Shimano SLX Group First Impressions- by Grannygear

shimano SLX 29er

With a bunch of boxes full of shiny Shimano SLX bits and pieces, I considered what bike to put them on.  In the end I decided to revive a bike that I think falls into the category where the new ‘trail bike’ focus of these parts lives.  Shimano is coming to market with new gearing, lower in tooth count, to try and entice 29er pilots to their take on things.  In the past, it seemed that Shimano was not really accepting of the notion that gearing on 29″ers typically needs to be a bit lower to keep things even-steven compared to a smaller wheel.  Now, with the announcements in this post  of a 40T-30T-22T triple and the 38T-24T double, all partnered with an 11-36T 10 spd rear cassette, it gives you a lower gear ratio option that was not an option before in Shimano gearing.

As well, the 180mm front rotor paired with the Ice Tech brakes and, along with the Shadow Plus rear der, well, it seemed like a trail bike approach to the build made some sense, although these benefits…lower gearing, cooler brakes, and less of a clangy chain… is welcome on any geared bike.  So I pulled the Project Long Legged XC out of the rack and built it up with the SLX group.  I already had a mix of 9 speed Shimano drivetrain on this bike now as far as gears went.  It was a 32T-22T front with a bash guard in the third, outer position and a 9 speed 11-34T rear SRAM cassette.  The brakes were a set of Hayes Primes, 185mm front and 160mm rear.  The fork was the reviewed White Bros Loop set at 130mm to match the 130mm rear FSR Brain-equipped suspension.  Easton Haven wheels and tubeless Bontrager 29-4 2.35 tires kept it rolling.  It took no time at all to build the bike and in the process, I swapped to a wider bar in a Truvativ Holzfeller riser and changed to a 70mm AKA stem to bring the bar a bit closer to me.  Answer grips finished it off.

shimano SLX 29er

shimano SLX 29er

Weight did not change much as I was swapping over comparable parts.  The bike with SPDs and a cage was 32 pounds pretty much and while that seems heavy these days with all the carbon framed longer travel bikes, carbon wheels, and costly drivetrain parts,  this is a reasonable build with very good wheels, so it is what it is.  Pedal harder.

After burning the bike in a bit on a quick back yard ride, the first real outing was a 24 mile loop with 4k feet of climbing, half of that gain up a rugged fireroad and half on a old paved road.  The two singletrack descents were quite techy with exposure, peeler log switchback drops, loose off camber corners and some off-the-saddle, dropper post steep sections that lasted long enough to get the brakes hot.  It was a typical So Cal ‘little of everything’ trail ride.  The first thing I noticed when the dirt path pointed up for 4 miles or so was that the 38T-24T crank gearing was marginally low.  I was concerned about this from the beginning of the build.  Now it was not horrible as 24/36 is pretty low, but add a 32 pound 29er, a long steep grade, and a few hours of riding and I would have enjoyed a 22T granny on the crank.  As well, the 38T seems a bit high.  Give me a 36T-22T 2x crank option.  Now obviously gearing is very individual…where you live, ride, how fit you are, the type of bike, etc…makes all the difference.  This same gearing on the current test Epic Marathon, a 38T-24T crank, is more than low enough.  But that bike is almost 10 pounds lighter and climbs like a crazy thing.  So this new SLX crank may or may not be trailbike gearing…yet…depending on your needs.  However, the triple that Shimano offers in that 40T-30T-22T has hope.  As well, there is a SLX level 3×10 crankset.  Swap the 30T for a 32T or 34T, swap the outer for a bash ring and have at it.  Oh…I did smack the 38T ring on a peeler log roll-in so a bash ring would be nice on a bike like this.  However, that 38T CR is pretty tough looking and if the chain is on that ring at the time, I bet it would take more than a glancing blow on a log to hurt it.

shimano SLX 29ershimano SLX 29ershimano SLX 29er

The brakes have a great feel at the lever and the shape of the levers themselves is just killer!  One finger or two, they just feel sweet.  I did have the rear brake get hot enough to howl pretty good on long, slow trail descents, but I never lost power or modulation.  On the cruise back home, I noticed that the rear brake pads were dragging a bit but I have not had time to see why.

The Shadow Plus rear der is quite a treat.  I cannot tell any increased shifting effort or lag yet it does a great job so far of reducing chain slap.  I have not yet gotten into a rough and fast stretch yet but it sure seems to be a super solid improvement in drivetrain, which has been the impression of others as well.

I have to say that the parts are handsome too.  That crank is a nice piece of work and I like the way the whole group looks on this bike.  Yeah, just vanity, but we all like our bikes to look good if possible, yes?

I will be out in the hills more and getting the FSR into some rougher trails to see how it all treats me.  Stay tuned.

Note: Shimano sent over this SLX group at no charge 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.