Hairy Hands

My racing Colnago weighs 16 lbs with tubular tires, my Rando bike weighs 29 lbs loaded with 35mm Vittoria Rando Hypers. Both frames carbon fiber. I am 2 mph slower overall on my Rando bike on the flats and worse on climbs. What's causing this? Weight should not affect me on the flats. What do you think?

joewein

On the flats sustainable top speed should come down to aerodynamics, given the same engine. Wider tires will have some more air resistance. What about the shape of the frames?

c.miller64

Less aero on the flats, extra weight on the climbs. It's as simple as that.

Carbonfiberboy 

Put your Colnago wheelset on the rando bike and test. Then test the rando wheelset with the Colnago's tires. 29 lb. carbon bike? That's kind of amazing right there.

max-a-mill

gonna bet it is mostly the tires.

i'd be interested in the results if you do any of the testing carbonfiberboy suggests!

people say wider tires are not slower but they sure feel slower to me. i never ride with a computer though so i have no idea if it is all in my head...

Hairy Hands

I do have a more upright position on the Specalized for long distance comfort. I knew it would not accelerate as fast as the C50 but the bike does feel sluggish. I would bet the Specialized frame is more aero than the C50 and I have Tri-Bars on it. Weight difference of wheels and tires is Huge.

Any better rolling wide tires out there? I feel safer at night on wider tires and they seem somewhat more comfortable. I can use 38mm widths to 28mm.

Bye the way anyone heard from Homeyba lately?

lonesomesteve

Your position on the bike can make a very big difference.

The wheel-swapping experiment is an interesting idea except that you won't be able to fit the 35mm tires on the Colnago so you'll be introducing other variables with different tires, so it won't tell you too much. But definitely try the Colnago's wheels and tires on the Specialized and see what happens. My guess is that it will make very little difference on the flats.

Definitely. Try Grand Bois Cypres ~32mm. They'll be more comfortable and slightly faster, but no tire is going to make you 2 mph faster.

Homeyba

I'm around. I was really (hospital) sick and then with RAAM just not posting much (actually not at all ).

unterhausen

I didn't think of position when I read the OP. When I started riding my current bike, I had about an inch of spacers so that the cable run to the front brake was better. After a year of that, I dropped the spacers and it was like a whole new bike. Everything was better. Just amazing what a difference that can make

Hairy Hands

Well as you can tell I was missing you. Glad to hear your doing better. JP

Homeyba

Thanks for the thoughts. It is getting better but I still have a ways to go. It's been going on since April so it's getting pretty old.

fietsbob

Its the Bubba in the saddle .. air resistance of the rider through it..

Hairy Hands

Well, I figured out some of my problem. While doing routine maintence I noticed my BB30 crank was a bit stiff when turning it by hand. So when I tried to disassemble it I needed the strength of 5 guys to get the crank bolt loose, then the bearings were knotchy and noisy when spun by hand. I replaced the bearings with new units and properly torqued the cranks. Much better. I think the massive torque on the crank had the bearings preloaded too much and basically destroyed them.

I'm going to also try the Grand Bois 32mm tires but Jan is out till late summer.

skiffrun

In addition to Homeyba, I'd been wondering about "lonesomesteve" and whether he had stopped randonoodling-about.

And then, in the space of about one day, "lonesomesteve" posts and the randonoodler returned.

knobster

I have them on my bike and I'm amazed sometimes how fast they roll. Being thinner tires with very supple sidewalls I was very worried about flatting a bunch, but I haven't had a flat yet and it's been 3 months and several hundred miles. Much faster than the 700x28 Gatorskins I had on it.

mr_pedro

I have one of these for commuting: https://www.miyata.nl/admin/images/lar_3158DSCN0805.JPG
And a road bike for exercise. I often go on easy rides with a friend that is a bit slower. On one day I was riding my commuter bike with him on his regular road bike. We did a short sprint and it felt like I was going really fast, but afterwards he said that he could keep up easily.

So in this little sprint with me standing out of the saddle I don't believe tires or wind resistance mattered much. I think the biggest driver was the stiffness of the frame. With the road bike, more of the power you put in is actually being used to push you forward.

lonesomesteve

I had a little run-in with the law, and they refused to give me internet access in the "big house." Rest assured, I have now repaid my debt to society and will resume regular posting.

Bent42

Weight matters. You mentioned your speed on a "flat" route. I live and ride in central Indiana, which is about as flat as you can get. Even so, there are always small undulations in the road, and anytime you slow down for a corner, cross road, etc, you need to accelerate again, and then the weight matters. There is a 13 mile route I used to ride frequently - flat as a pancake, with several corners. During a 3 year span I lost 10 lbs each year, and my average speed on that ride went up 1 mph each year. You also said your speed difference was greater in the hills - again that points to weight. Aerodynamics and rolling resistance are obviously very important, so your slower speed is probably due to all three factors. Try removing 10-15 lbs of gear from the rando bike and then ride the same route.

zzzwillzzz

for 32mm tires try the serfas tuonos, i've had good luck w/them on my tandem and cross bike. relatively light and reasonably priced.

JAG410

There's more than one place to get them! https://harriscyclery.net/product/gra...-tire-3339.htm

Hairy Hands

Thanks but I'm waiting on the all black version that is currently back ordered