Dahon Speed P8 & Scwhalbe Marathon Supremes
 

Currently on my Dahon Speed P8 it came with Scwhalbe Big Apples in 20 x 2.0 tires. They are comfortable but not very fast. I have an average speed according to my bike computer of about 13-14mph. I would like to go about 18-20mph. Would switching to the Scwhalbe Marathon Supremes in skinnier 20 x 1.6 have me be able to do this ?? I know I would be giving up some comfort. Thanks for any info and sharing any experience in this.

In a word, no. Yes, they will be lighter. The Supreme is supposed to be a bit more grippy and durable than the Big Apple, according to schwalbe.com. However, they aren't going to give you over 30% extra speed on the same bike (as opposed to getting something lighter, stiffer and lower drag). Only you can do that.....

With the less drag and weight from switching from the Big Apples to the Marathon Racers, how much speed do you all estimate that I can gain ?? Thanks again for any info.

sure I sell you some .... those are ultimate ... after all

30 % faster will only work if you push them pedals down much harder ...
I do have a Bionix for sale.... that will do that and more than 30 % but tires..... never ...unfortunately ...otherwise this ole farth would have them on his bike .....

than again I do have ultimates on my bike....lol

thor

first off an average speed of 14 mph is pretty fast. That typically means you are able to cruise 21 or 22 mph on a flat smooth road.

I switched my tires from from the stock Kenda tires on the dahon D7 to much heavier winter studded tires. My average speed only dropped 10%. So if you're only incrementally going to a smaller tire I would not expect more than a two or 3% speed increase.

I switched recently from Marathon to Kojak and they definitely *feel* faster and smoother and that's good enough for me ;-)

Kam

I don't think that the science and/or data is precise enough to give a good estimate. For instance, I can't find estimates of rolling resistance for the tires you mention and then the appropriate method for translating it to everyday riding. But assuming moderate distances and my own anecdotal experience, I would guess that you could add 1 mph through testing out different tires/pressures if you are riding through a semi-urban environment with stop signs, lights, and traffic.

The longer the ride, the more endurance and efficiency play a role. In other words, my commute is ~7 miles. I can ride a clunky bike pretty quick for 7 miles just through extra effort. But if you want to do a brevet, then small efficiencies accumulate over the miles.

Actually it can be the other way round. I did, for example, do a couple of test rides on my commute to work. This is 18km in Berlin, Germany. I did that on a Dahon Mu SL. It came with Stelvio tires. I also comparatively tested to Marathon Racers and Big Apples 2.0". Surprisingly: I was fastest with BA. The gain was approx 5% over the Racers. And 15% (!) over the Stelvios which were slowest. Partially this was because of many stop-n-go on red lights, and I can stand-n-hammer on the BAs, while the Stelvios would throw me off the pedals (MKS detachables). Quick release pedals however might work though.
Difference in rolling resistance of all these 3 tires on perfectly smooth road is negligible, I would estimate less than 3%. Only the Stelvios have less air drag if you are really going fast, i.e., over 40km/h and more. Otherwise, on less than perfect road again, BA have least drag, as they smooth out bumbs. This difference can be pretty high, over cobblestone, for example , I can run 40km/h with BA, on Stelvios I have to slow down to <10km/h. The trick is that I do this stand-n-hammer, on the Stelvios this simply throws me off pedals (or probably might break my Mu frame at these kind of impacts).

Actually I meant CRUISING speed not average speed. :D I have a cruising spped of about 14mph. Sorry if I confused anyone.

pibach, can you explain how the Stelvios throw you off the pedals.

Thanks,

Kam

There are two effects. First is pretty simple. The narrow tires have no volume to absorb impacts. In case of street irregularities this will hit you straight. Can kick you off the pedal, when standing. Or, if you remain seated, kicks your but. And results in high stress on the frame. As I am 95kg, it might break.

The second effect is due to wheel weight. Stand-and-hammer gets difficult if wheels are very lightweight. Try it out. You easily slip off the pedals. Good pedals though can make a huge difference. I prefer platform pedals, bought a pair of Wellgo MG1 which have a much better grip than the MKS detachables that came stock on that Mu SL.

Having both tires, I do not believe that you will see a substantial speed gain over the Big Apples with the Marathon Supremes.

The largest reasons to change to the supreme are:
1. A lighter folding bicycle to lift
2. A desire to have greater puncture protection. Big Apples are good, Supremes are very good.
3. Supremes fold, which can be good for carrying spares on tour

Supremes are available in large balloon-ish sizes, but not in the 20" category. You will only find the 20x1.6 model, which will not conform to road irregularities to the same degree the BA will.

I have ridden with Big Apples on both wheels, Supremes on both wheels and toured with a big Apple on the front with a 1.6 Supreme on the rear. The only way you'll go from 14mph to 20mph is putting out a LOT more effort. There is no way a tire can make that much of difference. I used the Supreme on the rear for better puncture resistance. If you can't cruise at 16mph with an inflated Big Apple you won't be able to go 18mph with a racer or other fast tire. My $.02 is that an inflated Big Apple is fast enough. 18mph+ territory is where wind resistance and a good tuck make a difference. My Bike Friday came with 1.75 Kendas with small deep knobs, nice grippy all purpose tread but the Big Apples roll better.

Don't do it. Unless you just want to.

I have a Speed P8 with Big Apples and a Jetstream XP and an Ignio bike with Marathon's. My GPS says I don't really go any faster on the Marathons.

But it's your bike. If you want to take a crack at the Marathons go for it and make sure you post back and tell us what your impressions are.

John