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Mixing wheel sizes, is it time to broaden the appeal?

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Donkeeboy

· Nurse Ben
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Discussion starter · #1 ·
I have a Foes Mutz, a full suspension fat bike, it's become my test bed for a lot of wheel riding experiments. My Mutz is outfitted with a 150mm travel Wren fork and a CCInline 140mm travel shock. I have ridden it with 26 x 4" wheels and 29+ wheels (rear barely fit), but my standard wheelset is 27+.

This year Foes and Timberline bikes release a bike theey developed that is frame specific bik for a 29/27 mixed wheel set. They have two set ups, the Trail version with an HTA of 67.5 deg, 150mm travel fork, and 140mm travel shock, and the Enduro version with an HTA of 66.5 deg, 160mm travel fork, and 160mm travel shock.

The neat thing about having a full suspension fat bike like the Mutz is that it has the space to accommodate a lot of wheel and tire options, including a mixed wheelset...and I just happen to have a lot of wheels :)

Earlier this week I swapped out my front wheel (27+) for a 29+ wheel off my tandem. Both wheels run the same hub (Onyx of course) and Scraper rims. The 29+ front wheel is shod with a Dirt Wizard, the 27+ rear wheel is shod with a WTB Trail Boss 3.0

The Foes Mutz starts life with a 67 deg HTA and a 70.5 STA, these angles are based on the Bluto 120mm travel fork. I am running a 150mm travel Wren fork which adds 30mm HT rise, so ~1.5 deg to the negative. So my "base" HTA with equal sized tires is ~65.5 deg. By changing my front wheel to a 29+ I added an additional ~10mm of HT rise, leading to a ~65 deg HTA, which is pretty durn slack for a trail bike.

First things first, being the doubter that I am, I take my Mutz up the hill behind our house; I aint gonna waste a dedicated ride on this craziness. Granted, the hill behind my is big and it leads into some rugged terrain and great single track. First impression: "hey, this thing climbs pretty good".

I was suprised, but still not sold, so I took my bastard Mutz out to a local short track area to run it through some tight turns and over a few jumps. This was a very telling trial because I ride at this area often and I have ridden it with many different bikes, hardtails, FS, fat bike, even muni.

I found that the mixed wheels took some time to learn the handling, firstly because the wheels took very different lines, secondly because the front wheel was sticking like glue! I found that I needed to push the front wheel into the turns and initiate early to stay on line, whereas in the past with 27+ I was more concerned about my front wheel blowing through the turn. The big front wheel really dug in, like it was on rails. I used to ride motos and the way the front end handled felt sorta like a dirt bike.

One of the things I noticed was the slack front end and big front wheel were not necessarily a compliment. Part of the problem with initiating turns on tight terrain was how slow the front end was due to the decreased HTA, aggravated by the bigger and heavier wheel. However, all these complaints aside, I actually liked the combination enough that I went home and took the next step: added an angleset.

Last night I installed a +1 deg angleset, which returned me to ~66deg HTA. There was some additional stack from the gimbals, maybe 4-5mm at the bottom cup and another 4-5mm at the top cup. I was only able to take a short ride up the backyard hill, but right out of the driveway the quickened handling was obvious and I no longer felt the weight and size of the 29+ wheel.

I was once a doubter, but now I'm a believer, hallelujah!

Of course there are problems inherent with running a taller wheel in front including increased stack, decreased HTA, and decreased STA. HTA and STA can be adjusted through the use of an angleset, but stack increase is more difficult to accommodate unless you want to run less fork travel. For these reasons, Foes built a frame that adjusted for these differences.

So my plan is to ride this mixed wheelset for a while and see if it improves my riding in all scenarios: tech climbs/descents, flow. and XC riding. I have no doubts this set up is good for descending as I already appreciate 29+ wheels for their terrain gobbling abilities.

Granted, Foes has a mixer specific frame design, but it's not as though a 27+ bikes can't be made into mixers with a the use of an angleset, all you need is a big wheel/fork and a little elbow grease :)

and then I started thinking, what about a 27+/26+ mixer...
 
#3 ·
Paging dRj0n and Bonesetter!! These 2 have a decent bit of time on the mixed wheelset and seem to like it.

dRj0n on his Jones and Bonsetter on his Stooge.

I'm contemplating the same on my Singular Puffin as I would like the roll and ability of the 29+ to not fall in holes. My front stock/rigid fork will fit the 29+ easily, however my rear will not fit a 29+. That said it will fit as wide a B+ as there is made.
 
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#4 ·
I ran my Ventana El Gordo for a few rides with a 29+ front and a Big Fat Larry on 90mm for a few rides, just because I could, but I didnt see any benefits over 29+ front and rear. As such, ive stuck with 29+ for dirt and fat for snow.
 
Discussion starter · #5 ·
rth009 said:
I ran my Ventana El Gordo for a few rides with a 29+ front and a Big Fat Larry on 90mm for a few rides, just because I could, but I didnt see any benefits over 29+ front and rear. As such, ive stuck with 29+ for dirt and fat for snow.
Click to expand...
It could be that you need some suspension to see the benefits of this set up or it may be that it doesn't do much for a bike that isn't used aggressively.

I notice the difference most when charging hard into turns, jumping, rough terrain, but just cruising along it felt like a bike.

I've got an El Gordo/Lauf build coming up, it'll be my wife's daily driver (29+) for three season use and our hardtail fatty (27.5 x 4) for snowbiking. I will probably give it a whirl.
 
#6 ·
I've done it. 650B+ rear, 29" & 29+ front and I liked the 29+ on the front, but the 3" tyre just barely had clearance on the F34, would like a true 2.8" 29+ and running B+r/29f it doesn't feel much different. I personally like the raised BB and slacker HTA on my Paradox, guessing it would take it somewhere down around 67* un-sagged, which when sagged I'd guess puts it around 68*, which for me I like.
 
#7 ·
Nurse Ben said:
I have a Foes Mutz, a full suspension fat bike, it's become my test bed for a lot of wheel riding experiments. My Mutz is outfitted with a 150mm travel Wren fork and a CCInline 140mm travel shock. I have ridden it with 26 x 4" wheels and 29+ wheels (rear barely fit), but my standard wheelset is 27+.This year Foes and Timberline bikes release a bike theey developed that is frame specific bik for a 29/27 mixed wheel set. They have two set ups, the Trail version with an HTA of 67.5 deg, 150mm travel fork, and 140mm travel shock, and the Enduro version with an HTA of 66.5 deg, 160mm travel fork, and 160mm travel shock.The neat thing about having a full suspension fat bike like the Mutz is that it has the space to accommodate a lot of wheel and tire options, including a mixed wheelset...and I just happen to have a lot of wheels :)Earlier this week I swapped out my front wheel (27+) for a 29+ wheel off my tandem. Both wheels run the same hub (Onyx of course) and Scraper rims. The 29+ front wheel is shod with a Dirt Wizard, the 27+ rear wheel is shod with a WTB Trail Boss 3.0The Foes Mutz starts life with a 67 deg HTA and a 70.5 STA, these angles are based on the Bluto 120mm travel fork. I am running a 150mm travel Wren fork which adds 30mm HT rise, so ~1.5 deg to the negative. So my "base" HTA with equal sized tires is ~65.5 deg. By changing my front wheel to a 29+ I added an additional ~10mm of HT rise, leading to a ~65 deg HTA, which is pretty durn slack for a trail bike.First things first, being the doubter that I am, I take my Mutz up the hill behind our house; I aint gonna waste a dedicated ride on this craziness. Granted, the hill behind my is big and it leads into some rugged terrain and great single track. First impression: "hey, this thing climbs pretty good".I was suprised, but still not sold, so I took my bastard Mutz out to a local short track area to run it through some tight turns and over a few jumps. This was a very telling trial because I ride at this area often and I have ridden it with many different bikes, hardtails, FS, fat bike, even muni.I found that the mixed wheels took some time to learn the handling, firstly because the wheels took very different lines, secondly because the front wheel was sticking like glue! I found that I needed to push the front wheel into the turns and initiate early to stay on line, whereas in the past with 27+ I was more concerned about my front wheel blowing through the turn. The big front wheel really dug in, like it was on rails. I used to ride motos and the way the front end handled felt sorta like a dirt bike.One of the things I noticed was the slack front end and big front wheel were not necessarily a compliment. Part of the problem with initiating turns on tight terrain was how slow the front end was due to the decreased HTA, aggravated by the bigger and heavier wheel. However, all these complaints aside, I actually liked the combination enough that I went home and took the next step: added an angleset.Last night I installed a +1 deg angleset, which returned me to ~66deg HTA. There was some additional stack from the gimbals, maybe 4-5mm at the bottom cup and another 4-5mm at the top cup. I was only able to take a short ride up the backyard hill, but right out of the driveway the quickened handling was obvious and I no longer felt the weight and size of the 29+ wheel.I was once a doubter, but now I'm a believer, hallelujah!Of course there are problems inherent with running a taller wheel in front including increased stack, decreased HTA, and decreased STA. HTA and STA can be adjusted through the use of an angleset, but stack increase is more difficult to accommodate unless you want to run less fork travel. For these reasons, Foes built a frame that adjusted for these differences.So my plan is to ride this mixed wheelset for a while and see if it improves my riding in all scenarios: tech climbs/descents, flow. and XC riding. I have no doubts this set up is good for descending as I already appreciate 29+ wheels for their terrain gobbling abilities.Granted, Foes has a mixer specific frame design, but it's not as though a 27+ bikes can't be made into mixers with a the use of an angleset, all you need is a big wheel/fork and a little elbow grease :) View attachment 1067032 and then I started thinking, what about a 27+/26+ mixer...
Click to expand...
As I have shared with mike at timberline cycles: discarding preconceptions and considerations of cost, practicality etc; it is actually surprising that MTBs wound use matched wheel sets given the degree of asymmetry in dynamics (I.e. totality of forces, torques etc.) that obtain between front and rear. But, of course, proof will always be in the riding. And ever since the Foes Mixer, my curiosity around this has only increased. I look forward to your reports. Would love to try mixing it up with my Stumpjumper fattie, and go 29x3 up front, which should fit (I could also see going a bit slacker) Maybe at some point will give it a go. Til then curious to see how it goes for you.
 
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Discussion starter · #8 ·
Fifteen mile loop tonight, moderate climbing on single track, 2k or so, lots of switchbacks, not much technical, but a ton of turns on the way down, pretty fast on places, banked, flat, and off camber turns, really worked at laying down the front end, never really lost the front end but was able to wash out the backend.

It's hard to compare accurately because I have just the one set up, but my gut impression is 1) I suddenly got a whole lot better at planting my front end and controlling my back end OR 2) the 29 wheel up front rails and the 27 in back is easier to manage. :)

My buddy tried it, he normally rides a Knolly Warden, tonighy he was on a Chromag, and he said it felt pretty good.

If you have 27+ now, a 29+ wheel should clear your fork, in which case it could be as easy as borrowing a wheel.
 
#9 ·
as mentioned, I have been messing around with 29+ front/27.5+ rear and I like it a lot.

the front keeps all the obvious advantages of a 29+ - roll over, not falling into holes, good grip with a mildly knobbly tyre and the rear *seems* to stay highly manoeuvrable. Because it is a hardtail, i tend to ride slower than you might on a full bounce bike, and i tend to try and skip over rough stuff rather than plow through.

indeed, I like it so much I have a specific bike coming from Vertigo cycles that will run this combo. it will have an Enve fork up front with the 29+ and with a swap to a fox boost 34, it will remain geometrically the same but use a 27.5+ front wheel. i'm a short rear centre sort of rider, and like to be over the back wheel. It will have a ~410 back end, 177 spaced and a 83mm bb (nominal) width 1x11 - a set up I'm used to (and actually am beginning to prefer) from my other Vertigo (BA) and my 44bike. It is gong to be a fun bike for sure and although it is just in planning stage, when it's done I'll report back - if i can stop riding it for long enough!

Will be interesting to compare and contrast.

The Jones currently has a 27.5 Hodag front wheel and it is better for that bikes geo - the 29+ brought the front end up a tad more than ideal.

I am also curious about the Barbegazi in 27.5x4.5 and will likely try this combo on the front with a 27.5 x3 or 3.8 rear at some point, maybe on my fatty.

This has a 4.5 front and a 3.8 rear- currently...

its funny in some ways - bikes now look a bit weird to me if they DONT have a bigger wheel up front!
 
#10 ·
As you may know I am thinking about going with 29+ FS, but I am really wanting to try 29+ front 29x2.35" rear on my Tallboy, but I need a fork that can handle it (Manitou Magnum/MRP Stage?). For now I will just be trying a 29x2.5" Maxxis Minion DHF on my FlowEX to see hoe it compares to the 2.35" Nobby Nic (old version) I have, and also compared to the PRO TRANSFORMER I have on my Krampus.

The biggest thing 29+ has done for me is improve cornering grip, and of course smooth out bumps on my rigid Krampus. But on a FS bike other than the obv grip advantage from a 29+ tire, I don't know if I will need anything more than 2.35" in the back.
 
#11 ·
The mixed wheel size has been around since the Pennyfarthing, but never seems to stick. Cannondale and Trek put it out there but they no longer do it.
Mixed wheel sizes have their problems in that you have two tire sizes and I don't think the looks appeal to most of the buying public.
Beyond that if a larger wheel has better roll over performance and reportedly better traction then why compromise if you don't have to? Also why not try to match tire grip, rollover and performance by matching tire sizes?
I understand people with existing bikes trying to get in the plus game but do I think that it brings something groundbreaking to the table? No I don't.
 
#12 ·
richwolf said:
Beyond that if a larger wheel has better roll over performance and reportedly better traction then why compromise if you don't have to? Also why not try to match tire grip, rollover and performance by matching tire sizes?
Click to expand...
The simple answer to your question is that the front and rear wheels have two different jobs to do. For bikes with the same wheel size it's quite common to run different tread patterns, tire sizes and rubber compounds to tune the performance of each wheel. The mixer wheel size bike just takes that one step further.

A front wheel that stops in a hole pitches you over the bars making roll through far more critical on the front than the back. If your front wheel loses traction in a turn you go down. If the back wheel loses traction in a turn you make a BRRRAAPPPP! sound and slide around the curve. A smaller rear wheel allows for shorter chainstays and improves maneuverability. I can go on, but I think that makes the point that optimizing either end of the bike towards different objectives makes sense.

It's interesting that the people who are actually trying the idea are finding it worthwhile enough to pursue with custom bikes and in the case of bike companies with dedicated frames. Ventana did the same quite a while ago.
 
#13 ·
vikb said:
The simple answer to your question is that the front and rear wheels have two different jobs to do. For bikes with the same wheel size it's quite common to run different tread patterns, tire sizes and rubber compounds to tune the performance of each wheel. The mixer wheel size bike just takes that one step further.

A front wheel that stops in a hole pitches you over the bars making roll through far more critical on the front than the back. If your front wheel loses traction in a turn you go down. If the back wheel loses traction in a turn you make a BRRRAAPPPP! sound and slide around the curve. A smaller rear wheel allows for shorter chainstays and improves maneuverability. I can go on, but I think that makes the point that optimizing either end of the bike towards different objectives makes sense.

It's interesting that the people who are actually trying the idea are finding it worthwhile enough to pursue with custom bikes and in the case of bike companies with dedicated frames. Ventana did the same quite a while ago.
Click to expand...
I've been messing around with a 29er
front wheel on my B+ bike for a few months now. I usually run a 3" and find it a bit vague at times so I pulled the front wheel off my 29er,put the biggest non plus tire I could find on it and did some back to back testing.The 29 setup is 11 mm taller in radius so it slacked out the front end a bit so it's not apples to apples but it did give me some idea of how it worked.

In spite of the smaller front tire,2.8 in the rear,it did corner better and steered more accurately but got knock of line a LOT more in the rougher sections.No surprise.My fork has lots of room for a bigger tire but don't want to get back into the plus size so I'll wait for the 2.5 Maxxis to give it another go.
 
Discussion starter · #14 ·
vikb said:
The simple answer to your question is that the front and rear wheels have two different jobs to do. For bikes with the same wheel size it's quite common to run different tread patterns, tire sizes and rubber compounds to tune the performance of each wheel. The mixer wheel size bike just takes that one step further.

A front wheel that stops in a hole pitches you over the bars making roll through far more critical on the front than the back. If your front wheel loses traction in a turn you go down. If the back wheel loses traction in a turn you make a BRRRAAPPPP! sound and slide around the curve. A smaller rear wheel allows for shorter chainstays and improves maneuverability. I can go on, but I think that makes the point that optimizing either end of the bike towards different objectives makes sense.

It's interesting that the people who are actually trying the idea are finding it worthwhile enough to pursue with custom bikes and in the case of bike companies with dedicated frames. Ventana did the same quite a while ago.
Click to expand...
Braaaaap! :)

The front and rear wheels have two different jobs, more so in moden mountain biking where slarving, manuals, etc are becoming more the norm.

Kinda reminds me of the changes in ski design and binding placement, shaped skis, riser tips, forward mounts, this ain't your parents ski/bike gear.

I agree that same size wheels look "normal" and that's what John T Public expects, but I think there are things that Mr Public doesn't know and I think there are things worth doing that are not normal.

If anyone gets over my way ,Central WA, I'd be more than happy to show you my mixer :)

Meanwhile, my slarving machine awaits!
 
#15 ·
Image


Only semi-mixer...my old 29er bikepacking rig re-vamped with a 3" 29+ tire in front and a 2.4" 29er tire in the rear. Best setup for this bike so far. :thumbsup:

No room in the rear for a B+ tire or anything plus so my ability to experiment is limited. :nono:
 
#16 ·
Vik, at least you're playing with it!

Gotta appreciate the experimentation peeps post about in the forum. The imagination and creativity that goes on sometimes results is a sweet ride!

Carry on...
 
#18 ·
I currently have a 2016 Kona Wo with a Manitou Magnum Pro 29+ upfront. I had a chance to try the Comp version of the fork with a Maxxis Chronicle before buying and liked it even on the snowy trails. Now the front tire is a Surly Dirt Wizard on a WTB Scraper laced to Hope Pro4. On the rear I have the stock wheel (Jumbo Jim on Mulefut). I got the fork because riding a rigid fatbike downhill wasn't so nice when the speed gets higher. This setup feels nicely balanced. It has nice and quite even float on softer terrain (front tire doesn't go deeper than the rear tire). I can even ride on wet swamp with the front grannygear. Rear dropouts are quite close to the shortest position.
 
#19 ·
enemy1 said:
I currently have a 2016 Kona Wo with a Manitou Magnum Pro 29+ upfront. I had a chance to try the Comp version of the fork with a Maxxis Chronicle before buying and liked it even on the snowy trails. Now the front tire is a Surly Dirt Wizard on a WTB Scraper laced to Hope Pro4. On the rear I have the stock wheel (Jumbo Jim on Mulefut). I got the fork because riding a rigid fatbike downhill wasn't so nice when the speed gets higher. This setup feels nicely balanced. It has nice and quite even float on softer terrain (front tire doesn't go deeper than the rear tire). I can even ride on wet swamp with the front grannygear. Rear dropouts are quite close to the shortest position.

View attachment 1067378
Click to expand...
I really like your rear fender set up. Custom or off the shelf? I was thinking for bikepacking if you could have the front of the fender attach to the seatpost with rear strut supports like you have and the ability to lash on a dry bag it would be the bomb!
 
#20 ·
69ers were popular and common at the dawn of the 29er era, but people dropped them after more straight 29/29 bikes became available. My own time on various mixed size configurations has convinced me that for XC riding, you basically need the rear wheel to act about the same as the front, different jobs notwithstanding. Even for gravity stuff, your wheels are on the ground the vast majority of the time, and I could never get used to having to plan for each wheel to do different things when rolling over an obstacle.

I think when slapping on a new setup, it's also important to not forget the novelty factor. A new bike, or dramatically new setup is FUN, because it's novel and makes things feel different and interesting. That doesn't mean that when you swap back in 6 months you won't be amazed all over again by how great matching wheel sizes is.

But at least we have choices these days. You can end up with all kinds of whacky combos now due to the crazy diversity of wheel and tire sizes. Fun times.

-Walt
 
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