EMTBs with mixed size wheels

[Carlos Muralhas]

Hey guys.

What do you think of what some brands are doing by putting a 29" wheel up front with a 2.35 - 2.5" tyre and a 27,5+ on the back with a wider 2.8" tyre? Canyon does it and explains why but there are several other brands that have eMTBs like this also.

In theory the back wheel is wider to have grip for the climbs and the front is a larger diameter to have less bump resistance against trail obstacles and more speed when descending and with a less wider tyre to help with trail feel and stability in turning. To me in theory it sounds very sane as concept but I haven't tried it yet...

Anyone has experience on a setup like this?

Thanks and best regards,
Carlos

 

[R120]

Seems like a lot of the German brands are jumping on this bandwagon, with Ghost and Conway doing the same. I am intrigued by the Conway MX Hardtails, as i can see the logic on a hardtail of having a grippier/more forgiving rear tire.

On Test: Conway eMT 627MX: Hard and fast – lots of fun to be had with this E-Hardtail – eMTB-News.de

For me the most important thing on any bike is that is has a balanced feel (which will vary from rider to rider due to styles) so along as you get the benefits without losing the feel between the two ends, it makes some sense.

Personally i am more interested in seeing more emtb's with 29 at both ends - i don't buy into the whole thing that a Plus tyre on the back is of huge benefit. I took a focus Bold 2 29'r out and didn't notice any negative effects from having the 29 on the back

 

[knut7]

I'm not sure I get the reasoning behind this. We get a wide rear tyre for traction and comfort. So they're saying we get less traction on the front wheel? Why would I want less traction up front? I usually run the grippier tyre up front.

Also, why are they suddenly coming up with this now? Why haven't they done this a long time ago on analogue bikes? I guess it's because of the motor, and they're inspired by motocross bikes. But the motor isn't very powerful, is it necessary?

I'm not saying it's not, I just don't get the reasoning. I'm testing it my self. Currently my electric Ghost hardtail has a 29x2.3 front, 27.5x3 rear. None the wiser as of yet.

 

[R120]

I'm not sure I get the reasoning behind this. We get a wide rear tyre for traction and comfort. So they're saying we get less traction on the front wheel? Why would I want less traction up front? I usually run the grippier tyre up front.

Also, why are they suddenly coming up with this now? Why haven't they done this a long time ago on analogue bikes? I guess it's because of the motor, and they're inspired by motocross bikes. But the motor isn't very powerful, is it necessary?

I'm not saying it's not, I just don't get the reasoning. I'm testing it my self. Currently my electric Ghost hardtail has a 29x2.3 front, 27.5x3 rear. None the wiser as of yet.

Which Ghost have you got?

 

[knut7]

Which Ghost have you got?

It's the Hybride Teru B2.9 with the mighty Suntour XCR 34 fork And I've fitted a properly cheap dropper post. I mostly use it for kindergarten runs and grocery shopping with a trailer. But it occasionally gets some trail time.
Bike - Hardtail - Hyb Teru B2.9 AL

Edit: I need to include a photo of mine as well

 

[R120]

Cool - i have this on my hardtail shortlist:

Bike - Hardtail - Hyb Kato S4.9 AL

 

[Doomanic]

Not bad, but I like fat tyres. And orange...

 

[R120]

Yeah i am kinda torn - If i wasn't looking at getting E Hardtail i would be looking at getting a Nukeproof Scout 275, or a Kingdom/Stanton Slackline style ti frame depending on budget.

With the motor, i am tempted by something a bit more trail orientated, and 29'r wheels, as my main use (with current thinking) is more of a winter bike on less technical trails, and something to put longer distances rather than full on playtime which is all i think about on my FS

 

[R120]

The Ghost website is dangerous

Bike - Hardtail - Hyb Kato S8.7+ AL

 

[knut7]

I prefer plus front and rear for winter riding. If I want to use my bike all year I prefer using 3" studded tyres during winter. A bike with mixed wheelsizes won't let me use 3" on the front wheel. Unless I've got two wheelsets. Which I have. For the Ghost hardtail.

 

[Robsen]

I tested an bike with wt on the rear and an 2.4 on the front last weekend. Both in 27.5" size. It is the bike of a friend and I hope to test it soon again and put a 29" wheel in the front. But I can't imagine that it is good to ride.

Emtbs are heavier weight as an usual bike. They have around 10 kilos more weight and specially while pushing hard on the Trail it feels not good. Still had the feeling to loosing the front wheel. Didn't have this feeling on the first generation of the Levo.

For trailbikes it should work. Specially uphill on an technical trail. There should be an benefit of the bigger wheel.

I'm more an enduro/trail rider with a bit of an downhill background. Not fast, not slow.....but pushing as hard as I can. I think that I gonna buy an e mtb with more than 160mm of travel and with tires with 2.6/2.8 at least.

 

[Eckythump]

The plus tyres are prone to squirming & deforming on the front if you are pushing hard, particularly when going downhill when more weight ends up on the front of the bike. You might feel this as the front washing out or have the sensation of loosing grip when the tyre is actually folding.
The narrower 29”tyres are inflated to a higher pressure so do not deform as much so feel more stable. Not as plush though....
The rear doesn’t tend to get as much sideways loading so better to keep the benefits of grip and comfort of a plus tyre.

 

[Dax]

Sounds like a Big (s)Hit from back in the day:

 

[Doomanic]

Holy (s)Hit! Look at that head angle!

 

[galaga187]

The plus tyres are prone to squirming & deforming on the front if you are pushing hard, particularly when going downhill when more weight ends up on the front of the bike. You might feel this as the front washing out or have the sensation of loosing grip when the tyre is actually folding.
The narrower 29”tyres are inflated to a higher pressure so do not deform as much so feel more stable. Not as plush though....
The rear doesn’t tend to get as much sideways loading so better to keep the benefits of grip and comfort of a plus tyre.

I lost the front end on the Levo running low pressures whilst riding around a basic berm, your comment makes sense to me.

 

[Mabman]

I have been running a similar setup on my franken bike for the last 9 months but have eyed the concept for a few years.

It has i35 ChiBon rims with CK hubs and uses a 650b 2.8 in the rear, all that my 13yr. old frame will allow after some crimping of the stays, and a 700c 2.3 in the front end. Both run in the 15psi range tubeless.

My reasoning was that I can't stand wider than a 2.3 tire in the front of my bikes. Although as noted above the common use for mtb is a wider tire in the front and a narrower one in the rear the larger contact patch has never made sense to me for my style of riding. The larger the contact patch the better the grip but with that extra grip the front end steering becomes grabby and less precise than a narrower tire with a lower tire aspect ratio that prevents the squirm effect even at lower psi that has equal traction ability. While in the rear traction is key and the larger contact patch of the 2.8 provides that in spades.

I have ridden this bike in all types of soil surfaces and even in deep soft sand it goes where I point it. I attribute this more to the low psi than anything though as I ride my 35 psi 45c tired bikes in soft sand and loose soil with comparable results. Plenty of roots and rocks where I ride here in Oregon and front end control has never been an issue and helpful, at least on a hardtail, to have the plush rear tire to absorb the inevitable hit and maintain traction after getting your front wheel up and over a trail feature.

So while it seems that some of the manufacturers are finding similar results it is perhaps less of a fad than that they have reached the same conclusion as I have, that it works. Probably not for everybody of course but bike life is all about options and making use of them to your liking.

 

[Carlos Muralhas]

I'm not sure I get the reasoning behind this. We get a wide rear tyre for traction and comfort. So they're saying we get less traction on the front wheel? Why would I want less traction up front? I usually run the grippier tyre up front.

Also, why are they suddenly coming up with this now? Why haven't they done this a long time ago on analogue bikes? I guess it's because of the motor, and they're inspired by motocross bikes. But the motor isn't very powerful, is it necessary?

I'm not saying it's not, I just don't get the reasoning. I'm testing it my self. Currently my electric Ghost hardtail has a 29x2.3 front, 27.5x3 rear. None the wiser as of yet.

The resoning behing the front wheel being bigger and less wide is not to reduce traction on the front wheel.

Each wheel in a bike has a bigger function: the rear wheel is traction and grip (that's where the force to advance arrives and spinning on the ground happens less te wider the tire is) while the front wheel has to deal with hitting obstacles and bumps (a bigger 29" wheel is better for that) and has to control direction (curving) so a more precise feel that comes from less volume air space inside the tire (a less wide tire) helps in better cornering. That's the theory of it at least.

Regarding just now coming up on this, that's not really true... although it was a very "freerider" thing. In the distant past it was somewhat common for freeriders using a 24" stronger wheel on the back and a 26" wheel in the front. I used it on my yellow Santa Cruz bullit (still was mono-pivot) and loved the feel of it.

 

[Carlos Muralhas]

In more news about this: the first Intense eMTB will be called Tazer, be a beautiful Carbon frame in great Yellow, use a Shimano E8000 motor with the external battery (but inside the frame like Pivot uses) and also have the bigger 29" wheel at the front and 27,5+ on the back.

The New Intense Tazer Is Nothing Like The Old One!

 

[Carlos Muralhas]

Sounds like a Big (s)Hit from back in the day:
View attachment 2404

Yes, exactly it. I used this setup on a Santa Cruz Bullit around 2003 or 2004.

 

[Blackbird]

I have Nobby Nics in 29x2.6 front and rear, ran 15 psi last weekend, tons of grips but could feel the front folding over on fast turns. I'll probably pump up the front to 20 ish and check next time. So far no reason for me to go 27.5 on the rear.

 

[Carlos Muralhas]

I have Nobby Nics in 29x2.6 front and rear, ran 15 psi last weekend, tons of grips but could feel the front folding over on fast turns. I'll probably pump up the front to 20 ish and check next time. So far no reason for me to go 27.5 on the rear.

I understand you, 29x2.6" has a lot of traction and grip on the rear for sure

 

[Eckythump]

I have Nobby Nics in 29x2.6 front and rear, ran 15 psi last weekend, tons of grips but could feel the front folding over on fast turns. I'll probably pump up the front to 20 ish and check next time. So far no reason for me to go 27.5 on the rear.

If you are happy with running the same width tyre front and rear there is no point looking at a smaller dia rear wheel.
If increasing air pressure in the front tyre doesn’t result in the squirm control you are looking for a narrower front tyre (2.35” Schwalbe/ 2.5”Maxxis) mixed with a 27.5” rear with a 2.6” Schwalbe/2.8” Maxxis maybe an ideal solution.
A cheaper option might be looking at a Hans Damf or MM in super gravity which have much stiffer side walls.

It’s funny coz my finger was hovering over the buy button on a 29” EX1501 wheel this morning as I can never get the 2.8” Minion on the front of my bike to behave the way I want but I managed to convince myself it is an unnecessary first world problem

 

[Carlos Muralhas]

If you are happy with running the same width tyre front and rear there is no point looking at a smaller dia rear wheel.
If increasing air pressure in the front tyre doesn’t result in the squirm control you are looking for a narrower front tyre (2.35” Schwalbe/ 2.5”Maxxis) mixed with a 27.5” rear with a 2.6” Schwalbe/2.8” Maxxis maybe an ideal solution.
A cheaper option might be looking at a Hans Damf or MM in super gravity which have much stiffer side walls.

It’s funny coz my finger was hovering over the buy button on a 29” EX1501 wheel this morning as I can never get the 2.8” Minion on the front of my bike to behave the way I want but I managed to convince myself it is an unnecessary first world problem

Ahahahah I had the same hard time than you but couldn't resist it... I now have an 29" HX1501 with a 2.5 Maxxis Minion DHF at home all assembled and waiting for my Merida eMTB to arrive. My decision also took in account that the Merida has an head angle of 66,5 degrees and I would prefer it to be a liitle bit slacker.

 

[Eckythump]

Thanks, that’s not helping buy, buy, BUY!!

The reduced head angle is an added advantage. Have a 160mm airshaft kicking about somewhere too......

 

[Carlos Muralhas]

Thanks, that’s not helping buy, buy, BUY!!

The reduced head angle is an added advantage. Have a 160mm airshaft kicking about somewhere too......

Ahahahaha sorry.