What's with these tire sizes ?

ZeroPete

New Member
Sep 13, 2023
9
1
Belgium
1990's : 1.7, 1.8 and 1.9 on lightweight hardtails
Noughties: 2.1 and 2.2 on the outside on race FS bikes, sub 10 kg on a scalpel
2010's : 2.35 on enduro, and maybe a 2.4 on the Gen 2 Bosch ful sus bikes
Now : 2.6 and 2.8 on my Levo ? I assume they have their place when you want to go mud bogging, but really ?

Has anyone gone back to - say - 2.35 on their e bikes ?

Thanks,

Pete
 

Semmelrocc

E*POWAH Master
Dec 28, 2021
308
779
Germany
I'd say the majority today, especially on 29ers is running 2.3" to 2.5" wide tyres. Bigger sizes are rather a thing of 27.5+ settings, which are not that common imo, are they?
 

Paulquattro

E*POWAH Elite
May 7, 2020
2,351
1,302
The Darkside
Hi
wider tyres need less pressure to work giving you a wider footprint if needed
Also a wider tyre will give better small bump compliance and more grip for the majority of riders ,we are not all world champion DH riders although some think they are :)
The weight of the bike also has a bearing on tyre size heavier bike bigger tyre
im in the 2.4" camp i wouldn't go any less on a 25kg plus bike personally but we are all different .
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,668
5,227
Coquitlam, BC
A few years ago I changed my tires, rims, hubs, number of spokes and psi. I was having too many tire issues with the terrain I typically ride in and the type of use for the bike. The variations can be endless for every MTB rider.

The terrain I typically ride on is rock, loam, some roots, some mud, ‘gold’ (the perfect base IMO), and snow. I climb a lot therefore good grip on a straight-ish attack is important. Down hill berms or tight switchbacks were not as important.

A local bike shop, who build wheels, helped me decide on wheel type based on my type of riding.

Raceface Arc, 35mm wide alloy, 32 spoke, Maxxis 2.6 Assigia, CushCore (rear only), Project 321 hubs, butted spokes. Wasn’t cheap …but didn’t break the bank either.

I can now use lower psi without the risk of burping the tire, I’ve increased the surface grip, no broken spokes, stiffer wheel…my climbing has improved.

I don’t ride on pavement and the rolling resistance is not that great. But it’s perfect for my style of riding.
 

RustyIron

E*POWAH Elite World Champion
Subscriber
Jun 5, 2021
1,865
2,925
La Habra, California
Has anyone gone back to - say - 2.35 on their e bikes ?

Yeah, Pete. I jumped on the fat tire bandwagon. I went as big as 2.8 for a while. Nowadays I prefer 2.4 in the back. It gives me a quicker, more precise feel. I think the fat tires kind of lumber along, like Rosie O'Donnell after a long night at the All-You-Can-Eat Buffet.
 

arTNC

Member
Feb 1, 2024
240
282
Texas
With the advent of full power, longer travel, emtb bikes, I think there's very little downside to using 2.5/2.6 tires. To each his own for sure, but having recently come from an emtb that wouldn't accept bigger than 2.35 tires in the rear, I assess that the smaller tires suck in comparison for real trail use.

Additionally, aren't there tests that indicate rolling resistance is minimally different between tire sizes like 2.35 to 2.6? Of course rolling resistance isn't the only element we care about, but when you have strong pedal assist the size issue becomes even less. For those who aren't riding any challenging trails, I can see the option of smaller tires. Otherwise, why?
 

arTNC

Member
Feb 1, 2024
240
282
Texas
2.4 rear 2.6 front has been the sweet spot for me.
I find it interesting how the sizing category of 2.35 compared to 2.4 sounds like a miniscule difference. However, in real side-by-side comparison, the 2.4 is noticeably larger. 2.35 tires look so small to me now. What ever happened to that "size really does matter" mantra? :ROFLMAO:
 

Bndit

Active member
Jul 14, 2022
334
394
Finland
2.4” front and back. But Bullit came with 2.5” Assegai in front, no complaints there. For me 2.4” front comes from bikepark riding, excellent traction so I use it trail riding too. 2.4” is lighter than 2.6” so you can use thicker casing so you get better damping and even more traction.
 

irie

E*POWAH Elite World Champion
Subscriber
May 2, 2022
2,750
2,820
Chichester, W.Sussex, UK
Trek Rails. We have 30mm inside rim 29" wheels. Run Magic Mary Super Gravity Ultra Soft fronts when it's muddy, they're 2.4". When it's dry like now we run Assegais front and rear, they actually measure 2-3/8" wall to wall = 2.375" but measured with the outer knobs they're 2.5". Run Maxxgrip DD fronts which swap to rears when they start losing grip. DD because rears don't puncture so the rears start as fronts.

Edit: have tried EXO and EXO+ but have had rear rips/punctures with South Downs flint/chalk. But to be fair latest construction might be different.
 
Last edited:

RickBullotta

E*POWAH Elite World Champion
Jun 5, 2019
1,853
1,583
USA
I find it interesting how the sizing category of 2.35 compared to 2.4 sounds like a miniscule difference. However, in real side-by-side comparison, the 2.4 is noticeably larger. 2.35 tires look so small to me now. What ever happened to that "size really does matter" mantra? :ROFLMAO:

I usually run Maxxis tires, and they have a "wide trail" option optimized for wider rims, which I tend to also run. Makes for a great tire profile.
 

Jackware

Fat-tyred Freakazoid
Subscriber
Oct 30, 2018
2,102
2,323
Lancashire
Yeah, Pete. I jumped on the fat tire bandwagon. I went as big as 2.8 for a while.
I think the correct phrase for 2.8" tyres is 'slightly plump'

Now these are fat🤔🤪

PXL_20240429_103340006~2.jpg
 

mustclime

Active member
Apr 19, 2023
454
361
New Jerzy
I run a 2.8 x 27.5 on a 40mm iw wheel on my Kenevo. Skinny high pressure tires are way easier to spin out. Dirt bikes run 4+ wide tires…… now if I could just find an app that would produce two stoke sounds when I am on the power…😎
 

bheiser1

New Member
Subscriber
Jun 18, 2024
13
9
Sierra foothills, California
This is all interesting as a beginner. When I bought my bike, it came with 29x2.6 front and rear. But the rear was a Rekon, which I already knew from my research that I wanted to replace. The store rep suggested getting the rear replacement in 2.4, and suggested that a narrower rear tire would add agility. But I hadn't heard of that configuration and ended up getting the replacement (Assegai) in 2.6 to match the front. With experience I guess I'll be better informed in deciding when it's time to replace it again.
 

arTNC

Member
Feb 1, 2024
240
282
Texas
This is all interesting as a beginner. When I bought my bike, it came with 29x2.6 front and rear. But the rear was a Rekon, which I already knew from my research that I wanted to replace. The store rep suggested getting the rear replacement in 2.4, and suggested that a narrower rear tire would add agility. But I hadn't heard of that configuration and ended up getting the replacement (Assegai) in 2.6 to match the front. With experience I guess I'll be better informed in deciding when it's time to replace it again.
No doubt more experience and use with your bike and setup will help deciding tire size later, but you may end up staying with the 2.6. Depending on where you ride, how you ride, etc., a 2.4 or 2.5 may suit you better. I'm guessing, hoping the store rep quizzed you about what kind of terrain you primarily ride in to make that suggestion of the 2.4, because that can make all the difference.

On my Trek Rail 7 I went from the OEM 2.5's to 2.6's. I also ride dirt motorcycles and appreciate as much traction from a burly tire as possible...within reason. Yes, you can go too big on the emtb and a dirt motorcycle, so hopefully some time on your bike will show you what you need. Beauty is that if 2.4's didn't work out ideally, you can go to another size.
 

Downhillr

Active member
Jul 2, 2021
304
159
SF Bay, California
I find it interesting how the sizing category of 2.35 compared to 2.4 sounds like a miniscule difference. However, in real side-by-side comparison, the 2.4 is noticeably larger. 2.35 tires look so small to me now. What ever happened to that "size really does matter" mantra? :ROFLMAO:
Was she talking about length or width?!
 

Downhillr

Active member
Jul 2, 2021
304
159
SF Bay, California
Was she talking about length or width?!
My bike came with Maxxis 2.4 DHRII rear, it would lose traction on climbing wet/slippery rock or mud so I switched to Conti 2.6 (with very similar tread to Maxxis) it was better but also seemed too big, slow response in dry, fast downhill twisties. I’ve been running the new Michelin “Raceline” e-wild 2.6 that came out in March and really like tire… it’s visually smaller and also less draggy than Conti, grips better than Maxxis
climbing same trails and conditions and corners more like the Maxxis. If you try it be sure you get the new “Raceline” version which is different rubber and tread pattern (more Moto).
 

bheiser1

New Member
Subscriber
Jun 18, 2024
13
9
Sierra foothills, California
No doubt more experience and use with your bike and setup will help deciding tire size later, but you may end up staying with the 2.6. Depending on where you ride, how you ride, etc., a 2.4 or 2.5 may suit you better. I'm guessing, hoping the store rep quizzed you about what kind of terrain you primarily ride in to make that suggestion of the 2.4, because that can make all the difference.
Unfortunately he didn’t quiz me, though as a beginner I can only say what I think I’ll want to know, without knowing for sure.

I like the 2.6’s so far. I’ve been surprised at how they’ve handled rocks, roots, ruts, gravel, and whatever. I like the stability over agility, at least at this stage.
 

rzr

Active member
Sep 26, 2022
408
259
bcn
Now : 2.6 and 2.8 on my Levo ? I assume they have their place when you want to go mud bogging, but really ?
you can still put 2.4-2.5 on your Levo
previous generation was a bit of an abomination (6fatty?)
 

RickBullotta

E*POWAH Elite World Champion
Jun 5, 2019
1,853
1,583
USA
I am literally the complete opposite
2.4 front for better turn in and 2.6 outback for drive and grip
I also run full 27.5 as I find 29 too sluggish for my liking
We’re all different 👍

For a motorcycle, that makes a lot of sense and what I ran (in fact I ran a fatty up front also). For an MTB, you're definitely in the minority. But who cares! If it works for you, that's all that matters...
 

Bikerchef1

Member
May 21, 2023
15
9
perisher valley australia
Ive been riding fatbikes (analogue) exclusively for the last seven years.I have a neck injury and the extra lushness makes riding a bit less battering for me,lus I manage a ski lodge so actually get to ride snow quite often.but a really good deal came u on some ex rental bikes locally so i picked u a norco sight VLT for a very good price.Ive been digging it but the first thing i did was swa out for bigger rubber and wheels so it was plusher and a tad more forgiving.I have wtb i45 rims with a 3.0x29 on the front and the same wheel with a 2.8 on the back(the 3.0 is to tight a squeeze out back).Personally I love the way it rides and steamrolls over rocks and roots.im used to 27.5x80mm rims with a 4.5 u front and 4.0 out back which have a 29 diameter anyway so it doesnt feel cumbersome or slow to me.I just spent 3 weeks riding the bike parks down in tasmania,Australia and it was such a fun time.

derby.jpg
 

MountainBoy

Active member
Mar 4, 2022
231
212
Washington State, USA
I don’t ride on pavement and the rolling resistance is not that great. But it’s perfect for my style of riding.

Everyone should choose the width that works the best for them. It's largely a function of weight and the type of surfaces you ride on.

But I see a lot of people talking about rolling resistance differences between wider/narrower tires. Rolling resistance and tire width don't have a strong correlation, compared to tread design, rubber compound, air pressure, total weight, and the efficiency of the sidewall construction.

What people are perceiving as slower on a wider tire mostly comes down to aero on an e-MTB where average speeds are higher. You can illustrate this to yourself by pedaling the two comparison tires in a sturdy bike stand (or upside down on the seat/handlebars). Use the highest gear and pedal at a normal cadence feeling the resistance of the crank to maintaining a constant speed. A knobby will create quite a fan-like effect, it will make a "breeze" all the way around the perimeter of the tire. All else being equal, the wider tire will take a noticeable amount more of pressure to maintain speed. And this is only a fraction of the total aero drag compared to a bike actually being ridden through the air. Even at relatively slow speeds this amounts to considerable drag because the top of the tire is travelling at double the ground speed through the air.

If you put on a fat slick, the effort to maintain a steady speed on the bike stand drops dramatically. Now you are largely only feeling the resistance of the bearings, chain and derailleur.

I'm not saying fat knobbies might not be a good choice for you, they have many advantages and it's really up to your preferences and, on an e-bike, the reasons to run skinny tires are minimized. I'm simply explaining that the drag difference is mostly aero, not rolling resistance. The contact patch size doesn't change with tire width, it changes with total weight and tire pressure.
 

arTNC

Member
Feb 1, 2024
240
282
Texas
Ive been riding fatbikes (analogue) exclusively for the last seven years.I have a neck injury and the extra lushness makes riding a bit less battering for me,lus I manage a ski lodge so actually get to ride snow quite often.but a really good deal came u on some ex rental bikes locally so i picked u a norco sight VLT for a very good price.Ive been digging it but the first thing i did was swa out for bigger rubber and wheels so it was plusher and a tad more forgiving.I have wtb i45 rims with a 3.0x29 on the front and the same wheel with a 2.8 on the back(the 3.0 is to tight a squeeze out back).Personally I love the way it rides and steamrolls over rocks and roots.im used to 27.5x80mm rims with a 4.5 u front and 4.0 out back which have a 29 diameter anyway so it doesnt feel cumbersome or slow to me.I just spent 3 weeks riding the bike parks down in tasmania,Australia and it was such a fun time.

View attachment 142659
I'd actually like to try a 2.8 DHF front, but the Maxxis site shows them jumping from 2.6 to 3.0...no 2.8 DHF. I'm running 2.6 DHF/DHR front and rear, and they're good. Still, I'd like to give a 2.8 front a go. 3.0 seems a little big for my application.
 

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