Does 650B still make sense when you can fit 700x45 tyres?

Especially for light weight issues concerning cyclocross / touring bikes & parts.

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warthog101
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Joined: Wed Sep 25, 2013 10:05 am

by warthog101


Karvalo wrote:
warthog101 wrote:
Sat Nov 20, 2021 8:49 am
Karvalo wrote:
warthog101 wrote:
Sat Nov 20, 2021 6:05 am
I am wondering what terrain is being ridden for 700x40 to be too small?
Sand, mud, snow?
Bike loaded for touring?
Rocks and roots. Places where it's silly not to be riding an mtb :P
He makes that point in the 2nd video. ;)

Still, if you aren't after speed, and riding in soft stuff, loaded bike packing, then fair enough I guess
What point? I can't be bothered to watch quarter of an hour of gcn waffle to find one opinion.

I don't ride big 650b for soft stuff, I use it for hard, bumpy and jagged stuff.
If 40c aint big enough due to rocks n roots etc, then your mtb is a better choice anyway.

Karvalo
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by Karvalo

warthog101 wrote:
Sat Nov 20, 2021 11:48 am
Karvalo wrote:
warthog101 wrote:
Sat Nov 20, 2021 8:49 am
Karvalo wrote: Rocks and roots. Places where it's silly not to be riding an mtb :P
He makes that point in the 2nd video. ;)

Still, if you aren't after speed, and riding in soft stuff, loaded bike packing, then fair enough I guess
What point? I can't be bothered to watch quarter of an hour of gcn waffle to find one opinion.

I don't ride big 650b for soft stuff, I use it for hard, bumpy and jagged stuff.
If 40c aint big enough due to rocks n roots etc, then your mtb is a better choice anyway.
True - but what that point misses is how perversely fun it is to wrestle a gravel bike around terrain that everyone around you is tackling with 140mm+ of suspension. It doesn't sound fun, I didn't even think it would be fun until I got dragged out to try it.... but damn it is fun.

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tritiltheend
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by tritiltheend

warthog101 wrote:
Sat Nov 20, 2021 11:48 am
If 40c aint big enough due to rocks n roots etc, then your mtb is a better choice anyway.
I suppose that's true if your ride has nothing but MTB type of terrain. But the whole point of a gravel bike is to handle mixed terrain. A gravel bike with 45-50mm tires is still going to be way faster on the road than any serious MTB, especially if you choose a tire that rolls well. If you have a ride with a wide mix of terrain, from pavement to light MTB terrain where a wider tire helps, then a gravel bike with wide tires makes a lot of sense.

warthog101
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by warthog101

tritiltheend wrote:
warthog101 wrote:
Sat Nov 20, 2021 11:48 am
If 40c aint big enough due to rocks n roots etc, then your mtb is a better choice anyway.
I suppose that's true if your ride has nothing but MTB type of terrain. But the whole point of a gravel bike is to handle mixed terrain. A gravel bike with 45-50mm tires is still going to be way faster on the road than any serious MTB, especially if you choose a tire that rolls well. If you have a ride with a wide mix of terrain, from pavement to light MTB terrain where a wider tire helps, then a gravel bike with wide tires makes a lot of sense.
I am fairly new to gravel.
However wide tyres like that aren't what I am seeing with respect to gravel bikes where speed matters.
The first video I linked shows an ex protour rider who now gravel races.
Using under 40c from what he said, unless snow, sand or slop, where you need more surface area to avoid ploughing.
The recent gravel race I did was gravel road.
No wide tyres seen at all.

If you are just cruising around, loaded or riding soft stuff or really rough stuff, then yeah go large.
Going to be slower on gravel tracks/roads though.



BuffHamster
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Joined: Tue Oct 26, 2021 11:23 am

by BuffHamster

I run 700x50 and 650x2.1(54) but both tyres have differnt purposes. 700c is for general use and gravel up to grade 3/4 while the 650b is a MTB tyre for grade 5 gravel and anything requiring MTB grip.

So 650b is dead for a large group of people who have gravel bikes but those that push the limits of their gravel bike, 650b still has a purpose assuming you use MTB tyres with it.

eljamoquio
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by eljamoquio

warthog101 wrote:
Sat Nov 20, 2021 11:48 am
Karvalo wrote:
warthog101 wrote:
Sat Nov 20, 2021 8:49 am
Karvalo wrote: Rocks and roots. Places where it's silly not to be riding an mtb :P
He makes that point in the 2nd video. ;)

Still, if you aren't after speed, and riding in soft stuff, loaded bike packing, then fair enough I guess
What point? I can't be bothered to watch quarter of an hour of gcn waffle to find one opinion.

I don't ride big 650b for soft stuff, I use it for hard, bumpy and jagged stuff.
If 40c aint big enough due to rocks n roots etc, then your mtb is a better choice anyway.
I really like drop bars. Not that it's impossible for drop bars to go on a mtb, but I don't a bicycle with that setup.

kode54
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by kode54

BuffHamster wrote:
Tue Nov 30, 2021 9:12 am
I run 700x50 and 650x2.1(54) but both tyres have differnt purposes. 700c is for general use and gravel up to grade 3/4 while the 650b is a MTB tyre for grade 5 gravel and anything requiring MTB grip.

So 650b is dead for a large group of people who have gravel bikes but those that push the limits of their gravel bike, 650b still has a purpose assuming you use MTB tyres with it.
Makes perfect sense....but 700x50 is pretty fat for doing a multi purpose ride. I use a 42mm Ultradynamico tire which measures 40mm on an Enve G23 rim on my Factor LS. I think the height/diameter of the 700x50 (larger) vs. 650x2.1 (smaller) would be extreme. You can get away with a 38mm or 42mm wide tire on 700 and still be okay on mixed road surface.

I think if I were to do a 90/10 gravel to pavement ride...I'd go with the 650b with a 2"+ tire. Most of my rides are 80/20 to 60/40 pavement to gravel and the 38mm is good (80/20) and 42mm good for 60/40.
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Nohands83
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Location: Leeds, UK

by Nohands83

I ride quite a bit of singletrack on my gravel so I've recently picked up a set of 650b wheels specifically to run MTB tyres - Race Kings.

I've also got a set of 700mm wheels which are great for actual gravel but on more technical stuff (particularly tight turns) when running tyres larger than 42mm they steer like a tank.

On a 29er MTB suspension allows you to 'run-over' obstacles (within reason) that you can't navigate around. Frames with long reach and short stems also keep the steering much more responsive.

I suspect bike geometry plays a considerable part in peoples experiences of both, bikes like BMC URS mimic MTB geometry more closely so are probably better suited to using 700mm wheels on singletrack.

Ultimately it depends on what terrain you ride and how much fun you have when doing it. Though if I was racing gravel I'd be using my 700mm wheels for sure.

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Nohands83
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by Nohands83

Just a word of warning on Race kings - had my first 'wipe out' using them this morning - front tyre slide right out from under me and I ended up hugging a bush.
Was only on less than 1" of mud on a very gradual turn.
Was aware that they're not a wet / mud specific MTB tyre but thought I'd be able to get away with it as I would only be using them in pretty tame MTB territory.
Think I'll be sticking with my Terrenos for the mud.

Karvalo
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by Karvalo

Nohands83 wrote:
Fri Dec 03, 2021 11:41 am
Was only on less than 1" of mud on a very gradual turn.
Only? A thin layer of slick mud over hard is one of the lowest grip conditions you can find IMO. No traction from the surface and no traction from the tyre sinking in either.

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Nohands83
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by Nohands83

Karvalo wrote:
Fri Dec 03, 2021 12:53 pm
Nohands83 wrote:
Fri Dec 03, 2021 11:41 am
Was only on less than 1" of mud on a very gradual turn.
Only? A thin layer of slick mud over hard is one of the lowest grip conditions you can find IMO. No traction from the surface and no traction from the tyre sinking in either.
Noted. It was on a trail I've ridden pretty regularly in fairly similar conditions with Vittoria Terreno and Pirelli Cinturato M without issue.
Tempted to give Vittoria Barzo's a go - anyone got experience with these?

Karvalo
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by Karvalo

Nohands83 wrote:
Fri Dec 03, 2021 4:12 pm
Noted. It was on a trail I've ridden pretty regularly in fairly similar conditions with Vittoria Terreno and Pirelli Cinturato M without issue.
Tempted to give Vittoria Barzo's a go - anyone got experience with these?
I've been riding 2.1" Barzo front and Mezcal rear and been very impressed. Great compound for wet rock/root grip as well as tread pattern. Different class to the Race King.

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Nohands83
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by Nohands83

Karvalo wrote:
Fri Dec 03, 2021 5:14 pm
Nohands83 wrote:
Fri Dec 03, 2021 4:12 pm
Noted. It was on a trail I've ridden pretty regularly in fairly similar conditions with Vittoria Terreno and Pirelli Cinturato M without issue.
Tempted to give Vittoria Barzo's a go - anyone got experience with these?
I've been riding 2.1" Barzo front and Mezcal rear and been very impressed. Great compound for wet rock/root grip as well as tread pattern. Different class to the Race King.
Thanks - really good to hear. Will get some ordered this weekend.

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