Rear Derailleur Protector

[am4zin]

hey all,

im a 2nd year engineer at warwick and for one of our modules we've been put into groups of five and been told that we have to come up with an idea, research if the product/service is viable and then to draw up a business plan so we can do a sales pitch to our lecturers (Y)

anyway, an idea i had was to make some sort of protector for the rear derailleur, because apparantly riders have been known to misperform big sidehops, and then screw up their rear derailleur (i wouldnt know, because i can only sidehop to the left and even then i cant do anything higher then a curb!).

i'm sort of thinking along the lines of the sort of guards that you had on your old apollo when you were a kid, although i'm pretty sure you need special mounts on your frame to put them on.

does anyone know if these sort of things are actually available, and if not is there a reason why?

any feedback or even other ideas i could look into would be great;

sorry to all those who thought that when they clicked on this thread they'd have a nice easy post to read through!

dan

[Blackghostknife]

I think they are available in action-bikes.. i think anyway cause was thinking about them like last year (Y)

[ollie]

hi first of all good luck

and you don't need special mounts on your frame for them ones from when you wer a little kid

i still have my bike, well it in bits (i kept it for spares) and the protector just goes onto the skewer/axel behind where the druraller (sp)? goes

hope this helps

ollie

[MaXsteri]

Although its not the same style, Onza do a derailleur saver. Although i've never seen it for sale or found any more information about it.

That might be more along the lines of what you should be thinking about? As the old apollo style protectors are very very basic which might get you a lower grade?

[djb]

I tried bodging one of those cheapy ones off a crap bike onto mine. With a bit of fiddling you can use the QR skewer to hold it on but it rotates round if you hit it hard and the wheel would come loose on occasions. You would need to find some way of connecting it the bike so it was rigid, bearing in mind no trials specific frames have those lugs for panniers or any other area where one could be attached.

Another problem is they only protect the side of the mech. If you're sidehoppding up stuff and come up short you tend to land on the back or the bottom of the mech which is not protected. I've broken so many barrel adjusters you wouldn't believe. You can't simply extend the tubing below the mech and bend it over as it would crush up into the mech and even using metal sheet to make a box wouldn't be strong enough unless it was really thick and then you're looking at a really ugly and heavy component that's just not worth it.

Personally I can't see their being a big demand for such a product especially with most modern trials riders being obsessed with weight!! Sorry to make it sound like your idea's shite, i'm not saying it is - i'd love there to be a way of not knackering my mech so often but i think it would be very difficult to come up with something that did the job. You've got to remember the ones on cheapy bikes are so the mech doesn't brake when you drop the bike on the floor, in trials the impact would be much greater and also from a completely different angle.

Don't let this put you off, the sign of a true designer and engineer is someone who can make the seemingly imossible and prove everyone wrong.

Daniel

[am4zin]

djb, i like the point you made about landing the derailleur ON to the object you're trying to sidehop on; what if you made the protector so that it's basically a U-shape, with one end so that it attatches to the rear axle/skewer, and then having the other end press against the bottom of you're rear stay, if you see what i mean - in the middle of this U-shape will be you're derailleur.

i was studying the picture of the onza saver that maXsteri posted, and i think if one end of the U-shape could attatch to both the rear axle/skewr, and also the point on the rear hanger that the derailleur attatches to, then that should the guard pivoting around (i think!)

[djb]

I think I know what you mean and if i'm understanding you right it could work, though i'm still not sure about durability. Any chance of you scribbling on that onza image to make it a bit clearer what your thinking?

[wayneone]

djb, i like the point you made about landing the derailleur ON to the object you're trying to sidehop on; what if you made the protector so that it's basically a U-shape, with one end so that it attatches to the rear axle/skewer, and then having the other end press against the bottom of you're rear stay, if you see what i mean - in the middle of this U-shape will be you're derailleur.

i was studying the picture of the onza saver that maXsteri posted, and i think if one end of the U-shape could attatch to both the rear axle/skewr, and also the point on the rear hanger that the derailleur attatches to, then that should the guard pivoting around (i think!)

Thats a realy good idea. Id buy one forsure if it was light enough, I hate it when mechs get bashed. (Y)

[am4zin]

I think I know what you mean and if i'm understanding you right it could work, though i'm still not sure about durability. Any chance of you scribbling on that onza image to make it a bit clearer what your thinking?

i jus spent the last 5 minutes on paint drawing in the protector but i dont know how to insert images into posts!

[wayneone]

Go to a site like photobucket.com make a account. Then upload your image from your hard drive. Then come on here theres a picture of a tree click on that and paste the url of the picture in there and heypresto. (Y)