YT Jeffsy AL Base Review

Should I Buy this Bike?

The Jeffsy AL Base is our Editor's Choice Award winner and an impressively capable mid-travel trail bike that is very reasonably priced. YT has been making the Jeffsy for a few years now and the AL Base 29 model we tested is a new design for this year. Previous versions of the Jeffsy have felt okay but not great, and YT has addressed some of the issues in this redesign. Due to the fact that YT is a consumer-direct brand, the Jeffsy AL Base comes with an impressive build for the price that other brands can't touch. This bike has a truly impressive all-around performance that simply feels good all the time. Whether you're climbing or descending, riding full speed or taking it easy, the Jeffsy feels dialed and performs well above the asking price. If you're looking for a bike that can do it all and doesn't need any upgrades to be trail worthy, the Jesffsy AL Base has you covered.

Fun Factor

The Jeffsy AL doesn't exactly excel at any particular aspect of its performance, instead, it's just really good at everything. This bike feels comfortable with especially well-balanced trail manners and capabilities and components that exceed the price of admission. This excellent all-around performance makes the Jeffsy one of the most fun bikes to ride in this review.

It doesn't take long to get comfortable on the Jeffsy, in fact, testers found there was nothing to worry about other than shock pressures to dial it into their liking. Pretty soon, we found ourselves pushing it hard on this bike and gunning for KOM's on local trails, something we normally reserve for our $7K+ superbikes. The Jeffsy didn't flinch, and we never found its top speed. Unlike some bikes, you don't have to ride it full speed to have a good time, it works well at low and medium speeds and can handle chunky and technical riding as well or better than other bikes in this test. It's moderately playful and doesn't mind manuals or popping off side hits, though it has a stable and planted feel that's undeniable.

The Jeffsy's geometry is nothing particularly notable, especially by today's standards, and the numbers are really quite moderate, but this is one of the reasons that this bike feels so capable in so many different situations. The Polygon Siskiu T8 boasts a similarly high fun factor for much the same reason as the Jeffsy. It turns out that well-balanced bikes with great all-around performance are just plain fun to ride. We also had a blast atop the Cannondale Habit 6, though that bike's fun-factor was more one-dimensional and downhill oriented.

Downhill Performance

Testers found the Jeffsy to be a competent and confidence inspiring bike in all situations on the descents. Again, the well-rounded performance was truly impressive with a great combination of agility, stability, and balanced suspension that works well everywhere. Slow or fast, smooth or chunky, we never found ourselves out of place on the Jeffsy.

The Jeffsy tips the scales at 31lbs 10oz, not exactly lightweight but still far from heavy. It doesn't feel especially heavy while you're riding it, but we feel the weight may detract from this bike's overall playfulness. This Jeffsy's geometry numbers are bordering on conservative by modern trail bike standards. It has a flip chip in the rear suspension linkage that allows you to put the bike in a high or low setting depending on your preference. Flipping the chip to the low setting slackens the head and seat tube angles by half a degree and lowers the bottom bracket slightly. We tested it primarily in the high setting which we found to feel a little more lively and less prone to pedal strikes while the low setting made this bike feel glued to the ground. Interestingly, when we measured the bike in the high setting, we found the head tube angle to be 0.6 degrees slacker than advertised at 66.9 degrees. We measured the reach at a shorter 444mm, a moderate 1192mm wheelbase, and long-ish 444mm chainstays which help to give the bike some added stability at speed. These measurements combine to give this bike its well-rounded demeanor, nimble and snappy yet surprisingly stable.

The 140mm of front and rear suspension is handled by a nicely balanced Fox suspension combo. The Float Rhythm fork has 34mm stanchions that feel stout enough most of the time and is highly tune-able with an adjustable air spring, rebound, and compression settings. This fork feels nice and plush and pairs well with the Fox Float DPS Performance shock in the rear. The 4-bar linkage feels supportive when you want it to be, it handles chop and chunk pretty well and has a relatively linear feel when absorbing bigger hits. We've ridden previous versions of the Jeffsy and this is a dramatic improvement. With 140mm of front wheel travel, this bike can get overwhelmed in super gnarly and steep terrain, in those situations its best to pick a line rather than let it run.

Compared to other bikes in this review, the Jeffsy is most similar to the Polygon Siskiu T8 which is similarly well-rounded and capable in all situations. The Trance 3 falls a little bit behind both bikes with a preference toward smooth and fast terrain. The Cannondale Habit 6 excels on the descents but it prefers fast speeds and straight lines. On the other end of the spectrum, the Kona Hei Hei has a super playful attitude but falters when things get steep or rough.

Uphill Performance

For a bike that's as capable on the descents as the Jeffsy we're impressed by its uphill performance. Often it seems like a bike is good at one or the other, but this bike does both well. The 74-degree seat tube is steep enough and the reach feels longer than the 444mm suggests, we never felt cramped on this bike. Power transfer feels good and there is little bob in the suspension while climbing until you get out of the saddle. The suspension is quite supportive and it maintains a high level of traction while climbing, plus it has meaty Maxxis Minion DHR II tires to help you claw your way up anything.

Due to the moderate length wheelbase and 66.9-degree head tube angle, the Jeffsy handles well on the climbs. It responds well to steering input and can tackle sharp uphill switchbacks and technical sections of climbing quite well. There's plenty of range offered by the NX Eagle drivetrain even with its 34-tooth chainring, though if your typical rides have lots of steep climbing you may want to install a smaller size. You may notice the weight of this bike if you're tackling some longer climbs, and we suggest using the compression damping switch for extended periods of paved or fire road climbing. We typically left the shock in the open setting while climbing on trails as it is quite supportive and helps to maintain traction.

Testers found the Polygon Siskiu T8 to perform similarly on the uphills to the Jeffsy. The Cannondale Habit 6 rolls very fast thanks to its lower profile tires, but the more progressive long and slack geometry gives it a less responsive front end that doesn't do as well in tight or technical sections of trail. On the other end of the spectrum, the Kona Satori has a very steep 78.1-degree seat tube and a 67.5-degree head tube that put the rider in a very upright climbing position with weight right above the bottom bracket and it scrambles up and over things with the best of them.

Build

YT is a consumer direct bike company which gives them a leg up on the competition when it comes to delivering a quality component specification at a reasonable price. The build on the Jeffsy AL Base is very impressive considering the price point and it's ready to get after it as soon as you put it together.

To control the 140mm of front and rear wheel travel YT has spec'd a balanced combination of Fox suspension components. Up front, you'll find a Fox 34 Float Rhythm fork with relatively stout 34mm stanchions, an adjustable air spring, and rebound and compression adjustments. This fork feels solid and much sturdier than the RockShox Recon models found on many bikes in this price range. In the rear, YT has bolted a Fox Float DPS Performace shock that provides a great balance of support and cushion, with a 3-position compression adjustment to adapt it to your needs.

The Jeffsy rolls on a pair of DT Swiss M 1900 Spline wheels. This is a solid trail riding wheelset and definitely nice considering the price point of this bike. The wheels are stiff enough and they have a nice 30mm internal width that pairs well with today's wider tires. We aren't in love with the slower freehub engagement on this wheelset, but that's really our only complaint. YT has mounted a pair of Maxxis Minion DHR II tires with the EXO casing in a 2.4" width. We love when bikes come with tires you actually want to ride, and the DHR II is a great choice, especially in the rear. We aren't the biggest fans of the DHR II as a front tire, we prefer something with a more directional center tread, but this tire spec is better than you find on most bikes in this price range.

The cockpit setup is also dialed right out of the box. The front end is nice and roomy with a Race Face Aeffect R 35 handlebar that is 780mm wide. They attached that handlebar with a Race Face Aeffect R 35 stem in a 50mm length to create sturdy and responsive steering. They've attached a set of ODI Elite Motion lock-on grips that are plenty comfortable. A YT branded SDG Fly Mtn saddle sits atop an SDG Tellis 150mm dropper seat post (small frames get a 125mm post) that has an excellent 1x remote lever. This was our first experience with the Tellis dropper and it worked flawlessly through the course of our testing.

SRAM's 12-speed Eagle technology has trickled all the way down through their drivetrain component range and the Jeffsy comes equipped with their NX Eagle setup. The cranks, shifter, derailleur, and cassette are all NX Eagle. The 34-tooth front chainring is paired with an 11-50 tooth cassette that provides ample range for nearly any ride or steepness of trail.

Best Applications

This is a well balanced and incredibly capable mid-travel trail bike that is suitable for just about anyone and any type of riding. This bike is a great all arounder that is a comfortable climber, confident descender, and comes with a build that doesn't disappoint. It's not a super light XC bike, nor is it an enduro brawler, instead, YT nailed the middle ground which we think is high praise for a bike in this price range.

Value

With a retail price tag of only $2,299, we feel the Jeffsy AL Base is an incredible value. Due to the fact that YT sells direct to the consumer, this bike has the most dialed component specification of all the bikes in our best under $2500 review. This bike's build, along with its balanced trail manners and excellent all-around performance make it our favorite budget-friendly trail bike and the winner of our Editor's Choice Award. Sure, there are less expensive models in this review, but you'd be hard pressed to find a better mid-travel trail bike at this price.

Conclusion

If you're looking for the best all-around trail bike you can buy for under $2500, then look no further. The Jeffsy AL Base impressed our testers across the board with a versatile and capable ride and an exceptional price to performance ratio. This bike just feels comfortable and well balanced at all times and comes with a build that is ready for anything straight out of the box. If you want high performance but you don't want a high price then take a look at our Editor's Choice Award winner, the Jeffsy AL Base.

Other Versions

• The Jeffsy CF Comp, $3,499, is their least expensive carbon framed model. It has the same geometry as the AL Base model we tested but comes clad with Fox Performance suspension, SRAM Guide R brakes, a Shimano XT drivetrain, and an e*Thirteen TRS wheelset.

• The Jeffsy CF Pro, $4,299, is their mid-range carbon offering. It comes equipped with RockShox suspension, SRAM Guide RS brakes, a SRAM GX Eagle drivetrain, and e*Thirteen wheels.

• The top of the line Jeffsy CF Pro Race retails for $5,699 and comes completely tricked out with Fox Factory suspension, a Fox Transfer dropper, Shimano XTR drivetrain, SRAM Guide RSC brakes, and e*Thirteen TRS Race wheels.