Spare tube (etc) placement
There have been a few threads in recent days about aero setups, and I had a question about something I've done. I've put a tube, 2 CO2 cartridges, and levers underneath my seat on a Cervelo seatpost and an Adamo saddle. This means that on training rides I can easily stick my wallet, phone and multitool in my bento bag. OTOH, if this is some horrible aero sin I've created, it's not a big deal to put that stuff in the bento and carry the rest in a jersey. Just not as convenient. My theory is/was that my legs (etc) are so close to all this junk that it doesn't make much aero difference, even if it's a bit ugly.
What do y'all think?
0
Comments
Looks good to me. I'd be curious to see your position on the bike because with an Adamo slammed all the way forward = riding a very steep seat tube angle = potential to go VERY low in front, in general.
@Rich: I'll get a new photo - it's a 2007 model P3. I just lengthened the front stem a bit about a month ago, which helped flatten my back. The drop from the widest point of the Adamo to the the center contact of the arm pads is right around 13 cm (5+ inches). The distance from the top of the top tube to the top of the saddle (again, at the widest point) is right about 23 cm. I never had the steering tube cut, but all the spacers are above the stem, which runs approximately parallel to the ground. My LBS guy went to Cervelo training, who told them that they thought that pulling the bars a few degrees up from horizontal was superior to having them parallel to the ground if your elbows were pretty narrow (and mine are...I can barely fit the water bottle in there). This slight up-angle is less comfortable to me than having them just flat (more shoulder stress), but I'm getting used to it. What if anything do you know about that bar angle business without getting actual wind testing done?
Bar tilt is a function of personal preference. Put it where your arms want it to be vs where Cervelo says it should be for aero reasons. That said, bars horizontal or even downturned a bit usually transfer into the rider pulling up on the bars to gain/feel like they are getting more leverage when riding hard. Bars up a bit = less leverage, less pulling on the bars = probably more conducive to you just relaxing at IM pacing and falling asleep on the bars. Basically, as I go from sleeping/riding at IM pace to HIM pace to FTP to climbing in the aerobars, I'll go from hands draped loosely over the shifters to loose at the ends of the bars to gripping the bottom of the bars and pulling up to choking nearly all the way back.
Seach the blog for a post back in May '08 where I showed a variety of positions and hand placements that I use while riding different situations.
Rich, FYI, here's the link to your blog post, but the pictures don't seem to come up. Tried with a couple different browsers. Thanks for pointing me to it, though.
Rich-
Here are some photos. Tried to pick ones showing the front leg extended and pulled up from among those of the mailbox or the tree... :-)
Let me know what you think. (I did move the bars back down a bit!)
Thanks!
Nice bike William!
I am interested in hearing your comments Rich. I was told by the fitter at my lbs to lower my seat a little so that my foot was flat at the bottom of the pedal stroke. Before the adjustment, my foot looked similar to Williams in these pics (that being the toes pointed down at the bottom of the stroke) I went to your blog site but like others, could not see your pics to compare.
Yes, we had that "toes" discussion too. Turns out that I "toe down" (or at least try to) no matter where the saddle is, so we set the height such that my knee angle was still good at full extension. When I first got the bike a couple years ago, we had the saddle lower to try to flatten my toe angle, but I'd come in a couple times a year for tweaks, and we ended up giving up on that (since i would routinely pedal toe down anyway) in favor of opening the hips (saddle up and forward, longer stem), and I feel more comfortable. And, to be fair, these were taken under very low load (just cruising by at a few mph) so the ankle angle may be a unrepresentative just due to me barely pedaling and bringing my legs around sloppily.
[Every time I see a picture, though, I keep thinking I need some kind of implant to straighten my back!!
]
LOL! I had the same toe "discussion" except my "discussion" was a series of slaps with a yard stick with the fitter saying, "drop that heel! SMACK! drop that heel!"
I am the same way William. Maybe I need to just go with it too.
Listen to the podcast on bike fit with Todd Kenyon (used to be on the train map, can't seem to find it now. Help, wiki workers!). I asked the same question about toe point. He said that almost everybody rides naturally with about 20-30 degrees of downward toe point in the aerobars, and not to fight it, just go with it.
@William, I'd think that if you're looking at flattening your back, you might want to consider the following.
the slightly arched back seems to be coming from a preference to have your weight closer to your sit bones, which is causing you to tuck your pelvis under, as opposed to laying your spine down flat, and finding the saddle position that supports you there.
Riding straight on the nether region takes some adjusting, but it would get you closer to that flat back you're thinking about. In order to do it, though, you'll have to slide the saddle back and up a touch.
Mike
Some pictures of Flat Back from the recent TOC TT. Compare Dave Z and TommyD (#s 8 & 9) to Chrissie and Macca (#s 16 &17). Remember, more important than your back is where you head (the first thing to see the wind) is relative to your shoulders and back (compare photo 8 to 9).
@Mike - had to look up "grundle"! :-) A little more seriously, when you pull the seat up and back, don't you narrow the hip angle (making it that much harder to breathe)? Curious to know what the trade off would be there.
@ William,
short answer, yes.
longer answer: Any time you make your back flatter, you narrow the hip angle. We narrow the hip angle going from a road bike to a tri bike. So, a narrowing of the hip angle isn't necessarily a bad thing, if you're trading it for a substantial upgrade in your CdA. When you keep your pelvis tilted up (often in search of that 'open hip angle'), you open up more of your chest and belly to the wind, making your upper body a parachute.
To really open the hips, you want to keep the pelvis tipped forward, and move the seat as far forward as you can, and then adjust the bars in space to the point where they support you in a flat position. My recommendation was considering keeping your bars where they are (having just bought a new stem and all).
Somehow, typing grundle seems more inocuous than typing taint.
Mike
Interesting. The way it has been explained to me before is that the TT position is supposed to be more or less comparable to the road bike position, save that the whole thing is "rolled" forward somewhat by the forward saddle, low front, etc. This was one reason, I thought, that the roadie obsession (I use the term loosely) with not pointing toes down is less of an issue for TT position.
Fortunately, none of this is all that hard to play with.
Unfortunately, what IS hard is to test things adequately so you know what you're getting for what you're giving up, e.g., how much power loss (cost) for how much CdA loss (benefit). :-)
PS The bike fit ebook is in the wiki