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All New Koppenberg MAX25SL Plus - Fat Boy Rim for the bigger biker 25mm wide & just 1440g/pr

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Hand built to order in around one week

Fat Boy Rim for the power riders 80kg and over!

Rider weight limit: 100kg

The Koppenberg M25 / MAX25 wheels - our first full 25mm width alloy wheelset - was a really big hit with our customers and with professional bike reviewers alike. Super-expensive money-no-object wide profile carbon wheels were easy to find, but not easy to find a high quality lightweight alloy wheel nearer the other end of the price scale.  The Koppenberg alloys filled this void nicely, so we had to think long and hard about how and if we could improve on it.

Well, here's what we managed to come up with, and what we've left unchanged with the all-new M25SL rim for 2016, available in limited numbers right now.

  • Profile: a complete overhaul of the rim profil - from the box section square and blunt M25 rim, to a wind cheating 25mm deep fat toroidal shape for the M25SL
  • Diet: M25SL went on a severe race diet - the old M25 rim weighed in over 500 grams whilst M25SL tips the scales at just over 430g on average
  • Width: M25SL has lost considerable weight, but hasn't slimmed down!  M25SL is still the full fat 25mm wide external, and almost 19mm internal
  • Tubeless-ready: Like all the wheels in our line up, just add your favourite tubeless specific rim strip, valve and tyres and you're ready to spin tubeless

So what're they like to ride, Mister?
If you've never ridden precision hand built wide profile wheels before, you're in for a shock - an entirely bike transforming rather good one. Slot the Max25SLs into your bike and immediately you'll exerience super fast rolling, precision, sure-footed turn-in and huge amounts of mid-corner grip.

This is all down to the stiff & wide 25mm Fat Boy Rim section, which permits standard 23-25mm tyres to open up to achieve their optimal tread and sidewall arc profile. Combine the arc profile with a significantly lower requirement for air pressure and what have you got? Low rolling resistance on the straights means more speed for no extra effort. Greater tyre to ground contact area when your bike is banked over means more grip for carving through the twisty stuff. Lower tyre pressures means more road shock and buzz is absorbed for significant gains in all-day ride comfort.  

All this top-end performance, great reviews & light weight seems reasonably priced! So I suppose you just sub your production out to Far East mega factories like everyone else? 
In fact the answer is No - the Spin Dr. likes to make all of his own wheels and keeps costs down by simply not allowing money to be spent on anything that doesn't directly enhance our bikes and wheels. And rather than hiring in help to do stuff that other companies regularly call in outside consultants and experts for, we just get on and figure out how to do it ourselves. 

So, every wheel we make, from the least to the most expensive in our range, is precision hand built in the Spin Dr.'s old shed, deep in the Stratford countryside. We call our shed the Speed Shop because inside is where we create the Spin to enhance your speed and enjoyment on the bike.  

Building every wheel by hand from start to finish means a great deal of attention to detail gets paid at every stage, and starts with matching spoke selection and lacing to rider weight. Making wheels this way allows us to ensure every one is built with the right balance of high and even spoke tensions, necessary to deliver sufficient lateral and torsional stiffness to transfer every watt of power and degree of steering input directly to the road, providing the perfect platform for secure stable handling in all conditions. It's also the vital key that means our wheels are strong enough to take a regular pounding and still keep on spinning!

And by actually making our own wheels there's an added bonus that you probably never think about when buying shiny new bike gear. The people who make our wheels are right here, ready to answer all your questions, advise on builds, service issues, and spare parts. Plus we regularly turn around our customers' wheels sent for service or repair in as little as 12 hours.

All Spin Koppenberg road wheels are built on our well proven superlight forged & 3D machined alloy hubset which features fail-safe 48-point drive engagement for instant power with zero lag whenever you put the power down. And naturally for wheels this utterly Rock 'N' Roll, our freehubs go all the way up to 11. 

Average 1440g / pair. Rider weight limit - 100kg. Get the even lighter Max25SL if you're a mere featherweight under 80kg. 

Scroll down to read customer reviews and even further for the complete Product Specifications.

Stop Press!

The 2016 Koppenberg Fat Boys' direct predecessor - the original MAX25 superwide alloy wheel - is consistently rated amongst's handful of top wheels and upgrade recommendations for your bike.

They're also on's list of the top 20 cycling products of 2014

K2 Koppenberg M Series Alloy: bullet-proof wide pro rim extrusions 23mm SuperWide 3D2 metal matrix rim profile Sapim CX Ray aero bladed spokes Instant pick-up with HyperDrive-48 engagement 11 speed compatible Shimano / SRAM / Campag

Product Videos

See How We Make 'Em: Spin Koppenberg Bike Wheels 01:39

Watch the Spin Meister turn a freshly laced Koppenberg X Series carbon road wheel from a wibbly wobbly tangle of bendy spokes into a light, fast & beautiful precision road racing weapon of massive speed.

  • See How We Mak...
    Watch the Spin Meister turn a freshly laced Koppenberg X Serie...

Warranty Information

Warranty - One year
Crash Replacement Program - Five Years

Product Specifications

Weights (average, grams):
Front 640 / Rear 800 / Pair 1440
Rim Width, Depth (mm) & Finish:
25 wide x 25 deep / 3D Black MetalMat
Spokes Front - 20 Radial:
Sapim D-Light / Race
Spokes Rear - 24 Two-cross:
Sapim D-Light / Sapim Strong
Sapim Polyax brass - nickel silver
11 Speed Drivetrain:
Shimano/SRAM standard, Campag Optional
Tubeless Compatible:
Yes - with optional tubeless rim tape, sealant, valves & tyres
What's In The Box:
Rim tape, Quick Release skewers, 10/9/8 speed freehub convertor
Maximum Rider Weight:

Find Similar Products by Tag

25mm  alloy  k2  metal  wheels  

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