Abu Mahendra

hi...I am in Indonesia, not India...thanks. glad you like the bikes. there's more in the pipeline...

Rick Imby

Multiple runs on both bikes with the same workout level will give a range as to the difference. I agree the results will not be perfect. There are too many factors to eliminate. However 5 runs on this ride on each bike will give a pretty good idea of the difference in efficiency----for me.

I will be doing the "course" in full race mode on both bikes also.

Well as to which bike is slower at 16 mph that is like the old question which weighs more a pound of feathers or a pound of lead. ---joke---

However my workouts are relatively consistent. I have a lot of rides under my belt with strava on my mountain bike.

I was wondering if there were guys on this forum that have a lot of comparative rides---For instance if someone rides to work everyday and it is not interupted by traffic and they have a lot of reps on each of a 20" wheel vs 700c.


Yes I have become a bit of a folding nut. I have a 451 bike coming also to compare.

prathmann

It should give you a good idea of the relative efficiency of those two bikes, but not any general conclusion about 700c vs. 20" bikes overall. As I wrote previously, my 451mm wheeled bike is in between two of my 700c road bikes in speed when ridden with the same amount of effort. Wheel size is only one factor and others such as body positioning, tire choice, frame flex, etc. will also influence the overall efficiency.

fietsbob

+1, A 451-32 tire wont slow you down any more than a 622-32 will , you are just turning the wheel around more often

Per Mile, than the Bigger Wheel.. Higher gear to achieve the same speed proportional to the wheel size..

acceleration will feel Quicker with the Smaller wheel..

Bike Friday's Pocket Rocket is Quite like it is called..

Biggest source of drag is the rider's body air resistance, .. a constant, if the same guy is on the saddle, pedaling,

which you all should have memorized by now.. Air Resistance goes up 4X as the speed goes up 2X ..






'/,

mirfi

I'm a small wheel guy. Numerous bikes. Upgraded gear inches (Sheldon Brown) to theoretically go as fast as the 700c people. 100psi tires, etc. But always felt I was working too hard and it never felt 'right' or safe at speed, especially descending. Never could keep up with my crew. Bought a $600 700c road bike from BD. Now when riding with the crew, I just roll, it just glides better. It's like the tall wheels are long legs. Just my experience.

danduva1

Subjective Effects?

The Tioga Powerblock tires on my 20” Mercier Nano make more noise than the Continental GrandPrix 700C on my Cannondale SR 500 and I think that this subjective effect somehow makes it mentally harder for me to work as hard. I think that since I feel like I am going faster due to the sound effect that I don't work hard enough to actually go faster. I am about 1 1/2 MPH slower on the 20” wheeled bike over similar routes (10-50 miles hilly but not mountainous) as the 700C as measured by Cyclemeter on an Iphone in my pocket. I have done the same route a few times using the same gear inches on each bike and still come up slower on the little bike. I could maybe try putting the phone where I can see it on the handlebars and see if I can maintain a faster average MPH.

The components on the Mercier Nano are cheaper and surely much less efficient than those on the Cannondale which probably contributes to some of the slowness as well. There are too many variables for me to correct for. I give up and will continue reading this thread with interest.

fietsbob

Have 2 R'off, 16t standard Cogs; 20" wheel- 53t chainring; 26" wheel- 38t chain ring... the gear range is similar with Both ..

Neither have a speedometer and the Owner is not in a Hurry.

Air resistance which pushes back, 4X , when speed goes up 2X is a constant issue.

now back to the parts shopping discussion..

Schwinnsta

I was looking at the Schwalbe Shredda. Available in 404 40 and 44. However, the pricing of the the Folding bead, Liteskin, is three times as much as the wire bead, Performance line. $67 vs $22. Is that justified in terms of performance? I would prefer the Folding, it is lighter, and can fold, but still.

Abu Mahendra

I think the folding Shredda is outrageously overpriced. Wire may be worth a try, though a Maxxis DTH folding is probably the same price and probably lighter.

Abu Mahendra

Looking at NVO's website, i think the stem is about 300grams which, while twice as heavy as a normal stem, is not too bad for the increased functionality. I think a new Cane Creek headset is in the cards before a new stem. Cheers...

12boy

Jan Heine in Bicycle Quarterly has a method that could work for you. Find a long hill and coast down it without pedaling with two bikes and time the run. I would think one steep enough to go over 20 mph would handle the air drag issue fairly well. Give each bike the same pedal stroke to get going. Mr Heine uses this more to test tires, I believe,than bikes but it should work for both. Be interesting to know if Schwalbe Marathon Pluses,for example, compare to Primo Comets or the cheap 100 lb Kenda Kwests. of course wind or the lack of thereof would be a factor. i was thinking that to be fair you would have to have similar types of tires, handlebars (for wind resistance etc ) but maybe not. At the end of the day I would want to know how the bikes as I had them set up would compare.

Rick Imby

Interesting, thanks

Rick Imby

Interesting comment about the perception of speed. This is really true with full suspension vs hardtails in mountain biking. Our perception of speed while mountain biking is to a large part the vibration we feel through the bike. Hence even though faster on full suspension we feel faster on a hard tail..

Rick Imby

I am headed out to race my folding swift to try to beat my 700c time---recorded at workout speed. I just added bar ends to stretch me a little on the swift. Swapping my clipless pedals on also.

I love strava...

Paul Braithwait

I have a Xootr Swift with 20" wheels and a Bianchi road bike with 700c wheels and I don't think there is much difference in speed between them. I use a Garmin GPS computer to log my rides and my average speed for both bikes is pretty much the same with the Bianchi being a mile or two quicker.

It may be that the Bianchi is lighter than the Swift, has more gears and encourages 'sportier' riding; as someone else has mentioned, riding position can affect speed more than the size of the wheels. The Swift is a great all round machine while the Bianchi is more sports orientated so it is, perhaps, unfair to judge speed simply on the size of a bike's wheels.

fietsbob

Think You could Go Head to Head with all those guys in the Olympic Motos, on your 700c bike and win?

Rick Imby

So I put the max air pressure 65psi in my Swift, added a set of bar ends to give a little better position, put clipless pedals on and went on a "race" ride. I did my route at 16.9 MPH up from just over 14 mph before on the swift. In just normal workout mode on my 700 c bike I averaged 16.1 mph. Now to do a "Race" ride on my 700c bike to compare. I think I have 23mm front and 28mm rear tires on my 700c. I am going to order some lighter narrower 20 tires for my Swift to play with also. It is hard for me to take tires off a bike that have maybe 400 miles on them and are not even starting to wear. But they will end up in my exess pile and get sold on ebay probably.

Rick Imby

It kinda depends on how expensive money is to you. I don't wear out a lot of tires with several bikes and about 2k miles a year in riding spread over all of them. I only buy folding bead tires and try for the lightest with the tread design I am after. Tire, tube and rim weight have the most leverage against you for accelleration. Taking 4 ounces off the tires has way more impact than 4 ounces off the frame.

mirfi

If 406's were faster than 700's then the professionals would be using 406's.

prathmann

Professionals racing under UCI rules are restricted to the range of wheel sizes given by those rules (55 - 70cm diameter).

jur

When Moultons were allowed in racing in the early days, they proved almost unbeatable. The smaller wheels allowed closer draughting which conferred an advantage to those using them. They were banned as a result. If smaller wheels were slower then they would not have had much advantage.

Also, in speed record velomobiles, smaller wheels are used from build convenience point of view. If they were really significantly slower, they would not be used.

mirfi

Thank you, that is something I never knew. Puts a whole new light on things from my point of view.



Now gonna read up on Moultons.

Rick Imby

Great info Jur, I did not know that. It seems the 20" wheels accelerate more easily in sprints also. The combo of better drafting and better acceleration in a sprint puts them off the front in a lot of races.

I have no scientific verification on the 20" wheel accelerating better. Just my feeling and many others have stated the same.

The other advantage to smaller wheels is they are normally stronger.

Rick Imby

In road racing there are many limitation put on the bike by the sanctioning body in Europe. They want the Race bike to "look" a certain way. Aero tubing is significantly limited and for many years the top tube had to be level. "They did not like the Look" of sloping top tubes. In Triathalons it is kinda like if it has two wheels (I think 3 are legal too) and it rolls under the power of the rider then it is legal. Drafting is illegal in Triathalons so the small wheel benefit there is not relevant.

ttakata73

https://www.moultonbicycles.co.uk/heritage.html
Check out the Records and Racing section.

The UCI has held back the progress of the road bike for decades to keep competition even. Think how long MTBs have had disc brakes and they are still only testing them in UCI road races. Luckily the manufacturers sell the smarter buying public more progressive bikes with disc brakes, fatter tires, or lower weights than the UCI dictates. It's sort of ridiculous that you can buy a lighter and or safer to ride bike than what the UCI pros ride. A UCI race is becoming a competitive vintage rally.