Road Bike Tires on a Hybrid Bike Speed Question
 

Hello,

I bought a Kona Dew about 2 years ago for commuting and I am now starting to ride longer distances. I want to do a century this year and I've been thinking about how long it would take at my average speed which about 15mph, (I'm sure I will average less when going that long of a distance), so I'm looking for things that will give me a boost in speed.

I have been reading that smaller tires are faster. I found links to page below that lead me to believe I can use tires as thin as 700x28.
http://www.sheldonbrown.com/tires.html

http://www.konaworld.com/09/09_dew_en.cfm
Current Tires: Continental CountryRide 700x42C
Current Rims: Rigida Cyber 10
The inside of my rim measures about 19.3 mm

I am hoping to get some ideas as to what kind of a difference smaller tires will even make and some possible size recommendations.

Would going from a 700x42 to a 700x32 be a large enough gap or should I try for the smallest possible 700x30 or 700x28 maybe?

My commute to work is pretty short, just 5 miles each way. I was looking at road/cyclocross bikes earlier today, but I'm not sure I do enough of these events to justify buying a new bike.

Thanks in advance for any help. I really appreciate it.

I went from 700x42 down to 700x25. I found out by calling Nashbar that I could go with 25s, and I am happy with them so far. It did give me an extra mile or two in speed. Also, you can get the tubes with Schrader valves, if that is important to you.

700-28 smooth road tires will fit and work fine and should reduce both rotating weight and rolling resistance a very noticable amount. Remember you will have to change the calibration on your cyclocomputer if you change the tires.

Narrower and higher pressure tires will be faster and easier.

Wheels are a great approach. And I think for a century ride, that might be workable. But I have a friend who rides an aluminum 700c hybrid like the Kona Dew and he just attempted the Davis Double. He bonked and died (figuratively) after 3 segments totalling 94 miles in the saddle. His analysis:

A) bike was too tough, stiff, and fixed and beat him up.
B) rolling resistance was too great. He now wants 700x25C or narrower.
C) He should have gotten a faster bike and road with a pack. He and his buddy on the ride couldn't keep up in their bikes and lost the benefit of riding and drafting.
D) He thought he had been training and getting in shape, but he wasn't even close.

I used to solo ride up Mt. Diablo in the East Bay SF Bay Area from the town of Concord. From our home to the top and back was 60 miles. I had another solo route from home down to San Jose, then to Fremont and take BART back to Concord. 85 miles RT. At my size, it's probably thousands of calories to spend a day like that in the saddle. I've done this with fat slicks on an MTB framed bike, thin slicks on an MTB bike, 700x32C slicks on a touring bike, and a classic road bike with 53/42 front, 12-23 rear with 700x25C slicks, two water bottles and two granola bars, pump, tube, ID, mini first aid kit.

My experiences taught me that the MTB frame beat me up after 4 hours. Fat slicks were better, but slower. I got beat up after 3.5 hours on thinner tires because of stiffness, but I bonked on the fat slicks after 4 hours because I ran out of blood sugar and couldn't drink/eat fast enough. The rolling resistance was greater with fatter tires and although I was comfortable, the required caloric output was just beyond what I could sustain for more than 4hours. Therefore, the gain in time/total distance was offset. Both were not the correct solution. Just too stiff and too heavy. Good for a commute and workout, but not for recreational distance riding. I decided that going forward, on rides over 50 miles, I'd take a softer steel framed bike.

I also learned something on these rides. I installed drop bars on all my mountain bikes. Not because I bumped into Grant Peterson on BART or riding in Berkeley regularly, but because it made sense. I switch hand positions constantly while riding. I see these wannabees on road bikes with super long seat posts on a super small frame in super scrunched positions to look "aggressive," and a mile later, they're panting at the next intersection exhausted and uncomfortable, and then they casually mozy the next 5 miles with hands most comfortably on the tops of the brake levers or next to the stems where they aren't as low. For me, it's all about being comfortable on a bike and not necessarily aero all the time. Riding isn't to show others how cool we look, unless we want to impress the rednecks barrelling down on us with a side mirror so wide out that it's about to kill us. Riding is about being able to ergonomically spin the cranks around and around for an indefinite time.

And frankly, I recall heading out with a crew up Mt. Diablo on summer day, where we met up near the north gate in Walnut Creek to start the 11 mile ascent. Everyone had road bikes, and these guys left me in the dust last time when I had my fat slick mtn bike. This time, I was able to make the ascent in 1hr 45 minutes honking and spinning, and in a 42x23 ratio. I was granny-gearing for an hour longer than that with my version of a hybrid. And coming down was swift and exhilarating because I was left with more energy on the ascent.

And I think it makes a huge difference in these century/double century rides. If you have a competition road bike, you can keep up with a peloton and draft in the group. Even a small breakaway group of just 4 guys can reduce wind resistance by 40% and the power required goes up as the cube of wind speed. So you could average 20 mph (reason to get a 53x11 or 53x12 big gear). And that means 5 hours in the saddle, a couple of breaks and you've got your century and look, Ma, no sag wagon!

For me, I remember the 70 - 85 miles from north Concord to San Jose and back to Fremont BART. Road bike average speeds with several equally capable riders: 21 mph. Solo with fat slicks on a hybrid: 16 mph.

My friend and I were talking about his Davis Double experience, and he vowed to conquer it next year and at least finish. He went out and dumped some $$$ on a full carbon road bike with Ultegra gruppo. He's now training with that bike and realizes just how different the bikes really are.

Narrow/smaller tires are always lighter but higher pressure is not always faster.

http://www.bikequarterly.com/images/TireDrop.pdf

A good 28 or 32 tire should be noticeably lighter than what you have and should allow for some cushioning, compared to truly skinny tires.

just FYI, ditch the fenders, they're like permanent parachutes on your bike. Yes, the wider fenders add more drag than the narrower ones.

in terms of aerodynamic benefits, where a change can make the biggest difference: Rider position > bags > fenders > tires > frame/fork.

How long it takes to ride 100 mi depends on the particular ride, hills, heat, wind. If it is an organized ride you should be able to find people to draft with. With a little experience drafting can easily cut 25% or more from your ride time.
I think I would put 25 mm tires on your hybrid and ride them at the maximum recommended pressure in the rear and slightly less in the front.
Most people can ride faster and farther on a road bike than on a hybrid. On your hybrid if you can average 15 mph on a fairly flat 100 miles I'd say you are doing well.

So many replies already! So going to a smaller tire seems like a good plan. Does anyone have a suggestion for a brand or model tire I should look for? The prices seem to vary a good amount.

The only things I worry about with the smaller tires are the rough areas of the roads and sometimes we ride on a bike path that has some gravel. I'm guessing I may get flats more often.

Thanks again for all the suggestions.

A good reason to consider 700x32 tires. Panaracer Pasela TG are a good balance of light and rugged with a flat protection belt.

A lot of people over-inflate their tires, thinking harder equals faster.
There have been a lot of discussions about that.

There are various helpful guides out there, although I wonder why they all give different results.

Michelin: http://www.michelinbicycletire.com/m...rpressure.view

Bicycling Quarterly (PDF): http://www.bikequarterly.com/images/TireDrop.pdf

Jan Heine: http://www.dorkypantsr.us/bike-tire-...alculator.html

28mm is a useful size for efficient road riding, with an occasional piece of good, unpaved trail and gravel, with an unladen bike.
I regard 32mm as more suited to the same application for a loaded tourist.
If you are a heavy rider then you need to step up a tyre size.
As Sheldon's guide suggests, your rims may be to wide to mount 25mm tyres in an efficient shape.

28mm is a particularly variable width, some brands are closer to 25mm, some to 32mm.
There is also a lot of variability in sidewall flex, which is a major factor in efficiency.

Tyre efficiency includes rolling resistance, aerodynamic resistance and weight.
Aerodynamic resistance and rolling resistance are fighting against each other , ie a fatter tyre has lower rolling resistance (at same pressure) but higher aerodynamic resistance.
If you ride very fast, a thinner tyre is better but if you ride moderately, then a wider tyre is more efficient.

OK. I ran into some issues today. I went to three different local bike shops looking to buy tires and basically asking the same question I asked here.

1st shop, Performance Bike: They had trouble identifying the size of my tire, but said 28s should be fine. They only had Gator Hardshells and some 13 dollar forte tires. My tires are now confusing me too. They have multiple measurements on them.
37 - 622
28 x1 1/8 x 1 5/8
The first shop thought they were probably 35s.

2nd shop, Century Cycle: These guys also said 28s would be fine with out even looking at my bike. They suggested Gator hardshells as well. I asked if they could just quickly take a look at the bike to make sure 28s would work. ( I had to wait a bit since they were busy) finally a guy took a look for literally 5 seconds and said they'd be fine. Never looked up close at the tire or anything.

3nd Shop, Place I actually purchased the bike: They said that I shouldn't put a smaller tire on at all because the rim is too big!? This shop was going by this measurement 28 x1 3/8 x 1 5/8. They thought the 1 3/8 measurement was the width making the tire 35mm.

What is also confusing is that if you go by the 1 5/8 measurement for the width it equals 42mm which is what the tires are listed as on the Kona site. http://www.konaworld.com/09/09_dew_en.cfm

The quote below is from the Sheldon Brown site. If I went by this then the 37-622 on the tire would indicate I have 37mm tires.

"For example, a 700 x 20 C road tire would be a 20-622; a 700 x 38 hybrid tire would be a 38-622"


Now I am more frustrated, confused, and irritated than ever. :lol:

Does anyone know which numbers on the tire I should be going by? I can post pics or something if needed.

622-37 is the same as 700-37. 622-32 or 700-32 (same size, remember?) would be noticeably thinner, but not as thin as 622-28.

The make up of the tire will have as much bearing on the performance as the size. A high end 700 x 35 can be as fast as a budget 700 x 23; look at somthing like a Schwable Dureme for a high end fast larger tire; also the Kona Dew isn't a racer, and is designed for larger tires, if you want to go skinny, get a racer, not a Hybrid.

For the idea of ditching the fenders, Long distance / Audax riders have been using these for decades with no 'parachute' effects, they have more pros than cons, especially in the wet

I've done probably 50 centuries and I don't think I've ever seen a hybrid on one. It's not because they're a little slower, it's because they're a lot more uncomfortable on longer rides. That comfort you get from sitting upright on the bike trail on the way to work turns into crotch numbness and hand numbness after 30 miles or so. I did see some MTBs on Seattle to Portland but the guys were obviously very strong riders who spent a lot of time in the saddle and had no problem.

Just some unsolicited advice. Go do some 30 and 40 mile rides on your hybrid with your current tires and decide if you can do that for seven hours before you spend money on trying to make your hybrid a little faster.

The Dew is actually one of the nicer higher performance hybrids out there. If you want to work on it you can fix it up to be a decent long haul road bike. Not as good as a serious touring or road bike but not bad.

First off I'd say you can easily go with 28mm tires and you should. The tires you want to get for the best results should have thin almost floppy feeling sidewalls and a tread area that is not too thick and has little or no sipes. Sipes being the grooves in the tread. Don't worry about having "slicks". Bicycle tires form a boat like contact patch on the road which very nicely squeezes the water to the side when it rains instead of aquaplaning. You'd have to be doing a good 50 ot 60 mph on a bicycle to even begin to worry about aquaplaning. So thread sipes are all about either gripping on dirt or for peace of mind of those who think they need to be there. Now if you find some nice supple and light 28's you'll be more than happy with them.

You'd get a big increase in acceleration if you went with a new wheelset and some 25's. But that's likely out of the budget and if you were beginning to think that way then it's time to buy a different bike.

If you've got trigger shifters you could change your Dew over to bullhorn bars and turn this bike into a very nice road bike. The mounts on the trigger shifters would need to be hogged out a little with a Dremel or big coarse round file and using a drum sander for the final touch. But you CAN hog out the mounts to fit over the road bar sized bullhorn bars. Then you would go with time trial or TT brake levers. This along with the right length ROAD size stem, would stretch you out and lean you forward a bit to a lot to where you can get into a more aerodynamic road riding posture. Even if you don't go "all the way" with this lean the bullhorn bars offer more hand positions from aggresive to doddlin' along. In a pinch adding some bar extensions to your flat bars would sort of do the same thing but not as nicely or as lightly. They are a LOT nicer than flat bars because of the variety of hand positions they offer. Yet without the dedicated and VERY aggresive drop down to the lower drops that comes with a "proper" road bike drop bar.

Tires, this handlebar and shifter mod and perhaps a better saddle is about the only things I'd suggest you change. If you want to do more than likely you've outgrown the Dew and it's time to move on to something more suitable in every manner.

As far as tires go, I'd suggest Schwalbe Marathon Supremes. 28s would be nice, but they're popular and hard to find. 32s would be almost as efficient, and about half the weight of the the stock tires which are supposed to be Continental Country ride? Anyway, the supremes are a very comfy, grippy tire, with great puncture protection, and can be pumped up to 95 psi if you wish. ( I'd only go to 80 )

Drop bars are a definite improvement you should be looking at, but sorting out the brakes and shifters is going to make that more expensive.

No need for 53x11 or 12. I use a 50x19 or 50x18 for 20 MPH. By the time I get into my 50x13 big gear I'm some where either side of 30 MPH and once I've spun that out I'm going down hill and just going to tuck.

That's assuming you want to ride 20 MPH. If it means staring at guys' asses for five hours I'll pass.

"Literally 5 seconds" is all it takes to make sure you don't have some monster wide downhill MTB-type 29er rim.

The numbers on your original tires don't matter. The rim size is all that matters. You already know they are 700c (aka 622) rims, thus only the width is in question.

I rode a century a few months ago. It was not an organized ride. I did 100 miles cruising around Austin, Texas. I did the first 50 miles on a MTB with street tires. It had only one water bottle holder and this was in January and the city was scared of pipes freezing and had shut off all the water fountains. So I stopped at my shop and traded for my hybrid with two water bottle holders to ride the second 50 miles. At the end of my urban century I hung out for an hour until my friends met me for our evening group ride and I did another 12 miles. I am 65 and moderately strong. The 112 miles on MTB and hybrid left me a little tired but no butt problems and no more than occasional tingling hands I always experience.

I have ridden other long rides. None of my bikes have road bars, all have platform pedals and I wear levi shorts and a T-shirt when I ride.

Don in Austin

An excellent point Don. I agree with you that flat or other alternate bars are not the "kiss of butt death" that some seem to think. A lot has to do with how the bike is set up and the style of the saddle.

And on top of that there's likely lots of us that, like me, just are not flexible enough to properly bend down into a flat back style tuck and still be able to breath well.

I currently use these on my hybrid commuter - Continental Ultra Sport

Had them for two seasons ... comfy, smooth ride and no flats.

$ 27 @ MEC

In 700c/etro-622, the Jack Brown a "33" wide, is a nice rolling tire, features Kevlar Bead,
a light, (rather than heavy-duty) slick tread.
http://www.rivbike.com/products/show...en-blue/10-092
Kevlar tread belt or not,

Bio-metrically, even the guys on the Tour de France, during time trials, will go with slightly longer crank arms and SLOWER cadence. For someone not used to a century, slower cadence is going to be 4 out of the 5 hours spent in the saddle. Bigger ratios, but 5 mm longer crank arms. Just gotta watch the cornering while pedaling. But a 53x11 will mean also that that optimal chain line will be when the big ring lines up with the 15 or 17 cog. Just FYI.