OBP Pedal Box- Accelerator Cable Bike Carbs

[MikeB]

I've had an attempt at fitting the accelerator cable to my OBP pedal box.
I'm really not happy with it.

I was using a mountain bike brake cable, but I'm not convinced this is going to be robust enough.

Currently I drilled a whole in the pedal arm and have the adjuster sitting above it.
Current issues are:

1. As the cable comes through the adjuster the angle varies a lot, when in the zero throttle position its at its worse. First picture shows this
2. There's no pedal stop to stop the pedal coming back past 0 throttle,
3. Not enough return spring from the carbs spring only (zx6r carb), so pedal feel isn't good and slow to return. Not a nice snap back feel it should have. So I need to find a way of getting a second spring in there somewhere.
4. I have a solderless nipple on the pedal end that isn't great and if it comes loose will be a complete pita.

http://farm9.staticflickr.com/8336/8364416030_1fd8c265b6.jpg (http://www.flickr.com/photos/62740914@N04/8364416030/)
20130105_151940 (http://www.flickr.com/photos/62740914@N04/8364416030/) by mjb22001 (http://www.flickr.com/people/62740914@N04/), on Flickr

http://farm9.staticflickr.com/8370/8364416110_0fb4fd711c.jpg (http://www.flickr.com/photos/62740914@N04/8364416110/)
20130105_151928 (http://www.flickr.com/photos/62740914@N04/8364416110/) by mjb22001 (http://www.flickr.com/people/62740914@N04/), on Flickr

I want to get it right next time as I need to permanently fix my side panels and scuttle and don't want to be down there once thats done.

Any pics of a OBP to help me out towards a better solution.

Thanks

[Oscar]

For the return spring, could you weld a small bracket belom the pedal mounting point, with the spring extending under the swivel point? This would only need to be small and should fit under without fouling.

I definately dont like the look of the cable, needs some way of either moving the exit point from the tube further away, or altering the existing mount so that it can swivel.

All depends on how much you want to modify the existing setup. easiest way to ensure throttle return would be another/stronger spring on the carbs. All race-going cars are required to have at least 2 for safety.

[voucht]

Might be stupid remark (sorry if it is :p ), but regarding your point 3. are you sure the nylon locknut of the pedal pivot is not too tight, which would explain the slow return? Loose the nut until you get a play, and tighten it just until the play disappears, not more.
I had a quick check on Internet, and I found this forum. The guys have the same problem as yours, and one of them publish pictures of his solution. I think using a car throttle cable is actually a good idea. Then he welded some bits to fit it, as well as a pedal stop bolt.

http://bbs.22b.com/forums/showthread.php?3990-Obp-pedal-box

Hope this will help :)

[robo]

Upper pedal stop is a must, without it you could get nipples jumping out of their location hole. No throttle can be as dangerous as a stuck full throttle. Pedal spring return is best done with one of these torsion springs on the pedal fulcrum point, then there is no undue strain on the throttle cable and linkage.
http://www.lesjoforsab.com/technical-information/torsion_springs_id537.jpg

bob

[Oscar]

Told you there'd be smarter people than me along :D ;)

[MikeB]

thanks peeps.

The solution inthe pictures is unfortunately a different design so the cable can come in form the back of the pedal box, mine seems to be top entry type and I've yet to see a solution for that type.

Hopefully there is enough room on the pedal to fit a torsion spring as that would be the easiest solution