Specialized Levo Comp Gen 4 Suspension

[Chubba]

Hi @Greg Watts, my current fork is a 160mm FOX FLOAT 36 Rhythm GRIP. What do you think about replacing this with a RockShox ZEB Ultimate? Is it worth the change and what benefit will it have?

 

[Greg Watts]

Hi @Greg Watts, my current form is a 160mm FOX FLOAT 36 Rhythm GRIP. What do you think about replacing this with a RockShox ZEB Ultimate? Is it worth the change and what benefit will it have?

Good upgrade to be thinking about, and the FLOAT 36 Rhythm is the obvious weak link on the Comp Alloy - it's the part most Levo 4 owners flag first. So you're upgrading the right thing.

The honest headline: going from a 36 Rhythm to a ZEB Ultimate is a real, noticeable jump - but it's as much about the chassis and damper grade as it is about the brand.

What you're actually buying: • Stiffer chassis - the ZEB runs 38mm stanchions vs the 36's 36mm. On rocky, rooty Cape Town tech with fast descents, that extra fore-aft stiffness means less flex and more precise tracking when you're loading the front through chunder. This is the biggest real-world gain for your terrain.

• Proper damper - the Rhythm uses Fox's basic GRIP damper (rebound only, no low-speed compression adjustment). The ZEB Ultimate gives you a far more tunable damper with independent high- and low-speed compression. For someone with a suspension bent like yours, that's the difference between "it works" and "I dialled it in."

• Small-bump and support - the Ultimate damper and air spring are simply a higher tier than the Rhythm, so you get more sensitivity off the top and better mid-stroke support.

One thing worth flagging at 80kg: the ZEB Ultimate can be a bit of a faff to tune - some lighter-to-mid riders find it takes fiddling to get genuinely plush, and a few prefer a Fox 38 for that reason. @Astro66 rates the ZEB over a Podium for more downhill capability, while @ntm95 puts the ZEB 3.1 just behind a Fox 38 X2 - so it's not a clear-cut win on plushness alone. Both are big steps up from a Rhythm.

A couple of practical checks before you buy: • Your Levo 4 Comp Alloy runs 180mm front travel as stock - match the ZEB to that, not 160mm. (Your post says 160mm; the EVO platform is 180/170, so worth confirming what's currently on yours.)

• Steerer is tapered, axle is Boost 110×15 - standard, no issues there. Is it worth it? For your riding - yes. Whether ZEB or Fox 38 comes down to feel and tuning patience. Want me to lay the two side by side?

 

[Chubba]

Good upgrade to be thinking about, and the FLOAT 36 Rhythm is the obvious weak link on the Comp Alloy - it's the part most Levo 4 owners flag first. So you're upgrading the right thing.

The honest headline: going from a 36 Rhythm to a ZEB Ultimate is a real, noticeable jump - but it's as much about the chassis and damper grade as it is about the brand.

What you're actually buying: • Stiffer chassis - the ZEB runs 38mm stanchions vs the 36's 36mm. On rocky, rooty Cape Town tech with fast descents, that extra fore-aft stiffness means less flex and more precise tracking when you're loading the front through chunder. This is the biggest real-world gain for your terrain.

• Proper damper - the Rhythm uses Fox's basic GRIP damper (rebound only, no low-speed compression adjustment). The ZEB Ultimate gives you a far more tunable damper with independent high- and low-speed compression. For someone with a suspension bent like yours, that's the difference between "it works" and "I dialled it in."

• Small-bump and support - the Ultimate damper and air spring are simply a higher tier than the Rhythm, so you get more sensitivity off the top and better mid-stroke support.

One thing worth flagging at 80kg: the ZEB Ultimate can be a bit of a faff to tune - some lighter-to-mid riders find it takes fiddling to get genuinely plush, and a few prefer a Fox 38 for that reason. @Astro66 rates the ZEB over a Podium for more downhill capability, while @ntm95 puts the ZEB 3.1 just behind a Fox 38 X2 - so it's not a clear-cut win on plushness alone. Both are big steps up from a Rhythm.

A couple of practical checks before you buy: • Your Levo 4 Comp Alloy runs 180mm front travel as stock - match the ZEB to that, not 160mm. (Your post says 160mm; the EVO platform is 180/170, so worth confirming what's currently on yours.)

• Steerer is tapered, axle is Boost 110×15 - standard, no issues there. Is it worth it? For your riding - yes. Whether ZEB or Fox 38 comes down to feel and tuning patience. Want me to lay the two side by side?

I don’t have an evo, it’s the normal Gen 4. What do you suggest as the best fork replacement? The bike has a 150mm GENIE - FOX FLOAT X Performance shock. Should I look at replacing this?

 

[Greg Watts]

I don’t have an evo, it’s the normal Gen 4. What do you suggest as the best fork replacement? The bike has a 150mm GENIE - FOX FLOAT X Performance shock. Should I look at replacing this?

Fair correction on the platform - thanks for setting me straight, the standard Gen 4 it is. So, two questions in there. Let me take them in order.

The fork. The FLOAT 36 Rhythm is still the obvious upgrade target - basic GRIP damper, rebound-only, and it's the part most owners flag first on the alloy builds. For your terrain (rocky, rooty, fast Cape Town tech) and at 80kg, the two front-runners are:

• ZEB Ultimate - 38mm chassis, Charger 3.1 damper with independent high/low-speed compression. Stiffer front end, more precise tracking when you're loading through chunder. The catch: the 3.1 can be a faff to tune and a few lighter-to-mid riders find it never gets quite as plush as they'd like.

• Fox 38 - also a 38mm chassis, and for a lot of riders the standard 38 is the easier fork to get genuinely comfortable, with GRIP2 giving you the same four-way adjustability. Generally regarded as more "just works" plush than the ZEB for riders in your weight bracket.

Both are a big step up from the Rhythm. Honestly, at 80kg I'd lean Fox 38 for the easier tune - but if you want maximum chassis stiffness and like fiddling, the ZEB's there too.

One genuine thing to confirm before you buy: what front travel your bike actually runs as stock, so you match the fork length rather than guessing. I don't want to quote you the standard Gen 4 Comp's exact travel from memory - I can only stand behind the 180/170mm figure for the EVO, which you've told me you don't have. Check the sticker on your lower or the Specialized spec for your exact model and we'll match to that.

The shock. You've got the FLOAT X Performance with the GENIE air system. Short answer: I wouldn't rush to replace it. The FLOAT X is a genuinely good performer, and GENIE (Specialized's larger-volume air sleeve) is designed to give you more usable mid-stroke and bottom-out support without harshness - it's not a weak link the way the Rhythm fork is. The Performance grade does without low-speed compression vs the Factory, but for most riders that's a "nice to have", not a "need to fix".

I'd do the fork first, ride it a good while, then decide if the shock's actually holding you back. Often it won't be. Want me to lay the ZEB vs 38 side by side on tuning and feel for your weight?

 

[Chubba]

Fair correction on the platform - thanks for setting me straight, the standard Gen 4 it is. So, two questions in there. Let me take them in order.

The fork. The FLOAT 36 Rhythm is still the obvious upgrade target - basic GRIP damper, rebound-only, and it's the part most owners flag first on the alloy builds. For your terrain (rocky, rooty, fast Cape Town tech) and at 80kg, the two front-runners are:

• ZEB Ultimate - 38mm chassis, Charger 3.1 damper with independent high/low-speed compression. Stiffer front end, more precise tracking when you're loading through chunder. The catch: the 3.1 can be a faff to tune and a few lighter-to-mid riders find it never gets quite as plush as they'd like.

• Fox 38 - also a 38mm chassis, and for a lot of riders the standard 38 is the easier fork to get genuinely comfortable, with GRIP2 giving you the same four-way adjustability. Generally regarded as more "just works" plush than the ZEB for riders in your weight bracket.

Both are a big step up from the Rhythm. Honestly, at 80kg I'd lean Fox 38 for the easier tune - but if you want maximum chassis stiffness and like fiddling, the ZEB's there too.

One genuine thing to confirm before you buy: what front travel your bike actually runs as stock, so you match the fork length rather than guessing. I don't want to quote you the standard Gen 4 Comp's exact travel from memory - I can only stand behind the 180/170mm figure for the EVO, which you've told me you don't have. Check the sticker on your lower or the Specialized spec for your exact model and we'll match to that.

The shock. You've got the FLOAT X Performance with the GENIE air system. Short answer: I wouldn't rush to replace it. The FLOAT X is a genuinely good performer, and GENIE (Specialized's larger-volume air sleeve) is designed to give you more usable mid-stroke and bottom-out support without harshness - it's not a weak link the way the Rhythm fork is. The Performance grade does without low-speed compression vs the Factory, but for most riders that's a "nice to have", not a "need to fix".

I'd do the fork first, ride it a good while, then decide if the shock's actually holding you back. Often it won't be. Want me to lay the ZEB vs 38 side by side on tuning and feel for your weight?

Body weight it 96kgs, bike is 160/150.

 

[Greg Watts]

Body weight it 96kgs, bike is 160/150.

Two useful updates - thanks for those. Weight: 96kg (updating from the 80kg I had on file - that changes the suspension picture a bit)

Travel: 160/150mm - so a proper trail bike setup, not the enduro EVO numbers I was wrongly working from earlier. The fork

At 96kg on rocky Cape Town tech, the case for the ZEB over the Fox 38 gets stronger. The extra chassis stiffness of those 38mm stanchions earns its keep at your weight - you'll load the front hard on fast, choppy descents, and a flexy fork is the last thing you want. The ZEB Ultimate's damper also gives you the independent high/low-speed compression to tune it properly for your weight; the stock Rhythm simply doesn't have that. Both the ZEB Ultimate and Fox 38 Factory are solid choices here, but at 96kg the ZEB's stiffness-first character suits you well.

The shock - worth revisiting now I said earlier not to rush on the shock, but at 96kg that's worth a second look. The FLOAT X Performance is a capable shock, but the Performance grade lacks low-speed compression adjustment - and at your weight on technical terrain, being able to fine-tune support through the stroke matters more than it would at, say, 75kg. A FLOAT X Factory gives you that control, or if you want to go further, a coil conversion (Fox DHX2 or RockShox Super Deluxe Coil) is worth considering - coils can feel more supple and consistent under sustained loading, which suits heavier riders on demanding trails.

Still do the fork first. But the shock's a closer second than I suggested before.

 

[Chubba]

Two useful updates - thanks for those. Weight: 96kg (updating from the 80kg I had on file - that changes the suspension picture a bit)

Travel: 160/150mm - so a proper trail bike setup, not the enduro EVO numbers I was wrongly working from earlier. The fork

At 96kg on rocky Cape Town tech, the case for the ZEB over the Fox 38 gets stronger. The extra chassis stiffness of those 38mm stanchions earns its keep at your weight - you'll load the front hard on fast, choppy descents, and a flexy fork is the last thing you want. The ZEB Ultimate's damper also gives you the independent high/low-speed compression to tune it properly for your weight; the stock Rhythm simply doesn't have that. Both the ZEB Ultimate and Fox 38 Factory are solid choices here, but at 96kg the ZEB's stiffness-first character suits you well.

The shock - worth revisiting now I said earlier not to rush on the shock, but at 96kg that's worth a second look. The FLOAT X Performance is a capable shock, but the Performance grade lacks low-speed compression adjustment - and at your weight on technical terrain, being able to fine-tune support through the stroke matters more than it would at, say, 75kg. A FLOAT X Factory gives you that control, or if you want to go further, a coil conversion (Fox DHX2 or RockShox Super Deluxe Coil) is worth considering - coils can feel more supple and consistent under sustained loading, which suits heavier riders on demanding trails.

Still do the fork first. But the shock's a closer second than I suggested before.

Thanks. Please give me the specific model details and specs of both the Zeb and factory shock for the Levo Gen 4 Product ID 221343.

 

[Greg Watts]

Thanks. Please give me the specific model details and specs of both the Zeb and factory shock for the Levo Gen 4 Product ID 221343.

Happy to give you exact models - but I want to give you the right ones, not numbers I've half-remembered.

Here's the honest position: Product ID 221343 isn't in my verified database, and I couldn't pull its confirmed stock spec from a search either. So rather than guess your bike's exact fork length and shock dimensions, let me tell you what to grab and what to match - then the kit picks itself.

What to check on your bike (two minutes): • Fork lower sticker - confirms travel (160mm) and gives you the exact model.

• Shock - the eye-to-eye and stroke are printed on the body or the sticker (e.g. 210×55, 205×60 etc). That number is what you must match.

The ZEB (fork) For 160mm travel at 96kg, you want:

• RockShox ZEB Ultimate, 160mm, 29", Boost 110×15, tapered steerer, Charger 3.1 damper, DebonAir+ spring.

That's the trim with the proper high/low-speed compression adjustment - the bit that earns its keep at your weight. Just make sure you order it at 160mm, not 170 or 180, so you don't slacken your geometry by accident.

The Factory shock • Fox FLOAT X Factory - same air platform as your current Performance, but the Factory grade adds the 2-position lever with low-speed compression adjust and the better seals/finish. Order it in your shock's exact eye-to-eye × stroke (read it off the current shock) so it bolts straight in.

• One wrinkle worth flagging: your current FLOAT X runs Specialized's GENIE air sleeve. A standard aftermarket FLOAT X Factory won't have GENIE - it'll be a normal large-volume air can. Still a good shock, but it's not a like-for-like on the air spring, so worth knowing before you spend.

Once you've got the model off the fork and the dimensions off the shock, fire them back and I'll sanity-check fitment and we can talk setup for 96kg.

Tag me anytime - good luck with the build, @Chubba.

 

[Chubba]

Happy to give you exact models - but I want to give you the right ones, not numbers I've half-remembered.

Here's the honest position: Product ID 221343 isn't in my verified database, and I couldn't pull its confirmed stock spec from a search either. So rather than guess your bike's exact fork length and shock dimensions, let me tell you what to grab and what to match - then the kit picks itself.

What to check on your bike (two minutes): • Fork lower sticker - confirms travel (160mm) and gives you the exact model.

• Shock - the eye-to-eye and stroke are printed on the body or the sticker (e.g. 210×55, 205×60 etc). That number is what you must match.

The ZEB (fork) For 160mm travel at 96kg, you want:

• RockShox ZEB Ultimate, 160mm, 29", Boost 110×15, tapered steerer, Charger 3.1 damper, DebonAir+ spring.

That's the trim with the proper high/low-speed compression adjustment - the bit that earns its keep at your weight. Just make sure you order it at 160mm, not 170 or 180, so you don't slacken your geometry by accident.

The Factory shock • Fox FLOAT X Factory - same air platform as your current Performance, but the Factory grade adds the 2-position lever with low-speed compression adjust and the better seals/finish. Order it in your shock's exact eye-to-eye × stroke (read it off the current shock) so it bolts straight in.

• One wrinkle worth flagging: your current FLOAT X runs Specialized's GENIE air sleeve. A standard aftermarket FLOAT X Factory won't have GENIE - it'll be a normal large-volume air can. Still a good shock, but it's not a like-for-like on the air spring, so worth knowing before you spend.

Once you've got the model off the fork and the dimensions off the shock, fire them back and I'll sanity-check fitment and we can talk setup for 96kg.

Tag me anytime - good luck with the build, @Chubba.

2026_25 RHYTHM SERIES 36 FLOAT 29 160MM GRIP​

Serial number: 1187751-0051-T
Part number: 910-27-194
Description: 2026_25, 36, A, FLOAT, 29in, Rhythm, 160, Grip, Sweep-Adj, Matte Blk, Std/Matte Blk Logo, Kabolt X 110, BLK, 1.5 T, 58HT, 44mm Rake, N/M OE

 

[Greg Watts]

2026_25 RHYTHM SERIES 36 FLOAT 29 160MM GRIP Serial number: 1187751-0051-T Part number: 910-27-194 Description: 2026_25, 36, A, FLOAT, 29in, Rhythm, 160, Grip, Sweep-Adj, Matte Blk, Std/Matte Blk Logo, Kabolt X 110, BLK, 1.5 T, 58HT, 44mm Rake, N/M OE

Good stuff - that's exactly what I needed. The sticker confirms everything: Your fork: Fox FLOAT 36, 29", 160mm travel, GRIP damper (Sweep-Adj rebound only), Kabolt X 110 Boost axle, 1.5T tapered steerer, 44mm offset, 58HT (so a 58mm head tube).

That's your confirmed spec to match against. Here's what it means for the upgrade: ZEB Ultimate - confirmed fitment:

• 29", 160mm - match the travel exactly • Boost 110×15 axle - direct swap ✓

• 1.5T tapered steerer - direct swap ✓ • 44mm offset - match this. The ZEB comes in 44mm or 51mm; you want 44mm to keep your handling geometry where it is

So the exact model to search for: RockShox ZEB Ultimate, 29", 160mm, 44mm offset, Boost 110×15, tapered steerer. The Charger 3.1 damper and DebonAir+ spring are standard on the Ultimate trim - that's the one with full high/low-speed compression adjustment.

One thing worth noting: your current fork has a 58mm head tube. The ZEB's steerer will be cut to length on fitting - no issue there, just flag it to whoever's doing the install.

Also: (5 posts from the ton, @Chubba - nearly there )

 

[Chubba]

Good stuff - that's exactly what I needed. The sticker confirms everything: Your fork: Fox FLOAT 36, 29", 160mm travel, GRIP damper (Sweep-Adj rebound only), Kabolt X 110 Boost axle, 1.5T tapered steerer, 44mm offset, 58HT (so a 58mm head tube).

That's your confirmed spec to match against. Here's what it means for the upgrade: ZEB Ultimate - confirmed fitment:

• 29", 160mm - match the travel exactly • Boost 110×15 axle - direct swap ✓

• 1.5T tapered steerer - direct swap ✓ • 44mm offset - match this. The ZEB comes in 44mm or 51mm; you want 44mm to keep your handling geometry where it is

So the exact model to search for: RockShox ZEB Ultimate, 29", 160mm, 44mm offset, Boost 110×15, tapered steerer. The Charger 3.1 damper and DebonAir+ spring are standard on the Ultimate trim - that's the one with full high/low-speed compression adjustment.

One thing worth noting: your current fork has a 58mm head tube. The ZEB's steerer will be cut to length on fitting - no issue there, just flag it to whoever's doing the install.

Also: (5 posts from the ton, @Chubba - nearly there )

Is it worth replacing the rims and hubs in the future? Is so, with what? I don’t want carbon so allu recommendations.
Rims
Specialized, hookless alloy, 30mm inner width, tubeless ready
Front Hub
Alloy, sealed cartridge bearings, 15x110mm thru-axle, 28h
Rear Hub
Alloy, sealed cartridge bearings, 12x148mm thru-axle, 32h
Spokes
DT Swiss Industry

 

[Greg Watts]

Is it worth replacing the rims and hubs in the future? Is so, with what? I don’t want carbon so allu recommendations. Rims Specialized, hookless alloy, 30mm inner width, tubeless ready Front Hub Alloy, sealed cartridge bearings, 15x110mm thru-axle, 28h Rear Hub Alloy, sealed cartridge bearings, 12x1...

Honest answer: the stock wheels are a sensible "ride them until they give you a reason" component, not a weak link like the Rhythm fork was. Specialized's hookless alloy rims with sealed-cartridge alloy hubs and DT Swiss spokes are a perfectly decent OE package. At 96kg on rocky, rooty Cape Town tech you'll find out soon enough if they're up to it - dented rims, loose spokes, or hub play are the tells. Until then, I wouldn't spend.

When you do want to upgrade, here's what matters more than the badge: Rims - staying alloy is a sound call at your weight on sharp rock; alloy dents where carbon can crack, and a dent still rolls home. Good alloy options:

• DT Swiss EX511 - the go-to tough enduro alloy rim, 30mm internal, takes a beating from heavier riders. • WTB KOM Tough / Stan's Flow EX3 - both proven, burly 30mm alloy hoops.

Stick around your current 30mm internal width so your 2.4" tyres keep their profile. Hubs - where money actually buys you something. The stock sealed-cartridge hubs are fine but basic; a faster-engaging, better-sealed hub is the real felt upgrade, especially for grunting up techy climbs where instant pickup helps:

• DT Swiss 350 - workhorse, dead reliable, Ratchet system, easy to service. The sensible default. • Hope Pro 5 - UK-made, great bearings, loud, and Hope's spares support is genuinely good wherever you are.

Match the drilling and axle standards you've got: 110×15 front, 148×12 rear, and whatever rotor mount and freehub (likely SRAM XD/T-Type) your current setup runs - confirm the spoke count when you build so the wheelbuilder laces to the right rims.

My steer: don't buy wheels speculatively. Ride the fork upgrade first, and if a rim takes a hit or the hubs start feeling notchy, build a set on DT 350s or Hope Pro 5s with EX511s. That's a wheelset that'll outlast the bike.

Get the fork sorted first though - that's the upgrade you'll feel on every single ride.