99cc rack mount 3 speed spoke drive MTB
- Thread starter silverbear
- Start date
I wouldn't say that I'm worried about it, but I am aware of it and that it will be different from what I'm accustomed to. I think it having 24" wheels will be better in that respect than if it had 26" ones. The engine isn't terribly heavy, nothing like an old Briggs or Tecumseh, but heavy enough. I have thought to myself while putting this together that a better engine choice would have been a 50cc Huasheng which is very light. Had one, but sold it. With the gears and spoke drive it might make the perfect little trail bike.
I do think that having the engine centered will be a help in keeping it balanced. I guess that road time is what will tell in the end. If I hate it then I can change the components over into a cantilever Schwinn with the engine in frame and the drive hub on the seat post. I could be wrong, but I think it will be okay, though. This has more to do with proof of concept and experiencing the 3 speed S.A. as a spoke drive hub than it is to make a great cruiser. Guess, we'll find out, eh?
SB
I do think that having the engine centered will be a help in keeping it balanced. I guess that road time is what will tell in the end. If I hate it then I can change the components over into a cantilever Schwinn with the engine in frame and the drive hub on the seat post. I could be wrong, but I think it will be okay, though. This has more to do with proof of concept and experiencing the 3 speed S.A. as a spoke drive hub than it is to make a great cruiser. Guess, we'll find out, eh?
SB
That's why I like to see what Cannonball 2 is up to. Always interesting.
Welcome to the forum, by the way...
SB
Thanks for the inquiry about Mom SB. She has taken a sharp downward turn and is nearing the end I believe. Will probably transfer to hospice today from the nursing home. I have promised her to do all possible not to let her linger on, so faced some tough decisions about with holding sustaining care. I hope she goes quickly, she never wanted to be in this situation.
The Schwinn bike with a similar engine install was easy enough to ride so that my wife rode it many times with no issues with balance or handling. If any were going to show up it would be with her. Many people took it for spins before I converted it to an inframe. I agree the 24" wheels will lower the CG/ balance point considerably. If the jackshaft runs to the extreme back of the rack there should be clearance to run the belt forward to the hub swung either off the front of the rack swing arm style or post mounted. Using the smallest pulleys you can for the return belt will keep clearance issues down.
Run your clutch to the 6" pulley on the outside the return with 3" on the inside if a 3 will work with the hubs sprocket, mine may have been a 3.5. With the hub on a swing arm off the rack then the hubs driven pulley will be inside the arms. The swing arm can be made what ever length to get the hub where you want it between the seat post and tire. A threaded rod can be added to the hub and an anchor point on the seat post to add driving tension. Looks workable, Im sure there will be kinks to iron out.
The Schwinn bike with a similar engine install was easy enough to ride so that my wife rode it many times with no issues with balance or handling. If any were going to show up it would be with her. Many people took it for spins before I converted it to an inframe. I agree the 24" wheels will lower the CG/ balance point considerably. If the jackshaft runs to the extreme back of the rack there should be clearance to run the belt forward to the hub swung either off the front of the rack swing arm style or post mounted. Using the smallest pulleys you can for the return belt will keep clearance issues down.
Run your clutch to the 6" pulley on the outside the return with 3" on the inside if a 3 will work with the hubs sprocket, mine may have been a 3.5. With the hub on a swing arm off the rack then the hubs driven pulley will be inside the arms. The swing arm can be made what ever length to get the hub where you want it between the seat post and tire. A threaded rod can be added to the hub and an anchor point on the seat post to add driving tension. Looks workable, Im sure there will be kinks to iron out.
CB2 wrote:
"Thanks for the inquiry about Mom SB. She has taken a sharp downward turn and is nearing the end I believe. Will probably transfer to hospice today from the nursing home. I have promised her to do all possible not to let her linger on, so faced some tough decisions about with holding sustaining care. I hope she goes quickly, she never wanted to be in this situation."
Sorry to hear about your mom, Ben. I know what you're going through is hard. It may happen everyday all over the world, but that doesn't make it any easier. Your mom's choice is also what mine will be when the time comes, trying to be graceful about leaving this world.
SB
"Thanks for the inquiry about Mom SB. She has taken a sharp downward turn and is nearing the end I believe. Will probably transfer to hospice today from the nursing home. I have promised her to do all possible not to let her linger on, so faced some tough decisions about with holding sustaining care. I hope she goes quickly, she never wanted to be in this situation."
Sorry to hear about your mom, Ben. I know what you're going through is hard. It may happen everyday all over the world, but that doesn't make it any easier. Your mom's choice is also what mine will be when the time comes, trying to be graceful about leaving this world.
SB
This is where we are at beginning of the day. I have re-positioned the rack, raising it at the front end as much as it will go and have moved the side supports to both raise the rack to level and also make room for the jackshaft pillow block bearings. I've also returned the stock air filter now that the engine is aimed the right way and removed the stock exhaust. I stole the exhaust manifold I made for the 99cc Predator and will make up a new one for it when I pick up another cast iron street elbow and have the welder out. The pipe is cobbled together from conduit with copper water pipe inside it and a copper coupling at the muffler which was cut off of a China girl muffler. Don't know how good that muffler will be, but at least the exhaust is pointing the right way. I have also removed the governor hardware and begun making up the bits for controlling the carb with a China girl twist throttle.
So, I have set the engine in place where I think it needs to be and will make the holes in the rail slotted so that the engine can be moved a bit fore and aft for tightening the belt from clutch to jackshaft. While the pillow block bearings for the jackshaft will mount from the side of the rails, I have one sitting on top to indicate where it will be located. Lots of slow drilling today in mounting up the jackshaft as that bed rail is hard stuff. I also have a length of flat stock for making up the swinging mount for the 3 speed hub drive which will sit under the tail end of the rails and engage the wheel at about the mid point. The arms will be drilled for mounting springs attached at the other end at the rear wheel axle area to provide tension for the spoke drive against the tire tread.
Also pictured is a 1960's Sturmey Archer twist grip shifter for the 3 speed transmission. This was missing a couple of parts and had no cable, but I found that a new cable for a derailleur could be modified by filing down the lead "button"at the end of the cable that fits inside the shifter. The knurled fitting the cable fits in to came from a Shimano shifter. The only thing left is to find the right sized ball bearing for inside the S.A. shifter. Install that and it will be as good as new and even better since it is vintage. It will go on the left handlebar.
Things are coming together.
SB
So, I have set the engine in place where I think it needs to be and will make the holes in the rail slotted so that the engine can be moved a bit fore and aft for tightening the belt from clutch to jackshaft. While the pillow block bearings for the jackshaft will mount from the side of the rails, I have one sitting on top to indicate where it will be located. Lots of slow drilling today in mounting up the jackshaft as that bed rail is hard stuff. I also have a length of flat stock for making up the swinging mount for the 3 speed hub drive which will sit under the tail end of the rails and engage the wheel at about the mid point. The arms will be drilled for mounting springs attached at the other end at the rear wheel axle area to provide tension for the spoke drive against the tire tread.
Also pictured is a 1960's Sturmey Archer twist grip shifter for the 3 speed transmission. This was missing a couple of parts and had no cable, but I found that a new cable for a derailleur could be modified by filing down the lead "button"at the end of the cable that fits inside the shifter. The knurled fitting the cable fits in to came from a Shimano shifter. The only thing left is to find the right sized ball bearing for inside the S.A. shifter. Install that and it will be as good as new and even better since it is vintage. It will go on the left handlebar.
Things are coming together.
SB
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I got the 3/4" holes for the jackshaft drilled today which was no minor task. The bed rails are very hard metal. I also cut the two swing arms and will get them mounted tomorrow with slots cut for the geared roller drive. It appears that the engine will need to be offset just a wee bit for the clutch pulley and jackshaft pulley to align perfectly, but I think I'll wait until the pulleys are all mounted before drilling the engine bolt holes. With the pulleys in place I can measure for belt lengths and know right where the engine needs to go. Engine bolt holes will be slotted fore and aft to tension the primary drive belt and the hub drive slots will allow tensioning of the final drive belt. The jackshaft will be in a fixed position.
Curt says he has found both a 4" and 3" pulley for the inside of the jackshaft. I think the 3" would be good and then buy a matching 3" weldable pulley for the 3 speed hub (weld to the sprocket). Gearing ratio is established by the clutch pulley and 6" standard pulley mounted to the outside of the jackshaft.
Added oil to the engine crankcase lest I forget later on. Also just about done setting up the carburetor throttle control. Tomorrow is to be another day of sunshine so there should be some good progress. Getting closer...
SB
Curt says he has found both a 4" and 3" pulley for the inside of the jackshaft. I think the 3" would be good and then buy a matching 3" weldable pulley for the 3 speed hub (weld to the sprocket). Gearing ratio is established by the clutch pulley and 6" standard pulley mounted to the outside of the jackshaft.
Added oil to the engine crankcase lest I forget later on. Also just about done setting up the carburetor throttle control. Tomorrow is to be another day of sunshine so there should be some good progress. Getting closer...
SB
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Thank you every one for the best wishes for my Mom! Have just about finished taking care of her affairs. Death is a major ordeal legally! Its all good though every thing is in order and it just a matter for time to bring to close the wonderful life she has had.
Ok no more death talk. Its a wonderful thing this hobby we share here Its a great way to relieve stress(sometimes) and keeps the mental processes going.
SB looks like you finally have it coming together. Since you are using flange bearings instead of pillow the shaft is going to get pretty close to the mount rails. Will the jackshaft pulley align with the hubs pulley and not hit the rail?
Ok no more death talk. Its a wonderful thing this hobby we share here Its a great way to relieve stress(sometimes) and keeps the mental processes going.
SB looks like you finally have it coming together. Since you are using flange bearings instead of pillow the shaft is going to get pretty close to the mount rails. Will the jackshaft pulley align with the hubs pulley and not hit the rail?
"SB looks like you finally have it coming together. Since you are using flange bearings instead of pillow the shaft is going to get pretty close to the mount rails. Will the jackshaft pulley align with the hubs pulley and not hit the rail?"
Do you mean whether or not it will hit the top of the rail? I think it would, so where it would will need to be cut away to give clearance. Or do you mean will it hit the side of the rail? If need be I can move the whole rail mount a bit to one side or the other as I have washers acting as shims at the front end of the rails. Or am I not understanding your question?
SB
Do you mean whether or not it will hit the top of the rail? I think it would, so where it would will need to be cut away to give clearance. Or do you mean will it hit the side of the rail? If need be I can move the whole rail mount a bit to one side or the other as I have washers acting as shims at the front end of the rails. Or am I not understanding your question?
SB
Drilled holes for mounting the flange bearings and the swing arms for the hub drive. Have yet to cut slots in the swing arms for mounting the hub drive, but everything appears to be lining up okay. I'll cut away over final drive pulley at the jackshaft on the right hand rail once I have the pulley in hand and can see how much needs to be cut away for belt clearance.
Tomorrow rain is forecast so I'll make a run into town for bolts of the right length, a ball bearing for the shifter and a couple of springs for putting tension on the swing arms.
I also did some initial work on a new exhaust manifold and will pick up hardware for that tomorrow. I ordered a small engine sausage shaped muffler to screw onto 3/4" pipe and that will be here Tuesday. What I cobbled together with the China girl muffler is pretty rough and I don't know how well it would have worked anyway as it looked restricted inside and could not easily be opened up for freer flow. With a four stroke it could do without a muffler, but I'd like to keep the neighbors (including the wild things) relatively undisturbed by my activities.
After that it will be a matter of waiting for pulleys to be in hand, doing some measuring for belts and then giving it a run. Finishing the throttle will be simple, the shifter and cable will go easily enough, adjust brake cables and then see how the roller drive works... dial in the adjuster so that it hits all three gears and I guess that's it. Maybe a bottle generator and a simple head and tail light for visibility in the evening hours. Might also run up a little flag pole off the back to make myself more visible. Hook up the kiddie trailer for Miss Mooshy and ride off into the sunset on me new to me pony.
Time also to put the 99 Predator back into the Panther and get that up and running. Summer is almost here and I'm ready to ride!
SB
Tomorrow rain is forecast so I'll make a run into town for bolts of the right length, a ball bearing for the shifter and a couple of springs for putting tension on the swing arms.
I also did some initial work on a new exhaust manifold and will pick up hardware for that tomorrow. I ordered a small engine sausage shaped muffler to screw onto 3/4" pipe and that will be here Tuesday. What I cobbled together with the China girl muffler is pretty rough and I don't know how well it would have worked anyway as it looked restricted inside and could not easily be opened up for freer flow. With a four stroke it could do without a muffler, but I'd like to keep the neighbors (including the wild things) relatively undisturbed by my activities.
After that it will be a matter of waiting for pulleys to be in hand, doing some measuring for belts and then giving it a run. Finishing the throttle will be simple, the shifter and cable will go easily enough, adjust brake cables and then see how the roller drive works... dial in the adjuster so that it hits all three gears and I guess that's it. Maybe a bottle generator and a simple head and tail light for visibility in the evening hours. Might also run up a little flag pole off the back to make myself more visible. Hook up the kiddie trailer for Miss Mooshy and ride off into the sunset on me new to me pony.
Time also to put the 99 Predator back into the Panther and get that up and running. Summer is almost here and I'm ready to ride!
SB
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Looking good SB! The swing arm mount should work well. Due to the moment arm the loading to the tire should be quite good with lower tension on either springs or rods. Maybe a pair of springs from the mounting struts to a point past the axles center line by an inch or so. If you anchored the springs to a pair of eyebolts at one end you could adjust the tension. The springs will still allow a bit of flex for tire run out.
Now that the mechanics have been worked out should go together pretty quickly. This will truly be the proof of concept of this idea as it will be the first build with a torquey 4 stoke.
Spend time getting the gear selection perfect there is a very fine line between getting second and not. Set the cable when the preload on the tire has been established and be sure the cable anchor is mounted to the swing arm. The hub should last a long time as its not under the loading(if Im thinking correctly) it would be in the wheel pedaling even.
Now that the mechanics have been worked out should go together pretty quickly. This will truly be the proof of concept of this idea as it will be the first build with a torquey 4 stoke.
Spend time getting the gear selection perfect there is a very fine line between getting second and not. Set the cable when the preload on the tire has been established and be sure the cable anchor is mounted to the swing arm. The hub should last a long time as its not under the loading(if Im thinking correctly) it would be in the wheel pedaling even.
CB2,
Thanks for the encouragement! The next few days should see progress and then it will be a matter of waiting for the pulleys, measuring for belts, bolting the engine in place... final tweaking and LIFTOFF. While waiting I'll put the panther back together.
SB
Thanks for the encouragement! The next few days should see progress and then it will be a matter of waiting for the pulleys, measuring for belts, bolting the engine in place... final tweaking and LIFTOFF. While waiting I'll put the panther back together.
SB
Rain off and on so I'm doing inside stuff. Having robbed the exhaust manifold from the panther I'd like to give it back and make a new one for this new engine.
Photos show what I'm up to. I removed the new muffler from the new exhaust manifold and you can see what at odd configuration it is. Using the side grinder with a cut off wheel I cut away all but the basic flange which bolts to the engine, ground away the former weld and opened up the 3/4" opening slightly at the front edge.
At the hardware yesterday I bought a 3/4" cast iron 90 degree street elbow, meaning that at one end it has female threads and at the other male threads. I checked to be sure the threading was compatible for a 3/4" copper male coupling to fit into the female end of the iron fitting. Yes, they fit together. I can cut a section of 3/4 copper water pipe to fit, give it a female copper fitting at the other end which will receive a small engine muffler.
Today I ground away the threading on the male end of the cast iron fitting which will get welded to the exhaust manifold flange. Took a little while with the grinding wheel and I did it on a taper so that it fits inside the flange, but is thick enough at the outer edge to receive a good weld. What I had done for the Panther was basically the same, but instead of copper I was using conduit so I could bend a much longer pipe in a pipe bender to conform to the panther frame. It had no muffler and just had a fishtail at the end of the pipe.
(cont.)
SB
Photos show what I'm up to. I removed the new muffler from the new exhaust manifold and you can see what at odd configuration it is. Using the side grinder with a cut off wheel I cut away all but the basic flange which bolts to the engine, ground away the former weld and opened up the 3/4" opening slightly at the front edge.
At the hardware yesterday I bought a 3/4" cast iron 90 degree street elbow, meaning that at one end it has female threads and at the other male threads. I checked to be sure the threading was compatible for a 3/4" copper male coupling to fit into the female end of the iron fitting. Yes, they fit together. I can cut a section of 3/4 copper water pipe to fit, give it a female copper fitting at the other end which will receive a small engine muffler.
Today I ground away the threading on the male end of the cast iron fitting which will get welded to the exhaust manifold flange. Took a little while with the grinding wheel and I did it on a taper so that it fits inside the flange, but is thick enough at the outer edge to receive a good weld. What I had done for the Panther was basically the same, but instead of copper I was using conduit so I could bend a much longer pipe in a pipe bender to conform to the panther frame. It had no muffler and just had a fishtail at the end of the pipe.
(cont.)
SB
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