step on the pedals for the first time, you can look forward to full propulsion; when accelerating while pedaling out of the saddle, it is immediately noticeable that the Rondo Ratt is quite handy - especially in direct comparison to more trail-oriented gravel bikes, the similarity to the racing bike is striking. An impression that is confirmed on a fast asphalt lap: the 47 mm wide Maxxis tires roll extremely easily despite the rather low pressure, and the bike willingly follows the steering commands, where many gravel bikes react rather sluggishly. The wheelbase of the 54 test bike is less than one meter and the steering angle is steep for a gravel bike – so the riding impression is reflected in the geometry data.



Peculiarities when cornering

So is everything great? Actually yes, but of course the wide tires are not without their own peculiarities. When cornering, a little more lean angle is necessary, and overall the bike develops a certain life of its own here, which differs noticeably from the racing bike on 25 or 28 tires. That doesn't mean that the Rondo Ratt can't be controlled and calculated at all times - but on winding roads you can feel that you're not sitting on a conventionally equipped racing bike.

Two grub screws press a clamping segment against the seat post.
The angular, wide stem leads the brake lines into the frame.
The flip-chip dropouts allow geometry changes, but make wheel installation more difficult.

The Rondo Ratt has enough space for big bikes

Of course, the Rondo isn't limited to 650B wheels. In the test setup, it is noticeable that there is still plenty of room on the frame and fork, and in fact even 47 mm wide 28-inch tires fit through. However, the rear wheel can no longer be turned in this experiment because the tire profile collides with the derailleur socket. However, 40 mm wide 28-inch tires should fit easily, and of course anything that is narrower - then the Ratt will give you even more racing bike feeling. However, you should not necessarily mount narrow tires on the 650B wheelset. This would lead to the bottom bracket moving down by one to one and a half centimetres, which entails the risk of the pedals hitting the ground when cornering.



Various kinks on the rear end of the Rondo Ratt...
... should improve comfort, which also seems to work.

Comfort and fiddly wheel installation

In addition to the successful driving characteristics, the Rondo Ratt also pleases with its decent comfort; In addition to the tires, low seat stays and a far extended carbon seat post are responsible for this. Typical Rondo is the design language with the kink at the lower end of the struts, which should also have a shock-absorbing effect, the slight kink in the top tube and the fork with the noticeable forward offset. The flip-chip dropouts at the front are also typical of the brand: If you turn them around, the front of the racer sinks a little, which results in a steeper steering angle and other small changes in geometry. The process isn't easy though, as the front brake caliper also needs to be rebuilt; In any case, the Ratt is very handy and agile, as described. In addition, the Vario dropouts have a major disadvantage: the stop for the front wheel is missing, which makes it much more difficult to install. Actually, you need three hands - with one each you hold the wheel and fork in position, while with the third you slide in the thru axle. Installing the rear wheels is also fiddly.

The wheelset labeled Rondo looks solid and is not very heavy.
The "North Shore" saddle offers unobtrusive comfort.


Technically more a racing bike

As far as the mounting options are concerned, the Rondo is more of a road bike than a gravel bike: mudguards can be fitted, and a dynamo cable can also be routed through the fork, which of course doesn’t really do justice to the Ratt’s intended use. Threaded holes on the top tube are missing, which is rare in the Gravel scene; a third bottle holder is also not provided.

Two grub screws entering from the back of the seat tube press a clamp segment against the seat post, which looks nice and works well - however the segment can fall into the seat tube when the post is removed. Then the wheel has to be turned upside down and vigorously shaken. The stem, which has angular shapes and is milled, has already been mentioned; through it, the brake lines are routed inside the frame and fork. Rondo breaks new ground in aerodynamics with the flat head tube at the front, which braces itself against the headwind.

43/30 teeth at the front ensure a wide range of gears.
The Sram Rival AXS on the Ratt works great.


Well equipped with Sram Rival AXS

The test bike comes with Rondo wheels and a complete Sram Rival AXS 2×12 – a very good choice, especially for the all-road racing machine. The unusual 43/30 chainring gradation, together with the 10-30 cassette, offers a 1:1 geared mountain gear and a sufficiently long geared overdrive; the cassette is nicely graduated. Electronic shifting such as hydraulic brakes work perfectly, so that a lot of driving fun is guaranteed in this respect as well.

The Rondo Ratt will initially be available in two versions with Shimano GRX components, the Ratt CF1 with GRX800 for 4.499 euros and the CF2 with GRX400 for 3.599 euros. Further specifications are planned for 2023; then maybe there will be a variant with Sram Rival AXS. In any case, one thing is certain: If you are looking for a gravel bike that is specifically aimed at racing cyclists instead of being optimized for bikepacking, the Rondo Ratt is an attractive option.



Back to: List of the best high-end gravel bikes from 4.000 euros - Gravel bike dreams and those that can come true

Conclusion: Rondo Ratt

Pro

  • Interesting concept
  • Sporty driving characteristics
  • Great freedom in wheel size and tire width
  • Well equipped

Contrary to

  • Impeller installation cumbersome

Facts

frame materialCarbon
BrakeDisc brake Hydraulic
Weight9,16 kg op
Pricefrom 3.599 euros (with Shimano GRX400)
Website www.rondo.cc

Overall rating

78%

Value for Money

80%
An all-road race bike with 650B wheels and wide tires? The concept of the Rondo Ratt works to a large extent. Handy steering and a sporty seating position please, and the bike is quite comfortable and well equipped. However, the small, wide tires are not without compromises. But if you want, you can also install a 28 wheel set and then ride everything from real racing bike tires to 40 mm gravel tires. But Rondo could omit the flip-chip dropout here - the Ratt is sporty enough and installing the front wheel is a test of patience...
Tags:#VMgravelgravel bikegrv_b22RondoTest

More than Caspar Gebel

Caspar Gebel has been on a racing bike for 40 years. The specialist journalist and non-fiction author works for Velomotion and also for the magazines Procycling and Fahrrad News.

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