login
how many watts lost
-
No new posts
 2016-06-28 8:07 AM |
Member  1748     Exton, PA |  Subject: how many watts lostSo I changed my rear tire this past weekend, and I switch from a 23mm to a 25mm. Knowing that I may have some rub issues so I would have to take a good look at it. Once it was on the wheel would not even turn it was touching the frame, so I flipped it over to get a good look at it and realized I had some problems from before that I did not ever notice. the wheel was not straight in the frame. I took the wheel off and adjusted the 2 screws back( the right one an extra 1 1/2 turns to straighten it) and before putting the wheel back on noticed that there where rub marks on off centered on the frame. I always check my wheels before I ride to make sure they spin freely but I'm thinking that this rubbing for a while but probably only under hard efforts and cornering. Makes me wonder how much power I have been given up to friction over the last year or two  |
| 2016-06-28 8:16 AM in reply to: mike761 |
Champion 7136  Knoxville area | Subject: RE: how many watts lost some, but probably not all that much. If it had been rubbing too much you'd have flatted / had seriously noticeable issues. Still, some matters a lot sometimes. |
| 2016-06-28 8:16 AM in reply to: mike761 |
Champion 7136 Knoxville area | Subject: RE: how many watts lost some, but probably not all that much. If it had been rubbing too much you'd have flatted / had seriously noticeable issues. Still, some matters a lot sometimes. |
| 2016-06-28 9:18 AM in reply to: Leegoocrap |
Veteran 1900 Southampton, Ontario | Subject: RE: how many watts lost 5.7watts |
| 2016-06-28 9:29 AM in reply to: DaveL |
Pro 15655 | Subject: RE: how many watts lost Prolly lost a spot to Kona. |
| 2016-06-28 9:43 AM in reply to: Left Brain |
Member 1748 Exton, PA | Subject: RE: how many watts lost Originally posted by Left Brain Prolly lost a spot to Kona. No my run, is why I lose the Kona spot  Picture a bulldog running- that's me. |
| 2016-06-28 10:50 AM in reply to: mike761 |
Regular 694 Tucson, AZ | Subject: RE: how many watts lost It depends on which tire it was. Same 23mm to 25mm, may be lower RR on the 25mm, but likely less aero. As for the rubbing, no clue, but now you can ride in bliss. |
| 2016-06-28 11:23 AM in reply to: ThomasGerlach ProTri |
Extreme Veteran 5722 | Subject: RE: how many watts lost Originally posted by ThomasGerlach ProTri It depends on which tire it was. Same 23mm to 25mm, may be lower RR on the 25mm, but likely less aero. As for the rubbing, no clue, but now you can ride in bliss. less aero on the rear ? |
| 2016-06-28 11:59 AM in reply to: marcag |
Member 1748 Exton, PA | Subject: RE: how many watts lost Originally posted by marcag Originally posted by ThomasGerlach ProTri It depends on which tire it was. Same 23mm to 25mm, may be lower RR on the 25mm, but likely less aero. As for the rubbing, no clue, but now you can ride in bliss. less aero on the rear ? Only changed the rear tire to a 25mm the front is still 23mm. Since the frontal area of the rear tire is about 80% shielded the aero loss should be next to nothing but I will gain in rolling resistance( and comfort) |
| 2016-06-28 12:05 PM in reply to: mike761 |
Extreme Veteran 5722 | Subject: RE: how many watts lost Originally posted by mike761 Originally posted by marcag Originally posted by ThomasGerlach ProTri It depends on which tire it was. Same 23mm to 25mm, may be lower RR on the 25mm, but likely less aero. As for the rubbing, no clue, but now you can ride in bliss. less aero on the rear ? Only changed the rear tire to a 25mm the front is still 23mm. Since the frontal area of the rear tire is about 80% shielded the aero loss should be next to nothing but I will gain in rolling resistance( and comfort) Which is why I was surprised by Thomas' comment |
| 2016-06-28 5:58 PM in reply to: 0 |
Veteran 945 South Windsor, CT | Subject: RE: how many watts lost I'm surprised by the actual variability of tires. My 'measured' 25's that I have on right now at race PSI (using 45%/55%) 80 and 100 psi measured 26 and 27 mm by calipers recently. There is a bit of dependency on the rim size too...in terms of aero, but I agree that a back wheel should be much more shielded and less likely to have issue to aero and optimal rolling resistance/comfort with wider tires has been a trend for a few years now, right Marc? (and yes, I had to make adjustments on my Cervelo P2 to accommodate the larger tire on the back by adjusting the back screw for my 25 tire and conti 4K tires...) I'd be interested to hear why Mr G said that. Edited by dtoce 2016-06-28 6:01 PM |
| 2016-06-29 10:20 AM in reply to: dtoce |
Member 1748 Exton, PA | Subject: RE: how many watts lost Originally posted by dtoce I'm surprised by the actual variability of tires. My 'measured' 25's that I have on right now at race PSI (using 45%/55%) 80 and 100 psi measured 26 and 27 mm by calipers recently. There is a bit of dependency on the rim size too...in terms of aero, but I agree that a back wheel should be much more shielded and less likely to have issue to aero and optimal rolling resistance/comfort with wider tires has been a trend for a few years now, right Marc? (and yes, I had to make adjustments on my Cervelo P2 to accommodate the larger tire on the back by adjusting the back screw for my 25 tire and conti 4K tires...) I'd be interested to hear why Mr G said that. Your psi sounds high, how much do you weigh? I'm 170 and have been riding 23's at 90 & 100, and really should be a little lower by some of the charts/info I've read. Now I am planning on trying the rear tire at 80 to 85 which looks right for 55% to 60%(respectively) distribution on the rear. |
| 2016-06-29 11:29 AM in reply to: mike761 |
Veteran 945 South Windsor, CT | Subject: RE: how many watts lost lets not hijack the thread...we can have a lengthy discussion on tire pressures; weight distribution, tire size etc...this is always a fun topic and people like to weigh in on it I've done some personal experimenting, making my N=1 good for me...ha! |
|
|
|
| |||
| |||
| |||
| |||
|
| ||||
|
| |||
|
View profile
Add to friends
Go to training log
Go to race log
Send a message
View album
CONNECT WITH FACEBOOK