Riff Ratt

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Joined
Jan 21, 2009
Messages
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Location
Zambales, Philippines
It's already almost noon here, 13 hours ahead of CST.
I'm going to add this to Class 2 because I'm going to cut the rear off this frame and replace it with a suspension.
Using this frame and accumulated parts, it will look like trouble is coming to town, like riffraff. Hence the name "Riff Ratt". It'll have some shiny parts but still have patina.
I usually get up around 6 and drink coffee and sit around. Today I laced up the wheels for this bike. 57mm rims, new SS spokes and a pair of Jetson style hubs I've been saving. A pair of 26 x 3 tires I brought over from Hawaii folded up in a box will look good on those rims. The wheels just need a truing at the bike shop.
The front is a Sunlite springer that will get some modification also.
frame parts.jpg


It only took 30 minutes to lace both wheels.
wheels.jpg


tires.jpg
 
Great parts collection brother!! Especially for the Philippines.
I like the build name too.
 
I'll cut the rear end off the frame where the lines are drawn, then flatten the ends and drill 3/8ths holes to mount the shocks to the seat stays and the one piece chain stay. Then round off the ends.
new - Copy.JPG

That's the plan right now. Instead of two chain stays, it has to be one piece to give it some strength, it will loop around at the front where it mounts up and then the shocks will have struts that attach to the stay somewhere along the length, where ever the angle of the movement fits between the top and bottom. I'll have to lay it out and see where everything would line up. I want to lower the rear so the seat tube slants backward, this frame has a steep angle like a road bike. I may have to make the stays longer and add some stretch. That will change the angle of the forks too, they may have to be lengthened so the pedals don't scrape.
 
I picked up a heavier set of cottered cranks and may do the two speed conversion using another chain wheel from before. I'm still not decided, may just do a single freewheel.
new cranks hubs - Copy.JPG

Another look at the hubs, I have to remove the spacer for a cluster when I use a single cog. I have 20, 22, and 24 tooth cogs to choose from. With the weight I think this bike will be, probably a 22 with the 44 chain wheel will give the right ratio. 56 gear inches. If I use the extra chain wheel which is 40 tooth, I'll have a low gear of 51 gear inches but I'll need to use the tensioner I have. It may not fit the look I'm after.
rp8 20 mar 21 - Copy.JPG
 
You're keeping us in 'suspens-ion' with that rear end mod! Great pile o' parts to start!

RaT oN~!
 
I cleared out my office to use the tiled floor as a graph. Crude engineering. I wanted to see how the angles would work and make adjustments to my ideas. I wanted the seat tube to slant more and it looks like it does, about 35 degree angle. I'll use a laidback seat post so I can sit flatfooted.
mockup 2 May.JPG

The front wheel will sit differently after I add extensions. The tire is touching the crown here. The tire will sit where the line on the tile is. It can go an inch or two higher if I need more pedal clearance. I had a pair of extensions made before, but I need new ones with some finesse to them.
The rear mockup showed some changes I need to make to my plan. It's a good thing I didn't cut the stays off yet. It wouldn't have worked, the angle of the shock would have been way off.
rear may 2.JPG


I may cut the seat stays back at the dropout and have the shop put a nice bend in them that follows the curve of the cantilevers in the front, only curving upward. Somewhere along that upward curve would be the best spot to drill a hole to mount the shocks, then trim off the rest to make the seat stays.
This shows the angle of the chain stays, the pivot point is up near the cranks, so the shock must be in line with that. The shock can mount anywhere along the chain stay but closer to the hub would look better and probably be stronger.
angle May 2.JPG


The wheels still need to be trued, but all my budget is gone until June getting my bike bunker done. I'll be using a band brake on the rear as the only brake as of right now.
wheels 2 May.JPG
 
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The band brake doesn't give much stopping power, so I thought a fixie hub would be just as good. Then I had an idea. :39: I could use two freewheel cogs, one on either side along with 2 chain wheels and get the same effect as the fixed hub. Since it's a cottered spindle, both sides are identical, I can put a chain wheel on both sides and run two separate chains. Then I would just apply backward pressure to try to stop, like a fixed hub. The cogs and chainwheels wouldn't have to match up. I would use a 24 tooth cog and 40 tooth chainwheel for the rearward motion to get the most leverage. I'll also have reverse. Maybe two forward speeds. I'll have to get another crank as one is shorter than the other.

dual chainwheels 2 May.JPG
 
Something didn't seem right so I spun the wheel to see how it did. With 2 opposite cogs it's got no freewheeling back or forth. A fixie of course. I should've known that. So the chainwheels and cogs must match up. I've got two 44 tooth chain wheels and two 24 tooth cogs so that's the plan. That's only 51 gear inches. I'll change that if it's too low. I'll order a new chainwheel because one has a much longer arm. They don't specify the arm length so whichever old one matches the new one will get used.
3 May frame mod.JPG

After rechecking a few times, I made the first cuts to the frame. I'm saving all the parts I cut off in case it's some kind of valuable frame that was left at the city scrapyard for years. :rofl:
The swingarm (chain stays) will be one piece and attach just behind the chainwheels with a bolt that runs through both sides. The seat stays (with dropouts attached) will arc upward high enough to provide the mounting point for the shocks and struts. I kept the drops on to give as much leeway as possible for setting the angle of the shocks. Excess will then be cut off and the edges rounded. It sounds easy but I know that issues will arise.
 
Sweet build. I have a similar but different situation for a solid swinging chainstay. I think I'll be using a repurposed fork if I can find one the correct width. It's just an idea...

GC.
 
Something didn't seem right so I spun the wheel to see how it did. With 2 opposite cogs it's got no freewheeling back or forth. A fixie of course. I should've known that. So the chainwheels and cogs must match up. I've got two 44 tooth chain wheels and two 24 tooth cogs so that's the plan. That's only 51 gear inches. I'll change that if it's too low. I'll order a new chainwheel because one has a much longer arm. They don't specify the arm length so whichever old one matches the new one will get used.
View attachment 156125
After rechecking a few times, I made the first cuts to the frame. I'm saving all the parts I cut off in case it's some kind of valuable frame that was left at the city scrapyard for years. :rofl:
The swingarm (chain stays) will be one piece and attach just behind the chainwheels with a bolt that runs through both sides. The seat stays (with dropouts attached) will arc upward high enough to provide the mounting point for the shocks and struts. I kept the drops on to give as much leeway as possible for setting the angle of the shocks. Excess will then be cut off and the edges rounded. It sounds easy but I know that issues will arise.
Dual drive
 
Sweet build. I have a similar but different situation for a solid swinging chainstay. I think I'll be using a repurposed fork if I can find one the correct width. It's just an idea...

GC.
I've got a BMX fork that might work. I'll check it out. That would save me getting the metal fab shop to make up something.
 
My largest fork is a 26" BMX style fork, too narrow for the 3" tire at the top of the fork. But a 29" fork would work, or extensions on the ends, it only needs an inch to fit, and the brake bosses need to be removed or used for brakes.
It would easily be stout enough as a swingarm.
 
I was listening to that same song when I came up with the name. I was playing that because I remembered an incident at my work center after I was called up after 9-11. Since I was National Guard, the active duty sergeants were siphoning off their "problems" into my section to boost their own ratings. I wound up with a bunch of riffraff who weren't capable of doing the job without constant supervision. I hate constant supervision as much as micromanagement. We handled most of our business over the phone and one airman was afraid to talk on the phone among other things. We were getting bad reviews by the customers. I only had one good worker left out of seven. I realized what was going on and mentioned that to my officer in charge "They're throwing us all the @#$% riffraff!" He went straight to the Squadron Commander and told him the exact same thing I did, including the "colorful" language. I thought I was going to get chewed out, but over the next couple weeks, our riffraff went back to their own sections and we got some quality airmen back in the section.
I'll crank up some AC/DC a little later, the live version of Riffraff. it's only 8am here.
 
It looks like the BMX fork will work. I cut off the brake bosses and laid it out to see how it looked. The shocks will bolt to the dropouts, but there will be an extension where the wheel bolts to, a few inches back from the shocks are. If the tire needs more clearance the fork can be spread open a little further, there's no axle width to worry about on the ends.

The big thing is the pivot point where the fork bolts to the frame. It has to be a good solid fit so there's no left and right play in the swingarm. I'll have the chain stays flattened and squared up in line with the frame (red arrows) , then have 3/8ths holes drilled for the thru bolt. The fork tube is round but it has to be square to mate up to the chain stays. I think the best way would be to weld on a piece of square stock just above the crown. (yellow circle) Then with a bushing or two will make a solid pivot with no play
swingarm - Copy.JPG
 
Doing some more thinking. I've got a long way to go before I can spend any money so there's a lot of different ideas so far.
Instead of the struts on the springer, I have 2 more of those little shocks that will make it a real springer, not just knee action. I need to make up the struts and flanges. The flanges I'll just make out of cardboard and let the steel fab shop cut them out. It will be a dual action springer.
8 springs.jpg

8 springs counting the seat springs.
Then I changed my mind and will go with a band brake instead of fixie. Only two chain wheels, both on the same side. Safety first and I'll have a freewheel with 2 speeds. I may have some kind of friction brake as an extra.
 

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