Wider tires

Discuss light weight issues concerning road bikes & parts.
guadzilla
Posts: 53
Joined: Sat Mar 19, 2011 6:55 pm

by guadzilla

Hey guys, a couple of questions related to wider tires (am updating my fleet of bikes after 7 years, and a LOT has changed!):

1/ For those of you running 28c tires on tarmac and still caring about performance/aero - what rims are you using? I have Roval CLX64s (27mm outer diameter) on my Venge, which is designed for their 24c Turbo Cottons. This expands to about 26mm when mounted, which seems about right for the 105% rule. I had S-Work Turbo 26s on earlier, and those were over 28mm on the rim - ie, wider than the rim, which is an aero no-no. I would imagine a marked 28c tire would spread to 30 or 31 - doesnt that get wider than most rims, or have most of you switched to super-wide rims? Are you guys taking a small aero hit for the greater benefit in RR and grip? Or is 28c still more a gravel thing?

2/ For those of you still using inner tubes* and running, say, a 25c tire that has expanded to 28c, do you fill it as a 28c tire or a 25c tire? My rule of thumb has beeen 100f/110r for 23s, 90f/100r for 25s and 80f/90r for 28s and at 180lb, that has worked well for me for nearly a decade. Context: I am gonna put Veloflex Corsa 25c on a pair of wheels with 28mm OD, and expect it to be around 28mm when mounted. Am wondering if i should treat it as a 25 or a 28 when pumping in air.

(*Yup, i have already converted one of my wheels to tubeless, which seems to be going well. But lets not make this a tubeless vs tube debate, please)

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BikeEatSleepRepeat
Posts: 50
Joined: Wed Dec 04, 2019 5:13 am

by BikeEatSleepRepeat

For inflation, I only consdier the real life effective tire width on a particular rim, and not whatever static measurement the sidewall claims it to be.

scale29
Posts: 138
Joined: Sat Jun 04, 2011 5:40 pm

by scale29

I run 28mm turbo on my CLX32's and Tarmac, they stretch out to about 30.5mm on those. I give not one crap about any potenetial aero negative as they ride so well. My pro racing days are over however, so someone racing may probably consider it a problem.

carbonazza
Posts: 46
Joined: Wed Apr 10, 2019 9:14 am

by carbonazza

I ride gp5000 in 28mm, on lightbicycle AR56 rims.
The rim is 30mm wide, and the tire at 5bar is between 29 and 30mm.

I never raced, but I care about performance.
Maybe a confirmation bias :smartass: ... but in group rides, in some descents where everyone is freewheeling, I definitely gain more speed than most. I'm lighter than most with a non-aero frame.

guadzilla
Posts: 53
Joined: Sat Mar 19, 2011 6:55 pm

by guadzilla

carbonazza wrote:
Sat Jan 18, 2020 9:34 pm
I ride gp5000 in 28mm, on lightbicycle AR56 rims.
The rim is 30mm wide, and the tire at 5bar is between 29 and 30mm.

I never raced, but I care about performance.
Maybe a confirmation bias :smartass: ... but in group rides, in some descents where everyone is freewheeling, I definitely gain more speed than most. I'm lighter than most with a non-aero frame.
Ah, that's perfect as I was planning an AR56 rim myself. I am not looking for a full race setup (have the CLX64s for that), but I am not looking for a full-on training setup either, where I only have about watts and not speed.

So I dont mind giving up a wee bit of aero for something that is comfier for long, fast group rides where I am not always able to avoid small potholes and such. But I dont want to be at a massive aero disadvantage either.

Looks like a true 28c on the LB AR56 would work well.

guadzilla
Posts: 53
Joined: Sat Mar 19, 2011 6:55 pm

by guadzilla

BikeEatSleepRepeat wrote:
Sat Jan 18, 2020 6:54 pm
For inflation, I only consdier the real life effective tire width on a particular rim, and not whatever static measurement the sidewall claims it to be.
Makes sense, thanks.

guadzilla
Posts: 53
Joined: Sat Mar 19, 2011 6:55 pm

by guadzilla

scale29 wrote:
Sat Jan 18, 2020 8:40 pm
I run 28mm turbo on my CLX32's and Tarmac, they stretch out to about 30.5mm on those. I give not one crap about any potenetial aero negative as they ride so well. My pro racing days are over however, so someone racing may probably consider it a problem.
So I spent 7-8 years training on a cross bike with 32c tires and while it was a plush ride, it was a very dull and unexciting ride.

Now I am running 23s and apparently the last person in the world that still does so. I love the responsiveness but road chatter on group rides gets to me after 2-2.5 hours.

Am hoping 28s will be a good compromise that takes the edge off road buzz but still allows some road feel and doesnt disadvantage me too much on fast road rides.

jlok
Posts: 1171
Joined: Tue Jun 30, 2015 3:30 am

by jlok

The best aero rims I had for 28c tires were SES 4.5 AR. Mate perfectly with Rubino Pro TLR 28c.
Litespeed T1sl Disc / BMC TM02 < Giant Propel Advanced SL Disc 1 < Propel Adv < TCR Adv SL Disc < KTM Revelator Sky < CAAD 12 Disc < Domane S Disc < Alize < CAAD 10

RK250
Posts: 6
Joined: Mon Aug 12, 2019 12:48 pm

by RK250

For jlok:
I tried to send you dm, I don't think you have your contact on this site so apologies to op.
Your Rubino TLR is marked 'mount hooked rim only' yes? Your 4.5AR are hookless. Did you confirm w Vittoria or Enve that it's okay? Reason for asking is I new 3.4AR and bought Rubino Pro TLR 28mm. They mounted super easy, dumped around 1.5 oz Stans, holding well. I'll run them at 50 psi as I weight sub 150. All that said, I sure don't want an equipment mishap especially when there was a clear warning involved.
Thanks.

jlok
Posts: 1171
Joined: Tue Jun 30, 2015 3:30 am

by jlok

RK250 wrote:
Sun Jan 19, 2020 10:57 pm
For jlok:
I tried to send you dm, I don't think you have your contact on this site so apologies to op.
Your Rubino TLR is marked 'mount hooked rim only' yes? Your 4.5AR are hookless. Did you confirm w Vittoria or Enve that it's okay? Reason for asking is I new 3.4AR and bought Rubino Pro TLR 28mm. They mounted super easy, dumped around 1.5 oz Stans, holding well. I'll run them at 50 psi as I weight sub 150. All that said, I sure don't want an equipment mishap especially when there was a clear warning involved.
Thanks.
Enve says it's ok in email reply as well as in their website.
Litespeed T1sl Disc / BMC TM02 < Giant Propel Advanced SL Disc 1 < Propel Adv < TCR Adv SL Disc < KTM Revelator Sky < CAAD 12 Disc < Domane S Disc < Alize < CAAD 10

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tommasini
Posts: 1366
Joined: Sun Nov 02, 2003 6:48 am
Location: Central USA
Contact:

by tommasini

carbonazza wrote:
Sat Jan 18, 2020 9:34 pm

Maybe a confirmation bias :smartass: ... but in group rides, in some descents where everyone is freewheeling, I definitely gain more speed than most. I'm lighter than most with a non-aero frame.
Not to throw darts too much at this comment by carbonazza as the forum is about sharing exeriances....so please forgive me for what I'm about to say.....what are the variables here in this example.......bearing quality and maintenance (generally very piss poor if done by a local shop), what quality tires are the others riding, what is their position on the bike, carbonazza notes that he is on the ligher scale so that would actually give advantage to the average overweight "joe" in the pack..... But if those variables are not controlled / accounted for then I'll suggest we don't instantly associate faster roll down desending with tire diameter. Remember - wider tires at the same pressure do have an improved rolling resistance - but what is everyone doing....they are reducing tire presssure....so the rolling resistance benefits are negated.

RK250
Posts: 6
Joined: Mon Aug 12, 2019 12:48 pm

by RK250

jlok wrote:
Mon Jan 20, 2020 3:57 am
RK250 wrote:
Sun Jan 19, 2020 10:57 pm
For jlok:
I tried to send you dm, I don't think you have your contact on this site so apologies to op.
Your Rubino TLR is marked 'mount hooked rim only' yes? Your 4.5AR are hookless. Did you confirm w Vittoria or Enve that it's okay? Reason for asking is I new 3.4AR and bought Rubino Pro TLR 28mm. They mounted super easy, dumped around 1.5 oz Stans, holding well. I'll run them at 50 psi as I weight sub 150. All that said, I sure don't want an equipment mishap especially when there was a clear warning involved.
Thanks.
Enve says it's ok in email reply as well as in their website.
Thanks for the answer. I was unsure if there is more than 1 version of Rubino TL. The Enve cs rep is/was very quick and enthusiastic with getting back to me but he didn't have an answer to this. Vittoria inquiry went unanswered. Weight Weenie community is where the knowledge is!
Summarized, this is your set up and working without issues?
Thanks again.

jlok
Posts: 1171
Joined: Tue Jun 30, 2015 3:30 am

by jlok

yeah, my Rubino Pro TLR 28c was also printed "mount on hooked rim only", and it worked very nicely even in crit racing.
Litespeed T1sl Disc / BMC TM02 < Giant Propel Advanced SL Disc 1 < Propel Adv < TCR Adv SL Disc < KTM Revelator Sky < CAAD 12 Disc < Domane S Disc < Alize < CAAD 10

montster
Posts: 5
Joined: Wed Jun 19, 2019 6:23 am

by montster

For rims I have the Light bicycle falcon pro WR50. That gets your tires into the 30-31mm range which was my goal and still being aero within the 105 rule.

I used actual tire width for my PSI calculations

icantaffordcycling
Posts: 694
Joined: Wed Jan 09, 2019 5:03 am

by icantaffordcycling

guadzilla wrote:
Sun Jan 19, 2020 5:49 am
Looks like a true 28c on the LB AR56 would work well.
I would stick to 25c tires on the AR56s and WR50s for 28s to stay perfectly in the 105% rule.

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