tony_swift

The suspension system on the Sirrus, called Future Shock, is supposed to be great because it's lighter. However when compared to what's used on Trek's DS4, it isn't clear to me that it's superior, for the following reasons.

1. On the DS4, because it's using fork suspension, the whole rider is being protected by the suspension, not just the rider's arms as is the case with the Future Shock.
2. The suspension on the DS4 can be locked out, I didn't see a lock out feature on the Sirrus.
3. The DS4 suspension has a longer length of travel.

What do you guys think about these points? Am I missing anything here?

DorkDisk

In the early 90s, MTBs were very popular. The skinny light steel bikes were very similar at that point to road bikes but the riding was evolving. Suspension was an obvious development and eventually two philosophies emerged at this early stage:

1/ suspend the rider
2/ suspend the bike

Suspend the bike used a fork; the advantage is that the wheel tracks the ground and improves traction. The disadvantage is weight and mechanical complexity.

Suspend the rider used a suspension stem; the advantage is comfort and simplicity but zero traction

For MTB, wheel traction is a huge asset. Suspension allows one to stay seated and roll over everything; greatly reducing fatigue and improving speed as one can focus on the fastest line.

Lately, suspension stems are coming back to the market for road and gravel bikes. This industry likes to rehash old ideas. FWIW, Hank D won 3 XC world championships with an Allsop stem for Team Ritchey before suspension forks took over.

travbikeman

While I see the new Sirrus with the new suspension as really cool, I am always worried about proprietary parts. We had a recent thread on this forum (don't feel like looking for it) asking if regular Sirrus could be upgraded to this new suspension.

Looking at the schematics of this suspension, it involves replacing not just the headset, but the fork is a specific fork to the new suspension. Meaning to me, that you can't just change out one part for various upgrades with out changing the whole system.

Most likely not a big deal for anyone really wanting these bikes. But just food for thought if something breaks in the future and well, suspension does wear out and possibly break.

The fork suspensions are easily changed out for a better suspension or non suspension forks in the future.

DorkDisk

They're different bikes for different types of riding; I'd start there instead before comparing suspension systems.

badger1

This. The comparison in the OP apples and oranges.

badger1

True, the FS system is frame-specific and completely proprietary. Normally, that would have been a deal-breaker for me; heck, I don't even like press-fit b/bs.

However, I knew that going in and, for me, the FS worked exactly as advertised, and did exactly what Specialized claims it does. I was comparing my older Sirrus with a new FS one; same tires/pressure/fit (I have a great LBS) -- I bought the bike (2019 X Comp, now the X 5.0). For me, the benefits were/are real and outweighed the drawbacks of proprietary stuff.

Speedway2

tony_swift.....are you asking because you're thinking about buying a bike with either system? If yes....I'm wondering why you feel the need to.
I'm in the KISS camp and not a fan of budget suspension systems. They add weight, expense, potentially more maintenance/repair, etc.

tony_swift

I don't think that I need suspension, I just think that maybe it smooths out the ride and makes it easier.

Anyway after reading lots of posts about how suspension isn't good or required for the kind of riding I'm interested in, I decided to get an FX4.

Speedway2

Congrats on the FX4! It should give you many miles of enjoyment.

If you want to smooth out the ride a bit adjust the tire pressure(within specs). If you need a smoother ride then do your research on a different set of tires.

Post some pics. We love pics

Mojo31

Nice choice.

Suspensions do smooth out the ride, but they don't make it any easier from a cardio perspective. I have a Sirrus 4.0, and cross-shopped it with the FX4 last summer. Might have gone with the FX4, but couldn't find one. I found that the suspension on that type of bike is not needed.