Last weekend, I found myself behind the peloton by 75 seconds after losing my chain. I made up the gap in two full laps of the 8 mile circuit. Very little of the course was flat; either uphill or downhill; total of 1100 feet of climbing in that period. Average speed for the chase period was about 24mph. I'm considering what the time difference might have been for a few equipment changes:

I was using 2 x 117g standard performance tubes in pro races.

How much time would switching to performance's lightweight tubes (70g) have saved?

Also, for racing only, are those tubes so vulnerable to punctures that you don't use them? Does anyone use them only in the front?

I ride either Performance Lunar light or Maxxis Flylight tubes all the time, 49 gram tubes. I don't think I have more or less flats than anyone else does. At 6'2" and 155 lbs riding mostly oil and chip roads in Central Illinois, I had about 3 or 4 flats last year in over 5,000 miles of cycling.

Do they make a difference? I guess they do although it's not going to save much, just a matter of seconds in a road race. Is that worth it to you for the extra money you will spend on lightweight tubes?

Last weekend, I found myself behind the peloton by 75 seconds after losing my chain. I made up the gap in two full laps of the 8 mile circuit. Very little of the course was flat; either uphill or downhill; total of 1100 feet of climbing in that period. Average speed for the chase period was about 24mph. I'm considering what the time difference might have been for a few equipment changes:

I was using 2 x 117g standard performance tubes in pro races.

How much time would switching to performance's lightweight tubes (70g) have saved?

Also, for racing only, are those tubes so vulnerable to punctures that you don't use them? Does anyone use them only in the front?

Last weekend, I found myself behind the peloton by 75 seconds after losing my chain. I made up the gap in two full laps of the 8 mile circuit. Very little of the course was flat; either uphill or downhill; total of 1100 feet of climbing in that period. Average speed for the chase period was about 24mph. I'm considering what the time difference might have been for a few equipment changes:

I was using 2 x 117g standard performance tubes in pro races.

How much time would switching to performance's lightweight tubes (70g) have saved?

Also, for racing only, are those tubes so vulnerable to punctures that you don't use them? Does anyone use them only in the front?
Pro race are 230 grams :rolleyes: You could try vitoria ultraspeeds at 145 grams. Great race day tire. I have had good luck with lightweigt tubes, just be careful when you install them

How much time would switching to performance's lightweight tubes (70g) have saved?

For reference, saving 95 gm is worth 0.0017 mph on the flats, and 0.011 mph on a 6% grade. I'll let you calculate the time savings (in tenths of a second).

Pro race are 230 grams :rolleyes: You could try vitoria ultraspeeds at 145 grams. Great race day tire. I have had good luck with lightweigt tubes, just be careful when you install them

unless you have teammates who get the concept of waiting and getting someone back on after a wheel change. i would seriously not recomend going with a super light tire, been there, done that, and been off the back chasing trying to get back on after a flat. not fun at all and is why i don't race on sub 200 gram tires anymore the lighter ones are not noticeable faster and if and when you flat are a lot slower.

as for tubes it depends on how durable your tires (i've never ran pro race) are right now i'm running specialized mondo s-works tires (230) with specialized turbo tubes and have no issues with flats at all and the roads here are pretty littered with glass but if your tire isn't durable and picks up glass and cuts easy you might be better running what you've got now. lighter tubes and tires are only faster and not by much at all if they hold air.

Buy yourself some tubies.

Buy yourself some tubies.


I second that motion

Justin

I misread Kerry's numbers when I first posted this reply.

I'll admit, of course, those are pretty small numbers, but trying to be picky out of curiosity's sake... wouldn't the speed difference it makes depend on the rider's power? Like, if I can only sustain 200 watts (arbitrary number), but Lance can sustain 400, wouldn't he benefit more than I would?

Second, wouldn't the lightweight tubes make MORE of a difference in the hills? If not, then why is everyone so concerned about light wheels for climbing?

Aero wheels would have made much more of a difference in closing the gap then anything. Lightweight aero wheels would have helped with the inital and subsequent accelerations needed to do it as well. Thus something like a Reynolds Stratus DV or a Zipp 404 would be the only improvement enhancing addition in that situation.

In the prototypical hill climb / mountain top finish situation- the riders with expectations of winning do select ultra-light carbon wheels (ie Lightweights or Zipp 202 for example), with lightweight tubies because in this situation weight does play more of a critical factor, especially with the low average speeds making aero a much less important factor for once. Also, as the riders are pretty closely matched, so any legal advantage you can get at that level is certainly used.

So lightweight tubes may give a small improvement in the hill climb event, but not as much is the lightweight tubular wheel with a nice racing tub like a Continental Competition 22, or a Veloflex or Vittoria.


:)

i'll defer to kerry's numbers, but as i understand it wheel weight matters most in acceleration. technically, you're accelerating with every pedal stroke. however, when you're gaining great amounts of speed (coming out of a corner in a crit) or climbing (fighting the deceleration) you'll notice a bigger (bigger, not necessarily big) difference in your wheel/tire/tube/tubie weight.

i use performance light tubes--not the lunar lites-- and have had no more problems w/ flats than any other tube. whether they make me faster/more competitive, that's entirely up for scrutiny.

wouldn't the speed difference it makes depend on the rider's power?

I just assumed the 24 mph speed that the OP stated. Yes, the speed difference is different at different speeds, though the numbers are so small that it's meaningless.

Second, wouldn't the lightweight tubes make MORE of a difference in the hills? If not, then why is everyone so concerned about light wheels for climbing?

Most confused by this question. The numbers I posted showed 6x greater speed increase when climbing than on the flats. Still insignificant, but 6x "less insignificant." Maybe you could clarify your question?

as i understand it wheel weight matters most in acceleration. technically, you're accelerating with every pedal stroke.

Yes, wheel weight matters more when accelerating, but while you do accelerate with every pedal stroke, you decelerate as well. Think of the wheel as a flywheel that stores energy. You put the energy in when you speed up, and you get the energy back when you coast and slow down. You only lose the energy when you brake. Once you are at speed, wheel weight is no different than any other weight.

Clarification : I can't read at two in the morning. Now I understand. Thanks.

BTW, I decided to use the light tubes for race days; it's not like I was asking "would light tubes make me 5mph faster?" but "since I can shave 80g off the rims, why not, unless it would make me extremely puncture-prone -- but would I even notice?" I already bought a handful of the light tubes (along with a box of regulars) because I was already making a pretty big performance order, and they were on sale for like 3 bucks lightweight, 2 bucks regular.

Thanks for the input!

technically, you're accelerating with every pedal stroke.
You do not accererate with every pedal stroke. Acceleration is a change in velocity that is measureable. If you are maintaining a constant velocity, then your acceleration is actually zero.

FWIW I weighed a couple standard Performance tubes, and they were 90 & 95 grams each.