Folding Bikes - Copying the Raleigh Twenty?
Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.
ilovebicycling
07-31-06, 01:33 AM
Is there any law against copying the Raleigh Twenty?
I think the R20's frame is a good example of form and function.
With the prices for used R20's going fro around $200 (including shipping), I wonder if it would be better to just copy the design but with new steel tubing?
I don't know much about patent laws, but it's been several decades since the R20 was last produced. Will Raleigh's lawyers cease and desist me if I copy the design?
I believe if you copy it for personal use and don't make a massive assembly line to start selling it you will be all right.
There is one on Ebay now for 50 bucks though...
LittlePixel
07-31-06, 08:24 PM
The main tube is pretty full-on on a twenty and you might encounter problems finding something equivalent, but I agree the idea is seductive in it's way, other than the crappy fold that's being discussed in another forum. I'd try adapting the design to incorporate a good modern hinge, some standard non-imperial measurements and some v-brake bosses. You might be on to something here, though it will still weigh as much as a small walrus.
As to Raleigh sueing. We're english. We don't sue. Well it's unlikely given it's age. But if you were to produce them in their hundreds I'd steer clear of names with the numbers 2 and 0 in them... ;)
The main tube is pretty full-on on a twenty and you might encounter problems finding something equivalent, but I agree the idea is seductive in it's way, other than the crappy fold that's being discussed in another forum. I'd try adapting the design to incorporate a good modern hinge, some standard non-imperial measurements and some v-brake bosses. You might be on to something here, though it will still weigh as much as a small walrus.
It wouldn't weigh so much if you made the frame from chromoly instead of the carbon steel the raleigh was made with. Actually, that's exactly what a Dahon Boardwalk is, and you can get a new one for less than $200.
em
LittlePixel
08-08-06, 09:15 AM
It's true that the boardwalk isn't far off but I think ilovebicycling would want something that looks just right. Might I point you towards BikeCAD (http://www.bikeforest.com/CAD/index.php) over at BicycleForest; If you open the file I've just drafted up (see link to file below) with the BikeCAD application and send it over to a frame builder that uses the same software, they could whip you up a Twenty-clone with little or no bother.
The tubing between the downtube and bottom bracket aren't accurate as the software isn't configured to cope with a non-standard frame like this, but all dimensions are otherwise accurate; 406 wheels, my suspension forks and modern 130mm rear dropout width amend this drawing—but you can edit it to taste.
Don't forget that the stays between the downtube and bottom bracket are a pair and meet near the seat tube not the head tube... Also - the top tube is wider than the head/seat tubes so a more modern 'aero' tube here might fit better so it doesn't need to taper in to the two vertical tubes.
Raleigh Twenty BikeCAD file (http://www.littlepixel.info/twenty/raleigh_twenty.bcad)
http://www.littlepixel.info/twenty/raleigh_twenty_blueprint.gif
If you're seriously thinking about producing something, spend some time with an IP lawyer. My limited understanding is that patents expire after twenty (!!) years. http://www.bl.uk/collections/patents/apply.html#expire in the UK.