Re: General 5-Star Build - Fast 50cc Single-speed

Mikey Antonakakis /
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Chapter 9 - Small Things and First Test Ride

With the footrests done, there were plenty of other little things that got worked on to get it ready for a first ride. Stuff like adding an anti-rotation tab for the rear brake plate, as well as a cable mount/stop onto the brake plate itself. Nothing fancy, don't think I got any pictures of that.

Got the throttle mounted to the bars, realized I needed better spaces for the cheapo clip-ons from Treats. The General fork tubes are 26mm, and even though the clip-ons were advertised for that size, they kinda bottomed out, even with the spacers included in the kit. I cut up some thicker round tube stock to copy the spacers, much better. Might still need some sort of anti-slip compound, but they're okay for the time being.

Got the petcock, fuel lines, etc., all hooked up, air filter mounted, rear brake cable installed and adjusted, all that last little stuff. It fired up on the second kick!

Here's a shot from the first test run:

IMG_20190821_185446.jpg

No good video from that day, but the stock Pro Sr clutch was slipping at what sounded/felt like 8000rpm. Engine simulations showed a huge dead spot there, and the acceleration matched the sims. The road I was testing gets zero traffic, but it's short, so for a while never got out of the clutch slip while I messed with the needle.

I finally managed to get it above the 25mph or so for the clutch to engage by going around the block a bit, and when it finally climbed out of that dead spot and came onto the pipe, holy cow! It pulls HARD. At least as hard as my 65mph 50cc Peugeot, which has the clutch and variator absolutely dialed for maximum acceleration.

That Pro Sr. clutch setup, though, won't work at all for Colorado Springs. Plenty of 10% or greater grades in the area, plus 20% less oxygen than at sea level (means 20% less power), it simply won't climb them much faster than walking speed, slipping the clutch the whole time.

Two main options to deal with this: engage the clutch at a much lower speed, like 4000rpm. That's somewhere around 13-15mph with my current gearing (16:57 primary with 10:60 sprockets, geared for about 50mph at 15,000rpm). The sims show a dip in the torque at 8k, so at lower engine speed there is more torque, so easier to accelerate up to clutch bite. At that point, I may still struggle to blast up hills, but if I can climb into that dead spot at 8k, I'd at least be doing ~25mph which is the speed limit on most of those start-from-a-stop hills anyway. If I encounter a faster hill on a bigger road, no problem, I'm already on the pipe and can blast up it without issue. Not a terrible option, and can be improved immensely with something like ATAC or a trombone pipe (future projects once the bike is more complete). It's the "reliable" route, and conveniently the clutch springs from the KTM 50 SX Mini Adventure (significantly down-tuned version) swap right into the stock clutch, and should be set up for 4k-5k operation.

The other option is to raise the slip speed - I have a Tomar clutch on hand for this, much better than the stock three-shoe. It's set up for about 9500 out of the box, and has a good amount of easy adjustability (springs can be tensioned without removing the clutch, and options for spring size, too). By 9500, the engine should be making good torque again, making it no trouble to blast up hills (albeit loudly). Butt dyno on that first test ride tells me there's not a hill in the area that can stop me with this setup. But really tough on the clutch.

Here's a crappy flyby video, but you can at least hear it come onto the pipe:

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Subject Written By Posted
  General 5-Star Build - Fast 50cc Single-speedTopic by: Mikey Antonakakis Mikey Antonakakis 09/03/19 03:20PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 03:32PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 04:14PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 04:21PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 04:46PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Overpriced Parts Overpriced Parts 09/03/19 05:10PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 05:19PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 06:08PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 06:22PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 06:32PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 06:41PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 06:49PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 06:55PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 06:59PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 07:05PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 07:13PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/03/19 07:43PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Aaron Blair Aaron Blair 09/03/19 09:23PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Johnnie Distefano Johnnie Distefano 09/04/19 12:39PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/04/19 03:44PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Chris Squid Chris Squid 09/04/19 08:25PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: ken gilbert ken gilbert 09/05/19 05:32AM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 11:03AM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 11:23AM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 11:39AM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 11:47AM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 12:07PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 12:19PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 12:25PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 12:32PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 12:37PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 12:43PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Brandon Weiss (Detective brandon to you) Brandon Weiss (Detective brandon to you) 09/05/19 12:44PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 02:17PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: alex . alex . 09/05/19 02:03PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 02:20PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 02:26PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: ken gilbert ken gilbert 09/05/19 02:22PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 02:33PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 02:41PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 03:09PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 03:15PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/05/19 03:47PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/06/19 01:18AM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/06/19 01:46AM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/12/19 11:03PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/14/19 10:21PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Born to be WillD Born to be WillD 09/18/19 07:33PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/18/19 07:49PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Alex Hedrick Alex Hedrick 09/21/19 02:30PM
  Re: General 5-Star Build - Fast 50cc Single-speedRe: Mikey Antonakakis Mikey Antonakakis 09/21/19 10:16PM

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