Pretty positve the rolling resistance is the same it’s just that the larger diameter has the ability to roll over larger objects with less disturbance. In general I’m not convinced 700 is faster than 650 on a gravel bike because of the weight and geometry differences, it’s probably a wash on anything but super rough terrain.
Also I saw a MOG IRL, looked nice, didn’t seem to do any better or worse than anyone elses’ bike.
Wouldn’t it be all the same reasons as MTB. The approach angle and rollover will be improved with the 700c.
You’ll also have a larger rollout so for the same gear you are literally moving faster
It’s a completely different use case compared to mtn bike. This is closer to comparing road bikes which would imply road bikes should have larger rims if that was the case. A 650 with a 48mm tire is the same size as a road wheel with a 28mm tire.
Same argument for the roll-out - if that was a thing, road cyclists would be using 32 inch rims, no? That’s just a gearing issue.
Why are you comparing a 650x47 and 700x28mm again sorry?
I thought the question is why there would be potential speed increases in 650x47 and 700x47.
There’s probably a terrific argument for 32" rims except most cyclists are short arses and wouldn’t be able to get a leg over their bikes 
. Also you’re losing nimbleness. Gravel appears to be all about getting the highest straight line speed over slightly bumpy terrain. I dare say rollover isn’t irrelevant in that regard.
I’m comparing because they are the same effective diameter. Bike geometry and handling are built around rim and tire sizes. To accommodate large effective diameters, some things gotta give when you go 700x47. Chainstays get longer, front end HTA and fork rakes change, larger chainrings are hard to fit etc. The bike geo starts moving toward the mtn bike design. For really rough races this may make sense, but for what most people call ‘gravel’, what’s needed is more of a fat tire road bike.
Right. If you’re choosing between too wheel/tyre combos of the same overall diameter it becomes a bit moot.
I dare say a 700c carbon rimmed wheel with 28mm tyre has a lower rotational mass than a 47mm tyre on the same spec rim at 650b. But that’s really getting into the weeds.
The question to choose would be if you can get a 700c 45 or a 650b 45. The 700c may be faster in terms of rolling speed for the reasons above.
Anybody knows about this?
I’m thinking about a chunky gravel build using this “chassis”. Ideally I want a 46T 1x in front. However, it seems to be limited to 44T, why?. Is this confirmed?
From ENVE Mog FAQ How big of a chainring in general can you run?
2X: Shimano GRX double cranks (47mm chainline)
2X: SRAM WIDE double cranks (47.5mm chainline).
*Standard road double cranks WILL NOT fit.
1X: Max 44T for 44.5-45.5 chainline (SRAM 1x Cranks w/ typical aftermarket direct mount chainrings.
1X: Max 50T for 47+ Chainline (Shimano GRX, SRAM 1X WIDE)
1x Ekar has a 45.5-46.5 chainline. Cranks are offered with 38-44T options and all will fit MOG.
*Older SRAM Force 1 (or similar) 5-bolt cranks will NOT clear with the stock bolt spacers on the backside of the chainring spider. These cranks are compatible if the stock ring and spider is swapped for a direct-mount ring.
Rode Bighorn Gravel on my Mog this past weekend. Had Pirelli Cinturato Ms in 40mm and had a pretty miserable time on the chunky descents. What are people running these days?
Thundero 48, wanna try a thunder burt 2.1 next
That’s helpful. What kind of wheels are you running? I’m on AG25s and I’m curious how MTB tires might work. Sounds like Race Kings might also be an option? Those come in a 2.0 and a 2.2.
Just to be clear, the 2.0 Race King is not as fast as the 2.2 Race King Protection… I see people assuming that they’re the same, and jumping on the trend, but in fact they are different compounds, and test about 10w different from each other… With that said, if you can fit it, the slower 2.0" Race King is probably still a better tire than many gravel options in my opinion…
Thanks. I think people have fit the 2.2 Race Kings on the Mog. Wonder how well that works.
AG 25, I haven’t tried the thurder burt yet since it’s also out of stock everywhere, biggest I tried was a rambler 50c but thought it was too slow and that thing punctured a lot for me, did not like that tire
If you don’t mind buying from Germany, they’re in stock. I’ve had great experiences ordering here (I’m in the US). Shipping is $30 but if you buy a few tires the savings is typically worth it.
I buy a lot from R2, but you know it gotta have that Tan sidewall! they are a few weeks out of that one!
Here is my experience running the Mog with 2.2 Racekings/2.1 Thunderburts.
2.2 Racekings are tight, biggest issue is tire height and not width. I probably have around 500 miles on them in dry conditions and haven’t had issues. It is a couple mm’s at the top of the fork and the same on the rear seat tube. I did have the shave off the tire hairs, but that seems pretty common with these tires. Running 25 internal rims, I want to try a narrower rim but not sure if that would fix the tire height issue or not.
Thunderburts 2.1 fit extremely well all around, I was running them on 25 internal rims as well with the super ground casing. They feel pretty fast and I found they had a lot of grip in single track. I have punctured them 3 times already, but they sealed before I noticed every time with orange seal. I probably will not use them again, I can count the amount of flats I have had in the last 30,000 miles on one hand and these seem too fragile. These would be my go to gravel tire if they had more puncture protection, they do fit on my crux though if anyone was interested.
There’s part of me that wants to try the 2.1" Racing Ray/Ralph. Not quite as fast rolling as the Thunder Burt / Race King, but potentially better from a traction perspective and better puncture protection than the Thunder Burt. And, the Schwalbe’s I’ve tested have run small, with the 2.35 Ray/Ralph measuring closer to 2.25.
Wish the Race King fit better in the rear. I have a pretty used set I’ll throw on to test myself this fall when I get the bike built up.
Can’t confirm this, but logically narrower rims should make a tire height issue worse, wider rims could make it better. Stretching the tire wider = less vertical “deflection” because you’re stretching it tighter in the horizontal plane?
Might not matter at all in practice.