And is 90-100 rpm a good absolute TOP speed?
...still not exactly sure how I'm going to mount it because the downtube on my bike frame goes from a vertical oval, 0 to o to a horizontal oval, and thats just weird mounting for me...
mrderekcu wrote:So i drew up a CAD model of the reduction system, still not exactly sure how I'm going to mount it because the downtube on my bike frame goes from a vertical oval, 0 to o to a horizontal oval, and thats just weird mounting for me.
There is a visual representation of what I aim to do, the misaligned sprocket from the motor to the 60, I will fix by just flipping the sprocket 180. The motor is ridiculously close to hitting the inner wall, I may just do away with the extra motor mount, I also have a 63-54 without a skirt bearing I can use.
The gray washer looking thing is a flanged bearing.
The mount is adjustable for the motor as well as one shaft, this will allow me to account for any chain "stretch" along the way.
Any tips or comments are appreciated, and well needed to be honest
If you used 14t-60 for your primary reduction, compounded with a 12-60 your overall ratio's would be the same and it would be quieter.mrderekcu wrote:I will be using a two-stage reduction, taking that 6250 rpm and turning it into about 97ish rpm at the cranks through a 12-60 compounded with a 14-60 and finally a 16 to 48. The 48 tooth being the final one on the cranks.
mrderekcu wrote:I will be using a two-stage reduction, taking that 6250 rpm and turning it into about 97ish rpm at the cranks through a 12-60 compounded with a 14-60 and finally a 16 to 48. The 48 tooth being the final one on the cranks.
MitchJi wrote:If you used 14t-60 for your primary reduction, compounded with a 12-60 your overall ratio's would be the same and it would be quieter.
No. I meant that you are planning on using 12t-60t on your primary reduction and 14t-60t on your secondary reduction. The main combination of factors that increase chain noise are small sprockets combined with high rpm. So if you used 14t-60t on your primary reduction (bigger drive sprocket on your higher rpm primary) and 12t-60t on your secondary reduction you would have the same final ratio and a quieter system.mrderekcu wrote:I'm not sure what you mean by your first statement. Do you mean 250 rpm at the cranks?
I think the #25 will be fine, but if not I'd switch to #219 (smaller pitch than #35):mrderekcu wrote:#25 chain, weak I know, but I was trying to save money. I can always switch em out if it comes to that, the #35 ones
Matt wrote:You would be surprised how long that #25 chain lasts. My recumbent has over 1,000 miles on it with the same #25 chain. The PK Ripper has 500 miles of HARD abuse on it without any issues, no stretch, no tooth wear.
I just use light oil. I also neglect my recumbent chain because it is hard to get to. I lube it when the links start to bind. Even with that neglect, the chain is fine. Plus, this chain is so innexpensive, it is no biggie to replace it every couple years or so.
I run extra heavy-duty #25 chain from scooter parts.com. That chain is freaking DIRT CHEAP! I beat the crap out of that chain and in over 1,000 miles, have not worn one out, yet. But, it is so cheap, who cares!
...You will find that the position in which the chain and the sprockets engage fluctuates, and the chain vibrates along with this fluctuation. Even with the same chain, if you increase the number of teeth in the sprockets (change to larger diameter), vibration will be reduced. Decrease the number of teeth in the sprockets and vibration will increase...
Figure 2.14 Speed Variation Versus the Number of Sprocket Teeth