Sure, but you’d still run a bigger tire softer than a skinny tire, whether you were riding them both at normal pressure or a little softer than normal. Nobody would ride a 28mm tire at the same pressure as a 20mm tire; if the 20 were comfortable the 28 would feel like a rock.
So the fact that the 28mm tire would have less resistance at the same pressure isn’t real world relevant.
I disagree - if anything my narrow tyres feel harsher than my wider ones at the same pressure (I have both 20mm and 25mm tyres and do sometimes run them at a very similar pressure). I mean think about it - you’re effectively suggesting that a narrower tyre pumped up harder is just as comfortable as a wider tyre at lower pressure - that really makes no logical sense at all, and certainly isn’t my experience. I normally run 20mm tyres at 120psi and 25mm ones at 95psi and the 20mm ones feel way, way harsher.
It’s the absolute pressure that’s more important for comfort anyway - if you’re going to run a lower pressure you might as well run a wider tyre for more comfort and better rolling (assuming you’re not worried about aero - the 20mm tyres are on my time trial bike).
Though to come vaguely back on topic, we were talking about off-road tyres, where as I mentioned you actually get faster rolling at lower pressure.
It’s just physics in action; the tire pushes against the ground with a force of (area of contact patch) * (tire pressure). You just trade one vs. the other to get the same spring action when you hit a bump. Small contact patch at high pressure, big contact patch at low pressure, same result.
Imagine a slick 2" mtb tire at 60 psi (a rock) vs a 20mm road bike tire at 60 psi (super squishy) - there’s no question which would feel harsher.
Bigger tires have more room to absorb bigger bumps before they hit the rim, which is why they’re nice for offroad riding, but that’s a separate concept. It’s suspension, and more suspension can certainly make you faster, whether it’s a fat uni tire or 8" of travel on a DH bike.
So true, they say that full suspension bikes are faster because the bike can move “through the terrain” vs having to move “over the terrain”, I think the same is true for a uni to some degree.
There is a point at which more tire is too much, I found 4" tires to be very akward, reluctant to turn, and bouncy at times.
I’d like to see more “tuned tires”, but it seems the tuning is focused on bike suspension, though the better tires do seem to handle better and bounce less.
In playing with tubes and tubeless, I have found that each tire has a sweet spot in terms of whether a lighter or heavier tube (or tubeless) results in the best ride. On my Hans Dampf standard and Ardent I like a middle weight tube better than tubeless, but on the Hans Dampf Super Gravity and the Todd I like tubeless best.
650b Geared Muni is going in the trails for the first time tomorrow! Riding it on pavement is crazy fast compared to my geared 24x3. The 650b is also 1,5 pounds lighter! And still using a Steel frame! 
I’ll post my first review tomorrow, maybe sunday because I’ll be going on a more serious ride sunday 
Well, as promised, here it is! I haven’t ridden in trails yet though… 40km ride planned tomorrow!
Specs:
15lbs total, I was suprised, I thought it would be heavier than my old KH24 with that steel frame!
What a beauty! That looks like an awesome cheapo frame…
That looks awesome.
I’m diggin on the brown frame!
very nice. thats and Elite Uni build!
custom carbon nearly flat saddle base??? can you elaborate on that please?
If money was no issue ( always is ) only things i would change on your ride is tubeless a Hans SG tyre and alloy up the frame. but this will do the same job for sure!
Is this the first image even of a 650B Guni ?!?!?!
It works awesome, it climbs as well as my 24" if not easier, and riding 137s!
My custom nearly flat CF base is a seatbase I made for myself. You can see that it’s not completly flat, but it’s not as curved as a normal seatbase. Perfect IMO. I’ve been riding it for about 4 months now I think.
The SG Hans Dampf is the same price as the Trailstar, and there is one lying on the ground at work. I think the Trailstar will be fine though since I ride a really high pressure. If it happens to rip off or blowout I’ll get the SG.
I’m pretty sure it is the first G650B 
Looks great but on second look “Holy main bearing cap gap”? 
Glenn, that’s totaly normal, I’m using a cheapy steel frame that has bearing holders just like learner frames. I’ll have better once I have my custom Ti frame 
nice work with the saddle, hat off to a custom job!
Always wondered and thought how possible making a CF base is. Would you consider a new thread on building a CF uni saddle??
And why not go total flat. Its proven the curve is not needed once you adapt your riding to being on a flat saddle and have an adjustable post for the tilt. A flat saddle does not mean you will loose it every time we tackle a climb.
high tyre pressure you say? how high are your running the 650b and why exactly?
i used to be a high tyre pressure fiend but shown the light (thx Ben/ Killian) and there is some very sweet spots at lower pressures and a great tyre gets betters which is very hard to believe until you try!
Sorry for swaying of topic, least i am proficient and consistent as something hey. Those main 2 being…
going off topic (sorry) and effectively demonstrating UPD’s without command
Very nice 650B GUni!
I have plans to build a similar uni and I’ve already ordered the Velocity Blunt 35 650B rim. However, I don’t yet have the money for the geared hub and therefore I’ll first build the wheel with a normal hub. I’m planning to use KH29 frame and tubeless Hans Dampf SG tyre.
My choice of the wheel size is a compromise since I wasn’t able to decide whether a 26" or 29" geared wheel would be better for my needs
I love my 650 HD SG, it is just the right size. In comparison to a 29er, my climbing is easier, downs are easier and more fun, and I still have good rolling speed for obstacles without being so small that I spin out.
I could probably improve the ups and downs even more by going down to a 26", but I’d lose some of my rollover and speed, so for my needs the 650b is a nice tweener size.
I re-tired my 29er with a new style Racing Ralph 2.10 snakeskin, running high pressure, it is so light! Not sure where it’ll get used, I suppose flowing trails with lots of climbing where my 32 and 36 are too much work.
Now for a guni…
I did consider a new thread for it but I didn’t do it because I’m still working on better versions (stiffer/better looking/new mold). Some projects I’ll do once I have the time.
I still haven’t tested out tire pressures properly on my new setup, I’ve always been riding high pressure on all my tire (even my 24x3 and my fatty!) and I really like to have a hard tire, I’ve had some weird experiences of a bouncing like crazy with lower pressure. I know since the tire is tubeless it should make a difference, I will do my tests on the few next rides
So far, still only one Muni ride on it. It climbs like crazy! It’s really really fast! and I can feel the weight difference from my 24’'! I haven’t tested it on techy trails yet, I will on my next day off.
Ok cool,
Would love to here about the newer saddle base when its tried and tested. Take some photos as you make it. Thanks for sharing.
Super Cool 650B
Hi all i’m back
I got to Africa last year and had a good time cycling 2000km’s from Cairo I[/I] to Khartoum I[/I] where I got a little ill and find the Doctor’s in Khartoum not very good? I was died for a short time and this ended my cycle trip to Cape Town (South Africa) all ok now
Now 650B I[/I] has got me thinking about building up a Light Muni (no more Gear Hub’s for Me!)
I’m thinking that a 32 hole hub laced with DB spokes and a light wide rim, Tubeless tyre set up, disc KH cranks etc! is going to be a fun fast ride?
Any idea’s along this lines?
NZPeteG
Resurrections? Vampire transformation? Zombie? 
I am sure I have misunderstood, but it does sound like an adventure!
Scott