Predator 79 Transmission Options?
- Thread starter ColdCruiser
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ColdCruiser
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Man!That sounds like a rough trip you had!
Glad you and Maggie got home safe and sound.
Now you have some work to do this week.
Hope you get it all figured out and get you and Maggie's chin in the wind and your knees in the breeze!
Keep looking up! Ken.
It was exciting for sure. I don't know why I thought it would be a good idea to try and go that far. I suppose I just wanted to make sure it was broken-in and would then be reliable. It's not.
It will be awhile before I'm back on the road again. It needs a few hundred $$ worth of attention. I miss it already. The best part has been short rides to the grocery store. Many people want to talk about the bike or the dog, ...which are two of my favorite things.
ColdCruiser
Member
Yeah, it sux right after something significant is broken. But, atleast you could pedal the bike back home unlike a motorcycle
Thanks Bakaneko. The pedals are just for looks, lol. They help with climbing hills or getting started while using the engine but that's about it. This thing is a tank. It probably weighs ~100 lbs, plus the trailer and the 75 lb dog. On a good day I could pedal it 2-3 miles on flat ground, ...but this was not a good day.
One of the troubles we had was a flat tire on the trailer. I was able to ride it about another mile and got to a place where my friend with a truck was able to come rescue me. It would have been a long push home (~5 miles).
ColdCruiser
Member
March 25, 2016
Finally saved a little extra dough and got some new kicks for Maggie's trailer.
- 20" x 1.95" instead of 1.7"
- Thick "Thorn Resistant" innertubes
- Knobby off-road / all terrain tires
It ended up setting me back ~$65 but I should have done this right away because it was bound to happen. Why take the extra risk?!?
Finally saved a little extra dough and got some new kicks for Maggie's trailer.
- 20" x 1.95" instead of 1.7"
- Thick "Thorn Resistant" innertubes
- Knobby off-road / all terrain tires
It ended up setting me back ~$65 but I should have done this right away because it was bound to happen. Why take the extra risk?!?
ColdCruiser
Member
GEARING
Initially the bike came with a 30t chainring connecting to a 18t on the rear hub. This was very comfortable to ride until I hookup the 40lb trailer and put the 75lb dog in it, then it started to be not so much fun even just to get going. I replaced the 18t with a 15t (which is as small of a rear cog as I could find) and now it is much more acceptable. Next I tried switching the pedal chainring from a 30t to a 40t but this seemed like a step backwards because it made riding it feel more like pushing a wheelbarrow. So I put the 30t chainring back on. Currently without power and with a loaded trailer, it is possible to pedal it for a couple of miles but not very fast and not very fun.
PEDAL SPEED
Pedaling hard in first gets up to about 7 mph, 2nd gets up to around 10 mph, and 3rd might g0 15 mph (without engine).
CLUTCH
The clutch engages at around 2,500 rpm and the engine idles at around 2,200 so with just a little bit of throttle the wheels start spinning. With the motor geared down from 2500 rpm, it matches the bike speed at about 6 mph. In other words, the bike needs to be going 6 mph before the clutch engages or there will be a series of jolts and some unfriendly sounds while I try to pedal it up to match. I believe this jolt is what initially caused the hub to pull out and the chain to come off. Now with my heavy-duty tug-plate installed the stress of the jolt will be harder on other components (somewhere between the engine and the chainring).
NEW GEARING?
One of the few places left where I think I can change the gearing is the (#35) 33t connecting the clutch. Originally I was worried about the amount of space available in that spot, but now I have everything installed and the exhaust cut to fit correctly. I might be able to switch that gear with a 40t. That is likely the largest gear that will fit. However, the cheapest place I could find the part is on the other side of the country so it will cost $30 to ship the $35 part. A single gear and a little gear reduction is a bit expensive for $65 so I thought I'd ask for some feedback before making that decision.
ENGINE SPEEDS
In first gear the bike gets up to ~15 mph nicely with the load. Second gear will do 20 mph+ and third is useless at under 25 mph. This is more than acceptable. 30-35 mph on a bicycle with a trailer and a dog is faster than I'd like to go. If I ever change my mind, I can remove the governor and give it more that 3,500 rpms! Anyway, I think it would be fine if first-gear only went to 10mph, second to 15mph, and third up to 20-25 mph. ESPECIALLY, if this will make it safer or easier to ride or help with the "big jolt at slow speeds" issue.
Does anybody accelerate from a stop or from very slow speeds? ...or does every motorized bike require you to be moving before engaging the engine?
How would changing the gear mentioned help, if at all?
What other options might I consider? Torque converter from a 49cc? Special clutch adjustments? Cable clutch instead of centrifugal? Friction clutch on the chainring? Something? Ideas or thoughts?
Initially the bike came with a 30t chainring connecting to a 18t on the rear hub. This was very comfortable to ride until I hookup the 40lb trailer and put the 75lb dog in it, then it started to be not so much fun even just to get going. I replaced the 18t with a 15t (which is as small of a rear cog as I could find) and now it is much more acceptable. Next I tried switching the pedal chainring from a 30t to a 40t but this seemed like a step backwards because it made riding it feel more like pushing a wheelbarrow. So I put the 30t chainring back on. Currently without power and with a loaded trailer, it is possible to pedal it for a couple of miles but not very fast and not very fun.
PEDAL SPEED
Pedaling hard in first gets up to about 7 mph, 2nd gets up to around 10 mph, and 3rd might g0 15 mph (without engine).
CLUTCH
The clutch engages at around 2,500 rpm and the engine idles at around 2,200 so with just a little bit of throttle the wheels start spinning. With the motor geared down from 2500 rpm, it matches the bike speed at about 6 mph. In other words, the bike needs to be going 6 mph before the clutch engages or there will be a series of jolts and some unfriendly sounds while I try to pedal it up to match. I believe this jolt is what initially caused the hub to pull out and the chain to come off. Now with my heavy-duty tug-plate installed the stress of the jolt will be harder on other components (somewhere between the engine and the chainring).
NEW GEARING?
One of the few places left where I think I can change the gearing is the (#35) 33t connecting the clutch. Originally I was worried about the amount of space available in that spot, but now I have everything installed and the exhaust cut to fit correctly. I might be able to switch that gear with a 40t. That is likely the largest gear that will fit. However, the cheapest place I could find the part is on the other side of the country so it will cost $30 to ship the $35 part. A single gear and a little gear reduction is a bit expensive for $65 so I thought I'd ask for some feedback before making that decision.
ENGINE SPEEDS
In first gear the bike gets up to ~15 mph nicely with the load. Second gear will do 20 mph+ and third is useless at under 25 mph. This is more than acceptable. 30-35 mph on a bicycle with a trailer and a dog is faster than I'd like to go. If I ever change my mind, I can remove the governor and give it more that 3,500 rpms! Anyway, I think it would be fine if first-gear only went to 10mph, second to 15mph, and third up to 20-25 mph. ESPECIALLY, if this will make it safer or easier to ride or help with the "big jolt at slow speeds" issue.
Does anybody accelerate from a stop or from very slow speeds? ...or does every motorized bike require you to be moving before engaging the engine?
How would changing the gear mentioned help, if at all?
What other options might I consider? Torque converter from a 49cc? Special clutch adjustments? Cable clutch instead of centrifugal? Friction clutch on the chainring? Something? Ideas or thoughts?
ColdCruiser
Member
Yeah, it's up above. It's the fat aluminum channel-looking thing with the axle poking through it.
Nanonevol
Member
The best part is you're having fun and trying new things. Some people think they have all the answers and love nothing more than putting down your creative effort.
ColdCruiser
Member
UPDATE:
Got the beast all put back together and took a test ride w/ the dog. The new gearing is nice because I can accelerate from a standstill (almost). It is quite a bit slower though. First gear is now good up to 12-15 mph, second up to 17-20 mph, and third 24-27 mph. It has a better sound with the new muffler and maybe a little quieter but still pretty loud.
One of the issues I was having is that damn governor! I thought it would just stop revving up once it hit 3,500 rpm, ...but it doesn't! It starts bouncing the rpms around 3.5K-3K-3.5K-3K Whaw-whaw-whaw... it's awful! Unfortunately, since I just got it all put back together I do not feel like taking it all apart to remove the governor. So I disconnected it from the linkage and made a little rod to connect the throttle lever directly to the carb. It now has smooth acceleration! I will set the throttle-stop screw to prevent it from revving too high.
It should be awesome with a new air filter, some tuning, and PERHAPS a little bit of gearing back the other way (on a smaller less expensive gear somewhere!). I feel safe taking it up to 4,500 rpm but when I get around to removing the governor completely and can take it up to 5,500 or 6,500 it should be all the fun I need!
Got the beast all put back together and took a test ride w/ the dog. The new gearing is nice because I can accelerate from a standstill (almost). It is quite a bit slower though. First gear is now good up to 12-15 mph, second up to 17-20 mph, and third 24-27 mph. It has a better sound with the new muffler and maybe a little quieter but still pretty loud.
One of the issues I was having is that damn governor! I thought it would just stop revving up once it hit 3,500 rpm, ...but it doesn't! It starts bouncing the rpms around 3.5K-3K-3.5K-3K Whaw-whaw-whaw... it's awful! Unfortunately, since I just got it all put back together I do not feel like taking it all apart to remove the governor. So I disconnected it from the linkage and made a little rod to connect the throttle lever directly to the carb. It now has smooth acceleration! I will set the throttle-stop screw to prevent it from revving too high.
It should be awesome with a new air filter, some tuning, and PERHAPS a little bit of gearing back the other way (on a smaller less expensive gear somewhere!). I feel safe taking it up to 4,500 rpm but when I get around to removing the governor completely and can take it up to 5,500 or 6,500 it should be all the fun I need!
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ColdCruiser
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