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Reynolds Assault SLG disc brake wheels



Good, reliable carbon disc wheels that will suit cyclo-crossers and road disc early adopters

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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The Reynolds Assault wheelset has proved popular for road and cyclocross use since its launch, offering some clever aero technology at a fairly competitive price. Now the mid-depth clincher rim is available with a disc hub, making a compelling choice for cyclocross racers and early adopters of road disc brakes.

During our review we ran the Assaults on the road exclusively, so we can't comment on their off-road toughness, but in general deep-section carbon wheels tend to cope well off-road so we would expect they would work well in the mud.

The clincher rims are 41mm deep and 25mm wide, with the distinctive Swirl Lip Generator noticeable on the sidewalls near the spokes. The 2014 model has a larger lip than previously; Reynolds say the new Enhanced Swirl Lip Generator is in fact eight times larger at just under 1mm tall.

Reynolds claim that the Swirl Lip Generator "helps turbulent air passing over the wheel to reattach to the spoke face after flowing over the spinning rim" and that wind tunnel testing shows a 35% aerodynamic benefit compared to the previous generation rims without Swirl Lip Generator. Thirty-five percent sounds a lot, but this only relates to the drag of the wheel (itself a small proportion of your overall drag).

I am a little sceptical about how air flow measured around a stationary bike in a wind tunnel really correlates to real-world use, where the interaction between rider and bike, plus the side-to-side pedalling motion would surely complicate things. In any case, Reynolds have done more wind tunnel testing than I have, so perhaps we'll have to let that one be.

These wheels are sensibly built to take the extra forces experienced with disc brakes, with a higher spoke count (24 front and rear) and two-cross spoke lacing all round. Straight-pull Aero Comp bladed spokes from DT Swiss are used. The rims do not have a brake track, saving weight, and the result is a competitive 1565g claimed weight (compared to 1597g as measured on arrival here). Clinchers are available now and tubs will follow soon, and should be a bit lighter.

The hubs are 11-speed compatible (we ran them with the new Ultegra Di2 groupset) and compatible with six-bolt rotors only. We don't have too much other information about the hubs, but we had no issues with them during the review.

The wheels arrived true and remained so during the review period with no trueing needed, even after a fairly painful meeting with a pot-hole that resulted in a flat. They are a smart-looking set of wheels, with graphics not as garish as some. To our surprise, we found that the Reynolds logos started to come off after a few hundred miles: they don't appear to be protected by a top-coat.

We fitted the wheels to the Culprit Croz Blade in place of some fairly basic Shimano RX31 wheels and unsurprisingly the difference was noticeable, with the reduction in inertia giving sharper acceleration and the deeper section rims making it a little easier to hold speed once you'd got going.

At 41mm they are a mid-depth rim, which you'd expect to offer a decent compromise between aerodynamic efficiency and stability in the wind. We had a few issues with high-speed stability in the wind when they were paired with an aero frame, but on a standard-tubed bike they were well behaved even in very gusty conditions, so it was probably the combination of the frame and wheels together, rather than just the wheels, that was the issue. Reynolds claim that the Swirl Lip Generator reduces the side force on the rim due to cross-winds. Without seeing the data, this sounds slightly counter-intuitive, but we were not able to make measurements to confirm it one way or the other.

At this price-point Reynolds is positioning the Assault Discs below the really expensive exotica. Given that you're getting a wheelset specifically developed by a big-name brand with the benefit of their considerable aerodynamic expertise, and backed by the Reynolds Assurance Program (giving discounted replacement or repair in the event of a crash), we think they are decently-priced. Rim tape and quick release skewers are included; wheelbags are not.

These are reliable and reasonably fast wheels. Reynolds makes big claims for the efficacy of the Swirl Lip Generator that we were not able to prove or disprove. They are a reasonable price given they have been developed in-house rather than assembled from a Taiwanese parts-list. We'd expect them to be very popular amongst serious cyclo-cross racers and road-disc early adopters.


Good, reliable carbon disc wheels that will suit cyclo-crossers and road disc early adopters. test report

Make and model: Reynolds Wheelset Assault C Disc Shimano 2014

Size tested: Back - 890g Front - 710g

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?

Reynolds' 2014 Assault SLG Disc is one of our most exciting entries to this up-and-coming category. With an MSRP of just $1,850, Reynolds once again brings premium engineering and technology within reach for all.

The 2014 Assault SLG Disc is a full carbon wheel that is 41mm deep and 25mm wide. Our Enhanced SLG design, upgraded for 2014, offers improved aerodynamic advantage. The Assault is laid up as a disc-specific rim, completely without Reynolds' proprietary CTg brake track, which helps it to come in at a scant 1,565 grams.

The Assault SLG Disc is drilled 24h front and rear, and laced to Reynolds' racing design, 11spd, IS six bolt road disc hubs via DT Swiss Aero comp spokes. Clincher rims are available now, and Tubular rims will debut in Spring 2014.

The Assault SLG Disc is quite possibly the most dynamic and versatile wheel Reynolds has ever built.

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

Rim Constuction Clincher, Carbon

Rim Depth 41 mm

Width External: 25 mm, Internal: 17 mm

Design CFD maximized aerodynamic profile

Spokes 24 front / 24 rear

Spoke Pattern Front: 2X, Rear: 2X

Spokes Front DT Aerocomp, Bladed

Spokes Rear DT Aerocomp, Bladed

Weight 1565 g / set, Rim 445 g

Hubs Road Straight-Pull, 6-bolt ISO rotor compatible

Compatibility Shimano / SRAM / Campagnolo

Braking Disc Brake

Aero Feature SLG Swirl Lip Generator®

Nipples External 2.0 Alloy

Rate the product for quality of construction:

Well-built, strong wheels. The finish on the rims and hubs is good as we'd expect from Reynolds.

Rate the product for performance:

We were not able to discern the effect of the SLG. We're not saying it doesn't work, just that we couldn't tell the difference. Reynolds claim it'll shave 12.5 seconds off your 40km time (although they don't specify what they're comparing it with). We found them to perform about as well as other mid-depth aero wheelsets.

Rate the product for durability:

No evidence of wear to the wheels themselves, but we'd be a bit disappointed with the decals starting to wear off if it was our money.

Rate the product for weight, if applicable:

Disc brakes mean heavier hubs (but can also mean lighter rims, without the brake track). The weight is pretty respectable, therefore.

Rate the product for value:

Your money is paying for real wind-tunnel research here. Cheaper wheels are available, but not normally from people doing the sort of real R&D that keeps Reynolds, ENVE and Zipp at the top of most people's wish list. We think this is a fair price for what you're getting.

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

Fine - they were reasonably quick and completely reliable.

Tell us what you particularly liked about the product

The whole wheelset is built around disc brakes - sensible spoke-count and disc-specific rims give a strong build but not at the cost of weight.

Tell us what you particularly disliked about the product

I'd like to see more durable graphics, otherwise not much.

Did you enjoy using the product? Yes.

Would you consider buying the product? Yes, particularly for cyclocross (Reynolds reckon they're ideal for 'cross or gravel racing).

Would you recommend the product to a friend? Yes.

Overall rating: 7/10

About the tester

Age: 35  Height: 6  Weight: 78kg

I usually ride: Boardman CX team for the daily commute  My best bike is: Rose Xeon CRS

I've been riding for: Over 20 years  I ride: Most days  I would class myself as: Expert

I regularly do the following types of riding: road racing, time trialling, commuting, touring, club rides, sportives, general fitness riding, fixed/singlespeed, mtb,


Jez spends his days making robots that drive cars but is happiest when on two wheels.  His roots are in mountain biking but he spends more time nowadays on the road, occasionally racing but more often just riding. 

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Matt_S | 10 years ago

They need to get some centerlock hubs.

dave atkinson | 10 years ago

no, they're not a tubeless-compatible design

Gasman Jim | 10 years ago

Don't know if they're tubeless compatible. No info about that came with them so suspect not. What I do know is that the alloy rim is actually lighter than the carbon one!

G-bitch | 10 years ago

Missing a bit of vital info - tubeless compatible?

Gasman Jim | 10 years ago

Just last week I got a pair of Reynolds Stratos Pro disc wheels for my winter / wet weather bike. They're similar to these in that they have the same hub and spokes but with a 30mm deep alloy rim. They weigh exactly the same (1600g on my scales) as these carbon versions but cost about half as much. I don't think they have the swirl lip generator though.
So far I've only done 100 miles on them but I'm quite impressed. They're half a pound lighter than my previous Hope / Open Pro combo, and despite having far fewer spokes don't feel any less stiff. Above 20mph their aero benefits are definitely noticeable, the bike fairly flies along now.
I always dismantle any new components, partly to see how they go together in case I ever need to repair them but also to make sure things are properly greased etc. I can report that these hubs are very nicely made and easy to strip down with just a couple of allen keys, and the freehub uses 6 engagement pawls IIRC. However, in my opinion the bearings needed a bit more grease in them to cope with year round use in the UK.
Overall I'm very pleased with them, they're just what I've been waiting for since I first built a road bike with disc brakes about three years ago. So save your money and buy the alloy version.

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