C3 Aerobars Plus MagicShine

After a year of doing without, and making some very good rationalizations (like why do I need to ride at night, when I have all day to ride?), I finally pulled the trigger and ordered a MagicShine 900 lumen light with a 6Ah LION battery pack, helmet mount, and carbon fiber drop mount.


Planet Bike 1W Blaze and MagicShine 900

I decided to keep the Planet Bike Blazer 1W light on the bars until I'm sure the MagicShine is reliable, but as it turned out, having two is pretty useful anyway as the strobing Blazer marks me as a cyclist and not a motorcycle.

I also decided not to mount the light on my helmet, although that may change, I am still concerned about early reports that these lights were emitting so much radio frequency noise they were shutting down people's Garmins, and presumably, cooking their brains ala cell phones. I detected no problems with my Garmin, and it's mounted 5" away, but still being cautious.

(The evidence is very clear, although the cell phone mfgs are doing every last thing to suppress the studies, cell phones cause brain cancer when held against your head, so use a WIRED headset and don't end up a statistic. The last study I saw published came out of Scandinavia and was a 10yr study based on only a half-hour a day's use. That study showed a 6X increase in brain cancer ONLY on the side the user held the phone, and directly adjacent the ear.)

I wasn't sure if the drop mount, which clamps around the bar right next to the stem, has a 3" arm, and then a stub 1" round carbon tube about 2" long, would drop enough or be strong enough to hold the light in a stable way. It did, and I didn't even need to wrap the provided 3" rubber shim around the stub to get the light to mount firmly enough to prevent slippage.

Battery strapped on top of the top tube, resting on some foam shelf-liner. Nice cockpit view and the light isn't shining in my face.

I decided to just put the light right in front of the top tube, forward enough to not interfere with the cables with the handlebars turned in any direction. That turned out to be perfect. It stays cool, lights well, doesn't blind me with back-scatter, and seems about as aerodynamic a position as possible.

I could move it off to the right, as I am somewhat tempted to do, but as it is, the 6" of separation between the MagicShine and Blaze make the Blaze's strobe mode more visible. Otherwise it would just get lost in the flood of MagicShine light.

I went riding with a couple of friends from the Sacramento Bike Hikers Tuesday night, and they had their MagicShines helmet mounted so they could turn their heads and focus the light through turns and around riders ahead. Especially when I was in the middle, and offset 2ft to the right, this worked out very well.

My light provided constant illumination of the bike trail which allowed them to free-lance their helmet lights without losing sight of the trial's surface. Very nice for avoiding snakes. Counting 2 Blazes and 3 MagicShines we had over 3,000 lumens of white light ahead, and 7 tail lights behind mounted from mid-seatstay to helmet level. We were a flying Christmas Tree!

With the 3 of us riding together I was completely comfortable riding flat out - up to 25mph - with that amount of light. Riding home alone from the meetup site, the light was comfortable up to ~  20mph. Facing into streetlight going down a long hill I hit the brakes lightly to keep my speed down.

If I want to ride alone I will need more light to ride flat-out. The 4-LED MagicShine MS-872 Quad XP-G lighthead provides a perfect solution. It can be mounted on the drop stub, and my existing spot light moved to my helmet. With 1600 lumens it provides a full-width beam that lights the entire lane for at least 150ft - about 4 seconds at 25mph.

MagicShine MS-872 Quad XP-G Light employing 4 CREE LEDs

If you've studied the power consumption curves of LEDs you'll have noticed that as you push them harder and harder to get more light out of a single bulb, 2-3X as much power is dissipated as heat. Thus, one of the really great advantages of having 4 bulbs is that even on med-hi, it still puts out 900 lumens, and does so very efficiently. Good thing I got the big battery pack, as cranking out 2,500 lumens does take a toll on batteries, even LION batteries.

We had a lot of fun flying down the ARPT Tuesday night, and collected up a dozen or so riders who were riding with little or no light. By sharing the wealth of light, we collected a substantial paceline on the way from Sunrise to WBP, and at an average speed of 20.4mph.

Enjoying My Damned Hard Riding

I've been putting in a lot of miles, pretty much sticking to my 100 mile weeks, and am just enjoying the ride - having my gear dialed in well - finally.

I did a really wonderful ride last Tuesday evening with SBH, although it turned out to be just myself and the ride leader. I had made rice and left the stove on, so asked if we could swing by my house for a minute. That kind of set the spirit of adventure for the evening, and I ended up kind of co-leading the ride, showing her a bunch of new roads in my hood.

I took up the lead shortly after we left Sunrise on the ARPT, after stopping for a few minutes to take in a breathtaking sunset, and suck down some Gatorade. It was still warm well into dark. I spotted a fast pair way up ahead, and decided to challenge myself to try to catch them, as I started to really get my legs  under me.

It was a 2 mile sprint, ramping up steadily from ~22 to a peak of 27.3 mph. She was right on my wheel. Very impressive. I got us to within 50 yards when we got jammed by slow traffic and failing light. I pulled a bottle, and we turned on our lights while "coasting" down to 22 mph. Spent from pulling at such high speeds, I hung on for dear life for the next few miles as she put on her own display of speed.

We caught  a rider shortly after WBP who had no light, so we drafted her with me on the right, and Shon on the left. My Bike Planet 1W Bazer just barely filled in the shadow from Shon's MagicShine, but except for a half dozen snakes we didn't see until right on them, the light was good enough for Shon and I to average 20mph from Sunrise to CSUS ~ 12 miles. With all of the dips, rises and hairpin turns, that's very good speed, and excellent speed at night.

Yesterday I needed a 50 mile ride to make my 100mi/week goal, and managed to do so in spite of running a gauntlet of skateboarders, clueless riders withe zero situational awareness riding with headphones and earbuds, a 5 yr old on training wheels towed by her dad and slingshotted across the trail as we approached a turn, and peds walking 4 abreast with a belligerent attitude behind a blind hairpin turn with oncoming traffic. You name it, the stupidity was there.

To make matters worse, they haven't caught the arsonist on the ARPT, and he, or another arsonist burned a house a block down from me Sat night. I stopped at Riverbend Park and talked to a fire crew refilling their truck. They told me the neighbors along the ARPT are talking about setting up sniper hides to shoot the arsonist. No way that's going to end well. I hope they catch the guy soon though. He's burning a lot of nursery trees and tying up 10s of thousands of $$$ in fire fighting resources.

After putting it off for a whole year, I finally pulled the trigger and ordered a MagicShine 900 for myself. I'm also going to get a 2-3 watt rear red light, and mount my existing tail light on the back of my helmet. That should allow me to ride flat out after dark. With wx in the 90's again this week (near 100 tomorrow) riding at night is just too much fun to give up.

Interestingly, I got back from that smoking fast 34 mi Tuesday night ride and realized all I'd had to eat all day was a cup of sugared coffee and one slice of whole wheat bread. Eating more fat is not only suppressing hunger, helping me to lose weight, but appears to already be making my muscles more insulin sensitive, and eager to burn fatty acids for fuel. I went through 2 Gatorade bottles on the ride, but that was it. On my  50mi ride yesterday, 2 bottles and 1 PowerBar. About 700 calories in total.

My blog on eating fat last week has had a profound impact on my view of carbs. They're great for ride fuel, and for recovery, and perhaps spiking blood sugar just as a ride starts, but otherwise, glucose is a toxin that has to be very tightly managed. Better to eat fat. I am so much less hungry too.

The sensation isn't the 3-alarm fire of hypoglycemia it has always been in the past. Eating is something that can be done anytime in the next few hours, not a plunge into irritability and brain freeze. Nice too that shunning carbs, except as ride fuel, actually makes them more effective in that role!

Techie Tuesday - Optimal Wheel Spoking

This is a post I have wanted to do for months and months, and never seemed to find the time. I was motivated to do the post now because disk brakes are taking off for Cyclo-Cross racing, and Johan Bruyneel has been calling for at least rear disk brakes being used in the TDF to cut down on crashes caused by carbon wheel lockups. I happen to agree there.

While a rear-only disk wheel will not impact road wheels that much, front and back disk wheels would make radial spoked wheels disappear in a heartbeat. It would also introduce all of the torque-bearing considerations to the front wheel as are present in rear wheels.






Mid-1980s 36 hole low-flange hub with very little tear-out protection. Even laced 3X, the spokes have a significant concave path across the wheel. Note that on all 3X lacing, adjacent spokes pull in the opposite direction, offsetting each other's stresses on the flange.

Mid-1980s rear low-flange hub. The larger flange, relative to the front hub, creates a flatter, more optimal spoke path across the wheel.



Ultegra 6700 32 hole low-flange front hub laced 2X. The spoke path is even more concave than the 36 hole 3X spoking above. Better than radial, and with extra material to prevent tearout, it nevertheless is NOT warranted for radial spoking.

Ultegra 6700 32 hole low-flange rear hub laced 3X. Spoke path is very close to straight across. If they're ever made available in Ultegra 6700, 28 hole hubs should produce optimal 3X spoking.

Mavic Aksium: Drive-side spokes run perfectly straight across the wheel, the optimal 90-degree pulling angle for a torque-bearing spoke, from LR corner to UL corner here. Well done.

Mavic Ksyrium: A tribute to pig-headed stupidity and marketing arrogance. The beautiful convex spoke path on the non-drive side is completely negated by the use of radial drive-side spoking. The decision to use aluminum spokes, with no fatigue limit, guarantees failure.

These two wheels, identical in all other respects, show the difference a larger diameter rim makes on spoke path. As you can see, the 29r (~700c rim) spoke path isn't quite as optimal against tear-out as the 26r's is, although both are very good.

WTB Mtb 26r: Convex spoke path on 3X spoking, from LL to middle R on drive side and LL to UR on disk brake side here.

WTB Mtb 29r: Slight concave path from LL to UR on drive side, and LR to UL on brake side here.

The 24 hole drilling and 3X spoking creates straight-across path on the drive side. Uses a Hi/Lo flange strategy to make the wheel respond more symmetrically

Perfect straight-across spoking, which Mavic calls R2R (rim to rim) on their Cosmic Carbone all-carbon wheels. They must have fired some marketing people and hired some engineers.

  A few notes on ferrous (steel) and non-ferrous (aluminum) metals. The curves look like this. Note that 6061-T6 fatigues down to only 10% of original strength with symmetrical, oscillating, mean-zero stresses, and to only 4% with maximum asymmetrical stresses.

This textbook on metal fatigue spells it out much more starkly - non ferrous metals have no real fatigue limit. They fatigue to zero strength. Still think those Ksyrium spokes broke because you abused them?

As I remarked on before, drive-side spokes are tightened to about twice the tension of those on the non-drive side in an attempt to shore up the drive side's lateral strength. There are several strategies available to mitigate the resultant asymmetrical way the wheel responds to axial and lateral loads. In general, the goal is to have the spokes of the two sides yield equally with any applied stress, such that the effect on rim movement and deflection is symmetrical.

1. Radial spoking on the ND. This shortens its spokes, making them less elastic. Ironic that NDS radial lacing is used by mfgs who lace the front wheel radially to make it stiffer. The NDS is already too stiff visa-vie the drive side.  It also makes for a harsher ride, and precludes it from bearing any torque.
2. Use of a larger flange on the drive side. This moves the spoke bed outward, improving its angle, and can be helpful. It also bears torque better. It will also improve the spoke path, shorten those spokes, and thereby, stiffen them. 
3. Low (or very low) flange on the NDS. Effectively moves the spoke bed inward, and lengthens the spokes. Most helpful when combined with 3X lacing and thinner spokes to increase elasticity. 
4. Using more spokes on the drive side. This is rare, but it has the potential to soften up the NDS so the wheel responds more symmetrically to loads. One interesting option here is to use radial lacing and only populate every other hole. Fewer spokes would be more aerodynamic.
5. Heavier gauge spokes on the drive side. This was my personal choice, as I used 14/15 on the drive side, and 14/17 on the NDS. This makes for a rock solid wheel that is also supple.
6. Using a smaller freehub body, as found on Hope and Chris King single-speed hubs, and mount only 6-7 gears of a cassette. You'll have fewer gears, but a much stronger wheel. This idea is getting some traction in the mtb community. With a triple crank adequate gears are still available.
7. Off-center spoke drilling. Velocity's O/C rims can move the spoke bed over 4mm. It should help, especially if combined with other strategies. This directly attacks the problems of dishing a wheel.
8. Move the NDS flange inward. Disk brake rear wheels do this routinely. It usually results in a wheel that is laterally weak on both sides. Measure the flange to flange distance and buy accordingly.  Wider is better.
9. Use heavier spokes only where they are pulling torque. These would be trailing spokes on the drive side, and with disk brakes, leading spokes on the NDS. With caliper brakes and 28 hole drilling, only 7 spokes would have to be 14/15, all the other spokes could be 14/17. This should keep spoke weight to ~ 100 grams.

 

White Industries H3 road hub with titanium freehub body. 252 grams. Note the hi/lo flange strategy.

Tune MAG 150 weights only 150 grams. Note straight-pull zero-flange on NDS and large flange on drive side.

The Making of A Mature Cyclist

I went on a really fun group ride last night with the Sacramento Bike Hikers (SBH), and as the Tuesday night rides are usually blistering fast group rides with 20+ riders riding in a well-oiled paceline, that would have been the perfect seque into this blog post.

Alas, there were only 6 of us, and that turned out to be even more to my liking, even if not providing the perfect setup for this post. Three of us broke away and established a nice speed group -  some of our group were recovering from a long, hard ride the day before - averaging 21+ on the bike trail. Tons of fun, and smiles around, but waited up for the rest of the group back at the parking lot to say our goodbyes and thank yous.

This post on paceline etiquette has been making a huge splash, and not a moment too soon either. After my crash I have a much better appreciation of how serious biking accidents really are. A bad one will end your cycling, and a really bad one, your life. If you aren't happy with the level of paceline competence in your club, speak up! If things don't change, change clubs, or use http://www.meetup.com/about/ to start your own.

This article, published by Active.com, is a tour 'de force of what NOT to do in a paceline. Instead, it describes almost perfectly how to behave if you want to be widely known as the group asshole. Seriously, who was the editor that approved this atrocity?

First, when riding in a paceline, and for the most part, that is what riding in a peloton is for most of us club riders, you can't ride up front if you're in a paceline. You ride in your position, which rotates forward until it's your turn to pull, and then you drop off sharply on the left and soft peddle until you get to within a few bike lengths of the back, before putting some power down so you don't fall off the back and have to bridge up.

Second, hide your suffering? Why are you suffering? The whole point of paceline riding is the group can ride faster without any suffering. Unless you are new to the group, or coming back from a long layoff, you shouldn't be suffering. Do your suffering solo, and use your HR monitor to execute a well thought-out plan, but don't turn a club ride into a race.

Work smart? Are you kidding me? Be magnanimous. If you want to do a little suffering, do it to benefit the group. If you're the strongest rider, or strong at the moment, then pull a little longer, or when turning into a headwind, and enjoy the adulation of your group for being a generous, giving strongman who is always willing to share the wealth to benefit others. Sooner or later you'll get sick, or crash, or suffer joint pain and you'll be coming back from a long layoff. Imagine how many favors you'll have to call on then.

Did the guy that wrote #10, read, let alone write,  #9. Don't suck wheel, but suck wheel as long as possible to win the sprint? What sprint? After everyone else rode for the benefit of the group all day, they aren't going to appreciate you saving all of your energy to humiliate them in the last half mile. When riding into the parking lot, EVERYONE should be in exactly the same position they were all day in the paceline.

This article, by contrast, is dead on the mark. I am coping it here because things on the web have a way of going **poof**, and this is just too good to ever get lost.

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Although cycling has its benefits and is relaxing and fun, it’s always more pleasurable to ride with someone than to ride alone. However, riding with someone or riding in a group requires adherence to certain rules. It also requires skills that may take a little practice before mixing it up with the local club. 

No one likes a squirrel in the pack so I thought I’d outline several common sense "rules" of etiquette to follow when we are out there enjoying the scenery with a group of friends. These "rules" will increase your enjoyment and safety whether you are just putzing along or if you are hammering in a fast paced training ride. You surely don’t want to peel yourself off the pavement or cause someone else to be seriously injured by displaying poor riding habits. With this in mind, lets discuss some important issues!

1. Be Predictable—This may be the most important rule (even for solo riding) and it involves every aspect of riding from changing positions in the group to following the traffic rules. You might say that all the other rules support this one. Smooth predictable riding isn’t just a matter of style...here the word survival comes to mind! If unpredictability is the only predictable part of your riding style, you are a hazard to yourself and everyone else who has the misfortune to ride with you. Have you ever been on a ride where the group stops at an intersection and people scatter all over the lane? Some going through on the wrong side of the road and others turning left from the right side? Some running the stop sign and others doing it right? It’s confusing and irritating to drivers of vehicles as they approach a situation where cyclists are going in all different directions or just blowing through stops! Part of being predictable is riding within the rules of the road as a vehicle. Groups should maintain integrity when approaching intersections. That means staying in the correct lane, stopping together, and starting together as traffic allows. It goes without saying that if we demand the right to ride on the road, then we must be willing to ride responsibly...especially as a group.
2. Don’t Overlap Wheels—This habit will get you in real trouble. This is a good way to test your ability to do cartwheels if you don't adhere to this rule. Some people do it from lack of concentration, others may just not know any better, but sooner or later they'll crash. There is no recovery from a front wheel deflection.  All it takes is for the person in front to move sideways a few inches...if someone is overlapping his wheel, that someone will go down along with practically everyone who is behind him.  Many times the person in front can recover, but not the people behind.
3. Be Steady—This includes speed and line. If the person behind you fails to adhere to #2, you will contribute to a crash if you wallow around all over the road. When everyone is working for the group, maintain a steady speed as you go to the front. Ever notice how easy it is to ride behind some folks? If you take note of their riding style you’ll probably notice they don’t yo-yo around in the pack. They are rock steady. When they take the lead, they don't accelerate.  If they are strong enough to accelerate the group, they do it after the previous pull has rejoined the rear of the group and then only gradually so as to not string out the pack. When they are leading, they ride a straight line and their speed will be constant with the conditions. What a joy to ride with someone like this. Sometimes steady doesn’t just mean speed. It means steady pressure on the pedals…uphill or downhill, headwind or tailwind. When you are following someone like this, life is good! When they are following, they don’t make sudden moves or they know how to control their spacing by using their body position instead of using the brakes. Sudden braking will set off general alarms from everyone in the rear and make you very unpopular. If you do use the brakes, feather the front brake only and keep pedaling against the resistance. This allows you to moderate your speed without disturbing trailing riders
4. Announce Hazards—When you are in the lead, you are responsible for the safety of everyone behind you. You will become very unpopular very quickly if people behind you keep bouncing off of potholes, running over rocks, or reacting to unsafe traffic situations that you fail to point out. You need to be very vocal when approaching intersections, slowing, stopping, or turning and all actions should be smooth and deliberate.  Sudden, unannounced actions will throw terror into any peloton.  Riders in the pack should relay these warnings to the rear. When you are following, announce oncoming traffic from the rear…in this case others should relay this info toward the front.
5. Signal—Signaling lets everyone (vehicles and riders) know your intentions…remember #1? This makes you predictable. Also, it’s a good idea to make eye contact with oncoming traffic at intersections. One note here, use your right arm straight out to signal a right turn. It’s uncool to stick out your left bent arm to signal a right turn; more importantly, it’s impracticable and ineffective. In a big group combine this with a loud vocal warning of your intentions.
6. Don’t Fixate—If you are staring at something (i.e., the wheel in front of you), eventually you’ll hit it! When you walk in a crowd, you don’t stare at the back of the person in front of you…so you shouldn’t ride like that either. Learn to be comfortable looking around or through the riders ahead of you. This will allow you to see things that are developing in front of the group. With a little practice you will be able to "sense" how far you are off the wheel in front of you.
7. Stay Off Aero Bars—This shouldn’t require much discussion. They are much too unstable to be used in a group ride. Plus, you don't need to be on aero bars if you are in a pack as you will receive more aerodynamic effect from the other riders anyway. Maybe...one exception…when you are at the front pulling you can get away with it, but never, never, never when you are within the group or following a wheel. I know there are some people, usually triathletes, who are more comfortable on the bars. But, sooner or later, steering with your elbows in a group will add new meaning to the term "lunch on the road." Plus, it really tics off those behind you when you go down in a pack! Use aero bars for what they are meant for...solo fast riding.
8. Don’t Leave Stragglers— If you get separated at intersections, as a matter of courtesy, the lead group should soft pedal until the rest have rejoined. Another note here is that if you are the one who will be caught by the light, don't run the red light to maintain contact. If they don't wait for you to catch up, you may not want to be riding with them anyway. Also as a courtesy to those who may not be able to stay with the group, the pack should wait at certain points along the route to regroup. Especially, at turn points and if the stragglers don’t know the route. Now obviously this is not applicable during a race but we're not talking about a race...No one should be left alone on a group ride.  If you don't adhere to this rule, your "group" will get smaller each week until you're riding solo.
9. Know Your Limitations—If you’re not strong enough or too tired to take a turn at the front, stay near the back and let the stronger cyclists pull in front of you instead of making them go to the back of the line. Unless they are a complete...well you know...they will appreciate that more than having to get past you to get back to the front. Plus, it strokes the animal's ego as you admit that he/she is the stronger rider. Another point here, don’t pull at the front faster and longer than you have energy to get back in at the rear (Remember, your "pull" isn't over until you do). I've seen this scenario many times, it comes "biker wannabe's" time to take his/her pull and the pace is getting up there.  The thoughts running through his/her mind is, "I need to show these guys that I can pull 2 mph faster than everyone else has been pulling."  They go to the front and hammer.  Legs begin to burn after a monumental pull...now it's time to pull over and let some "lesser" rider take a turn.  Well, the "lesser" biker is all refreshed after tagging on a wheel and is ready to punch it up another notch.  It's bye-bye to the first rider as he/she gets blown off the back...toast! Testosterone and ego is a volatile mix (even for you females) and it can get you dropped in a heartbeat.
10. Change Positions Correctly—A common beginner faux pas is to stop pedaling just before pulling off the front. This creates an accordion effect toward the rear. Keep a steady pressure on the pedals until you have cleared the front. After pulling off, soft pedal and let the group pull through. As the last couple riders are passing through, begin to apply more pressure to smoothly take your position at the rear. If you don’t time it correctly, you’ll create a gap and have to sprint to get back on. A technique used to reenter the line is to move your bike sideways first then your body. Try it. It will feel awkward at first, but it is the safest way to move within a group. It's just a small subtle move not an exaggerated one. If you lean your body first and misjudge the speed or the person in front of you slows down, you’ll touch wheels and be leaning the wrong way…bad situation! If you move the bike first, you will have a chance to pull it back.
11. Climbing—Ever been behind someone when they stood up going up hill and all of a sudden you were all over them? If you need to stand, shift up a gear to compensate for the slower cadence and stand up smoothly keeping a steady pressure on the pedals. This will keep you from moving backward relative to the rider behind you. Apply the opposite technique when changing to a sitting position. Downshift and keep a steady pressure on the pedals to avoid abrupt changes in speed.  It takes a little practice, but your riding buddies will be glad you spent the time learning how to do it right.
12. Descending—The leader must overcome a much greater wind resistance as the speed increases. If you are leading, keep pedaling. If you don’t, everyone behind you will eat your lunch. Riders to the rear will accelerate faster downhill as drafting becomes more effective at the higher speeds. If you are following, back off a couple of bike lengths to compensate for the greater affects of drafting. If you are closing on the rider in front, sit up and let the wind slow you or use light braking to maintain spacing, but in both cases you should keep pedaling against the resistance. Keeping your legs moving not only makes it easier to keep the spacing, but also helps the legs get rid of the acid build up from the previous climb.
13. Relax—This one is really important. It will allow you to be smooth and responsive. You can bet that if you see someone who is riding a straight line and is very steady, he/she is relaxed on the bike.  It not only saves energy, but it makes bike handling much more effective. Anytime you are riding in close proximity of other riders there's always the chance that you may come into contact. If you have tense arms and get bumped from the side, the shock will go directly to the front wheel and you will swerve, possibly lose control, and possibly cause a massive pile up. If you are relaxed, it's much easier to absorb the bump without losing control. A good exercise is to go to a grassy field (which is softer than pavement if you fall) with a friend and ride slowly side by side.  Relax your arms and lightly bump each other using your relaxed elbows to absorb the (light) impact. You will become familiar with how to safely recover from that type of contact.  It may save you some road rash someday.

You might be labeled a "Fred" if you wear clothing that doesn’t match or you still use clip pedals and downtube shifters, but you can still be a valued member of the group if you practice good, safe riding techniques. Riding in a group can be fun and exhilarating…it can also be safe if everyone knows and follows the rules. Happy cycling.   Mike

On the issue of aerobars, use them wisely. If it's your turn to pull and the only way you can keep pace is by using them, I think you'll find everyone will be OK with you dropping down into the aerobars, as long as you call out debris loudly and ride VERY smoothly. No sudden speed changes, or erratic maneuvers. Stay in the center of the bike lane, or on the white line if on a road.

Don't use aerobars to increase the pace, or otherwise "show up" others in the paceline. When down in aerobars your draft is not as long or hearty as when riding up on the blocks, so the guy right behind you is working harder than he otherwise would. If you can arrange it, make sure that guy is the strongest, or one of the strongest riders. He will then ride up on the blocks to the great relief of everyone behind you, and will be a big strong rider who will nevertheless appreciate the somewhat diminished draft you are providing. You'll essentially be splitting the load of the locomotive position between you, which is just fine in strong headwinds.

Be attuned to when the peloton might transition from a headwind to a crosswind. If you don't slow the pace, the peloton will explode as the group's draft will largely disappear, and tired or weaker riders will not be able to keep pace. 

I have switched to a 25mm Michelin Pro Optimum rear tire. The Pro Optimum is a dedicated front and rear tire set. The front optimized for braking and cornering (very sticky), and the rear for putting down power and puncture resistance (thick and tough crown rubber). A benefit of running the 25mm in back is really great braking performance from the back wheel.  Having it be so effective, but still not skid, makes for smooth leads with gradual speed changes.

Don't ride in aerobars unless you are way off the back and trying to bridge up, or up front with no one in front of you for 30+ feet. The C3 Syntace bars, with brakes swapped, and left arm normally planted, is quicker to the brakes and more stable than down in the drops, but those you ride with will never believe this, and will not appreciate any riding in aerobars when in a paceline. Be cool. Trust is the glue that makes a paceline work.

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