Comments for Bicycle Design http://bicycledesign.net Sat, 04 Feb 2012 09:28:21 +0000 hourly 1 http://wordpress.org/?v=3.3.1 Comment on Mohsen Saleh’s RWS recumbent by Mohsen http://bicycledesign.net/2012/02/mohsen-salehs-rws-recumbent/comment-page-1/#comment-25498 Mohsen Sat, 04 Feb 2012 09:28:21 +0000 http://bicycledesign.net/?p=2863#comment-25498 Thank you Wuss and Petter for the links :) Andy!!! I do have sympathy with you about hub-less designs, and if i dont manage to stable this bike i would agree with you also for RWS one as well. take it as an experiment... Thank you Mike, @Victor...you are right, stability is the main issue with RWS designs, and actually the main reason that i began building this prototype was to investigate stability of my 4 bar linked steering mechanism. the first try was not as i expected but I am hopeful that with this configuration i would be able to build a bike that is stable in low speed as well as higher one. Thank you Wuss and Petter for the links :)

Andy!!! I do have sympathy with you about hub-less designs, and if i dont manage to stable this bike i would agree with you also for RWS one as well. take it as an experiment…

Thank you Mike,

@Victor…you are right, stability is the main issue with RWS designs, and actually the main reason that i began building this prototype was to investigate stability of my 4 bar linked steering mechanism. the first try was not as i expected but I am hopeful that with this configuration i would be able to build a bike that is stable in low speed as well as higher one.

]]> Comment on Mohsen Saleh’s RWS recumbent by Peter Eland http://bicycledesign.net/2012/02/mohsen-salehs-rws-recumbent/comment-page-1/#comment-25497 Peter Eland Sat, 04 Feb 2012 09:07:16 +0000 http://bicycledesign.net/?p=2863#comment-25497 Victor, the Rohloff is a lovely hub but how would it fit into a front drive like this? The pedals need to be attached to the same axis as the hub axle, and to rotate together. The axle joining them needs to be pretty hefty to resist pedalling forces, and the frame attachment also needs to be completely different (similar to a unicycle, hence the first comment). You would have to fundamentally redesign it, in fact the R&D effort would be no less than for making an entire new hub gear. ISTR that Kretchmer (referenced in the HUPI link above) did actually propose a suitable hub gear design with dimensioned drawings back in the late '90s - it'll be in his patents somewhere. But getting a working hub gear made is beyond the resources of most experimenters. BTW the Velayo is a commercially available rear steer trike which seems stable up to pretty good speeds, using a more elaborate linkage: scroll down to the last picture in the first link below for a look - not shown well on their own website. http://www.velovision.com/showStory.php?storynum=1011 http://www.fortschritt-fahrzeugbau.de/produktkonzept.htm Victor, the Rohloff is a lovely hub but how would it fit into a front drive like this? The pedals need to be attached to the same axis as the hub axle, and to rotate together. The axle joining them needs to be pretty hefty to resist pedalling forces, and the frame attachment also needs to be completely different (similar to a unicycle, hence the first comment). You would have to fundamentally redesign it, in fact the R&D effort would be no less than for making an entire new hub gear.

ISTR that Kretchmer (referenced in the HUPI link above) did actually propose a suitable hub gear design with dimensioned drawings back in the late ’90s – it’ll be in his patents somewhere. But getting a working hub gear made is beyond the resources of most experimenters.

BTW the Velayo is a commercially available rear steer trike which seems stable up to pretty good speeds, using a more elaborate linkage: scroll down to the last picture in the first link below for a look – not shown well on their own website.

http://www.velovision.com/showStory.php?storynum=1011

http://www.fortschritt-fahrzeugbau.de/produktkonzept.htm

]]> Comment on Mohsen Saleh’s RWS recumbent by Victor Ragusila http://bicycledesign.net/2012/02/mohsen-salehs-rws-recumbent/comment-page-1/#comment-25496 Victor Ragusila Sat, 04 Feb 2012 02:25:45 +0000 http://bicycledesign.net/?p=2863#comment-25496 Also as a follow-up, a modified Rolhoff might be really neat as a transmission system. Right now the 1:1 gear is the 11th, and most are slower. If there is a way to modify the hub such that it starts from 1:1 and goes to 1:5.1 it would make this transmission very nice and efficient. Also as a follow-up, a modified Rolhoff might be really neat as a transmission system. Right now the 1:1 gear is the 11th, and most are slower. If there is a way to modify the hub such that it starts from 1:1 and goes to 1:5.1 it would make this transmission very nice and efficient.

]]> Comment on Mohsen Saleh’s RWS recumbent by Victor Ragusila http://bicycledesign.net/2012/02/mohsen-salehs-rws-recumbent/comment-page-1/#comment-25495 Victor Ragusila Sat, 04 Feb 2012 02:22:28 +0000 http://bicycledesign.net/?p=2863#comment-25495 Unfortunately, stability is one of those things that you either do well, or dont bother building a bike. It seems so far that RWS is possible for slow speeds, but fails at higher speeds. I know track racers can ride their bike backwards, but i am not sure how fast. I look forward to see if anything comes out of this project. Unfortunately, stability is one of those things that you either do well, or dont bother building a bike. It seems so far that RWS is possible for slow speeds, but fails at higher speeds. I know track racers can ride their bike backwards, but i am not sure how fast. I look forward to see if anything comes out of this project.

]]> Comment on Mohsen Saleh’s RWS recumbent by Impossibly Stupid http://bicycledesign.net/2012/02/mohsen-salehs-rws-recumbent/comment-page-1/#comment-25494 Impossibly Stupid Sat, 04 Feb 2012 00:58:16 +0000 http://bicycledesign.net/?p=2863#comment-25494 I'd rather have the trike version. I long for an adult Green Machine . . . I’d rather have the trike version. I long for an adult Green Machine . . .

]]> Comment on Mohsen Saleh’s RWS recumbent by Mike http://bicycledesign.net/2012/02/mohsen-salehs-rws-recumbent/comment-page-1/#comment-25493 Mike Fri, 03 Feb 2012 23:18:05 +0000 http://bicycledesign.net/?p=2863#comment-25493 I wouldn't necessarily agree with that. First of all, he actually built this thing, which is more than can be said of any of the "designers" who have drawn hubless wheels we've seen on this blog (other than the university team who just wanted to see if they could do it). Second, I think he's identifying known issues with current recumbent designs (long chain runs, complex steering linkage, unsuitability for urban use due to size, personal sizing requiring either complex fittings for contact points or lots of design work for each size), not fixing what ain't broke. I think this is an awesome project, and even if working out stable steering geometry for this design turns out to be impossible he will have achieved a huge amount by proving that. I do think that the upper limit for how steep a grade you can climb on a front hub drive recumbent when the road is wet or unpaved is going to end up being impractically low. However, people have already worked on chain front drives with front steering that move the front wheel farther aft, so that nut can be cracked later when the rear steering is worked out (though of course a shorter wheelbase will change the steering). I wouldn’t necessarily agree with that. First of all, he actually built this thing, which is more than can be said of any of the “designers” who have drawn hubless wheels we’ve seen on this blog (other than the university team who just wanted to see if they could do it). Second, I think he’s identifying known issues with current recumbent designs (long chain runs, complex steering linkage, unsuitability for urban use due to size, personal sizing requiring either complex fittings for contact points or lots of design work for each size), not fixing what ain’t broke. I think this is an awesome project, and even if working out stable steering geometry for this design turns out to be impossible he will have achieved a huge amount by proving that.

I do think that the upper limit for how steep a grade you can climb on a front hub drive recumbent when the road is wet or unpaved is going to end up being impractically low. However, people have already worked on chain front drives with front steering that move the front wheel farther aft, so that nut can be cracked later when the rear steering is worked out (though of course a shorter wheelbase will change the steering).

]]> Comment on Mohsen Saleh’s RWS recumbent by Andy http://bicycledesign.net/2012/02/mohsen-salehs-rws-recumbent/comment-page-1/#comment-25491 Andy Fri, 03 Feb 2012 20:41:07 +0000 http://bicycledesign.net/?p=2863#comment-25491 RWS is the new hubless wheel RWS is the new hubless wheel

]]> Comment on Mohsen Saleh’s RWS recumbent by Peter Eland http://bicycledesign.net/2012/02/mohsen-salehs-rws-recumbent/comment-page-1/#comment-25490 Peter Eland Fri, 03 Feb 2012 20:10:37 +0000 http://bicycledesign.net/?p=2863#comment-25490 Thanks James. I meant front steer not front drive in my first comment of course! Thanks James.

I meant front steer not front drive in my first comment of course!

]]> Comment on Mohsen Saleh’s RWS recumbent by James Thomas http://bicycledesign.net/2012/02/mohsen-salehs-rws-recumbent/comment-page-1/#comment-25489 James Thomas Fri, 03 Feb 2012 19:58:59 +0000 http://bicycledesign.net/?p=2863#comment-25489 Interesting links! Thanks, Peter. ...I'll just add that <a href="http://www.velovision.com/" rel="nofollow">VeloVison Magazine</a> is always a great source for information about recumbents, folding bikes, work bikes, etc. Check it out if you are interested in such. Interesting links! Thanks, Peter.

…I’ll just add that VeloVison Magazine is always a great source for information about recumbents, folding bikes, work bikes, etc. Check it out if you are interested in such.

]]> Comment on Mohsen Saleh’s RWS recumbent by James Thomas http://bicycledesign.net/2012/02/mohsen-salehs-rws-recumbent/comment-page-1/#comment-25488 James Thomas Fri, 03 Feb 2012 19:56:10 +0000 http://bicycledesign.net/?p=2863#comment-25488 I don't know any serious unicyclists, but I am familiar with Schlumpf drive. I have mentioned it <a href="http://bicycledesign.net/2008/09/strida-mas-special-signature-edition/" rel="nofollow">on this blog</a> a <a href="http://bicycledesign.net/2010/09/friday-links-6/" rel="nofollow">couple of</a> times before...and I agree that it could work well for an application like this I don’t know any serious unicyclists, but I am familiar with Schlumpf drive. I have mentioned it on this blog a couple of times before…and I agree that it could work well for an application like this

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