More CETMA
I am late to the party, but The Lazy Randonneur has some Cetma Cargo Bike videos up, and a neat overview. The first thing I thought when I saw the video was that the stem/handlebar looks awfully close to the girl’s head, and sure enough, in the overview, the parent has switched the stem around (I think it was Sheldon who pointed out that this has less effect on steering than you might think), which would give more clearance.
Guessing, it looks to me that the CETMA, like the Larry vs Harry, has a steep (looks vertical) steerer tube angle, making for a horizontal tie rod. In contrast, the bakfiets.nl’s steerer tube is angled back, and then the tie-rod is angle up towards the lever on the fork – see the picture in the post below. That way, it moves the stem a bit further back from where the kiddy’s (or in this case, girl’s) head wants to be. However, with the bakfiets.nl, the cockpit setup is much more upright, and there’s not enough room to flip the stem around. On my bike, I’ve done the Clever Cycles Brompton seatpin mod, which makes for a more open cockpit. If I get a chance, I may flip the stem too, just to see how it feels… actually, I won’t. I forgot that the bakfiets.nl doesn’t have a stem that you can take the front off, so it would be a pain. Someone more committed than me will have to try that one.
The bike looks really nice, and being a custom bike, you can throw whatever spec at it you fancy. If I was in the market, I’d get the box made so that the top dimensions were the same as the bakfiets.nl bike, meaning I could use their raintent.
June 2nd, 2010 at 12:41 am
That is actually my bike/girl in the overview and I did in fact turn the stem around to increase the clearance for the kids heads. Lane from CETMA recommended it, he did it to his bike as well.
I have ridden the bakfiets.nl bike extensively and I much prefer the CETMA geometry.
June 7th, 2010 at 3:57 pm
Hi Doug – thanks for the comment. I’d love to hear more on how the CETMA rides compared to the bakfiets.nl bike. We’ve got the Cargobike and a Madsen, used to have the De Fietsfabriek 995, and have ridden the Burrows 8 Freight, Christiania Trike, Zigo Leader, Taga, Onderwater family tandem, Gazelle Cabby… maybe some others. Of that lot, the Cargobike short the best for me by a small margin over the long. I don’t think it’s perfect though. I’d prefer a little more reach, albeit not as much as the Harry vs Larry, which disinterested parties tell me is sketchy. The bakfiets.nl can be improved by a layback seat post. I reckon it could be further improved by further reducing the ratio on the steering (the de fietsfabriek had an adjustable ratio, and lower was better) and reducing the steering lock (it turns too far, and you can get yourself in trouble with it initially).
Of course, if they could make it stiffer, lighter… etc.
June 9th, 2010 at 1:51 am
The CETMA is overall sportier than the bakfiets. It has a much roomier cockpit and feels more stable at low speeds. It tends to get a little bit twitchy at higher speeds when unloaded. With a moderate load, at about 15 km/h I can ride for brief stretches with no hands. The steering stop is in exactly the right place to be able to turn sharply without as much danger of turning too far as on the bakfiets. There is somewhat lower ratio to the steering than the bakfiets which increases the head bonk potential of the handlebars. I initially tried a really high riser stem but I did not like the super high bars.
In contrast, I found the longbox bakfiets to be very light in front when unloaded. When I was using it, I tended to put 10kg in the front bin just to tame the handling. This is where I found the joe bike (short box bakfiets copy) to be much better than the long box – it handles fine without any load.
The CETMA feels bouncier, especially when loaded and yet is very stiff in the drive train which makes it both more comfortable and slightly faster than the bakfiets.
Where the CETMA really shines is going uphill. The roomier cockpit and the great slow speed handling mean that it can climb hills without wandering and so I can get it up steeper hills than I could with the bakfiets. Since I live at the top of a 100m (elevation gain) hill, this is very important to me.
Frankly, I could easily have lived with the bakfiets had it not been for the lack of disk brakes. Roller brakes are truly great but they are not up to the task of stopping a bakfiets with two kids and groceries on a steep hill. I had them fail (they lock – that is they cannot be modulated when they get too hot) twice when I was going down the hill from my house.
From a cargo standpoint, the CETMA has the edge since it can convert to a flatbed in about 3 minutes. It also handles reasonbably with 150 kg in the bin. http://www.flickr.com/photos/coldbike/4673286965/
I would lose my Canadian citizenship if I failed to mention that the CETMA handles really well in snow. It has clearance for huge tires (I had 2.35 inch big apples on it this winter) and the long wheelbase means that it is easy to correct slides. I am not sure why but the bakfiets is not as good on the slippery stuff. My intent for this winter is to get a pair of studded tires to put on when it gets icy.
If I was to change anything about the CETMA bike, it would be to turn the rear into a true mixte with double top tubes to improve the tortional stiffness. I am not sure if this could be done without affecting the separability.
Feel free to contact me if you have any questions.
June 9th, 2010 at 2:34 pm
The CETMA is overall sportier than the bakfiets. It has a much roomier cockpit and feels more stable at low speeds. It tends to get a little bit twitchy at higher speeds when unloaded. With a moderate load, at about 15 km/h I can ride for brief stretches with no hands. The steering stop is in exactly the right place to be able to turn sharply without as much danger of turning too far as on the bakfiets. There is somewhat lower ratio to the steering than the bakfiets which increases the head bonk potential of the handlebars. I initially tried a really high riser stem but I did not like the super high bars.
In contrast, I found the longbox bakfiets to be very light in front when unloaded. When I was using it, I tended to put 10kg in the front bin just to tame the handling. The Larry vs. Harry is the worst for this and feels positively skittish. This is where I found the joe bike (short box bakfiets copy) to be much better than the long box – it handles fine without any load.
The CETMA feels bouncier, especially when loaded and yet is very stiff in the drive train which makes it both more comfortable and slightly faster than the bakfiets.
Where the CETMA really shines is going uphill. The roomier cockpit and the great slow speed handling mean that it can climb hills without wandering and so I can get it up steeper hills than I could with the bakfiets. Since I live at the top of a 100m (elevation gain) hill, this is very important to me.
Frankly, I could easily have lived with the bakfiets had it not been for the lack of disk brakes. Roller brakes are truly great but they are not up to the task of stopping a bakfiets with two kids and groceries on a steep hill. I had them fail (they lock – that is they cannot be modulated when they get too hot) twice when I was going down the hill from my house.
From a cargo standpoint, the CETMA has the edge since it can convert to a flatbed in about 3 minutes. It also handles reasonbably with 150 kg in the bin. http://www.flickr.com/photos/coldbike/4673286965/
I would lose my Canadian citizenship if I failed to mention that the CETMA handles really well in snow. It has clearance for huge tires (I had 2.35 inch big apples on it this winter) and the long wheelbase means that it is easy to correct slides. I am not sure why but the bakfiets is not as good on the slippery stuff. My intent for this winter is to get a pair of studded tires to put on when it gets icy.
If I was to change anything about the CETMA bike, it would be to turn the rear into a true mixte with double top tubes to improve the tortional stiffness. I am not sure if this could be done without affecting the separability.
Feel free to contact me if you have any questions.