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24 Aug 2010

Fast

I like recumbents for their comfort, fun, practicality and safety. And their was something else too... Speed potential. This post isn't about cruising speed, or average speed. It's about the kind of speed less used and that's actually isn't important at all. This type of speed is there for only one reason, fun. I'm talking about top speed.

In the past weeks I found out that, without significant wind and elevation, Jenease's top speed is 61.5kph, when I'm riding. Thus far that is. Two years a go I reached 72kph down a large bridge with Yavixa. Complete with race hood and strong wind gusts from the side. My all time record is 76kph, down a small hill on my previous Fuego. The fastest descent ever reported about on a Fuego is 106kph. Set by Ian Fardoe in Great Britain. The bike feels rock solid at such speeds. He did it twice to make sure the GPS was right.

Yesterday there blew a strong wind over my flat country. Good circumstances to try to break the wind assisted record. You need a good location for such an attempt. When I reached to first location, a cyclepath next to the TT-circuit, the circumstances where ideal. The wind was so strong that I could feel my helmet being pressed against my helmet. However, I didn't turn around to 'max it', I went further on to Hooghalen. The road is wider there and I thought the wind would be similar.

It wasn't. I had a strong wind gusts from the side, and at normal speeds that doesn't bother me. Now I didn't go any faster than 64.4kph. Before doing this, I'd checked my tyres, just to be sure. I felt like more was possible and I headed back to the first location. Again, the wind was strong. The concrete cycle path was clean and all mine. There was a bit of lose gravel at some point. I turned around at the far end of the straight and accelerated.

30 was reached almost instantly, 40 didn't cost much power. Reaching 50 went surprisingly easy. The gravel was crossed at 50 too. I kept shifting at the right moment, at a cadence around 110-115. 60 was known terrain for me. The wind gusts did ask my full attention. The 2.5 metre wide cycle path started to look narrow now. It was a small movement of my right had that engaged top gear, sprocket number 10 on the mid-drive, at 63kph. From now on all I had to do was keep it steady and pedal really hard. The number on the speedo kept going up. I lifted the throttle once at 65 because of a minor left bend in the cycle path. I ran out of straight at 68kph. So 70 is reachable. Freewheeling at 60kph is great fun. I lightly tipped the brakes and took a turn right on to the military practice area. That piece of road is open to cyclists. I kept doing 45 for a while and everything went back to normal. 


Grotere kaart weergeven

The map shows the problem of this straight, it's only 1.3km long. The good things are that it's tree free and that the grass is at the same level as the cycle path.

Warning: 70kph with strong wind gusts feels alright to me. I've got over 40.000 kilometre of velomobile experience. Practice at lower speeds before attempting such high speeds. Mango's have gone faster than 100kph down hill. Humans are not made to travel at almost 20 metre per second.

17 Aug 2010

Racing Rütenbrock, a weekend

I arrived at the Bentlage campsite just after eight in the evening, last Friday. This family has a key roll in the organization of the event. They also offer the great possibility of camping in their yard. I was on of the first to arrive. Later that day I was followed by, Frank in his Milan, Paulus in his Quest and Daniël in a Ford Transit. He'd brought his Go-one Evo R.
That thing is about a 'racy' as a velomobile can possibly be. Small, 18kg, a bit of suspension and an expected price of  €12.000 It couldn't be my only velomobile, my Mango is way more practical, comfortable and so on, but my god it's pretty. And ludicrously fast too.

Saturday morning started with a good breakfast. After that I just relaxed and loitered around a bit. Until the idea came to line up the four velomobiles to compare them.

At some point in time the moment came to ride to the small town of Rütenbrock, three kilometres from the campsite. With almost an hour to go, the start/finish area already was boiling with activities. I did the usual pre-race things with my Mango (transponder, number, remove pump and battery etc.) and met 3 other Mangoteers. David, H@rry and Wilfred would also give it a go at this fun track. Besides us four there where 52 other participants. I took the time to explore the track. The first lap I road slowly, looking for edges and bumps. The second lap was done at a slightly higher pace. All that data was stored in my memory and used during the fast lap.

All 56 started with an individual lap. Mine went pretty well. In fact, it went well enough for a 9th place. An average speed of 40.7kph. Fastest Mango and not far away from number eight.

After filling up the water bottle, and having lost some water, I arrived at the already packed grid. Right on time for the parade lap. During the parade lap I found a way to the front of the field. My start wasn't really good, but within a few laps things started to go fine. The corners went a lot better, or faster, than I'd expected. I gave room to the few that did overtake me. And the many I overtook gave so much room that I didn't lose much speed. One time however, it did became a little scary. In the video, around 5:00, I lift up the left wheel a lot higher than planned. The Quest that finished in front had a lot of luck around 5:50. I started to slow down after half an hour or so. The bouncing at 40kph became tiring, the corners still needed my full attention. Hitting the apexes lap after lap never gets boring. (Judy made the photo with Wilfred's camera)

I ended in 10th position, closely behind the blue and the yellow Quest. My average speed was slightly higher than 3 years ago when I raced the Fuego. I'm stronger now, so on a track like this, a 3-wheeled, (considered a disadvantage) Mango isn't much slower than my favourite  2-wheeled semi low racer.

After the racing I treated myself with fries and ice cream. The barbecue in yard of the Bentlages was, like always, a good one. I heard up a funny question. Well known rider A asked well known rider B if he races more often. Rider B being a former world record holder...

All the racing and eating had made me sleepy. I went to my tent for an hour of sleep. After that, the evening went on 'till after midnight. The next morning I had another good breakfast, and a puncture too. I didn't trust the rim tape anymore, so I added a layer of strong tape. Than it was time to say goodbye and head home.

You'll find the 22 photo's I made here. And here's the video I made:

12 Aug 2010

A Nazca Fiero XS

No, I didn't buy another bike!

Almere is one of the biggest cities in the Netherlands. Getting there is an easy 125km ride. I've done that numerous times. Last Monday I went there again. This time, for the first time ever, by car. There was a good reason for that. That day, I was the expert helping a fellow 'bent rider buy a 'new' Nazca Fiero XS. She'd found it on ligfiets.net. She was looking for a XS version because she's only 1.58 metre tall.

The right address was easily found. The bike was in good condition. It still was a bit to long for her, so I did the test ride. The owner told us that, for some reason, she couldn't get the hang of it. So this little blue Fiero had spend most of his young live in the garage collecting dust. The deal was closed and after a cup of coffee we drove to Dronten. This 'velomobile valley' also is the home of Alligt. Not only does this company produce the Alleweder, it also sells and produces 155mm crank sets. A set of those would make the short Nazca perfect for short legged people. I did some measuring and I reckon that an x-seam of  97cm could be enough to ride this bike. The photo on the right shows how much clearance there still is between the cranks and the front wheel. Tight turns won't be a problem!

Back home I gave the bike a full check up. I adjusted the boom length and mounted the short cranks. I found out how little riding was done on this Fiero when I gave the computer a new battery . With a total distance of only 294km, this bike was practicably new!  New, easy to handle, the right size and agile.

During her first ride, everything turned out to be just fine. I did shorten the boom a few centimetres. One thing was a bit peculiar, the 42t up front. That should be a 52t. Now the bike had a silly low gearing. I'll take care of that when I've been to the little int. hq. of Nazca in Nijeveen.

Some specifications:
  • 3x9 dual drive
  • bar-end shifters
  • 40-406 Schwalbe Marathon Racer tyres
  • small luggage rack
  • sigma bc-1109 computer
  • kick stand
  • mudguards
It may be small, but it's a proper bike that looks good too.

10 Aug 2010

Durano vs Kojak

My Sinner Mango Sport Red Edition, or 'Jenease' to keep it short, first had Durano tyres on the front. They're fast, quite reliable and offer plenty of grip in the dry. But they are only 28mm wide and at a pressure of 8 bar, they're not as comfortable as I'd like tyres to be. So I became interested in Kojaks. They have a maximum allowed pressure of 6.5 bar and are much bigger. The nice thing is that they only weigh a bit more than Durano's. There was however, on big downside, rolling resistance.

Various test had shown that Kojaks are a lot slower than the very racy Duranos. But I liked the idea of more rubber. Fatter tyres would make riding on rough roads a better experience. The thing is that most of the roll out tests I've seen are done on perfectly smooth surfaces. And our cycle paths may be very good, they're not perfectly smooth. Some asphalt has an open structure and on small rural roads the quality can be, 'just over acceptable'.

So I wanted to do my own testing. Now, we don't have any hills followed by a nice long flat piece of road around here. That means that I have no idea how to do a roll out test. You'd need a 300 metre stretch of road for that. We do have small tunnels. My idea was to roll down and measure how many seconds it takes to cover a certain distance. I used tar lines in the road surface as a mark. Problem is that my tests weren't any longer than 25 or so seconds. But the results did say something. Especially because I tested on smooth and rough asphalt.

First tyre tested was the Durano, at the pressure I use them on, not the highest possible (9.5 bar). There's not much weight on Jenease's wheels and I prefer to have grip. And the higher the pressure, the less grip you have.

Second tyre was a set of rubbed in Marathon plus. They came of David H.'s Mango and he was curious how they'd do in a test. I'd never use such heavy and difficult to mount tyres. But since he is a fellow velonaut, I included them in the test. I used the pressure he rides them on, 6 bar.

Third tyre was my desired Kojak, at 6.5 bar.

The table below explains most of the results. Kojaks will, according to my test, make Jenease roll 0,7% slower on smooth asphalt. During the tests I didn't go much faster than 13kph or so. The total weight of Jenease and I was about 91kg.

Interesting to see is that on rough roads, the racy Durano increases it's lead over the other two tyres. In the end, I did stick with the Kojaks. Simply because they ride better. I did 90km on them last Sunday, and they do indeed feel a little bit slower.

Was this a very good test? No. It needed longer rolling. That would make the times less of an error factor. But the result, especially the difference the road surface makes, is interesting.

5 Aug 2010

Jagwire for Jenease

I'd read about this upgrade on Wim Schermer's blog. Than he wrote an article in the 'Ligfiets&' together with Wilfred Quemo Quest. Today I received my set of cables.

It's like going from plastic to metal brake levers. More stopping power, more 'bite', less flex. Jagwire brake cables, highly recommended for every drum braking velonaut. At a price of  €14,-, shipping within the Netherlands included, this a must have without downsides. I got mine from Velomobiel.nl

A normal brake cable is built up like a curling telephone wire. A shift cable is stiff, but could split open when used as a brake cable. I just was lucky when I used index cable on the brakes of my Alleweder. Jagwire combines the curly wire that doesn't split with the straight cables that don't flex. The result could be that your stopping distance at 35kph goes down from 8 to 7 metres. I don't know what my brakes performed like before the upgrade, but it sure feels a lot better now. From 36-0 costs less than 7 metres, possibly even just over 6. A fast velomobile needs stopping power too.

4 Aug 2010

22km Time trial Nijeveen

Saturday was the fourth time I participated in the time trial of Nijeveen. The recumbents are given a go at the track after the df's had their chance of setting a time. But that's not how the day started. It all begun when David H. and I left hometown Assen in our Mango's.

We didn't leave exactly on time, so we only spend a few minutes at the small meeting behind Nazca Recumbents. I did take time to adjust the cadence sensor. That had become mis-aligned after I'd moved the bottom bracket a bit closer to the seat.

Under a drizzling sky we rode to the event. It would be dry when it was our turn to race. We signed in at the canteen of the cycling club and picked up our starting numbers. There was quite a turn up. Thirty participants, accompanied by a couple of supporters. A mixed grid with ten or so velomobiles, including three Mangos.

I started without feeling warmed up. Probably because I didn't do a warm up. But I was up to temperature after five minutes. I kept a steady pace of 45kph. It took a while to find out why I was two to three kph slower on a long straight. I discovered I had some serious headwind. Main while, the cadence was a good 95-100rpm. Some corners where a bit slippery. That, combined with my little experience at velomobile racing, did affect my average. But not by much.

After the first lap I had to yell at some just finished and 'sleeping' df-ers. They where on the racing line and not paying attention to what was going on behind them. It did hurt my voice, but I got by them without slowing down. Some didn't appreciate me overtaking them on the right. All I can say to them is to 'get of the bloody racing line'.

Apart from this slightly exciting moment, the rest of the 22 kilometre went without any real drama. I was overtaken by three Quests and overtook numerous unfaired riders. You'll see most of that in my video. In the end I'd managed 43.3kph. Which is right in the middle, or just over that, of my expectation of 41-45kph average.

Afterwards there was the usual chit chat and socializing. That's when I made some photos.  David and I rode home the same way we'd gotten there, calm and steady, cruising at 36kph.

At first, it did feel odd to not race the Fuego in this event. But with this weather, and this result, everything turned out fine.  Last year, the conditions where perfect and I achieved an average of 41.3. This year, with the strong wind and the wet track, I was 5 percent faster.



And yes, my camera was mounted too low.