Mixing different wheel sizes was popular late in the ’90s and even some of the brands were doing it back in the larger or shorter tires on the front and vice versa, but soon they stopped it and the idea itself has bugged me ever since like would it be possible to run a bigger tire on the front and a smaller tire in the rear and what would be the results as far as the possibilities go its very much possible and as I said brands used to it as well
The shorter version of the answer would be.
It’s possible to run different size tires on a bike, for example, if a bike came with a 29″ wheelset and you had like to run a 29″ wheel on the front and a 27.5″ wheel on the rear but there are limitations to the size you are trying to fit on a particular frame like running 26″ wheels on a bike that came with 29″ inch wheel
So yes there are limitations but you can certainly do this kind of combination they are not very popular in these times and the combo might seem odd but people do it even today.
But as I said there are limitations its not all free and there are also the counterarguments that you might have in your mind like why it’s not the norm in the first place
So I will be covering all of this as much as I can in this article in detail so stick around to the end and before I start let me point out some things beforehand
These possibilities are restricted to some bikes only like mountain bikes because road bikes and other pavement bikes have different kinds of geometry and a lot goes into them like effects on aerodynamics
So if by any chance you landed on this article I will be mainly talking about mountain bikes because there are many factors and complexities involved in other discipline bikes and if I started discussing that it would become a very long read so I wouldn’t do that.
The concept behind using different wheel sizes :
If you happened to have landed on this article while searching for something else and the idea appealed to you let me go over the basic concept behind using different wheel sizes.
- Better rollover resistance
- Improving traction
These are the two main factors that people try these combos for rolling resistance is beneficial because you are not falling into too many holes and the tires roll over them smoothly while having better traction as well.
and for traction improvement, people modify or interchange tires to test better handling and better control on rough terrains.
Wheel size Combos on Front and rear and their benefits :
Each combo that you make like a bigger wheel in from or a smaller wheel on the front will have different effects respectively but the most common and most used combo in mountain biking is a bigger wheel on the front and a smaller wheel on the rear.
The benefits or aim of this combo is to utilize the benefits of the bigger tire for better roll over and the smaller wheel on the back gives you better control and your BB (The bottom bracket will form an angle) but the difference in height will not be that much
This kind of setup can be great but there are drawbacks to it and that’s why it’s not quite common as well.
Drawbacks of the front wheel being bigger and rear smaller :
Drawbacks of this kind of setup will be
- Extra weight
- more weight on the rear tires
- Not a very optimal setup for uphill
- Rear brakes burning out too quickly
While they might not seem much but they will have a significant impact on how your bike performs, Extra weight is of course always not good and if you are somewhat skinnier or weaker controlling the bike with that added weight might become harder on complex trails.
The biggest disadvantage by far is the amount of weight on the rear wheel even in usual MTB the front tire is only under 1/3 of your weight and if you put on a bigger front wheel there will be much more weight on the rear wheel and you will be burning them far too quick.
And because there will be somewhat of a lower weight on the front wheel and the effect on geometry like the seat angle will change and you would feel like you are riding a BMX and that would cause the bike to not perform well and lose traction and in some cases even flip over if the climb is too steep.
With less weight on the front wheel, the braking power would reduce to some extent as well and you would have to use rear brakes more often.
So these are some of the major disadvantages of this setup.
Advantages of having a bigger Front wheel :
Advantages to this kind of setup are there but you wouldn’t be able to reap them quite often
- Very effective setup for competing in time laps
- If used right away very good setup for technical trails
- Better for downhill riders
- Effect for technical maneuvers and cornering
You gain a better rollover with this kind of setup and if you are competing in time laps this setup might give you an edge if say you had a setup of 27.5″ rear and 29″ on the front this setup could win you a race against a 29″ setup bike.
Line choice is by far the biggest skill that mountain bikers need and if they understand it everything becomes easier but a bigger wheel, in this case, would be effective as well since even if you took a poor line you might be able to cut through and perform better because your front wheel has better rolling and your rear is them maneuvering the bike becomes much better.
Maneuvering and cornering become much easier as well because you can roll over the technical sections of the trails much faster and you are able to keep that speed around the corners.
What Kind of Set-ups can accept a bigger wheel on front :
Not all setups can load up a front wheel because for some setups it’s okay to use and for others, it would not be okay at all and there are reasons behind that as well like BB length becoming too short which would be disastrous
- You can mount a 29″ Wheel on a 27.5″ factory-released MTB
- You can mount a 27.5″ wheel on a 26″ bike
- you can mount a 26″ wheel on a 24″ bike
The way i put them this way is for beginner to understand that bikes are designed around the type of tires they are or will be best suited to put on them
Other than this we are left with 20″ inch bikes and trying this setup on those bikes will not be possible because you will bottom out the Bottom bracket or it will become too low to be driven on the trail.
Modifications and precautions you would need :
The only modifications you would need for this kind of setup would be getting bigger brake cables the ones on your current bike may fall short but if you didn’t trim them at some point then they may work but that would be on your part make sure that the tubes are not too tightly held with your handlebar and they are loose, a lot lose
The precautions you would need are to make sure that the wheel you are trying to fit has some clearance over the forks forcing the wheel and leaving very little clearance would result in a bad experience and you might be blowing dust in your face.
What MTB disciplines bigger tires are used in front and smaller on Rare :
Slapping on a bigger tire on any bike is not a wise choice there are 4 disciplines of mountain bikes
- XC/Cross Country
- Enduro
- trail / All mountain
- Downhill
you could presumably get away with using bigger tires on trail and XC bikes but they will not be well suited unless you run 26″ wheels on your XC or trail bike, Meaning that you run really low tires and they are not much sufficient.
This kind of setup you would see mostly on enduro bikes or All mountain/trail bikes and it suites them well as well since they are timing every second to reach the goals and having a bigger tire in front helps them achieve that of course many factors go into that choice as well like width and material of the tires
This setup is not as quite common in trail bikes as it is in enduro but trail bikes are moving more and more into enduro-style and XC style of it are fading more and more so it works well on trail bikes unless you are running 200 mm DH suspensions on them
in other disciplines like XC and downhill typically this kind of setup will backfire because for an XC bike weight is everything and for a Downhill bike traction matters alot and with a bigger wheel you would lose both of them because in both cases a bigger front wheel is not the optimal choice.
Why brands stopped producing these kinds of bikes:
As I mentioned earlier different brands like Cannondale and others used to produce these kinds of bikes but they stopped and there is no clear answer as to why they stopped it but from a third-person view like mine there could be 5 reasons that I can think of that would have happened
- bikes didn’t look pretty enough
- rear tires burning out too quickly
- Rear brakes taking some serious toll
- not very ideal for climbing
- Not very beginner-friendly setup
These are the reasons that I think that brands stopped producing bikes like these because if you think about it most of the new bikes are purchased by beginners and they would be more confused than understanding the reason behind it but no one knows the real reason why they stopped it
These are all the speculations people make just like I am but no one knows for sure what happened I think any newcomer when he realizes these kinds of things will be spooked
While I know rear brakes dont fundamentally play a part in MTB that much but still in this kind of setup braking power on the front wheel will drastically reduce and you would be forced to use rear brakes much more and they would heat up pretty fast
What kind of people this Set-up is not ideal for:
I have mentioned above as well but I wanted to make it clear that using different wheel sizes on front and rear is only useful or ideal for people who have a bit of experience
It’s not very ideal or better for beginners, it’s for the people who are somewhat bored and had like to try something new to change the mood a bit
I will include the link to another article about using smaller wheels on the front as well because it will turn out into a massive article if I kept on writing and if you had fun reading it I will add another one just like this one
Conclusion :
For better or worse the Setup does work and delivers but the drawbacks are obvious as well and if you had like to try something new on your MTB well now you know what you can do
But I wouldn’t recommend it as a permanent setup while it may seem appealing the extra costs of keeping this set can be on expensive side and i wouldn’t recommend it for the absolute beginners as well.