The narrowest tire I’ll run on my i45 rims is a 2.8, but I’d be more comfortable with an i40 rim.
i45 is fine
Fine yes. But i35 is definitely better.
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Starting point is a 2020 Trek Fuel EX5.
(Least expensive full-sus, 29x2.6, 130mm/140mm).
Goal is lighter snappier machine better on certain slow tech rocky sections, and which supports my man-of-substance weight better on faster downhills. Also where I don’t have to fiddle with the shock lockout much when in rolling terrain.
I want to try a 2.8 tire. Others report liking this bike when converted to 27.5 and I figure it won’t hurt for winter riding on compacted snow/ice trails.
The stock 29er Recon RL (32mm steel stanchions, not much adjustability, never felt like it supported my weight well, weirdly harsh over small stuff) is the first thing to go, mostly because I found a good local deal on this:
2020 Pike RCT3 in 160mm 650b-way. $250 with 50hrs on it, recent seals, includes some oil, tokens, and an annual service kit.
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Personally, I think carbon rims would help more with
than 27.5x2.8.
I dunno about slow tech rocky trails there, but here the bottom bracket dropped down that much going from 29x2.6 to 27.5x2.8 is not great for pedal strike. ymmv and all that.
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see if you can hold some 2.8" tires mounted on 27.5 wheels up next to your 29x2.6" to see what the actual diameter difference is. I think it’s gonna be a lot smaller. Usually the 27x2.8" is a substitute for a 29x2.3"-ish wheel/tire setup.
Also, I noticed at the shop a couple years ago when I was buying my Mojo (came with 2.8" Schwalbes) that some 2.8" tires on the floor were taller than others. I think the WTB ones were taller than the ones from Schwalbe and Maxxis, for example.
I think 2.8" seemed like the cutoff for when things start getting really weird/variable with tire profiles, a few years ago at least.
Yeah the 2.8 Maxxis are pretty undersized from what I’ve seen. 3" tires still exist too, that’s what I run and I like them a lot for just smashing through anything. Though I know a lot of people find them a bit too floaty, vague or slow.
Good points, I’ll see what it looks like. Ideally I will try to change one thing at a time. If I can get some 650b wheels with the i35 rims then I can really test a bunch of stuff.
This frame has a “flip chip” in the linkage, currently set to low/slack if I flip it will raise the bb 6mm and steepen head tube 0.5 deg. That plus the longer fork would put everything very close to where it sits now.
I rarely pedal strike and have yet to hit the chainring (kinda surprising). Going to a 28t ring and/or adding a bash guard would be ok with me if it becomes an issue.
That’s what I wanted to hear, because I really want to justify them!
does your stock 29" wheel fit in the 160mm Pike?
if not, would you dare pick up a takeoff 27.5+ front wheel as your next move?
I’ve run 29 tires since the first one (or earlier if you count Rock 'n Roads or Bianchi Project tires). A year ago a bought a used Big Honzo with the idea that I’d eventually convert it from 27.5 to 29, and get a little higher BB and longer stays which suit the rocky trails around here.
On hard rocks, rollover is king, and even with 27.5 x 3s you’re losing rollover versus 29 x 2.4s. There also are less rock-proof B+ tires - for example Schwalbe dropped the all their 27.5 x 3 Apex tires (the lightest reinforced sidewall), and a lot of the 27.5 big tires are based on the light and floaty adventure market. Go smaller to get stronger casings and you lose more rollover. You can make up for the casing with rim pro but B+ cushcores feel really porky. For rocks I think (but haven’t A/B tested yet) I’d rather have 29s with real casing and cushcore in the rear.
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Also I noticed that going to smaller but wider tires was a wash in weight so it didn’t make the bike snappier other than lowering the gearing a touch.
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I dunno man, 2.8 and lighter/snappier don’t really line up in my mind. Curious to hear how this feels on the bike.
Basically +1 drwelby
It also sounds like you could benefit from a few sessions with a shock wiz. If it is all set up well you shouldn’t be using lock out really at all except on fire roads climbs (atmo)
Agreeing with everyone who says 27.5+ is not snappier. If you want snappier and still supportive get some carbon rims and run a 2.3-2.5 with some hefty casings.
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Definitely this. A ~30mm ID rim will give that width of tire a more vertical sidewall. Couple that with a stiffer casing, and there should be less squirm when you give it the beans in corners.
Bonus points for running a Cush Core
Thanks y’all for reality checking this. Lots to think on. It’s gonna be a while until I can really try all this anyways. I do have a set of 27.5 i30mm wheels and 2.6 tires I might try first before swapping forks or anything else.
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If you can try it, you should, because ultimately it has to work for you.
The MoCo damper in the Recon is crude, just a single circuit through an adjustable hole. It will overdamp on high speed hits, the only real solution is to drop the oil weight, run it relatively open, and add some tokens. (the Nico V “more ramp, less damp” strategy).
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Isn’t 2.8 the point at which tires start to suck because something something the proportions just aren’t right? Like they all weigh way more than you would think they should weigh, or they shred like tissue paper? Someone wrote a blog post about this once.
-signed, 29" wheel fan.
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2.8 is probably not bad itself, it’s just a size that doesn’t fit unless the bike was built for it, so there’s no broad market outside of OEMs and adopters and then you end up in a chicken and egg situation.
http://lacemine29.blogspot.com/2016/10/climax.html is some interesting reading