"Do the Ton" rear sets - Lets do them cheap - No takers???
- Thread starter dixiedevil
- Start date
dixiedevil
Active Member
a friend did these... thought id see what yall thought about them...
andrew embassy
Been Around the Block
dixiedevil said:
Dude, those are brilliant.
dielectric
Grouch.
Honestly, I don't see those clamp-on rearsets working well at all. Even if you could reef them down hard enough to not slip, they'd cause some nasty stress risers in the tubes and likely lead to failure. The 6061 will probably strip out in the process anyway. The note about rubber bushings just made me giggle. Ever see those aero bars that bolt onto a road bicycle? No matter how tight you get 'em, they still slip if you pull hard enough, and that's just regular bicep force. If you knurl the inside to get a bite into the tube, that will certainly cause stress discontinuities and probably failure.
The only way I'd feel good about them is to snug 'em down then weld or braze the clamps to the tubes.
Edit:
I hate jerks on the Internet that tell you not to do stuff. So, I was in the shop and those little clamps kept rolling around in my head. It occurred to me that, given that he wants to make the clamps from 6061 and M/C frames are steel, welding is out. However, it's commonplace to glue airplanes together. Not that silly 5-minute stuff at the hardware store, but if one found some really good industrial epoxy, it stands a good chance of working. I'd round the edges of the clamps so you don't get a burr digging into the tubing, and take the paint off of everything before proceeding. Paint probably doesn't adhere as well as the epoxy should.
The only way I'd feel good about them is to snug 'em down then weld or braze the clamps to the tubes.
Edit:
I hate jerks on the Internet that tell you not to do stuff. So, I was in the shop and those little clamps kept rolling around in my head. It occurred to me that, given that he wants to make the clamps from 6061 and M/C frames are steel, welding is out. However, it's commonplace to glue airplanes together. Not that silly 5-minute stuff at the hardware store, but if one found some really good industrial epoxy, it stands a good chance of working. I'd round the edges of the clamps so you don't get a burr digging into the tubing, and take the paint off of everything before proceeding. Paint probably doesn't adhere as well as the epoxy should.
This is good to get some ideas and thoughts brought up...the drawings that Dixiedevil posted did say they were initial concepts. Like dielectric said, the rubber may not be the swiftest solution - perhaps the clamps collars are machined for particular frame size. After all that is just a pass of the ball nose cutter. However, I do think clamps would work. Do a quick look online, and even on this forum, for people who have used frame clamps from dennis kirk, or even mtb bicycle stem clamps. Here is a quick example:
http://dotheton.com/index.php?topic=6149.msg67826#msg67826
If one went as far as knurling the inside, I would be amazed if it caused frame failure due to stress - if this was the case people handlebars, or even their triple tees would be snapping left right and center. If a clamp can hold the force and weight of a motorcycle on a polished fork leg, then it should be able to hold your leg resting on the peg. Also, the forces to pull/strip the bolt from the 6061 is quite considerable. I've used Aluminum rearsets on racebikes with smaller bolts and no issues. Perhaps, and correct me if I am wrong here Dielectric, you're concern is stripping the threads from torquing down the clamps a huge force (to presumably keep them from slipping). The clamps would not need that much force, but I can see how that would, and is, an concern well made.
Dielectric does bring another good idea with the welding option. While the aluminum can't be welded to the frame, there is nothing to say that some tapped steel bosses can't.
Oh..and the bonding thing.I have more faith in a mech. clamp when it comes to metals , but that's a personal bias and subjective at best. I've found that strong bonds are either really brittle and can't handle vibrations well, or if they are designed for vibrations then they are pretty elastomeric (which would create similar issues to the rubbver shim/sleeve). If bonding can perform as well or better, then they speak for themselves. I'd be interested to see the specs on that stuff and it could be a great and clean way to do it. We have some really interesting bonding solutions we've used in our engineering department for various problems, so I am all ears to hear about new stuff.
Hanly has a neat idea with the pinning. A pinned arm with a tension plate to hold the angle could reduce the amount of material needed. I'd probably want to put a press fit sleeve into the hole to help with the forces and the frame. There are press fit inserts for sportbike swingarms, so I am not too worried about a press fit insert placed in one of the downtubes of a heavy steel frame.
Discussions and ideas amongst people help refine a product...so let's keep tossing some thoughts dixidevil's way
http://dotheton.com/index.php?topic=6149.msg67826#msg67826
If one went as far as knurling the inside, I would be amazed if it caused frame failure due to stress - if this was the case people handlebars, or even their triple tees would be snapping left right and center. If a clamp can hold the force and weight of a motorcycle on a polished fork leg, then it should be able to hold your leg resting on the peg. Also, the forces to pull/strip the bolt from the 6061 is quite considerable. I've used Aluminum rearsets on racebikes with smaller bolts and no issues. Perhaps, and correct me if I am wrong here Dielectric, you're concern is stripping the threads from torquing down the clamps a huge force (to presumably keep them from slipping). The clamps would not need that much force, but I can see how that would, and is, an concern well made.
Dielectric does bring another good idea with the welding option. While the aluminum can't be welded to the frame, there is nothing to say that some tapped steel bosses can't.
Oh..and the bonding thing.I have more faith in a mech. clamp when it comes to metals , but that's a personal bias and subjective at best. I've found that strong bonds are either really brittle and can't handle vibrations well, or if they are designed for vibrations then they are pretty elastomeric (which would create similar issues to the rubbver shim/sleeve). If bonding can perform as well or better, then they speak for themselves. I'd be interested to see the specs on that stuff and it could be a great and clean way to do it. We have some really interesting bonding solutions we've used in our engineering department for various problems, so I am all ears to hear about new stuff.
Hanly has a neat idea with the pinning. A pinned arm with a tension plate to hold the angle could reduce the amount of material needed. I'd probably want to put a press fit sleeve into the hole to help with the forces and the frame. There are press fit inserts for sportbike swingarms, so I am not too worried about a press fit insert placed in one of the downtubes of a heavy steel frame.
Discussions and ideas amongst people help refine a product...so let's keep tossing some thoughts dixidevil's way
man, how much pressure you guys putting on your rear sets?! i have run clamps on them in the past several times without any issues... only real pressure they see is when i stand up on them every once in a while to get some blood flow to my legs, VERY rare... if you have that much pressure on your rear sets i think i would look at body possition while riding and figure out a better spot to possition them... either way... everything that i have ever seen kodiak do just rocks! if you are worried about them sliding on the frame use a small piece of emry cloth under the clamp... i have CNC'd many many sets of custom risers and when they are used on bars without knurling a small piece of emry cloth will allow the clamp to really bite in and not scratch the piss out of the paint/chrome
Flugtechnik
My bike is not transportation, it is a respite
andrew embassy said:
I agree. These are pretty cool, and adjustable even.
I don't think the frame would have much of an issue supporting these and your weight. These old bike frames are pretty stout and not designed for minimum weight like the new sportbikes. They were designed to provide the stiffness needed for good handling and safety. Even with a knurled clamp, they should be fine.
I can see a potential for rotating about the frame, and agree with Joe that a simple stake pin would fix that.
I do however share the concern with stripping the threads in the clamp from trying to tighten it down too hard. I have stripped several holes that were threaded in aluminum and fear it would probably happen here as well. Not sure how you would fix that. That's why I'm a stresser and not a designer.
Flugtechnik
My bike is not transportation, it is a respite
kodiak said:
Or maybe just have the bolts go through from the outside with nuts on the inside. Some nice pretty socket heads. I'm all about "form follows function".
Really nice design work though. I wonder how much all those pieces would cost to make. Maybe source the pegs/bearings and fab the rest.
I have a anodizing/paint shop; if this project comes to fruition I can chromic acid anodize them for you guys.
Also. . . if you need a machine shop to pound out a few pieces I'm sure some of my clients would do gladly overlook some of the BS set up fees they normally charge.
PS. AL and SS stock is surprisingly cheep right now and most shops are looking for work !!
Also. . . if you need a machine shop to pound out a few pieces I'm sure some of my clients would do gladly overlook some of the BS set up fees they normally charge.
PS. AL and SS stock is surprisingly cheep right now and most shops are looking for work !!
jeckel30 said:
Dig the screen name bro... is that your last name? I catch shit all the time cause my last name is Heckle!! All the way through Marine Corps boot camp my drill instructors kept asking me where Jeckle was, so just to spite them I named my rifle Jeckle!!