Everyone wishes they could ride a "dream bike," but what if you could find a dream deal that's just as capable for way less? Today, we're comparing two Specialized Diverge gravel (or all-road) bikes that are separated by six years, two generations, and $2,400.
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The dream bike:
[product-block handle="2021-specialized-diverge-expert-m"/]
For those who dream of exploring remote gravel roads, the 2021 Specialized Diverge Expert is the ultimate getaway vehicle. The Diverge received a major update in 2021 with Future Shock 2.0 tech, longer and slacker geometry, SWAT internal storage, and increased tire clearance.
The deal bike:
[product-block handle="2015-specialized-diverge-comp-carbon-xl-2"/]
In 2015, gravel bikes were undefined as a genre, so the first-generation Diverge was billed as an “all-road” bike. It borrowed comfort features from the popular Specialized Roubaix endurance road bike to create a new, more capable platform. This original 2015 Diverge Comp is a great deal, and despite missing out on six years of gravel innovation, it can still satisfy riders looking to venture beyond the pavement.
2021 Specialized Diverge Expert vs. 2015 Specialized Diverge Comp
Bike |
2021 Specialized Diverge Expert |
2015 Specialized Diverge Comp |
Price |
$5,199.99 |
$2,799.99 |
Frame material |
FACT 9r carbon |
FACT 10r carbon |
Drivetrain |
Shimano GRX Di2 |
Shimano Ultegra / GRX |
Wheels |
DT Swiss G540 Aluminum, Tubeless |
Axis 40 A-Sym Disc Aluminum, Clincher |
Brakes |
Shimano GRX |
Shimano Ultegra |
Comfort tech |
Future Shock 2.0 |
Zertz, CG-R seatpost |
Weight |
21 lbs 3 oz |
19 lbs 11 oz |
Tire Clearance |
700c x 47mm / 650b x 2.1” |
700c x 35mm |
Frame
Both Diverge frames use Specialized’s FACT carbon. Interestingly, the 2015 Diverge uses the slightly higher grade FACT 10r carbon vs. the FACT 9r carbon used on the 2021 version. Specialized switched to FACT 9r with the second generation Diverge (released in 2018). It didn’t explain why, but it’s likely because the FACT 9r carbon is a slightly more rugged option for dirt riding, though it does have a slight weight penalty as a result. (S-Works models will use the lightest FACT 11r carbon.)
Internal SWAT storage on the 2021 Diverge. Photo: Specialized.
The down tube of the 2021 Diverge frame has also been enlarged to add internal SWAT storage. SWAT tech was imported from Specialized's mountain bikes and stands for “storage, water, air, and tools.” A trap door under the bottle cage opens to reveal a storage compartment that runs the length of the downtube. It’s large enough for a full repair kit plus some extras.
Drivetrain
Bike |
2021 Specialized Diverge Expert |
2015 Specialized Diverge Comp |
Chainring size |
42t |
36t |
Cassette size |
11-42t |
11-42t |
Both Diverges feature 11-speed Shimano 1x drivetrains. On the 2015 model, the GRX rear derailleur is aftermarket, as Shimano’s gravel-specific GRX drivetrain wasn’t released until 2019. It has previous-generation Ultegra mechanical shifters and a mix of other components like SRAM cranks and a SunRace cassette. The 2021 Diverge has an electronic GRX Di2 drivetrain which provides incredibly quick and reliable shifts, even in the harshest weather conditions.
Wheels and tires
Both bikes roll on aluminum wheels, but the DT Swiss wheels on the 2021 Diverge are tubeless-compatible while the Axis wheels on the 2015 Diverge are not. Tubeless tires are the standard for off-road riding, but in 2015, they weren’t common on drop-bar bikes. Tubeless wheels would be a worthwhile upgrade, but the 2015 Diverge complicates things with its SCS 12x135mm thru-axle. Riders will need to purchase wheels with an SCS rear hub.
The 2021 Diverge has the more gravel-friendly wheel and tire set-up.
The 2015 Diverge also comes with 28mm wide tires. These are great for road riding, but riders will want to swap to something wider for true gravel riding. The 2015 Diverge can clear a 35mm tire in the rear and a 38mm tire in the front. This isn’t wide by today’s standards but will be enough for the majority of gravel roads. If you plan to ride trails or ultra-rough gravel, the 2021 Diverge comes with 38mm tires and can fit up to 47mm wide tires for maximum traction and compliance.
Geometry
Bike |
2021 Specialized Diverge Expert |
2015 Specialized Diverge Comp |
Size |
58cm |
58cm |
Effective top tube |
589mm |
582mm |
Stack |
634mm |
621mm |
Reach |
401mm |
391mm |
Head angle |
71.8° |
73.5° |
Seat angle |
72.5° |
73° |
BB drop |
80mm |
74mm |
Chainstay length |
425mm |
418mm |
Specialized claims to have taken inspiration from its Epic Hardtail mountain bike when revising the 2021 Diverge geometry. The head tube is slacker, and the reach and chain stays are longer for more stability. The low bottom bracket also adds stability, and though it is lower than the 2015 Diverge, Specialized actually raised it 5mm from the second generation Diverge (85mm BB drop) to increase ground clearance. It still has one of the lowest bottom brackets in the business.
The 2015 Diverge has classic endurance road geometry. Though not as stable as the 2021 Diverge, it will feel more lively on paved roads and still be comfortable on all but the roughest gravel. The chain stay length is actually variable depending on frame size and all sizes have shorter, more agile chain stays than the 2021 Diverge.
Future Shock vs. Zertz
The Future Shock 2.0 system sits beneath the handlebars.
When the second generation Diverge was introduced in 2018, it received the same Future Shock system introduced on the 2017 Roubaix. Future Shock is a spring built into the headset which provides 20mm of active suspension under the handlebars to increase comfort. With the 2021 update, the Diverge’s Future Shock was also updated to Future Shock 2.0. It improves on its predecessor with compression and rebound damping to control the spring movement, and a dial on the headset cap to adjust that damping. This means you can firm it up for smooth road and sprinting or open it when you need more compliance on rough terrain.
The 2015 Diverge doesn’t have Future Shock, and instead, uses Zertz inserts in the fork legs, seat stays, and CG-R seatpost to dampen vibration and increase comfort. Some riders might prefer the more basic Zertz inserts because they’re lighter and simpler, and there are no moving parts.
Dream vs. Deal verdict
So which Diverge would I choose? For my everyday rides that are around 70% paved roads and 30% gravel, the older 2015 Diverge might actually be the better choice. It will feel faster and more efficient on the road, and it’s more than enough to handle most gravel. It really is an “all-road” bike that suits a wide range of road conditions.
The newer 2021 Diverge, on the other hand, is a true gravel adventure bike. With Future Shock and the ability to fit massive tires, it can ride ultra-rough roads that will stop the 2015 Diverge in its tracks. The trade-off is that it cost nearly twice as much as the 2015 model.
Bruce’s pick:
[product-block handle="2021-specialized-diverge-expert-m"/]
The extra off-road capability adds cost (and a bit of weight) to the 2021 Diverge, but I think it’s worth it. Even though the 2015 model is likely a better daily driver, I want the 2021 model for those special occasions when I decide to really veer off the beaten path and explore all the singletrack trails and forgotten logging roads in my local mountains.
Let me know which bike you’d pick in the comments!
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