When selecting a brand new wheelset, you’ll encounter completely different rim widths. On this article, we dive deep into the subject of what rim and tire width to decide on for street biking as a result of it’s an often-discussed matter.
KEY TAKEAWAY
If you wish to future-proof your self, select street wheels with an inner rim width of at the least 24mm and an exterior width of at the least 30mm. These rim widths are extra optimized for 28mm and wider tires, which have gotten more and more standard. They’re extra snug and sooner and supply higher grip and crosswind stability. Nevertheless, you’ll want to double-check that your body has enough clearance for such broad tires.
What Is the Ultimate Rim Width for Street Biking?
Present traits recommend that the perfect inner rim width for street biking wheels is round 25mm, with an exterior width of about 30mm. Rim width performs a key position in tire efficiency, aerodynamics, rolling resistance, and total journey consolation. As biking know-how advances, wider rims have gained recognition. They work particularly nicely with fashionable tubeless setups and wider tires, enhancing not solely efficiency and luxury but additionally stability and grip.
The next desk reveals the wheel and tire combos utilized by the groups within the 2024 Tour de France. All credit score to Velo journal for placing the information collectively.
TeamTireWheelRim Width (I/E)Tubeless
Alpecin–DeceuninckVittoria Corsa Professional 28 mmShimano21 mm / 26 mmYes
Arkéa–B&B HotelsVittoria Corsa Professional 28 mmVision21 mm / 31 mmYes
Astana Qazaqstan TeamVittoria Corsa Professional 28 mm and 30 mmVision21 mm / 31 mmYes
Bahrain VictoriousContinental Grand Prix 5000 S TR 28 mmContinental Grand Prix 5000 TT TR28 mmVision21 mm / 31 mmYes
CofidisMichelin Energy Cup28 mmCorima20 mm / 26 mmNo
Decathlon-AG2R La MondialeContinental Grand Prix 5000 S TRContinental aero tire28 mmSwiss Side20 mm / 27 mmYes
EF Training–EasyPostVittoria Corsa Professional 28 mmVision21 mm / 31 mmYes
Groupama-FDJContinental Grand Prix 5000 S TR28 mmShimano21 mm / 26 mmYes
Ineos GrenadiersContinental Grand Prix 5000 S TR 28 mmContinental Grand Prix 5000 TT TR28 mmShimano21 mm / 26 mmYes
Israel-Premier TechContinental Grand Prix 5000 S TR 28 mmContinental Grand Prix 5000 TT TR28 mmBlack Inc23 mm / 30 mmYes
Intermarché–WantyContinental Grand Prix 5000 S TR 28 mmContinental Grand Prix 5000 TT TR28 mmNewman24 mm / 33 mmYes
Lidl-TrekPirelli P Zero Race RS28 mmBontrager23 mm / 31 mmYes
Lotto-DstnyVittoria Corsa Pro30 mmZipp25 mm / 30 mmNo
Movistar TeamContinental Grand Prix 5000 S TR30 mmZipp25 mm / 30 mmYes
Crimson Bull-Bora HansgroheSpecialized Turbo Cotton (26 mm)Specialised S-Works Turbo (26 mm)Roval21 mm / 35 mmYes
Soudal-Fast StepSpecialized Turbo Cotton26 mmRoval21 mm / 35 mmYes
Crew dsm–firmenich PostNLVittoria Corsa Pro25 mmShimano21 mm / 26 mmYes
Crew Jayco-AlUlaVittoria Corsa Pro30 mmCadex22.4 mm / 30 mmYes
Crew Complete EnergiesContinental Grand Prix 5000 S TR28 mmENVE25 mm / 32 mmYes
Crew VismaVittoria Corsa Pro28 and 29 mmReserve24 or 25 mm / 30 mmYes
UAE Crew EmiratesContinental Grand Prix 5000 S TR 28 mmContinental Grand Prix 5000 TT TR28 mmENVE25 mm / 32 mmYes
Uno-X MobilitySchwalbe Professional One28 mmDT Swiss20 mm / 27 mmYes
Groups and the wheels and tires they used on the Tour de France 2024. Supply: velo.exterior.com
Primarily based on this data, you’ll be able to see that not all groups adhere to the Rule of 105. I’ll write extra about it under. Let’s now bounce into the advantages and drawbacks of wider rims and tires.
What Are the Advantages of Wider Rim and Tire Width?
The principle advantages of wider rims and tires in street biking embrace higher aerodynamics, journey consolation, grip, and crosswind stability. Let’s now discover every extra in-depth.
Tire-Rim Transition and Diminished Rolling Resistance
One of many predominant advantages of wider rims is that they permit higher tire-rim transition with wider tires, which impacts aerodynamics and dealing with. Higher transition ensures the tire maintains a pleasant aerofoil-like profile, decreasing drag, primarily at increased speeds. I’ve included some images under for comparability, displaying narrower and wider rims with the identical tire measurement.
When researching wheel options, you most likely heard in regards to the 105% rule, which states that the exterior rim width ought to be at the least 105% of the tire’s measured width for optimum aerodynamics. This might imply that the scale could be as follows:
Tire Width[mm]Minimal Exterior Rim Width[mm]
2021
2324.15
2526.25
2627.3
2829.4
3031.5
3233.6
3435.7
Tire width and minimal exterior rim width based mostly on the Rule of 105 for the most well-liked tire widths.
However that is solely part of the equation as a result of it doesn’t take into consideration the rolling resistance. The losses from vibrations on slim tires inflated to increased pressures will be increased than the aero good points from adhering to the rule 105%. So, it’s all the time necessary to decide on the correct mixture of rim width, tire width, and strain.
For instance, utilizing a 34mm tire on a rim with an exterior width of 25mm would possibly trigger greater aerodynamic losses than rolling resistance good points and diminished vibration losses. Nevertheless, it’s additionally necessary so as to add that the speeds at which most passion riders journey make this dialogue a bit irrelevant. Utilizing 28mm tires on 30mm or 25mm rims gained’t make a lot distinction.
Do you know that the identical tire width inflates to completely different widths on completely different rim widths? For instance, my 28mm tires can differ by as much as 3mm!
A number of assessments proved that wider tires are sooner. Wider rims enable tires to sit down extra naturally. They’re additionally run at decrease pressures, decreasing vitality loss from tire deformation. Silca describes this phenomenon in depth of their article. In brief, when your tire is inflated to excessive pressures, it might’t take up street imperfections. This results in increased rolling resistance, which outweighs the eventual aero advantages (i.e., smaller frontal space and higher airflow across the tire and rim) of narrower tires. This assertion wouldn’t apply to a wonderfully easy floor like a biking monitor. Right here, alternatively, it’s fascinating to have as little frontal space as potential since vibrations are minimal.
Within the following check by NorCal biking, 32mm tires have been the quickest on actual roads. I like to recommend watching it because it gives helpful insights. GCN got here to comparable conclusions.
Higher Using Consolation
Wider tires are inflated to decrease pressures, which results in decrease rolling resistance, as they’ll higher roll over street imperfections and higher driving consolation. The distinction was large once I transitioned from 25 to 28mm tires. Think about utilizing 30 or 32-mm tires. You admire driving consolation, particularly throughout lengthy rides, as you’ll have extra vitality and gained’t expertise as a lot “journey vibration fatigue.”
Higher Grip
Wider rims paired with wider tires additionally enhance the contact patch, enhancing grip in descents or moist situations. That is a type of advantages individuals don’t discuss that usually, nevertheless it’s an enormous distinction. Though I don’t push it to the bounds in descents, I really feel extra assured on wider tires. You’ll be able to usually make up treasured seconds within the downhills should you’re racing.
Higher Crosswinds Stability
The final good thing about wider rims is best crosswind stability, assuming we’re speaking about the identical rim depth however completely different width. That is achieved by a bigger contact space, the place the air stays “connected” to the rim longer earlier than separating from it and inflicting turbulence (and, subsequently, instability). In fact, deeper rims will nonetheless be much less steady than shallower ones. How massive is the soundness distinction, you ask? It’s exhausting to place any concrete numbers on this, nevertheless it’s noticeable, particularly in case you are a lighter rider like me.
What Are the Disadvantages of Wider Rim and Tire Width?
Wider rims and tires even have some drawbacks. Right here’s a deeper have a look at the negatives:
Elevated Weight
Wider rims and tires add further materials, which will increase the general weight of your bike. This further weight can have noticeable results on efficiency, notably when accelerating, climbing, or sprinting. The added rotational mass of the wheels could make the bike really feel much less responsive and make it slower to speed up. Whereas the burden penalty won’t be vital for informal riders (we’re speaking dozens of grams), it may matter to racers and riders who prioritize velocity and agility.
Compatibility Points
Many older street bike frames, particularly these manufactured earlier than 2020, have been designed with narrower tire clearances. In case your body has a most clearance for 25mm or 28mm tires, it could not accommodate wider rims paired with 30mm or 32mm tires.
This situation is especially related for bikes with rim brakes, because the brake calipers won’t open broad sufficient to suit a wider rim. Disc brakes typically have higher compatibility with fashionable broad rims and tires. In case your bike doesn’t have enough clearance, utilizing wider rims may end up in tires rubbing towards the body or fork, making them unusable.
Greater Frontal Space
Wider rims enhance the tire’s total frontal space. The elevated floor space of the broader setup creates extra air resistance, making it tougher to keep up velocity in comparison with narrower rims and tires. A narrower rim and tire setup will typically be extra environment friendly on easy, good surfaces (like velodromes), the place aerodynamics and rolling resistance matter most. On roads, the decrease rolling resistance often outweighs the aero advantages.
Conclusion
The perfect rim width for street biking is determined by your driving type, preferences, and bike body limitations. Older frames, for instance, usually prohibit tire widths to a most of 25mm.
Trendy traits lean towards wider tires, which require rims with an inner width of 24mm or extra and an exterior width exceeding 30mm. This mix results in higher tire-rim transition, which improves aerodynamics. Additionally, wider tires (e.g., 32mm) are much less vulnerable to vibration losses as a result of they’re run at decrease pressures. I presently use 28mm tires, which measure round 30mm when inflated. However I plan to attempt 32mm tires primarily for improved journey consolation.
Don’t fear about wider tires slowing you down due to the bigger frontal space. Advantages equivalent to journey consolation and decrease vibration losses (i.e., decrease rolling resistance) outweigh them. On the identical time, the speeds most passion riders journey at should not that related to minimizing aerodynamic drag. In different phrases, you most likely gained’t discover increased or decrease aerodynamic drag from tire-rim transition in your common velocity.
Pairing wider rims with wider tires gives just a few extra advantages. These embrace improved journey consolation, higher grip, or enhanced crosswind stability. For those who haven’t tried wider tires and rims but, now could be the time to present them a shot. You’ll seemingly be stunned by the general driving expertise (or at the least, I used to be once I transitioned from 25 to 28mm tires).
