After our introduction of Plan b here, and talking about the line of thinking that went into that decision, there were things going on that shaped how I looked at the model choice and there was some parts swapping. Those changes were made. Then I went riding.
So let’s take a look at the biggest improvement.
Wheels and Tires – How do we look at rim width for Plus?
The stocker Comp Carbon wheels are pretty plain jane. The Expert Carbon gets a step up in wheel quality with the Roval Traverse wheelset including DT Swiss internals (I suspect they are not Star Ratchet though but DT 360 based). That is part of the one grand price increase over the Comp Carbon which has wheels listed as Specialized Disc. The rim width is the same however. I have read (but not confirmed) that the weight difference is 1/2 pound between the two wheel sets.
I cannot think of anything that so impacts the feel of a bike as wheels and tires. A wheel and tire swap can turn a doggy bike into a fun mount. So even if I had bought the pricier Expert model 6Fattie, I still would have upgraded wheels. But what wheels to upgrade to? And more accurately, what inner width is right for Plus tires?
This used to be so simple. In the old days, we only ran wider rims if we needed stronger wheels. So most of the time we never paid much attention to rim width, although when Keith Bontrager rolled down some Mavic MA40s to 26″ size, that was a step into shedding wheel weight, but a step in the wrong direction for increased tire support.
But lately we have learned that a wider rim (now I am referring to the inner, or internal width in all cases) is a very nice thing. On road bikes, likely spurred on by the Adventure/Gravel genre, rims are getting wider too. 19mm-20mm would not be unusual now. MTB rims in 29er land at present would be typically 25mm-29mm internal. What we are buying with this increased width is the ability to run our tires at reduced air pressures and still have good sidewall support, avoiding a squirmy tire while still increasing traction and comfort.
And when Plus came along, it brought with it REALLY wide rims like 40mm and more. It makes sense, does it not? If a 29×2.3 tire favors a wheel like the 29mm internal American Classic Wide Lightning, then a 3.0″ tire should get a commensurate increase in rim width to be equally happy. That rim does begin to get pretty heavy though, as it gets wider. There is a trade-off here we need to look at, because if our tire weight increases, like it does with the typical Plus tire over a typical 29er tire, AND the wheels get much heavier, then that is not a great thing.
But do they need to be really wide, those Plus rims? If increased rim width is driven by the desire to run lower tire pressures, then, if pressures are NOT lowered, there is not much reason to run the wider, heavier rim. When I was running 25psi and above on 21mm internal MTB rims with a 29er tire, I never noticed any squirm issues. But the wider rims allow me to go to 21psi and even below 20psi and still be pretty solid. So where does that fit in with Plus tires?
On the bikepacking Plus bike, I typically run 15psi or so depending on the trip. I could go to 13psi with no issues and the rims are close to 40mm internal. That provides a lot of support for the 3.0 tire and it works to increase comfort a great deal. But the 6Fattie will see much higher speeds than the little hardtail will. I want to keep the rims off the rocks and decrease any tire squirm and self steer that low PSI brings with it, not to mention avoiding the flatter profile that a wide rim brings to any tire. And think about this: What is the equivalent of say, 25 PSI in a 29er tire, when we are talking about a Plus tire? If 12PSI is on the low side for a 27+ tire, equal to 18-19PSI in a 29er tire, then is 17PSI in a 27+ tire more like 25-26PSI in a 29er tire? Make sense?
Not sure, but in the end I went with a 30mm internal rim. We shall see how this works out, but this is what it came down to.
- I plan on running higher than the lowest PSI I can in the Plus tires, but below where they begin to skip around and bounce off things. That number is to be determined but I am thinking 17PSI.
- I want to keep the tire profile ‘peaky’ rather than flatter/rounder. That will draw in the 3.0″ tire sidewalls as well and let any side knobs fend off impacts.
- I do not plan on running 2.8″ tires, but rather 3.0″ versions, chiefly for BB height.
- If I were running 2.8″ tires, I would go wider with the rim, like 35-40mm internal, as that would add volume to what is a somewhat smaller tire.
- I was looking to reduce rim weight and narrow rims, all other things being equal, are lighter rims.
- There were a couple of industry guys that feel a 29-30mm rim is plenty and I respect their opinions.
This brought to mind a couple of wheel options. The American Classic Wide Lightning in a 27.5″ size would be right in there, is light and under a grand for the pair. The Roval Traverse SL Fattie 650b wheels were calling my name though. And although the cost was a good bit higher at $1500.00, they are based on a DT Swiss 340 hub with 54T Star Ratchets. And carbon is still pretty sexy, is it not?
The 2017 6Fattie Comp Carbon comes with Grid Purgatory tires, not Controls. Was this due to complaints over sidewall damage on the Control versions? Could be. But I am not ready to take the slight weight hit of the Grid casing…not yet anyway. If I start scrapping tires on the trail, I may re-consider. So let’s see what swapping to Control version Purgs and the Traverse SLs did for me?
I was more concerned with the overall result than each individual item. So I did weigh some things out as parts, but the entire package was more my goal. No rotor, no cassette, etc.
- The stock front wheel with tube and Grid Purg = 5lbs/3oz
- The Traverse SL front wheel, tubeless, with a Control Purg =4lbs/3oz
- The stock rear wheel with tube and Grid Purg = 5lbs/11oz
- The Traverse SL rear wheel, tubeless, with a Control Purg = 4lbs/5oz
That is pretty darn close to 2.5lbs. I’ll take it.
The stocker bars were a bit high with that 27mm rise and the bike has a pretty high stack to begin with, but I expect Specialized is hedging their bets against really big folks buying the XL. That meant I had to flip the stock stem negative and run no spacers under it to get the bars at least even with the saddle. Also they were only 750mms wide and I found myself always riding with the heel of my palms resting against the outside edge of the stock grips.
I picked up a very sweet looking stem from Spank in the Oozy Trail model rendered in an extremely cool shade of green ano – 65mm long with zero rise. I like a bar with some upsweep on a bike like this and I went with a Race Face carbon SIXC, 780mm wide and 20mm rise with 8° backsweep and 4° upsweep. I would have preferred less rise, but these were in JeffJs garage and we did some horse trading. And they were green. Originally I wanted to use some of the Spank Spike 800 bars with the Vibracore insert but could not get graphics I was a fan of. I might look for a bar with slightly less rise at some point, more like 15mm to get the spacers more even between above and below the stem (spacers in matching green ano natch). I also added a set of grips from Spank.
Everything else is stock.
The weight tally? Just under 31lbs with pedals, cage, and a spare tube and lever stuffed into the SWAT locker. So that means it’s under 30lbs with no pedals and no extras. I bet with a lighter tire I could get very close to 29lbs. Is that heavy? Yes and no. It is not that heavy for a big trail bike with Plus tires, at least not from what I have seen so far. Less weight is just a matter of money. Most of the time it pedals very light for that weight, although I feel it on those slight rises in the trail were it is less than rapid.
I am happy with it overall, but I have to ponder what it would be like with less of a hit at the weight scale.
On Trail – So far so good. Random thoughts as they come to me.
The feel of the bike overall is one of balance and I appreciate that. I went with an XL although I did not really want to get into a bike with a 1200+mm wheelbase. However, since wheelbase is just a result of all the other numbers that make up a bike, and those numbers largely make the bike what it is, then that wheelbase number is not too negotiable. On tral I found that in tight turns you can feel the larger diameter circle the front end is scribing as you go, but it is quite manageable. What is most excellent though, is that the front wheel is out where my weight is not over the centerline of the axle. That always feels weird to me on smaller bikes.
The short chainstays are, IMO, just right at 437mm…not too short to lose stability and balance, but short enough to let it move around corners and obstacles with hip motions and little drama.
I am still playing with the suspension settings, although I am almost there. I think the stock stuff is going to be fine for my needs, which is a good thing. I would have hated to get that wrong. It is a very stout chassis, this Comp Carbon 6Fattie. I can’t sniff out any wiggle or waggle and that big fork is sure solid. Mercy. I don’t think I can recall testing any bike that was stiffer stem to stern, although that is subjective. Needless to say, so far it has gone where it has been asked to go with no complaints or ideas of its own.
The gearing is very good, although that 28T front ring feels tiny at times. The low end is generous and allows you to spin even very steep sections of trail. Thoughts so far on 1×11, as the Comp Carbon 6Fattie will not accept a front derailleur: Its great. Now I have waxed eloquently on the merits of 2x gearing, so now lets talk about what is better about 1x on a bike like this. It is simple, it is rugged, the gearing gaps are there but in the situations this bike excels in, that is hardly noticed and might even save you from having to do a shift across two gears to get enough of change in difficult situations.. It also makes it easy to hit the left mounted dropper lever with no confusion. The lack of a higher end gear has not been an issue yet. 1X has its place and it feels right on the 6Fattie.
The wheels have been great as well. So far I have been running 17psi in the Control Purgs but I will be playing with that a bit. It has not been bouncy and there is no signs of tire roll at that pressure and very, very little self steer.
One thing I did not care for was the loss of the Torque Caps that give you such a bomber, wide interface between axle/hub and fork end. The fancy Rovals did not come with those end caps so let’s hope that the future will provide options there. UPDATE: I was sent a set of Torque Caps for the Roval wheels and was told that they will be included in new wheels going forward. Contact Specialized or your local dealer about this. You can see the new caps, and how they dwarf the old caps as far as surface contact with the fork end. It all adds up to more steering precision.
I really like FSR as a suspension system. Yes, I am sure there are nuances in other suspension types that will be better or worse here and there, but it works quite well and feels very snappy when pedaled hard, more so than the somewhat lazy feeling JS Tune VPP of the recent Primer and even better in that regard than the Split Pivot of the Horsethief.
If I could change one thing it would be to bring the BB height up just a bit. I appreciate Specialized’s bent toward lower BBs for the stability and low-in-the-bike-feel it brings, but this is a smidge too far IMO, based on the amount of pedal strikes I have been getting. This is one of those areas where making a bike work for two wheel sizes brings compromise.
“…the best mountainbike I have ever owned.”
I am in the semi-local forest pedaling up a singletrack that climbs hard right from the parking lot and only relents a little as it ascends the mountain. Narrow, off camber, rocky in some sections, buff and smooth in others with a few switchbacks thrown in for fun, it just keeps going up with the altitude keeping my heart tach’d out. It is a cool evening. The light is fading fast as the Comp Carbon 6Fattie puts mile after mile behind it. I feel like I am moving pretty well for being on a big, fattish-tired bike.
I created a Strava segment for this run just for my own use and I have been riding it every Tuesday night for the last couple of months now so I have a history of times to refer to. The fastest time on the segment was on the very light and nimble Intense Primer. 10 grand bike, pretty much. That night I set a PR on the 6Fattie. 4.7 miles. 1,666′ gained.
Was I working harder on the 6Fattie? Maybe. It did not feel like I was. I did really enjoy the 28T chainring though. I think a 30×42 as a low/low combo would have hurt more. Spin to win, but I only really needed that 42T in a few sections, sooooo….anyway, the 28T is a friend to old guys like me, at least until Eagle trickles down a level or two.
The descent over that same trail was a riot. Really, it was the most fun I have had on that trail…ever. Rock gardens? Meh! Loose off camber corners? Not an issue. I giggled out loud while rolling up to the parked cars and I was thinking this just might be the best mountain bike I have ever owned.
The next ride on the 6Fattie would be an 18 mile fireroad ride with 9 miles of nearly unrelenting climbing to gain about 3000′. Rocky, but non-technical, I was not thinking this was the best MTB I had ever owned as I spun up that on the 6Fattie. But I was not last to the top either. It was not all that bad, really, and the OHV trails near me were calling for the 6Fattie to put rubber to dirt. Could I withstand a boring, but epic climb on the 6Fattie if the reward was sweet trail time? You bet.
The 29″ wheel will never be eclipsed in its ability to work so well across so many mediums. Run a fast and light tire on a carbon wraith-bike and go win a World Cup XC race. Beef it up and hang it on a long legged bike and rage Enduro. Keep the needle in the middle of those two things and trail ride with your buddies all day long. It is an amazing thing and it improved the MTB riding experience a great deal. But this Plus is equally amazing in other ways, and whenever the trail gets loose, nasty, rocky, and iffy, the Plus tire is fabulous. When the trail is not all that bad, it is still pretty good, not getting in the way much and only with a slight weight penalty. I don’t see it as the answer to all kinds of riders or all types of trails, but it is amazing for what it does do and it is just getting started.
I have a lot more time coming up on the 6Fattie as well as resurrecting the 2nd bike in this dynamic duo. That one will have proper 29″ wheels.
I will be also be thinking out loud on the idea of Plus tires being for beginners, making things too easy, etc. What a funny position to take? Meanwhile, watch this. Too funny.
Note: The products shown here were provided at reduced cost to Twenty Nine Inches for test and review. We are not being paid, nor bribed for these reviews and we will strive to give our honest thoughts and opinions throughout.