| Author | Message | ||
     Jdemoxb9r |
Anyone know why erik didnt put ZTL brakes on the rear wheel? that would have been pretty cool if they did. | ||
| Piotr12 |
Overkill? Just a thought... | ||
| Jaimec |
Not necessary on the rear. Rear brake is used just to start the weight transfer to the front, then the front brake takes over. Other use for the rear brake is for very low speed maneuvering where you just need slight drag and not the "dropping the anchor" power of the front. Finally, what is the point of moving braking torque to the rim when driving force is still being transmitted through the spokes? | ||
| Nik |
Finally, what is the point of moving braking torque to the rim when driving force is still being transmitted through the spokes? Why transmit driving force through the spokes at all? I've seen perimeter brakes integrated with pullies. A combination pully and brake disc could be mounted in a ZTL fashion.} | ||
| Froggy |
If you want to reduce unsprung weight, you can relocate the rear brake to the front sprocket.  | ||
| Jaimec |
What you're proposing doesn't sound like it would save any unsprung weight at all. You'd either have a HUGE driving pulley (requiring an equally huge primary pulley to maintain the proper drive ratio), OR you'd have arms extending from the rim to a smaller, more reasonable sized pulley that would, by necessity, have to be just as strong as the existing spokes to handle the hp and torque of the Helicon engine. | ||
| Greg_e |
You could use an immense pulley on the rear and a huge pulley on the front to get the ratio you need. Look pretty stupid, but you could do it. The advantage is that you would have a larger circle for the belt/chain to run which would reduce the friction by a small amount. | ||
| Slaughter |
Divine Intervention: If I am supposed to stop, I WILL STOP Just THINK of the weight savings! | ||
| Oddball |
Friction drive maybe? Along with those huge full wheel bearing hubless designs. | ||
| Not_purple_s2 |
A huge belt pulley on the rear wheel could hit the ground at extreme lean angles *coughblast* You'd probably have to switch to chain drive in order to keep it narrow enough not to hit. | ||
| Nik |
Why would the pulley would have to be huge? If designing a new production bike you could integrate the wheel/pulley/brake anyway you wanted and have the gearing be whatever you wanted in the final drive or primary. In theory it would simplify the torque paths and allow a lighter overall assembly. In practice it would pretty much just be engineering bling. I have a pretty clear view in my head of how it would work, though it would be different from the Buell ZTL system. | ||
| Iamarchangel |
You guys are literally re-inventing the wheel. The designs you're talking about were used by NSU, Triumph, etc., in the 1910s. Not that new technology might make it worth revisiting but I would think that adding more length to the drive sequence is not a good idea. The belt strength, belt "whip", tensions would all be affected. But the OP about brakes has possibilities unless the fitting of the pads closer to the swingarm pivot would make it ungainly. | ||
| Iamarchangel |
And then there's this idea:    | ||
| Jdemoxb9r |
sign me up for one of those! or this... http://www.youtube.com/watch?v=yBkIc89gd5U&feature =player_embedded | ||
| Roysbuell |
I want to be on the waiting list for the Buell Blade! | ||
| Jaimec |
"Why would it have to be huge?" C'mon, how to you attach the rear drive pulley to the RIM without it necessarily having to be huge? Unless you're also proposing really tiny wheels too? | ||
| Greg_e |
Oh yeah! like the cars that people mod to have little tiny 10 inch wheels! That would be so kool! Thanks for backing me up on the gear size. | ||
| Midknyte |
And then there's this idea: rasterbation... | ||
| Nik |
C'mon, how to you attach the rear drive pulley to the RIM without it necessarily having to be huge? Unless you're also proposing really tiny wheels too? How do you attach a rear drive pulley directly to the hub?  | ||
| Jaimec |
That's an EASY question. See those six little holes on the hub on the wheel on the right?  What do you suppose bolts into that, hmmmmm? | ||
| Nik |
Must be a really tiny pulley if you're bolting directly to those holes in the hub... | ||
| Jaimec |
I deleted my last comment. That statement isn't worth a response. Look at a picture, then look at a pulley, and YOU figure it out. | ||
| Nik |
There's no reason the OD of the pulley has to be the ID of the rim on a perimeter setup just as why there's no reason the ID of the pulley has to be the OD of the hub on a traditional setup. That's all I'm getting at. | ||
| Iamarchangel |
Well, there are max and min limitations on the size of the pulley. There are weight parameters on any design. And then there is that math thing that always comes up. | ||
| Roysbuell |
Wasn't this a thread about a rear caliper once upon a time? | ||
| Jaimec |
Nik, Draw me a picture, would you? I want to see your design of a pulley mounted to the PERIMETER of the wheel that is the same size as the current pulley. Remember, it has to be LIGHTER than the current design you're trying to replace. | ||
| Nik |
Remember, it has to be LIGHTER than the current design you're trying to replace. The overall wheel/pulley/brake assembly has to be lighter. The weight delta of the individual components isn't important, as long as there is a net decrease in weight and no net gain in inertia. There would have to be something to connect between the ID of the rim and the OD of the pulley. This could be a separate carrier piece, part of the pulley or integrated into the wheel as a compromise (gee, kinda just like how conventional drive systems connect the ID of the pulley/sprocket to the OD of the hub... btw, on an XB the distance from the pulley to the rim is less than the distance from the pulley to the hub; less distance and lower moment = less material = cheaper and lighter.) The brake disc could be a smaller unit mounted inside the pulley to the carrier, pulley, or wheel depending on how the pulley was mounted; or it could be mounted on the opposite side and sized to the full rim diameter. All of this depends on cost, material selection and manufacturability also. Each method has its strengths and weaknesses when approaching the design of the wheel, brake, final drive and rear suspension as a whole. Like I said before, in the end it might not have any appreciable advantages over a conventional setup and just be 'engineering bling.' | ||
| Aptbldr |
Imagine life for the bearings between rims & rest of motorcycle! | ||
| Fresnobuell |
Use the rear brake like normal people and this whole thread is moot. | ||
| Jdemoxb9r |
If everybody just acted like normal people we wouldnt even have the XB's we love so much today. Hell we'd probably be riding in model T's still. |
