Hands up if you're old enough to remember the original blue RockShox SID. It launched in 1998, when XC racing was arguably at its peak, two years after the first time it was included in the Summer Olympics. The fork might have only had 63mm of travel, but it had a huge impact on the XC scene and has gone on to carve quite a legacy as the benchmark XC race fork, racking up countless race wins from local league to World Cup level.
This latest SID was launched as part of RockShox’s Signature Series line, which also includes the Pike and Lyrik. The fundamental chassis design for the SID hasn’t changed, but the foil graphics are new and there’s now new Maxima Plush damping fluid which is aimed at reducing friction and noise. The air-sprung fork uses a Charger 2 damper with an XC-oriented tune for more support during those out-of-the-saddle uphill sprints.
RockShox SID Ultimate Carbon Details
• Intended use: XC / marathon
• Wheel size: 27.5'' or 29''
• Travel: 100mm only
• Carbon fiber crown and steerer
• 2-position compression adjustment
• Boost thru-axle
• Offset: 42mm (27.5"), 42mm (29"), 51mm (29")
• Weight: 29" - 1,477g (3.18lb) actual weight (uncut steerer)
• Price: $999 USD
• www.sram.com Chassis DetailsSID, by the way, stands for Superlight Integrated Design and this top-level Ultimate Carbon model is a superb expression of that tagline. It’s a 100mm travel fork, no more or less than XC racers really need, with a carbon fiber crown integrated into the carbon steerer tube. More modestly priced versions with aluminum steerers are available, including the SID Ultimate which uses an aluminum steerer tube and crown to save money, and is offered in a 120mm version for riders who want more confidence and comfort on rough tracks. All forks have Boost spacing and a choice of 29 or 27.5" wheel sizes, and 42mm offset on both and an extra 51mm offset option on the 29" version.
The Ultimate Carbon combines the aforementioned carbon fiber steerer tube, tapered from 1.5” to 1 1/8” with an integrated bearing race. The lower legs are made from magnesium with as much material removed as possible to save weight, especially around machined dropouts compatible with SRAM's Torque Cap. I tested the 29" and 42mm offset version, and all forks have 15x110mm Boost width axle spacing. The 32mm diameter stanchions have sag markings neatly printed on them for easier setup.
Weight is critical for XC racers. Less weight obviously means you’ll get to the top of the climb quicker and with less energy expended, but it’s a fine line between being light and stiff, durable and reliable. On the scales, the 29” Boost fork with an uncut steerer tube is 1,477g.
SetupInstalling the fork was a breeze. I used a carbon-specific hacksaw to trim the carbon steerer tube to the desired length. A supplied headset compression bung cinches the stem and spacers down onto the frame, and I had no problems getting it all straight and tight.
Setting the air pressure is made easy with sag markings on the legs, plus a recommended air pressure chart on the back of the leg. There's even a handy app so getting up and running with a good setup is made as easy as having a mechanic do the job for you. Further tuning is available with Bottomless Tokens; two are fitted as standard and you get a small bag of spares so you can add more if you need. Adding or indeed removing tokens is simply a case of removing the top cap with a cassette lockring tool. I settled on 70 psi with two tokens.
PerformanceWhen you’re racing or riding on the limit you want your XC suspension fork to get on with the business of smoothing the rough while going largely unnoticed, with no excessive bob impacting speed on smooth trails and climbs. The SID delivered all of this, wrapped up in a lightweight and stiff package with easy tunability. It dealt with everything with buttery smoothness and adequate control, and handled all manner of impacts from square-edge ugliness to high-frequency ripples and smaller rocks and roots without any fuss. The damping ensures the fork recovers extremely well from successive big impacts and is ready for the next.
When you’ve got a mere 100mm of travel to play with, the suspension curve needs to work hard, ensuring you have a supple early stroke for dealing with small chitter-chatter that can buzz the handlebars, yet ramp up sufficiently to prevent bottom out over drops and jumps. The SID manages this tricky balance well. There's a smooth progression to full travel with no harsh bottoming out even if you ride like a complete ham-fisted idiot. On-the-fly adjustment is limited to open or locked out, but you can adjust the low-speed compression of the open model so you can tune the fork to suit different courses, say if one is really smooth and another is full of chundery rocks. The range of rebound damping is ample so you can run it quick or slow to suit your preference.
Measuring the stiffness of a fork outside of a rigorous lab test in the real world is a tricky old thing to assess, and there are so many variables, not least rider weight. Weighing in at about 150 lb / 68kg (on a good day) I didn't find the fork to flutter down the harder descents on my local trails or go vague when slamming into tight corners after a bunch of frantic braking to get the speed down low enough to be able to swing around the corner. The all-carbon steerer tube and the crown really aren't just for show and weight loss, it does seem to deliver impressive stiffness ensuring the front wheel goes where you point it, even when you're redlining and puking up your lungs. The steering is precise, it manages heavy braking and it's stout when you're heaving on the bars up a punchy climb.
Talking of climbing, the SID damping is well-suited when you're battling with the cruel mistress that is gravity. Whether you’re spinning a low gear on a smooth fire road or mashing a big gear out of the saddle up a rough boulder-strewn track, the SID fork didn't bob excessively - it just feel composed and stable. The Charger 2 damper prevents unwanted movement giving you maximum efficiency when you're on your limit and trying to extra every ounce of power to keep ahead or alongside your main rival in a race.
You can easily lock out the fork on the move with a flick of the Charger 2 dial. XC racers will probably want the optional OneLoc remote control for adjusting on the fly, but away from races and on fast trail rides where I wasn't against the clock I simply left the fork in the open mode, because it's composed enough that you don't feel at a loss in any situation. It would be nice to have a third 'trail' mode as with the Fox 32, though, for a bit more choice between fully open and locked out. The lockout mode does have a blow-off valve so if you forget to flick the switch before hitting a rough trail you won't blow your wrists to a thousand pieces when you hit the first obstacle.
How does it compare?The obvious comparison to make is with the
Fox 32 StepCast I recently reviewed. Both offer 100mm of travel, but if weight is a major factor in your buying decision, there’s no getting away from the fact that despite its obvious lack of carbon fiber, the Fox is the lighter fork. Granted, only by 34 grams, but grams are grams. When it comes to stiffness, I honestly couldn't detect a substantial difference between the two forks - they both felt solid with precise steering.
Suspension performance is very similar on the two forks too. Each fork can be tuned with volume tokens and there's also low-speed compression adjustment on the top dial so you can make small changes with no tools before a race, or bigger changes back at the pits. The Fox provides a bit more on-the-fly adjustment with three compression modes available from the top dial, while the SID is limited to open and locked. Testing both forks with the same volume tokens (1 per fork) and the same sag produced in the SID a more supportive feeling fork that was less active on the smaller bumps, whilst the Fox was more sensitive and active to smaller impacts. Both displayed good bottom-out resistance with ample progression when you land jumps or hit big holes.
Splitting differences then is tricky. They both offer top-level performance that any racer would be more than happy with. Both are high end forks providing top-level performance and each is offered in cheaper versions if money is a factor. Whichever fork you choose you’re not going to be unhappy.
Pros
+ Controlled, predictable, and smooth damping
+ Easy to set up
Cons
- Not the absolute lightest in this category
- Only 2-way adjustment
true mountainbike innovation
Not sure but I am sure that the fox was better on the downhills for some reason. LOL
This is the entirety of the review. The introduction is just a spec sheet put to words, the midsection is a description of mountain biking, and this is the attempt at product evaluation.
Either Mr. Arthur is unable to differentiate between products or these are the most similar forks ever created. The latter is possible. If so, don't be satisfied publishing this low-effort crap. Create or borrow a test fixture and measure stiffness. Send them to a suspension tuner with a dyno and have the dampers compared. Put a bending load on them and test binding. Do something - ANYTHING - but whatever you do, do better than this.
Also, most if not all suspension reviews whether it is motorcycle, auto, or even over priced mountain bike products only get into the subjective terms. "Feels good man" is all you can expect.
Bike geeks gonna bike geek.
Also, is it a surprise they are fairly similar?
No, it's not surprising the forks felt similar. They are, after all, highly evolved products in a well-established category. I'll bet they feel more different than road bikes in the same category, though, yet reviewers still manage to differentiate between those. Or, if they really are that similar, then compare them to the next model down to determine whether *all* forks now feel the same or flagship products are still worth the money.
A meaningful comparison with actionable observations will always be possible. If this reviewer can't do it, hire someone who can.
Depends on the ass I suppose...
Tapping the rods out of the lowers isn't too bad with a socket or right on the nut when there is no rebound adjustment shaft coming through the middle of the rod. Done it hundreds of times with no problem, seen it done at least a thousand times with no problem. Just definitely go by the recommended torque value when tightening those nuts back on. I've seen those break several times on RS and fox, but the fox ones seemed more sensitive, a few Newton's over torque and it is a sad day.
Regarding the crush washers: I don't exclusively open my forks to do a whole service. Sometimes I just check the grease or replace the bath oil. When following Fox instructions, one should replace them everytime you open the fork (which is obviously ridiculous).
You don't have to replace the crush washers everytime. It is just cheap insurance that you won't leak out your lowers oil. Both RS and Fox have that design but they are super cheap. Just saw a bag of 50 RS ones for $8.
It's one of the reasons (next to performance and value for money) that I prefer brands like Manitou (but they aren't the only ones I'd prefer to Fox).
My Mattoc is so much easier to work on than my Float 34, only requiring a slotted cassette tool and a thin wall 8mm socket as 'special' tools, both of which can be bought and modified if needed for far less then the Fox tools, are actually necessary from an engineering standpoint (instead of a sales standpoint) and can be bought from Hayes as a set costing less than a single removal tool for the 34 (of which I for some stupid reason require 2).
Keep in mind: a €100 tool for a €800 fork (which is also needed on their €500 forks) corresponds to a €5,000 tool on a €40,000 car. Would you be okay with that?
edit: €5,000 tool for a €40,000 part of a car.
Rock Shox SID Ultimate 2020 : torsional stiffness 25.9 Nm/°, brake stiffness 166.9 Nm/°.
Fox 32 Float Factory Fit4 SC 2020 : torsional stiffness 14.8 Nm/°, brake stiffness 175.7 Nm/°.
Both rated 'super'.
Fox 32 Float Factory Fit4 SC 2017 : torsional stiffness 10.8 Nm/°, brake stiffness 117.7 Nm/°.
More info here : www.bike-magazin.de/komponenten/federgabeln_daempfer/test-2017-federgabeln-fuer-tour-und-race/a36760-page4.html
The Rockshox RS-1 2015 fork's torsional stiffness was a lotgreater than the old Fox step cast 32 and nearly identical to the new chassis.
Rockshox RS-1 2015 : torsional stiffness 14 Nm/°, brake stiffness 265.5 Nm/°.
Rated 'super'.
More info here : www.bike-magazin.de/komponenten/federgabeln_daempfer/test-cross-country-federgabeln-2015-rock-shox-rs-1-29/a27859.html
... except for (really) supple forks that'll move out of phase. In this case the forks will have it's own ways so you are able to tell if it's moving without permission.
Still couldn't compete with Cannondale Headshock though, which was by far the best performing fork for years until travel started to kick up over 70mm.
"...and RockShox has bonded an alloy bearing crown in place - the headset bearings simply plops straight on top." Not simply misleading, but actually incorrect, and dangerous if somebody takes this literally.
OK!
No.
Actually it's a feature.
Pretty sure you can just pop a new damper in the same chassis. Correct me if i'm wrong.
After 8 years, you can still upgrade the internals and make it feel all new. That's pretty cool
Is the reviewer seriously saying that he doesn't know how the low speed compression adjuster knob works? Is he trying to adjust it with the allen key bolt that holds the adjuster assembly together? .
Marz came next with innovations in damping and longer travel, and then Fox hit the scene and was the first to deliver the whole package together with a high quality modern stiff chassis, decent air spring, and shim stack open bath damper in the same fork. IMO Fox really changed the game. RS didn't catch up until the Charger damper models, and Manitou faded away. Marz continued innovating in freeride/downhill, but didn't compete in lightweight trail/xc chassis until it was way too late.
WHATTTT???
Actually carbon fiber has 2 to 5 times more rigidity (depending on the fiber used) than aluminium and steel. Here is an interesting link: www.dexcraft.com/articles/carbon-fiber-composites/aluminium-vs-carbon-fiber-comparison-of-materials
7075 heat treated Aluminum has a Gpa up to 570!
7075 heat treated Aluminum has a significantly higher tensile strength.
This is one property of materials. I could research modulus of elasticity, shear strength ECT.
Thing is carbon fiber also has epoxy in the matrix. Too many variables.
My first dive into research found Aluminum to be much stronger than carbon fiber.
For example,a component made from standard carbon fiber of the same thickness as an aluminium one will offer 31% more rigidity than the aluminium one and at the same time weight 50% less and have 60% more strength. Use of carbon fiber of higher modulus and one-direction fabric may provide x 4 times the rigidity compared to aluminium.
Furthermore, the stiffness to weight ratio of carbon fiber is five times greater than that of aluminum. Carbon fiber will demonstrate more elasticity and, after momentary bending, will restore its shape following release of the loading (spring back effect), unlike aluminium, which can permanently bend. However, fabrics of highest modulus – will offer less resistance to damage. The more a component is reinforced with fabrics of highest modulus, the more it will be susceptible to breaking during bending. This where the expertise and knowledge comes in when using carbon fiber and why we see big differences in the manufacturing process between companies.
I have been into high end materials for a long time (RC's) and have had many aluminum frames, and even had an exotic "Scandium" Rocky Mountain frame, but would choose carbon fiber
Carbon fiber rims can be as light as 400 grams maybe a few grams less. The best Aluminum rims of the same size are about 450 grams. In theory one should be able to make a 250 gram rim that is 60 percent stonger with carbon fiber. According to your facts we should be able to have four pound DH frames and 250 gram rims made of carbon fiber. I trust the material that does the best job for the application. I see a slight reduction in weight with an extra 1000$ added to a frame and 300$ for a rim to save a few grams.
I'm not all impressed with carbon fiber.
But I digress.
The blog that was posted does not specify where they got the results from . I researched actual manafacturers of Al. and toray hi modulas carbon fiber. I also stated that areospace industry uses carbon fiber.
So why do we not have four pound carbon fiber DH frames. My guess an areospace engineer makes perhaps 100, 000 to 150, 000 dollars a year and would be at the top score in university. An engineer fresh out of university in a bike company probably makes 50,000 dollars a year to use a computer program that any one can buy. An areospace engineer would use proprietary software that you can't buy in fact they would hire an engineer to write to code for the software. A bike company then lets an out side source( China) to manafacture the frame . No comparison. Bike companies are not doing billion dollar contracts. No comparison.
Google how well carbon fiber cranks are for longevity. Far too many cranks fail.
Carbon fiber may be superior in theory but it's on par with Aluminum frames for strength to weight ratio not half the weight as the blog suggest.
Fork crowns are made from 2014 Aluminum for it's the best material for 3d forging.
These two forks suggest that 3d forged aluminum is superior to carbon fiber.
The bike industry is run by underpaid people that have a passion for bikes. The profit is minimal. The engineering is a joke compared to the areospace industry .
I'm a naive twit when it comes to the engineering aspects of bike manafacture. If you want better clarification do what I do . Give RC a PM with your question s . That man knows the bike industry better than any other individual.
crown race, carbon steerer also stolen from G-A