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Felt AR4



Fast, reliable, good looking, and reasonably priced alternative to the Cervelo S3

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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Felt's AR4 is, as the name suggests, the fourth rung in the American company's AR range – their take on the aero road bike concept as pionered by Cervelo, so how does it stack up?

At £2400 the AR4 it is the lowest of three models in the AR (aero-road) line up available in the UK, it's positioned below the AR2 (£3800) and the Team Garmin-Slipstream limited edition (£5000). The Garmin spec bike was an extremely limited edition and very thin on the ground. The new AR range was launched last week at Eurobike, but isn't slated to hit these shores until the end of the year, in the mean time the current AR range is still available in the shops, so let's focus on how the AR4 compares to the AR2. Even in it's least expensive guise this is not a cheap bike, but what does it offer in terms of performance and value for money?

The frame itself is a beautiful design. You can see why everything is there, the reasoning behind all the design features and why Felt have created a bike that moves away from ultra light weight advances and instead focussing on an aero advantage. Both the AR2 and AR4 use the same Ultra High Modulus carbon fibre frame, this is Felt's own fibre which they claim has up to 8 times the tensile strength of widely used titanium and is 3.3 times stiffer than 6061 aluminium. The real proof though is in the riding and yes, this frame is certainly stiff enough for my style of riding (churning a big gear on the flat in as much of an aero position as I can get with the odd sprint up climbs).

Full internally routed cables flow within the frame from a very neat unit at the front of the top tupe hidden out of the wind behind the headset and stem to aid aero advantage. A 1.1a carbon aero seatpost finishes the frameset. Carbon dropouts and a replacable hanger complete the set up.

Complementing the aero frameset is an Ultra High Modulus aero fork which is carbon throughout (steerer, tube, dropouts). This weighs in at 400g and works well with the frameset and stock wheels that Felt supply.

On to the componentry then, the AR4 comes complete with a full 20 speed Shimano Ultegra SL groupset with a standard 53,39 ratio up front matched with an 11-25 cassette at the back. Ultegra SL is slightly lighter (approximately 100g) than the standard Ultegra available at the release time of this bike (although the new Ultegra 6700 could well throw a spanner in the works). Superb shifting, high quality manufacture, suprisingly good braking all come as standard.

The rest of the componentry is Felt own brand starting with a semi aero A3 wheelset which has 27mm deep rims and DT aerospeed spokes laced onto AeroR3 sealed bearing aluminium hubs. These wheels are pretty heavy in feel, they seem to slow the bike down, perhaps its perception but when Ive ridden the bike with other, deeper, aero rims the feeling of speed is far greater. The A3 rims are shod in ever reliable Vittoria Rubino slick tyres which match the bikes pace. A Felt 3.1 aluminium stem and 1.3a aero aluminium bars along with Felt bar tape complete the set up at the front end of the bike. The bars, although designed to match the bike's aero pedigree are fairly wide for me at a claimed 420mm and arent that light, I would swap them for a set of Pro Vibe carbon bars as being tested on a Cervelo S3. My thinking is that the aero advantage a set of drops can give you is secondary to the comfort and even weight of the product. I have also swapped the standard Felt 1.2 saddle for my preferred Specialized alias but again this is purely personal preference, the supplied saddle performed very well indeed.

On the move the AR4 is reliable, it climbs well for a bike that isnt superlight (coming in at approximately 7.7kg for a 54cm), it rolls very quickly on the flat and there is a sense of speed that I haven't experienced on other, similarly priced, non-aero road bikes.


A strong move by Felt to tackle Cervelo's dominance in the aero road bike market. The AR4 is a different beast to the Cervelo S3s of this world (see review coming soon) but then you get a full AR4 bike for the price of an S3 frame. The gap between Ultegra SL and Dura Ace is fairly narrow so paying another £1400 for the upgraded spec of the AR2 (albeit with a step up in Felt branded wheels and Ritchey finishing kit) doesn’t seem necessary.

The AR4 climbs extremely well, the frame is responsive, quick and light enough to pull up hills easily.In a very competitive market, a £2400 bike needs to be exceptional to stand out above the competition. The AR4 is fast, reliable and a looker. I like it but for £2400 I would have appreciated some better rims and a more thought through bar choice.

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Make and model: Felt AR4

Size tested: 56cm

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?

The Felt AR4 is a carbon fibre road bike with some benefits gleaned from their time trial and triathlon range. Aimed at riders who are interested in fast road riding and for whom an alternative could be a Cervelo S3 or similar.

Felt say that their AR4 has amazing aerodynamics, unique, carbon fibre only frame design and superb componentry all at an affordable price. Affordable is relative, if you have £2400 to spend on a bike then this does give you a lot for your money.

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

Utilising Felt's own High Modulus Carbon they have been able to produyce a smooth and exciting looking frame with many aero benefits from their against the clock bikes. A 3k weave and matte carvon finish set the bike off well.

This bike is all about aerodynamics, from the obviously aero inspired frame and forks right through to the handlebars that offer a 'wingtop' design aimed at promoting smoother airflow. You dont get super light weight but lets be fair, a recorded weight of 7.7kg for the 54cm bike is by no means heavy.

Rate the product for quality of construction:

I have only had a couple of issues, the compression plug (star nut) within the fork has shaken itself loose several times despite being tightened why, on such a nice bike, scrimp on this? The build quality is great though, I have total faith in the frame and forks. Shimano Ultegra is well known for its durability but small things like the unit shaking itself loose are annoying. I know an AR4 who had this issue on their machine too.

Rate the product for performance:

It makes me feel fast on the flat, my Garmin 705 says my riding is consistently 2-3kmh faster over three of my regular routes without any discernable increase in heart rate. When being used in a race situation I felt slower than on my full on tri bike but not by much, the benefits I got from being able to climb hard and fast out of the saddle far outweighed any drawbacks from using drop handlebars.

I was pleasently suprised by the climbing performance of this bike, I didnt expect it to be as responsive or positive as it is.

Rate the product for durability:

This is being dragged down by the issues regarding the headset/fork area. Having this part of the bike work loose during a ride is an issue, one that Felt should know about, selling a bike for £2400 means that no parts should be cheap. Some may be unbranded or own branded such as, in this case, the wheels, bars and saddle but the low cost components should not compromise the bike.

Rate the product for weight, if applicable:

Not superlight but lighter than I was expecting. There is a lot of carbon in this frame, carbon fibre is light but using lots means the weight benefits could easily be lost. A neat, aero frame that delivers a fast pace on the flat but is light enough to provide strong climbing performance.

Rate the product for comfort, if applicable:

A very good performance comfort wise, the saddle is no slouch providing comfort and light weight (the standard issue saddle is a felt branded 1.2a with carbon inserts). I changed this to my own preference but this isnt to do down the quality of the saddle Felt provide. The bars are an acquired taste, the aero design is lost on me a little, I would prefer somthing along the lines of the FSA K-wing that offers comfort first but with an aero edge. These bars are good at what they do but I would consider an upgrade.

Rate the product for value:

A bike that provides a superb ride and a pacey performance. I have few complaints about the price tag on this bike, if you search online you can even find 20% off this so it has now come in below the £2k barrier. I expect one of the the reasons for this is another Felt bike, the Z15, which offers a full carbon road frame, albeit with totally different geometry, showered with a full dura ace groupset for a discounted price of £2400.

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

The AR4 is designed to be a fast, energetic road bike and it didn't disappoint. The aero frame certainly felt quick when riding at 35kmh+ and with a few choice upgrades I imagine it would be a rocket. I have ridden it with dura ace carbon deep rims as well as mavic cosmic carbones and the AR4 jumps ahead even more. Give it some new bars and I think it would be the finished article. You can argue of course that for £2400 it shouldn't need that amount of fine tuning.

Tell us what you particularly liked about the product

The frame and groupset. Ultegra is a workhorse that misses the spotlight hogged by Dura Ace but dont dismiss it, the performance and weight of the Ultegra SL groupset is superb. The frame delivers a positive, energetic ride that was great fun on the first ride and remains so. I know it should all be about performance but the bike looks good too and there is no harm in that!

Tell us what you particularly disliked about the product

I was frustrated by the lack of attention to one of the smallest and cheapest parts of the bike, the compression plug, this led to a decline in braking performance, positivity in handling and,likely, damage to the headset.

Did you enjoy using the product? Yes, a fast, fun bike.

Would you consider buying the product? I would.

Would you recommend the product to a friend? Within the tri community yes because its perfect for hilly triathlons. Everyday road cyclists have more choice and as such this may not appeal to the same degree but do not discount it, the 'sense' of riding faster than usual cannot be undervalued.

Anything further to say about the product in conclusion?

A stunning looking machine that offers a real alternative to Cervelo. The AR2 (£3800) may be even more competitive but with the AR4 coming in at a list price of £2400 you do get a lot of development and research for your money. This bike feels fast, rides well and delivers performance.

Overall rating: 8/10

About the tester

Age: 24  Height: 5ft 10  Weight: 66kg

I usually ride: felt ar4  My best bike is: i like my felt and my orbea ora tt bike equally

I've been riding for: Under 5 years  I ride: Most days  I would class myself as: Experienced

I regularly do the following types of riding: road racing, time trialling, commuting, club rides, general fitness riding, mtb, triathlon

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