The flip point: extremely narrow tires on velos

Tires have been one of my favorite subjects to investigate from the day I found out that the rolling resistance at moderate velo speeds is almost as high as the aerodynamic drag. Apart from reading a lot about it on the Internet, I have switched tires countless times (I have a closet full with half used tires) and almost every time I ride home I roll down from a small bridge to see how far the tires of choice will roll. This is of course not very scientific, but over the course of the years I have gathered a lot of insight on tires this way.
Rolling resistance is the energy that is lost when the tire deforms in contact with the road and the rubbing of the rubber molecules amongst each other. There are several ways to make these losses smaller. Narrow racing tires typically use the most advanced techniques to lower the rolling resistance (RR) like more and thinner threads to make a thinner and more supple tire possible and better rubber compounds. For wider touring tires, the tire producers tend to give more attention to puncture proofness and durability. I think I can safely say that the HPV scene is slowly changing this, because there are a lot of geeks among them that like to push the tire producers towards Speed.
Especially velos do not really need the low aerodynamic drag of a narrow tire, because they usually are embedded in wheel arches where they are almost completely out of  the airflow anyway. Since a wide tire deforms less than a narrow tire they can have a lower rolling resistance, but only when the rubber compound and the tire casing shows up similar techniques as the narrow racing tire. However, the narrow tire has a last line of defense! It can be pumped up much harder than a wide tire before bursting. A hard tire deforms less in contact with the road, so less RR.

The following question came to my mind: how practical is it to use narrow racing tires on a velo?
To come up with an answer, I have ridden Schwalbe Durano 28-406 on the front wheels all winter long and for a shorter period the most extreme 20" tire on the market: Schwalbe Ultremo 23-406.

Durano: a racy tire but much more durable than it's predecessor the Stelvio (not in produktion anymore). I managed to wreck the sidewall of a Stelvio in one race, but the Duranos' can handle almost anything I throw at them. Almost, for the one thing that took one of the Duranos' out prematurely was heavy braking to the point that I lock up the wheel. The abrasion was too much and the road simply scrubbed right through the canvas, also destroying the tube inside.

destroyed Durano, the canvas scrubbed through

Well, since then I have been braking in  a more sensible manner and didn't have that problem anymore.
As to the riding experience: the Duranos' are fast tires and they give the Mango the smallest possible turning circle, so agility is also better. The feel in corners is very direct, so I know exactly what is going on. Because of the 9,5 bar of pressure I keep in them,  they do not bulge under the heavy load in fast cornering like wide tires do, especially when the pressure is down to a very comfortable level. Especially in roundabouts the velo may become a "Gallopin' Gertie"  with the loaded front tire hopping up and down uncontrollably until you slow down. I like to go fast in corners, so this all is a big plus for me.
Not related to RR, but the light weight does also contribute to the riding experience, since I do relatively much riding in town. A lighter tire accelerates easier, since there is less  rotational weight to bring into movement. Likewise, braking is a bit quicker but as written before, it is wise to not let the wheel lock up completely.
On a sidenote: I have put on lighter wheels with narrower rims to have even less rotational weight. The narrow rim is also better suited to such a narrow tire.
Comfort is of course less than what I was used to, but since the Mango has good shocks it's not much of an issue. I got used to it soon enough, but I do avoid getting next to the road and ride much slower on cobblestones. High pressure in the tires does make the velo noisier as impacts are simply more intense. Despite the high pressure and ensuing small contact patch, there still is a reasonable amount of grip on the road. I was surprised by that, since I had the idea that the high durability (for a narrow racing tire) must have something to do with a hard, slippery compound. Not so: the grip is not much less than that of the wider Kojak.
To make things more interesting, we had snow for a while this winter and one might think that a narrow tire is not good for that. Sometimes it's completely the other way around then you'd expect: the Durano cuts through fresh snow easily and does not have to displace as much snow as wide tires, so riding takes less effort and you stay in contact with the road. The non-driven front tires do not need to give traction, so that is not an issue either.
 Apart from the above mentioned flat because of the abrasion of the tire, I had no flats all winter. The thin Raceguard protection that Schwalbe puts in seems to do a pretty good job.
Maybe you have noticed that I put in 1 bar more pressure than Schwalbe gives as maximum pressure. I do so, because high pressure cuts the RR from narrow tires enormously and I somehow have a lot of confidence that the Durano is strong enough, unlike the old Stelvio.
So overall the Durano is pretty practical, be it that you won't like to do dirt trails with it as it sinks away too easily there.

Ultremo: Given the rather good impression I got from the Duranos' it only seemed logical to take it even further. The even lighter, narrower Ultremo tire. The ultimate in the line-up from Schwalbe.

Ultremo: best kept on the shelve until racing day?

Putting the tire on the rim was a bit more tedious than with the Durano, but not really very hard to do. It got a whole lot trickier when I wanted to pump them up to their max. 11bar! It's not simply a question of a few pump strokes more. Most pumps do not get up to that pressure at all, but we have an excellent track pump at the shop that managed it. Alas the pressure gauge was bust, so I had to check the pressure with a separate digital gauge from Schwalbe. The problem was to not lose too much pressure while putting the gauge on the valve stem. It was almost funny how many times I had to pump and pump again to get close to the desired pressure, because the moment I pulled the gauge off the valve it could easily lose one bar in pressure! When I tried to pump it up a few days later at home again I found that my own big floor pump only just could manage to get enough pressure in the tire. Certainly my little pump that I always take with me in the Mango, cannot get even close to the desired pressure. Since I usually swap tube and tire in case of a flat it is no issue on a daily basis (simply put on a tire that does not need extreme pressure) but on multiday trips it IS a serious problem. I know, I just keep on rattling about high pressure, but it is truly vital for such a tire to have it topped up at all time. I noticed it on my roll-out course that the variation in distance rolled varied a lot, depending on how much pressure I managed to get inside! Furthermore the tire will no doubt be destroyed easily when the pressure gets too low. It's the high pressure that has to maintain the shape of the tire. Too low a pressure and the sidewalls will bulge the very supple sidewalls until the rim cuts it up. The infamous snakebite flat is therefore a very likely thing to happen when you do not keep a close eye on pressure.
In all other respects the Ultremo is a Durano on steroids and so far it also seems to be strong enough. Only the pressure that is needed to keep this tire going good, is enough for me to completely disqualify it as a practical tire. If you seriously want the max in speed however, this is it.

As you may know, I have an enormous collection of YouTube vids. Here is one featuring the Duranos:

Yep, they also come pimped (white tread)

Don't forget to alter the setting on the bicycle computer:
circumference Durano @9,5bar=146cm
circumference Ultremo @11bar=144cm

Weight weening in winter: Exustar pedal

Mango Sport in winter conditions

Riding in the winter can be fun, especially with a threewheeler. You can slide as much as you like, as long as you stay far enough away of hard objects like street furniture, trees and the few other occupants on the cyclepath. Unfortunately the snow presents a problem for my Speedplay Frog cleats: they attract snow to a point that I have to walk like a duck until I get in my trusty steed. Then it gets even worse, the snow turns to ice around the cleat and it becomes very difficult to clip into the pedals.
Since I changed to real wintershoes that do a pretty good job in keeping my feet warm, I thought that while winter lasts, it would be good to adopt a pedal system that can shed the snow without problem: good old SPD.

Unfortunately Shimano SPD is about the heaviest system around, but there are compatible systems. Sending in the clone: Exustar E-PM-25 that only weighs 139 gramms including cleat. The lightest Shimano MTB pedal, the PD-M980 XTR CX weighs 180gramms and is just as expensive. A road pedal like the Shimano PD A-600 is doing better with 168gramms and it's quite a lot cheaper than the beformentioned pedals, but since the Exustar was on sale on the webshop of my choice (e.g. the cheapest) I decided to go with that.
After two weeks of riding to work with them, I have no regrets. Clicking in seems easier than what I was used to from Shimano SPD's and unwanted exciting is less likely. The only downside so far is that the stunning look of these magnesium pedals with titanium axle will never be revealed, obscured from sight as they are by the beautiful body of my Mango Sport.

Weight wining, price fighting, part 2: the shifter.

If you want to make a bike lighter then you will need to look at all the components. But the bike has to perform well also, so sometimes it is better not to push to the limit. We have an interesting choice when it comes to the shifters: either I choose very good performance or I can choose the lowest in weight...

This is the 500TT shifter from SRAM. It is compatible with my X0 shifter since it pulls cable length at the 1:1 ratio that the derailer is designed for. Not compatible with Shimano components. Price is 112euro. It's not a very common component, so I didn't bother looking around for a lower price too much.
Thumb shifters in a Quest are unusual, but I have used Shimano Ultegra thumb shifters in my Mango Sport and I'm very pleased with the accurucy and ease of shifting. The steer in Mango and Quest are the same, so I see no reason why it wouldn't work.
It is not particularly light at 194gramm, but still some 20gramm lighter than the standard X9 gripshifters that come with the Quest. I could have bought the 900TT, but it's only 16 gramm lighter and costs some 40 euro more. Most probably both working equally well, so it's not worth the extra bucks.

This is a cheaper shifter at 63 euro incl. shipping (found it even cheaper later on at http://luckynino.blogspot.com, tip from Jeroen Koeleman). At the moment it is the only production 10-speed gripshift and it was only by accident that I saw them on the site of the lightweight cassette manufacturer RECON. The SEC S-light 10-speed shifter comes in a version for SRAM XX derailers and a slightly cheaper version for Shimano derailers. Their weight is minimal and also much lighter than the SRAM gripshifters. We had a Shimano type SEC shifter installed on a bike at work. My first impression was that it shifts precise enough, but very very light and not consistent in all the gears. When I made a testride, I sometimes upshifted unwillingly two gears at a time. Maybe it's something to get used to, we'll see.
The low weight is tempting, so I will try these first. If I find these shifters to be ok, I might sell the 500TT shifters.

More components will follow later.

Weight wining, price fighting.

I'm becoming more and more of a weight weenie, it's becoming a bit of an obsession.... That may be a bit strange for a flatlander, but I find the handling and ease of acceleration of a light velomobile so much superior, that I've decided to spend some time and money to find out how to make a lighter Quest (my Mango Sport already has lightweight components) without sacrificing any of the practical features. It's no use to have a lightweight velomobile when it's components are to weak, right? There are plenty of exceptions to the rule that lighter is weaker however. Take the KMC X10SL chain: it is tougher than most heavier chains and the Ti-N coating makes for less wear and better shifting. There are three typical racing-bike lengths lying on my kitchen scale here, that's about how much I need for a Quest. One length of 114 links is 742:3=247 grams. That includes a 'missing link".  I found a cheap webshop that doesn't sell the chain one length at a time in a nice package, but straight from the roll. It was 105 euro (shipping included) and that saved me 40 euros from the cheapest eBay seller!? Another nice thing: I don't have to link the three chains.
But what about the weight reduction? Well that depends what quality chain you compare with, but even when compared to other light 10-speed chains, this one gives me about 120gramms reduction.

 Chains run over a cassette and RECON makes the lightest of them all. 108 gramm for an 11-27 10-speed cassette is amazing. They usually don't come cheap and they are hard to find. A Taiwanese seller said to have some for less than 100euro but after ordering it appeared to be out of stock. I got a full refund, no problem but no cassette either. I even e-mailed the manufacturer in Taiwan and he replied very correctly that an Italian reseller had all possible cassettes from RECON. But I don't want all, I just want the cheapest 11-27! So I looked around again with google and finally found a shop at the other side of the ocean that had my size for 130 euro (incl. shipping). That's a lot of money for a cassette that wears and will have to be replaced. The enclosed drivetrain ensures a long life I reckon. Light cassettes from SRAM and Shimano are mostly twice the weight of this one and are pretty expensive nonetheless. That's why I chose this one, giving me the greatest bang for the buck.
The reason that these cassettes are so light is that they were CNC fraised out of a solid piece of aluminium. Everything unneccesary is simply "grinded" away, like Apple is doing with the aluminium frame of the MacBook, making it stiffer then when made of seperate small parts bolted together. Aluminium is not very wear-resistant, but the ceramic coating should help. I have had a RECON 12-23 cassette on my Mango Sport for about 2000km now and see no wear so far, so I'm pretty confident it won't wear before the chain does. (edit: I have paid way too much, you can find RECON cassettes on the blogspot of luckynino, tip from Jeroen Koeleman for 50euro excl. shipping)

The derailer I chose is the X0 SRAM with medium cage. They have a very good reputation and I have good experiences with the X5 that has the same construction. I could get a good deal on Marktplaats from a bicycle mechanic. It's brand new and he wanted 20euro below the normal price of about 160 euro, but looking at eBay I found one seller that was significantly cheaper at 117euro. I confronted the man with this fact and after some tough negotiating we agreed on 118,35euro (incl. shipping).

X5 would have costed me about 60euro and it weighs 300gramm. The X0 has significantly less play mounted to a derailer hanger. The X5 is good enough for 9-speed but I think I will need better quality for a 10-speed system. Together with a weight reducion of a third, I think I made a pretty good deal. A derailer can last very long in a velomobile and then you'd better have one that shifts reliably.


More components to follow.....