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Drum brake hub dynamos for velomobiles and a lot more

Published on 26 April 2013 16:02, edited on 27 April 2013 18:33 (2303 times viewed) 1Comments

In June 2011, I published an article on the (then newly founded) online-shop „Gingko Spezialradteile“. Meanwhile, Lutz Söhnchen and Jörg „Joggl“ Leupold became a well-known part of the velomobile market. Time to ask them about interesting items of the nearer future.

BentBlogger: When I reported about Gingko last time, modified and lighter Sturmey & Archer (S&A) hubs, wide rims and spokes in various length were products which were available almost only in your shop. How has the story gone on since then?
Lutz: We used the last year intensively to further broaden our spoke stock, and we added new tires and especially new wheel variants to our range of products. Especially the wheels become a more and more important part of our work. We can now offer the round profile rims, which are used for our velomobile front wheel sets, also for 26 inch rear wheels and also enable our customers to change to the Triathlon size 571.
Joggl: As Lutz wrote, we broadened our spoke stock significantly last year. We are proud to have the largest stock of short round and aero spokes worldwide, according to Sapim. Additionally, we took care of some new rim profiles for the racers. All this will continue in 2013.
BentBlogger: Recently, you announced in the velomobile forum that you will soon be able to offer S&A drum break hubs with integrated dynamo – of course with singles side 12mm axis as it is used in most velomobiles. What is so important about this product?
Joggl: The discussion popped up again and again in the forum and this made us get in touch with S&A, and not only once. In my opinion, it is important to have battery independent lights during the colder part of the year. Also when going on long tours, I can see a big advantage here.
Lutz: Unfortunately, we do only have insufficient information regarding the technical details of the new hub dynamo. This also refers to weights and degree of efficiency. But I think that STVO-permit will rather be of importance when looking at headlights.
BentBlogger: I had myself asked S&A why they did not offer their existing drum break dynamo hub (it had existed for a longer time as a dual side 9mm axis version) for trikes but I did receive a rather non-informative answer. How could you convince S&A (apart from ordering 10.000 pieces;-)
Joggl: We asked them again and again. The hub jackets with 2.5mm sprocket holes also originated in our efforts. Quest ( is ordering them like this as well now.
BentBlogger: When will the hubs be available in your shop? Which variants will be there (90mm/70mm, 38, 32, 36 holes)? How about the prices?
Joggl: There will be a 70mm and a 90mm version. Maybe there will also be a 2,4W and a 3,0 W-version. We concentrate on a 32 hole variant with 3W. As this means a considerable capital commitment, we will have to streamline the product range a little. Test are ongoing at S&A.
BentBlogger: Will it be sufficient to ride with one dynamo wheel or will you have to use two as you might be dragged to one side?
Lutz: Of course the wheels with hub dynamo will run with a little more resistance compared to normal drum break hubs. But to ensure a well tracked vehicle rather seems to be an issue of the entire steering settings. With a more sensible scrub radius this should be compensatable.
There will of course be riders with a higher need for electrical power due to diverse gadgets and additional electric devices. On the other hand you will have to think of weight as well when assembling two hub dynamos. For now, lets wait how heavy the hub dynamos will be in reality as again, we do not have this information yet.
BentBlogger: You also considerably extended tire-sales. What is special about the tires you offer?

Gingko owner

Gingko owner

Lutz: In essence, we yet do „only“ have the standard repertoir of different manufacturers as Schwalbe, Panaracer and Continental. However, our focus is of course primarily the sporty, fast tire plus some accessories. Our target group is crystal clear here: the fast rider. But there are some exceptions.
We included the Vredestein Moiree and the Panaracer RibMo in our shop, rather for the winter months. The first one is a popular and safe tire for wet conditions and mud. The latter one is THE mile-eater. With an acceptable weight of 350g, the RibMo can be ridden a third longer than comparable tires. Unfortunately, we did not yet manage to have it produced as a 406 tire.
Joggl: We almost made it to get the RibMo in 406. That would have been a hit. Unfortunatley, Panaracer withdrawaled shortly before production begin. But we keep picking on them, as with all other projects.
BentBlogger: There are rumours that you will soon offer the legendary Rinkowski-tire in Ertro 406. Is this right and what is so special about this tire?
Joggl: Here we are dependent on Matthias (BentBlogger:a user from the It should already have been produced but timely/family-oriented problems prevented production yet. We hope to have it produced in summer. However, this tire has to age for a year anyhow (just like a good vine;-)) before it is send to the light of the world. It is planned to make it in 35mm width or even slimmer, not in 47mm as the original. First, there will be a 20” version (ERTRO 432), maybe also a 26”. It is a tubed tire, this should be clear to everyone. The record riders are already waiting for this tire. We expect the rolling resistance of this tire to be smaller due to the steel cord than that of a Michelin Radial (Eco-Shell-Marathon)
BentBlogger: Which other parts will be definitely available in the next future, and which open projects are you still working on?
Lutz: Again, we will concentrate on wheels for special bikes in the next time. We believe that there is still a high potential for development.
There will be additional chain idlers. But sadly, this will rather happen in the second half of the year. Our aim is to deliver better durability and to reduce weights. The design will change significantly as well.
Joggl: I think of our ultra-light clincher rim. It is about 267g in 26”. A 20” variant is possible here. Would be nice to have a 20” rim with 210-215g. The rim looks pretty solid. Further, there will soon be titanium axes for the struts. In the subject of carbon fibre rims we now have contact to a rim manufacturer who delivers the quality we expect. We are also currently working on new carbon cranks. We thought of 150mm long ones here. Then there is another crank project we are working on. But we had to postpone it to 2014 for time reasons. Our target specification here is to have these cranks even lighter and stiffer than anything else on the market. Additionally, we think of responding to customer’s wishes with regard to crank length here. We are also thinking of using shorter axles to finally end up with sensible q-factors. Before all these new products can be sent to the customers, all of these parts will be tested by dedicated riders. The cranks will also be tested by a specialized lab.
BentBlogger: There was an interesting recumbent frame by Lutz. Will we see a commercial Gingko recumbent in the future?
Lutz: In spite of the fact that I am frequently obsessed by new bikes, I hardly have the time for this. A B2B tandem would be a big challenge. My ideas for this are in a quite elaborate status. But such a project would rather not aim at a commercial product, alas to my opinion, there is a market for B2B tandems.
Well, I think, for time-related reasons, you cannot convert all ideas to real items. Apart from this, there are meanwhile so fantastic recumbents on the market, I can hardly cope with that. Thus, we will rather continue to concentrate on components.

BentBlogger: So it only remains to say good luck for the future and thanks a lot for this interview.
Lutz: Thank you very much for your interest in our projects.
Joggl: Yes, thank you very much, also to our customers.


Comments (1)


Trommelremmen met een dynamo zou ik direct voor tekeken. Dynamo in combinatie met een kleine accu is zulk een krachtig iets voor een velomobiel.

RodePioneer, 30 Apr 2013 13:32 2.0

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