Bike with fat wheels

He thought this post was in Pet Corner where indeed the wheels are 28mm diameter....

NOT the case with motorcycles!

Tom

From Wikipedia:

Several factors affect the magnitude of rolling resistance a tire generates:

As mentioned in the introduction: wheel radius, forward speed, surface adhesion, and relative micro-sliding.

Material - different fillers and polymers in tire composition can improve traction while reducing hysteresis. The replacement of some carbon black with higher-priced silica–silane is one common way of reducing rolling resistance.[5] The use of exotic materials including nano-clay has been shown to reduce rolling resistance in high performance rubber tires.[48] Solvents may also be used to swell solid tires, decreasing the rolling resistance.[49]

Dimensions - rolling resistance in tires is related to the flex of sidewalls and the contact area of the tire[50] For example, at the same pressure, wider bicycle tires flex less in the sidewalls as they roll and thus have lower rolling resistance (although higher air resistance).[50]

Extent of inflation - Lower pressure in tires results in more flexing of the sidewalls and higher rolling resistance.[50] This energy conversion in the sidewalls increases resistance and can also lead to overheating and may have played a part in the infamous Ford Explorer rollover accidents.

Over inflating tires (such a bicycle tires) may not lower the overall rolling resistance as the tire may skip and hop over the road surface. Traction is sacrificed, and overall rolling friction may not be reduced as the wheel rotational speed changes and slippage increases.[citation needed]

Sidewall deflection is not a direct measurement of rolling friction. A high quality tire with a high quality (and supple) casing will allow for more flex per energy loss than a cheap tire with a stiff sidewall.[citation needed] Again, on a bicycle, a quality tire with a supple casing will still roll easier than a cheap tire with a stiff casing. Similarly, as noted by Goodyear truck tires, a tire with a "fuel saving" casing will benefit the fuel economy through many tread lives (i.e. retreading), while a tire with a "fuel saving" tread design will only benefit until the tread wears down.

In tires, tread thickness and shape has much to do with rolling resistance. The thicker and more contoured the tread, the higher the rolling resistance[50] Thus, the "fastest" bicycle tires have very little tread and heavy duty trucks get the best fuel economy as the tire tread wears out.

Diameter effects seem to be negligible, provided the pavement is hard and the range of diameters is limited. See dependence on diameter.

Virtually all world speed records have been set on relatively narrow wheels,[citation needed] probably because of their aerodynamic advantage at high speed, which is much less important at normal speeds.

Temperature: with both solid and pneumatic tires, rolling resistance has been found to decrease as temperature increases (within a range of temperatures: i.e. there is an upper limit to this effect)[51][52] For a rise in temperature from 30 °C to 70 °C the rolling resistance decreased by 20-25%.[53] It is claimed that racers heat their tire before racing.

Hehe, a lot of non-believers out there - this article explains the concept of wider tyres having lower rolling resistance quite nicely:

https://cyclingmagazine.ca/sections/...ng-resistance/

Of course, as said previously, rolling resistance isn't everything - many other factors play a role in how 'fast' a tyre setup is in the real world. There's a reason why roadies don't race on fat bikes.

It's not only resistance. Don't underestimate the factor of the additional rotation weight.

Nice piece of theory. 23 or 25 mm wide wheels are for races or highly motivated enthusiasts. I'd hate to ride in a fat 25 mm wide tire on a rainy day.

The discussion around here is between city bikes (35-40mm wide tires), MTB hardtails (50-60 mm) or fat bikes (75-100mm). Try pedaling to gain speed with 100m wide tires after every time you need to stop at a traffic light or let a pedestrian cross the street. Mind the tire width and rolling resistance, the challenge is in spinning all that rubber mass from zero. It's really hard to maintain constant speed in a urban setting, you're accelerating from zero to something most of time.

On the flip side of slow acceleration you get a flywheel effect instead. Great for cruising around on your cloud tyres.

In the end, I'd say the OP would be fine on any bike that's not running tyres under 30mm, I mean you could stick a wider tyre into a tramline but you'd want to be aiming for it.

If you're riding along tramlines just make sure to cut across them when leaving instead of drifting across them, the more perpendicular you are the better.

You're absolutely right - at a point, the higher rotational mass of a wider tyre will offset the benefit of its lower rolling resistance. Its larger surface area will also create more drag, which would become perceivable at higher speeds (which most wouldn't reach in day-to-day city riding scenario).

Anyhow, if I could pick any bike to ride in the city today, I'd probably go with something like this:

https://hotpoint.ch/work/koga-f3-4-0s/

The belt drive and internal-hub gears should ensure a long and very low-maintenance lifespan.

Of course, at CHF 1,899 it's not cheap (that's e-bike territory), but you get what you pay for.

Thanks all for your detailed replies so far. I just want a cheap bike so I can ride around on the weekend when it's quieter. I will go for a cheap mountain bike which has a little 'fatter' wheels on average.

Could I ask another question as I am such a rookie with bikes. I'm 5"11 (180cm) with an inside leg length of 34 inches. Swiss bikes seems to judge size of bikes by frames. What size frame should I be looking for? Is 29 inches (48.2cm) too small for my size?

Mountainbike frames normally come with a S,M,L,XL sizing.

29" is also a Mountainbike wheel size.

With bike brands being different with no standard scale, normally I'd look up the brand site.

A 29" frame would be for a giant. You should be somewhere around a Large/20"/54

EDIT - 48.2cm must be the size you're looking at, could be a touch small. (29" is 73.7cm)

If you're looking for a cheap bike you might as well head to Decathlon or Ochsner sport to have a salesperson help you find the right size. Also, there has been a lot of discussion about tire width and rolling resistance, I made the point that having knobby tires (vs. smooth) is what can really affect your rolling resistance. It should be perfectly possible to find a bike with wider, more comfortable tires that are still a bit "slick" so they roll easily.

If you're after a mountain bike, they mainly use the XS, S, M, L, XL etc. sizing system.

I'm the same height as you, and size L mountain bikes fit me best 90% of the time, although I know a few people my height who feel more comfortable on an M. Bottom line is that it's best to try before you buy. Note also that you can make a few cheap/free tweaks, like switching to a different length stem, or changing the distribution of steerer tube spacers, to adapt the bike to your liking.

One word of warning: buying cheap mountain bikes can be a bit of a gamble. Buy cheap and new and you will likely end up with a poor quality frame with sub-par components. Buy cheap and used and you may end up with a bike that has had a hard life (mountain biking can be very harsh on equipment).

Anyhow, I have no idea what you mean by 'cheap' (people in Switzerland seem to have a bit of a warped concept of the word :P), but if you're really looking to save your pennies, I'd perhaps look for an old fully rigid mountain bike - less to go wrong without a suspension fork. Then just swap out the tyres for slicks.

I'm way too slow XD

I think I'll check out decathlon as it's not terribly far from me. By cheap I mean the cost will be no more than 250chf. I hear bikes can be 500+chf here.

A large sounds about right for me. I literally just want to ride short distances when it's the weekend and roads are quiet. I won't actually be doing any mountain biking so the wear and tear of the bike will be minimal (I hope).

I don't think you'll find a new bike for that price. Maybe if they have a promotion in ALDI? So I'd check the used market, e.g. tutti.

Search Ricardo for an old hardtail or suspensionless mtb. I haven't looked up bike prices recently but I hear they've gone up during virus times.

Something like this: https://www.ricardo.ch/de/a/velo-bmc...-l-1130860022/