lfish

This is clearly the most enjoyable thread on RL IMHO. I'm really impressed with the cycling; as a recreational cyclist in the flat part of Ohio doing around 50 miles per week the century rides and hill climbs that you guys do blow me away. I googled the Lightweight wheels that Mooty mentioned (Obermayer); the light weight got me to thinking- is there a rim weight that sacrifices flywheel effect of a heavier rim or is adding lightness the ultimate goal for acceleration and climbing vs. steady state cruising?

spg993tt

unless time trialing, there is no flywheel effect of a heavier wheel you want. no matter what happens you have to turn the wheel over and over. generally you want the lightest, most aero, most durable wheel you can get, that your budget affords. typical trade off is aero for weight. the deeper the side profile (height) of the wheel the more aero it could possibly be. i say could be because over the year , manufacturers have tried various shapes that give you the same aero gains as a taller rim, and yet in doing so with the shorter rim, you end up with less weight than the taller stuff. so you get the same aero gains with less weight.
other aspect of wheels is rim width from edge to edge. the new stuff is wider. rims used to be 19mm no joke, back in the days of tubular nonesense. now they are 24, 25mm wide. that lets you run a tirer thats wider. i run 7x26s on my roval clx32 and that wider tire is better in turns, more rubber, more grip, more comfort. also lets me run lower psi which is another massive gain you can make. days of 120psi in clinchers is past. 85, 90 is the right psi for most. the wider tire offset is its slightly less aero.

and tire. tire choice is just as important as wheel choice. there is guy by the name of tom anhalt who does massive tire rolling resistance testing (crr) values. look atathis page:
http://bikeblather.blogspot.com/
onthe riht is is sdsheet. thedifference in rolling resistance/speed/watts required to maintain same speed between tires can be massive. and it sometimes changes from year to year as manufacturers try to make a faster tire, actually i think manufacturers dont care too much about speed as most consumers dont know or give a crap, but i think they sort of back into it/luck into it.

i train on continental GP4000 II S. the "S" is critical. the yare a massively fast tire with incredible puncture resistance. some low crr tires have bad puncture resistance or durability , ie the sworks cottons that mooty and i were discussing. fast tires, marginally faster than the GP4000s but 1/10th the puncture resistance. i raced them for 2 years in a series but towards the end of the series when i had it locked up, i checked down to the gp4000 to avoid a no-points DNF situation in the event of flats.

difference in watts between tires is can be 10 to 15 watts per tire. i could train max efficiency all year and never be able to gain 15 watts improvement on my last years fitness. you get that by choosing tires.

for racing, go with latext tubes. again, its a crr thing, a few watts, 2,3.

depends on the course, but 3,4,5 watts over an hour might be a minute or more. most 1hour tt's are won by a few seconds.

forget tubulars. a waste. horrible crr values (see spreadsheet). PITA to deal with. yes, very light. very smooth feeling but the new wide body clincher rims are as smooth or better, adn 10x less annoying and WAY faster tires are avaible.

i know, TMI, but there you go.

lfish

Thank you for your detailed response. You are clearly several log units beyond my cycling capability but the technical information is invaluable. My bike shop mechanic who also races recommended the Conti tires you referenced so that's what I'm riding. He also echoed your opinion re tire pressures and felt 85 psi was the sweet spot.

As with most of my athletic pursuits the limiting factor has rarely (i.e. never) been the equipment but it's great to know that a wheel upgrade can yield a significant performance improvement. Oh yeah, and logging a few more miles/ride would probably be helpful. Thanks again.

Dewinator

It amazes me how expensive bike wheels are. My buddy spent more on 2 carbon MTB wheels than I spent on 4 OEM Ferrari wheels.

Brian 96C2

Excellent post on wheels and tires as well as link to the testing blog. +1 for Conti GP4000 II S, great tire. I do like 25C at 90 psi. I will use Latex again for events. Kind of forgot about that option, been using butyl for many years.

I had a front flat in LOTOJA but that's because something cut the side wall, otherwise these are very puncture resistant.

mooty

copy that. if you accept 991 as a DIFFERENT TYPE of car. you will be fine. it's fun, but not the same TYPE of fun as longhood.

thx, this thread is all OT hahaha.
i "thougth" there were flywheel effect when i moved to LWT. but there's a 10 mile local TT route (i suck at TT) and i can't tell the difference. and as you can see spg993tt also thinks no flywheel effect.

yes, it was an eye opener for me. i releuctantly moved to 25 a year ago. then when i rode 700x26 turbo cotton on CLX32 (it really measures 28), i look down my handle bar and thoguth i was on somesort of MTB. they were fat.... but i thougth i got the tires, i shoudl just wear them out... then go back to 25. boy, i was wrong. i fell in love with with them. 95psi, soft and comfy... i come from 23/35mm at 115psi hahah

YES


that's one of my fav too.



i quit gluing rubber a while back. i just dont have the patience or the skill....








LOL



SPG993TT: i thougth with CF rims, we are not to use latex. i was told rim heat up under breaking and latex will blow...? urbar lore?

mooty

nice 60 miles 6000' ride this morning, great weather too



need some porsche content before they kick me out of RL; kids needed some chores.



the cayenne was too small, max wanted more challenge so he is working on the 3500 dually



i rewarded them with 2 gummy candies (one for each kid) and each get 1/4 of a pint of ice cream



for bonus, each got 1/2 can of soda and one oreo.. my neighbor thought i was too stingy.....

Nizer

tiger mom got nothing on

mooty

tiger mom is a push over.
ask RLsrer who met mia an max. i dont think any other kids behave 1/2 as well.

my niece. i often thought about ripping her head off.

4ng crcs

We know Mia/Max parentage.
Niece parents need training.

spg993tt

not exactly untrue. and i would never use latex on training normal rides. yes, you get better CRR rolling values (lower resistance, more speed at a given wattage), and you get better pinch flat resistance...but overall they are a fractional bit less durable, and they bleed air a lot. so you have to pump up before every ride. but they feel great. most tubulars are latex inner tubes which lends to their smooth feel.

they are faster for sure. its a couple of watts. how much does a couple of watts mean to you relative to risk of puncture? if im leading a race series, last race of the year, and all i have to do is finish to cap off a win...im riding fat butyl tubes.
with latex you can also use like the stans sealant which is great and raelly helps minimize punctures without giving up rolling values.

but the tires do more than the tubes, so get rid of the slow rolling tires put on great tires, adn then use butyl unless you're in a speed race and are willing to roll the dice to edge someone out. in a lot of my tt's you are hammering for 20 to 60minutes and its 4 seconds, 9 seconds. maybe midpack is 40 seconds back. so those 4 can matter. win or nothing at all...use latex.
for fun training rides, no.

in terms of heat..thats the case with any run surface. but to that i say, how often are you really full braking for long stretches? i mean, im not riding the brakes down big descents that is for sure a way to heat up things butyl or latex,. and its even WAY worse on alloy as the carbon takes much longer to get hot because of the carbon, and because carbon doesnt grip as much as alloy rims. everyoen knows alloy brakes better in the rain because it has far more bite. when im descending and braking im thinking taht way irregarless. i wont hammer the brakes and if i have a bit too much speed, ill touch the brakes every little bit, but no way ride it. bad crap happens when you ride brakes on a bike or a race car.

which lead syou to the disc brake discussion, which i refuse to consider. sorry i just dont brake that much, ever. im not descending 5000 feet in one stretch, i ahve climbs that are 15, 20minutes to climb and 2,3 minutes coming down adn im not using the brakes for the most part.

911Jetta

Love the bike theme. I used to race bikes, but my new favorite sport is the biathlon... driving, biking, then driving again.
Two hours of back road driving, change into riding gear and bike in Blue Ridge mountains, then curvy roads back home with weary legs.

My 58 cm road bike fits very well in the back seat, and is assembled and ready to go in a couple minutes. Have a rack, but prefer to keep the bike inside during spirited driving.

jj99c2

911Jetta - very nice! So bike fits fine w/ just wheels and saddle removed in the back of a 993?

tono

So I was about to pull the trigger on Lightweight Obermeyer tubulars until I started reading the last few posts. I been riding Enve SES 3.4 clinchers and wanted to upgrade. So, if you are going clinchers then Obermeyer's are not an option (at least that I am aware of). What do you guys recommend (light but with aero benefits)?

mooty

copy: butyl DD and lates racing

i am a convert to roval CLS32. cheap and fast. lighter than enve