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YT Jeffsy AL Base 2019 Review

The YT Jeffsy AL Base is a comfortable, capable, and versatile trail bike and the winner of our Editor's Choice Award.
The builds on bikes in this price range are steadily improving as technology trickles down. Consumer direct brands like YT also have amazing builds for the price like that on the Jeffsy AL Base pictured here.
Editors' Choice Award
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Price:  $2,299 List
Pros:  Versatile, solid all-around performance, excellent component spec for the price,
Cons:  Moderately heavy
Manufacturer:   YT Industries
By Jeremy Benson, Kyle Smaine  ⋅  May 6, 2019
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SCORE


RANKED
#1 of 8
  • Fun Factor - 30% 10
  • Downhill - 35% 9
  • Climbing - 35% 8

Our Verdict

It's rare that our testers get on a sub $2500 mountain bike and feel comfortable pushing their limits, but the YT Jeffsy AL Base is a special budget-friendly model. The Jeffsy boasts a component specification and solid all-around performance that far exceed the asking price. With 140mm of front and rear wheel travel, this is a mid-travel trail slayer that feels composed and balanced in all situations. This bike is downright comfortable and a blast to ride just about everywhere. On the descents, it has responsive handling and an excellent combination of agility and stability thanks to its moderate geometry numbers and dialed suspension. It's a touch heavy, but it performs well on the climbs thanks again to its geometry, wide range NX Eagle drivetrain, and grippy tire specification. The build is also dialed, for a bike in this price range, and it's ready to get after it straight out of the box. The Jeffsy impressed us so much that we've given it our Editor's Choice Award.


Compare to Similar Products

 
Awards Editors' Choice Award Top Pick Award Best Buy Award Top Pick Award  
Price $2,299 List$2,199 List$2,000 List$2,399 List$2,100 List
Overall Score Sort Icon
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Star Rating
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Pros Versatile, solid all-around performance, excellent component spec for the price,Nice component spec, well rounded performance, versatileMaestro suspension, Beefy tire spec, Stable at speed, AffordableBalanced suspension feel, good front tire spec, playful XC attitudePlush rear suspension, stability at speed, confident descender
Cons Moderately heavyCame with wrong size dropper post, moderately heavyFeels heavy, 1x10 drivetrain, Suntour fork is tricky to tuneLong stem, Steeper head tube angle, Recon forkNo dropper post, 10-speed drivetrain, unwieldy climber
Bottom Line The YT Jeffsy AL Base is a comfortable, capable, and versatile trail bike and the winner of our Editor's Choice Award.The Polygon Siskiu T8 is a solid all-around trail bike and one of our highest rated budget-friendly models.The affordable Giant Trance 3 is a capable trail bike and the winner of our Best Buy Award.Kona's Hei Hei Trail is a playful and balanced trial bike and the winner of our Top Pick for XC Trail Riding Award.The Cannondale Habit 6 has a long and slack geometry that excels on fast and flowy descents.
Rating Categories YT Jeffsy AL Base Polygon Siskiu T8 Giant Trance 3 Kona Hei Hei Trail Cannondale Habit 6
Fun Factor (30%)
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10
10
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9
10
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8
10
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8
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8
Downhill (35%)
10
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9
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8
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7
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8
Climbing (35%)
10
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8
10
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8
10
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7
10
0
8
10
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6
Specs YT Jeffsy AL Base Polygon Siskiu T8 Giant Trance 3 Kona Hei Hei Trail Cannondale Habit 6
Wheelsize 29 29 27.5 27.5 29
Frame Material Aluminum Aluminum Aluminum Aluminum Aluminum
Frame Size L L L L L
Available Sizes S, M, L, XL S(27.5), M(27.5 or 29), L(29), XL(29) S, M, L, XL XS, S, M, L, XL S, M, L, XL
Fork Fox 34 Float Rhythm 140mm RockShox Revelation RC Solo Air, 140mm SR Suntour Aion RC DS 150mm RockShox Recon Gold RL 140mm RockShox Recon RL Solo Air 130mm
Rear Shock Fox Float DPS Performance RockShox Deluxe RT3 DebonAir RockShox Deluxe R RockShox Deluxe RL Fox Float Performance DPS EVOL
Wheelset DT Swiss M1900 Spline Entity XL2 Disc Giant AM 27,5, 30mm ID w. Giant Tracker Hubs WTB STP i29 TCS Shimano MT400 hubs, WTB STX i23 rims
Front Tire Maxxis Minion DHR II EXO 2.4" Schwalbe Nobby Nic 2.35" Maxxis High Roller II 2.5" Maxxis Minion DHF 2.3" Maxxis Ardent EXO 2.4"
Rear Tire Maxxis Minion DHR II EXO 2.4" Schwalbe Nobby Nic 2.35" Maxxis High Roller II 2.4" Maxxis Tomahawk TR 2.3" Maxxis Ardent EXO 2.4"
Shifters SRAM NX Eagle Shimano SLX 11-speed Chiman Deore 10-speed Shimano Deore 10-speed Shimano Deore 10-speed
Rear Derailleur SRAM NX Eagle Shimano XT 11-speed Shimano Deore 10-speed Shimano Deore 10-speed Shimano Deore 10-speed
Cranks SRAM NX Eagle Prowheel Charm Praxis Cadet Race Face Aeffect Race Face Ride Cinch
Chainring 34T 32T 30T 30T 30T
Bottom Bracket SRAM DUB Pressfit BA Threaded Praxis Press Fit Shimano Press Fit Race Face Outboard
Cassette SRAM PG-1230 Eagle 10-50T SunRace CSMX8 11-speed 11-46T Shimano Deore 10-speed 11x42T Shimano Deore 10-speed 11-42 Sunrace 10-speed 11-42T
Saddle SDG Fly Mtn Entity Assault Giant Contact Neutral WTB Volt Sport Cannondale Stage 3
Seatpost SDG Tellis Drive Si 150mm Giant Contact Switch 150mm Trans-X Dropper Internal 150mm Cannondale C4 Alloy
Handlebar Race Face Aeffect R 35 Entity Expert 780mm Giant Connect Kona XC/BC 35 780mm Cannondale C3 Riser 780mm
Stem Race Face Aeffect R 35 Entity Expert 45mm Giant Connect Kona XC/BC 35 Cannondale C3
Brakes SRAM Guide T Shimano BR-MT500 Shimano BR-MT400 Shimano MT-500 Shimano MT200
Warranty 5 Years 5 Years Lifetime limited warranty on frame Lifetime limited warranty on frame Lifetime limited warranty on frame

Our Analysis and Test Results

The Jeffsy is a solid all-around trail bike and the clear winner of our Editor's Choice Award.
The Jeffsy is a solid all-around trail bike and the clear winner of our Editor's Choice Award.

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.

If you're strapped for cash and you just can't possibly justify spending that much, the Giant Trance 3 is worth a look. The $2,000 Trance is our Best Buy Award winner with aggressive intentions and solid performance for the price. Its build isn't nearly as impressive as the Jeffsy, but it costs $300 less…

If you've got some wiggle room in your budget we think the Polygon Siskiu T8 is another worthy trail bike in this review. It's a little more expensive than the Jeffsy, but it has a strikingly similar well-rounded performance that gave it a run for its money. If you're looking for a great mid-travel trail bike in this price range we don't think you could go wrong either way. If you're willing to spend a little more there are also lots of great bikes to check out in our Best Trail Bike Review.

The well-rounded performance of the Jeffsy along with the excellent component spec make it a blast to ride.
The well-rounded performance of the Jeffsy along with the excellent component spec make it a blast to ride.

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.

It may only cost $2 300  but there's no reason to hold back on the Jeffsy  this bike fun to ride.
It may only cost $2,300, but there's no reason to hold back on the Jeffsy, this bike fun to ride.

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 Jeffsy feels comfortable at a huge range of speeds and inspires the confidence to let it rip.
The Jeffsy feels comfortable at a huge range of speeds and inspires the confidence to let it rip.

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.

Testers found the Jeffsy to be highly capable on descents  performing above the asking price of this bike.
Testers found the Jeffsy to be highly capable on descents, performing above the asking price of this bike.

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.

The top of the suspension stroke is quite supportive helping to make this bike a comfortable climber.
The top of the suspension stroke is quite supportive helping to make this bike a comfortable climber.

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.

The Jeffsy is a little heavy  but it's a capable climber regardless.
The Jeffsy is a little heavy, but it's a capable climber regardless.

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.

The build on the Jeffsy is impressive for the price and one of the main reasons this bike performs so well.
The build on the Jeffsy is impressive for the price and one of the main reasons this bike performs so well.

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 has nicely balanced Fox suspension that control its 140mm of front and rear wheel travel.
The Jeffsy has nicely balanced Fox suspension that control its 140mm of front and rear wheel travel.

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 DHR II is a better front tire than most bikes come with in this price range  but we prefer it as a rear tire where its climbing and braking traction is more effective.
The Minion DHR II is a great rear tire  most of our testers run this on the back of their personal bikes.

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.

We have no complaints about the cockpit on the Jeffsy  it's dialed for trail riding.
We have no complaints about the cockpit on the Jeffsy, it's dialed for trail riding.

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.

The SRAM NX Eagle drivetrain has a 34-tooth front ring and an 11-50-tooth cassette that provide a huge range.
The SRAM NX Eagle drivetrain has a 34-tooth front ring and an 11-50-tooth cassette that provide a huge range.

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.

Testing the YT Jeffsy's stability at speed.
Testing the YT Jeffsy's stability at speed.

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.

If you're in the market for a mid-travel do-it-all trail bike we think the Jeffsy is a great value.
If you're in the market for a mid-travel do-it-all trail bike we think the Jeffsy is a great value.

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.

The Jeffsy AL Base is a solid trail bike at any price  it easily wins our Editor's Choice Award for bikes under $2500.
The Jeffsy AL Base is a solid trail bike at any price, it easily wins our Editor's Choice Award for bikes under $2500.

Other Versions


The Jeffsy AL Base we tested is offered in sizes S-XL and in deep blue/magnesium white or concrete grey/black magic (tested). It is also offered with either 29" (tested) or 27.5" wheels. The 27.5" version has 150mm of front and rear wheel travel and a half-degree slacker headtube angle. In fact, YT makes both 29" and 27.5" version of all of their Jeffsy models, prices and components are the same between the two different wheel sizes.
-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.


Jeremy Benson, Kyle Smaine