My Morning Commute

[TwoWheelsDC]

@TwoWheelsDC 157945 wrote:

Yesterday, I rode my Cervelo road bike, but when reviewing the ride I noticed the power numbers seemed a bit low compared to my ride on Monday (for the same segment) on my gravel bike. I figured it could be due to wind or fatigue or whatever, but today’s ride on my gravel bike seemed to confirm that either my Cervelo is waaaaaaaaay more efficient than my gravel bike, or there’s a calibration issue with one of my power meters (Stages on the gravel bike, Garmin Vector on the Cervelo, both left-side only. I always calibrate at the start of my rides). My suspicion is that the Vector pedal needs to be re-torqued, so I’ll try that first. If not, I’ll throw the Vectors on my gravel bike and see how the numbers line up with two power meters on the same bike.

Also, kinda crazy that the time/pace numbers here are for two drastically different bikes. 1st (Monday) and 3rd (today) are the gravel bike. Aluminum frame, 700×35 tubeless tires, ~21lbs. Middle (Wednesday) is my Cervelo. Carbon frame, 700×23 tube clinchers, ~19lbs.

Confirmed my suspicion this morning. Re-torqued my Vector pedal this weekend and got a much more consistent number on this segment today. 255W @ 12.8mph. Still lower power (but faster) compared to the higher numbers from last week, but I think my Cervelo is maybe 4lbs lighter than my gravel bike now, and with much faster wheels and tires, so I think that probably explains the gap.

[GovernorSilver]

“Hey! Hey you! You’re running a flat on your rear wheel! Just letting you know!”

I have yet to experience my first flat tire as a bike commuter. I looked down at my rear wheel several times but can’t really tell if it’s flat. When I’m stopped, the wheel is not sitting on the rim. I tried squeezing both tires with my fingers and they feel the same.

Before my ride I pumped both tires to 70 psi, within the 55-90 range printed on the tires.

The suggestion I might be riding a flat tire messed with my head. I rode through the Potomac Yards parking lot and sidewalk along Rt. 1 instead of my usual Potomac Ave route – just drained of confidence to take on the headwind while riding with car traffic. Rode down the bit of gravel/dirt from E. Glebe to the Target parking lot – didn’t feel any different than riding the C&O Gap Trail.

[Birru]

@GovernorSilver 158234 wrote:

“Hey! Hey you! You’re running a flat on your rear wheel! Just letting you know!”

I have yet to experience my first flat tire as a bike commuter. I looked down at my rear wheel several times but can’t really tell if it’s flat. When I’m stopped, the wheel is not sitting on the rim. I tried squeezing both tires with my fingers and they feel the same.

Before my ride I pumped both tires to 70 psi, within the 55-90 range printed on the tires.

The suggestion I might be riding a flat tire messed with my head. I rode through the Potomac Yards parking lot and sidewalk along Rt. 1 instead of my usual Potomac Ave route – just drained of confidence to take on the headwind while riding with car traffic.

IMO if you’ve been riding the same bike for a while you’ll know if you have a flat. A flat in the rear feels sort of like your rear tire is in mud, robbed of a little power and tracking a little squirrely. The numbers you mentioned also need some context. Are these narrow 23c tires on a heavy bike? 70psi sounds low but not flat so there may be a lot of visible sidewall deflection, but that depends on bike/rider/load weight. On 32c tires 70psi sounds like plenty for most people.

You might as well inspect the tire for any obvious signs of a puncture or tear. Since you made it to your destination, also check the tire again at the end of the day for any changes in pressure. Even better: buy a tire gauge and measure.

[KayakCyndi]

Ah, Spring in DC. Gotta love it.

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[ATTACH=CONFIG]14534[/ATTACH]

[Emm]

@Birru 158238 wrote:

IMO if you’ve been riding the same bike for a while you’ll know if you have a flat. A flat in the rear feels sort of like your rear tire is in mud, robbed of a little power and tracking a little squirrely.

This is a good explanation of what it feels like to have a flat, or lower-than desired tire pressure. You might just have low pressure causing your sidewall to bulge more than expected, or the person really just didn’t know what they were talking about. I know I’ve asked people on rides why they ran such low pressure on certain bikes, and it ended up being the right pressure for their bike/comfort/etc. But definitely check on your way home. When I have a sudden fear of flats I stop my bike, and look down while still putting weight on the bike. If the sidewalls are not bulging more than normal, I figure I’m fine. If one is, I know I have a problem…

[drevil]

@GovernorSilver 158234 wrote:

“Hey! Hey you! You’re running a flat on your rear wheel! Just letting you know!”
…

The suggestion I might be riding a flat tire messed with my head…

This is a common tactic that my buddies and I use at the start line of races

Other start line head games:

1. “Is this race 2 laps or 3?”
2. “Do we turn left at that tree, or right?”
3. Reach down at their tire, put finger on valve, and make the hiss sound.

They’ve become so common to say, it’s almost akin to “Break a leg.”

EDIT – if anyone gets upset, it’s always done in jest amongst other friends, (and generally not with newbies, people we don’t know, and/or with menace). I’m not evil…

[GovernorSilver]

@Birru 158238 wrote:

IMO if you’ve been riding the same bike for a while you’ll know if you have a flat. A flat in the rear feels sort of like your rear tire is in mud, robbed of a little power and tracking a little squirrely. The numbers you mentioned also need some context. Are these narrow 23c tires on a heavy bike? 70psi sounds low but not flat so there may be a lot of visible sidewall deflection, but that depends on bike/rider/load weight. On 32c tires 70psi sounds like plenty for most people.

You might as well inspect the tire for any obvious signs of a puncture or tear. Since you made it to your destination, also check the tire again at the end of the day for any changes in pressure. Even better: buy up a tire gauge and measure.

I’ve been riding this bike (Jamis Renegade) intermittently for about a year. Rode it on the C&O last fall, then barely rode it until this past March. Jamis calls it an adventure road bike – a bit heavier than a road racer but lighter than a touring bike.

I still have the stock tires on it – 35c Clement X’plors. I’ll check for signs of puncture/tear this evening and pump them a bit more, assuming the pump here at work fits Presta valves. Thanks!

[TwoWheelsDC]

I can’t imagine riding for several miles and then looking at my bike and saying “hey, when did I get a flat tire?” Even if your tire is low (assuming it’s not already leaking), the only real concern is susceptibility to pinch flats if you go over a curb or something. Tire pressure has a pretty minimal effect on rolling resistance.

[drevil]

@GovernorSilver 158253 wrote:

…assuming the pump here at work fits Presta valves.

A top secret squirrel secret that I learned when I was just a peanut: if you have a Presta tube, a schraeder pump and the inability to swap orientations of the pump, take off the cap, snip the tip, and put the cap back on backwards. The Schraeder pump should be able to pump the tube. This person made a nice pictorial:
https://www.purecycles.com/blogs/bicycle-news/11635993-macgyver-a-presta-schrader-adapter

[Birru]

@GovernorSilver 158253 wrote:

I’ve been riding this bike (Jamis Renegade) intermittently for about a year. Rode it on the C&O last fall, then barely rode it until this past March. Jamis calls it an adventure road bike – a bit heavier than a road racer but lighter than a touring bike.

You are clearly a very smart and attractive person. I’ve got a ’17 Renegade. 😎

[cvcalhoun]

@drevil 158242 wrote:

I’m not evil…

Of course you are. It’s right there in your name. :p

[DrP]

@TwoWheelsDC 158256 wrote:

I can’t imagine riding for several miles and then looking at my bike and saying “hey, when did I get a flat tire?” Even if your tire is low (assuming it’s not already leaking), the only real concern is susceptibility to pinch flats if you go over a curb or something. Tire pressure has a pretty minimal effect on rolling resistance.

Actually, I do not need to imagine – I have experienced it everytime my tires have been flat except one. Most times I get to the bike and it is flat – but when did that happen. Three times in the past year I have been riding and noticed one wheel or the other wasn’t acting correctly and looked at it. First time I asked the person I was biking with if a problem could be spotted – “Yes, your rear tire is pretty flat” – we had been on the C&O Canal and were nearly home at this point. I have no memory of riding over glass or anything else these times. They were slow leaks.

The only time that I can almost remember what happened was when a pedestrian coming towards me forced me to change lanes and go into a puddle that apparently had glass in it (and I say forced because her side of the trail had a puddle and she decided that she couldn’t stop a second while I passed and then change lanes to the dry side (which was mine) and told me that I had to go in the puddle so her feet wouldn’t get wet.). I heard hissing and saw bubbles, but it didn’t dawn on me it was an issue. Shortly after that I keep hearing a clicking sound. A mile or two later I stopped to check it out and eventually noticed the very large chunk of glass in the tire.

I have never experienced a sudden flat.

[KLizotte]

@drevil 158257 wrote:

A top secret squirrel secret that I learned when I was just a peanut: if you have a Presta tube, a schraeder pump and the inability to swap orientations of the pump, take off the cap, snip the tip, and put the cap back on backwards. The Schraeder pump should be able to pump the tube. This person made a nice pictorial:
https://www.purecycles.com/blogs/bicycle-news/11635993-macgyver-a-presta-schrader-adapter

This solution requires having scissors or perhaps a sharp knife on hand to cut the cap so in reality you may still be up a creek in some circumstances.

[GovernorSilver]

@Birru 158258 wrote:

You are clearly a very smart and attractive person. I’ve got a ’17 Renegade. 😎

A very smart and attractive person sold it to me. That I can say at least. 😎

[cvcalhoun]

When my tire is flat, I know it because it starts going thump, thump, thump as I ride. No one else’s does that?

[Author]

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