Sette Serum Pro Review: Part 2

As I noted in the last two posts, I bought a Sette Serum Pro to replace my ancient Mongoose mountain bike.

The Serum Pro is carbon light…haven’t weighed it but the specs claim 22.56 pounds for my 19″ size and I believe it. My old bike was in the 22-24 pound range depending on what was on it at the time for parts and this new ride is right in there.

I have some initial ride impressions to relate after a few miles both off and on road with it. I did end up putting a seatpost with a more normal set-back to the clamp on it which got the saddle back to where it should be for me. I also put a 120mm stem on, but this is still a tad short. I may eventually put a 130 mm on it but I’m waiting to transfer my bar ends over before I get too pissy. I initially hadn’t done anything to the forks except twiddle the dials…I did put the air pressure up to 120 psi for the last couple of rides.

So far, the bike is fantastic. Bottom Bracket and rear stay flex under heavy pedal pressure is probably my starting point for evaluating a frame and this one is rock steady. Jumps out just as you would want with no sign of weaseling or flex. I had been riding the Shimano external cup bottom bracket with SLX cranks for at least a year on the old rig so I’m not attributing it to that at all. Frame is solid.

Interestingly the XT M775 wheelset is a 24 spoke count…I’m used to 32 as a minimum and I was a bit worried. No sign of problem yet. They seem sufficiently stiff under heavy pedaling and under cornering….within the limits of the Kenda Small block 8 tires. This will be an area of interest in the long-term test situation.

My second point of consideration is the frame stability under turning and it is coming though with flying colors. Good design.

The M770 9speed Shimano XT shift train is excellent, as expected. They have seemingly returned to a more “positive” feel to the shifters. This means it clicks and clunks solidly so you know you are making a change. I like this. I did not like the ever-softening and quieting approach they were taking late 90s and into the 00s.

I am definitely still working on the fork. It has a lot more travel and compliance (springiness) then I am used to. Some of this may be set-up and some of this is undoubtedly that modern forks specified on a XC race-style MTB are designed for more activity than the old Mag21 I had. Which, btw, has probably been relatively immobile relative to original design for years since I’ve never done any recent maintenance on it. My issues with the Fox 32 F100 R Open Bath is that it is too soft for my (current) taste. The wheel drops down when you pull up on the bars, making quick elevations over bumps and curbs different from what I expect. This is intentional, I should note, as a way to improve bump compliance when you are not trying to lift the wheel. Correspondingly I’m fiddling with the compression damping (big lever, easy to switch on the fly) and the rebound damping knob (not so easy on the fly) to adjust the ride. The other problem of this squishiness is that the front end bobs when standing up out of the saddle on hills. This is something that needs to be fixed for my style of riding. Putting the compression lever all the way up helps and I may have to live with this.

Hey, going from a rigid fork to my original Mag21 took some adjustment too!

The on-road feel is a pretty good way to evaluate a MTB as well and the Serum has been good there too. It doesn’t resonate with the tires or ping or click or anything that I associate with Al frames. The frame is solid on-road too, where tire grip is good and one can really crank in the big ring. Instability in high speed cornering is minimal and right now I’m putting this down to the fork and my unfamiliarity with it / possible failure to set it up properly. The bars and stem are stiff, maybe even stiffer than I’d like. I have a 110 gram titanium bar on the old bike that, amazingly, is still alive and well. It was always a little tiny bit flexy which I actually liked.

The oversized seatpost specification seems to make up for a rather hefty bit of mast I have showing. Let me note that I have never been a fan of the sloping top-tube design. This one has more of it than my last one did which means slightly more seatpost is used. This has the potential to be flexy but I’m not noticing anything. The extra diameter over what was spec’d on my old bike may be the difference here…or perhaps my fears of flex from the seat post were simply unfounded.

So, to conclude from the first few rides, this bike is light, stiff and everything I expected in a carbon frame. I have the fit nearly dialed in so I can get to riding. The only spot of weirdness is going to be the suspension fork although this is down to my tweaking the adjustments and learning to ride with a modern type of fork.