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Spin Koppenberg MAX25 25mm Wide Fat Boy clincher wheels



Superb wheelset: light, stiff and a wide rim profile letting you enjoy the benefits of wider tyres

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

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Titanium frame and wheel brand Spin's Koppenberg MAX25 wheels combine a wide aluminium clincher rim with durable hubs in a lightweight 1,540g package at a good price.

Wide is the new narrow

There are many trends in road cycling at the moment, one of the more interesting is that wider tyres are gradually becoming accepted, even in the pro peloton. However, fit a wide tyre to a conventionally narrow rim and you get a light-bulb profile, which isn't desirable as it can lead to the tyre rolling over when pushed hard through corners, an issue that's worse at the lower pressures that wider tyres allow.

Fit a narrow tyre to a wide rim though, and you get the benefits of the wider tyre with a more stable tyre/rim interface. Spin designed their own 25mm rims for this very reason. We actually measured the external rim width at 24.75mm, but more important is the internal rim width of 19.49mm. That's much wider than many regular road rims.

With a 23mm Schwalbe Ultremo tyre mounted to the rim, I measured their width at 25.26mm. Essentially you're getting all the benefits of a wider tyre (increased contact patch and volume so you can run lower pressures) but without the extra weight of actually fitting a wider tyre.

There is also none on the aforementioned light-bulb effect, instead the rim and tyre have a nicely rounded profile. I was able to comfortably run lower pressures, as low as 80psi, and didn't experience any tyre roll or squirm when I pushed hard through corners. And I benefited from the increased comfort as well.

Tough and durable

The rims are laced to Spin's own SPN Precision hubs. These are their latest generation design, forged and machined aluminum shells that are light; 85g for the front and 210g for the rear. They've placed the flanges on the front hub as wide as they can. The HyperDrive 48-point freehub provides quick engagement and takes an 11-speed Shimano or SRAM cassette. There is a Campagnolo option too.

Sapim CX Ray and Laser spokes lace the rims to the hubs. There 20 of them in the front wheel with a radial lacing pattern, and 24 in the back wheel, laced 2-cross. They're well strung wheels, with good tension that remained that way throughout the test period.

They take a pounding these wheels. You just can't beat a good set of well built aluminum clinchers for all-round riding in a range of conditions. I ran them every day while I had them for test, in different bikes, from a steel frame/fork winter bike to a full carbon SuperSix Evo. They provided exceptional performance in both.

They have a really nice feel these wheels. There's noticeable stiffness when you push them hard, yet there's a hint of compliance that provides good comfort on longer rides, over a variety of road surfaces. They're good on the gravel too, where the stability and larger tyre volume works well.

They're also tough, something I found out when I hit a National Escort Group motorbike in a road race back in the summer. Despite clouting the bike, and the ground, pretty hard, the wheels were still perfectly true, not a bent spoke or rim to speak of. Spin offer a five year crash replacement policy which offers a nice bit of peace of mind.

So plenty of performance, comfort and that attractive wide rim, and they're competitively priced too. A comparison would be good here to offer some perspective. The Spin wheels are cheaper than the list price for Shimano's RS81 C35 wheels. The Spin wheels are significantly lighter, and they have the added advantage of the wider rim. Shimano use a 20.8mm external width on the RS81 rims.

All of which makes the Spin Koppenberg MAX25 wheels a really rather attractive package. The width puts them ahead of most of the competition (though some are slowly starting to catch up), they provide a smooth ride, top handling and they're light. Oh and they're really strong too.


Superb wheelset: light, stiff and a wide rim profile letting you enjoy the benefits of wider tyres

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Make and model: Spin Koppenberg MAX25 25mm Wide Fat Boy Clinchers

Size tested: n/a

Tell us what the product is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?

Get these K2 Koppenberg Fat Boys slotted in your bike and you'll experience super fast rolling with increased corner grip, incredible lateral stiffness and stable handling in all conditions thanks to the 25mm superwide section, 25mm deep 3D2 metal matrix rim profiles.

The matching superlight forged & machined alloy hubset from SPN Precision features HyperDrive 48-point fail-safe engagement and is 11-speed ready. And Sapim CX-Ray aero bladed spokes complete the build to compete very favourably against similar spec Zipp 30s, 101s and HED Ardennes wheelsets.

Tell us some more about the technical aspects of the product?


Front 690 / Rear 835 / Pair 1525


25 wide x 25 deep / 3D Black MetalMat


Sapim Race CX Ray


Sapim Race CX Ray Drive / Sapim Laser NonDrive


Shimano/SRAM standard, Campag Optional


Rim tape, Quick Release skewers

Rate the product for quality of construction:
Rate the product for performance:
Rate the product for durability:
Rate the product for weight, if applicable:
Rate the product for comfort, if applicable:
Rate the product for value:

Really good weight for the money, and the wide rim is really appealing.

Tell us how the product performed overall when used for its designed purpose

Fattens up a narrow tyre a treat.

Tell us what you particularly liked about the product

Wide profile rim.

Tell us what you particularly disliked about the product

They're not tubeless compatible.

Did you enjoy using the product? Yes.

Would you consider buying the product? Yes.

Would you recommend the product to a friend? Yes.

Anything further to say about the product in conclusion?

With such a good weight-to-price ratio, that all-important wide rim and solid and dependable reliability, it's hard to justify spending more. These are really good wheels.

Overall rating: 9/10

About the tester

Age: 31  Height: 180  Weight: 67

I usually ride:   My best bike is:

I've been riding for: 10-20 years  I ride: Every day  I would class myself as: Expert

I regularly do the following types of riding: road racing, time trialling, cyclo cross, commuting, touring, mtb,


David worked on the tech team from 2012-2020. Previously he was editor of and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds, and you can now find him over on his own YouTube channel David Arthur - Just Ride Bikes

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