Minarelli Builders Thread

Great info! Looking forward to getting more time on mine, situations interfere at the moment. From what I have ridden this thing is sweet. Guess I will have to go to the 3 spring clutch. Will finish break in first. I have hit the pipe (right at 40 like you say) and what a bunch of power it seems to have. Didnt let it band, but it shows what potential it has.
 
Here a couple pics of my clutch pads. It appears the slip occurs on the back side. On the base plate and not on the outer plate.
I guess this would be typical for any slipping clutch… the slip happens inside?

The inside of the pads is cooked well done. The side facing out looks fine.

I wonder if flipping the pads will buy a few more miles where it bites better… OR..are they already well done?

The slip only happens when I put a WOT load on the clutch. This happens above 45mph.
Maybe the clutch is talking to me. It’s telling me to chill. No need to go that fast. If I’m smart I’ll listen to it.
 

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I’m on my second Minarelli vertical top end. The first.. piston ejected the ring pin at 225 miles. I suspect excessive vibes probably contributed. No telling for sure. It was a cheap Aliexpress Chinese kit.

This new kit is an Athena.. kit 070100. I have put 100 miles on it.
I balanced & trued the crank this go round and it made a significant difference to the good. Vibes are way less.
The engine has a VM20 with 110/32.5 jetting… still very rich through the entire throttle range. Temperature stays between 160-185F.
The pipe is a modified to fit jog pipe..$65.
I did a few hard rips to see what’s up with it.
Whereas my first cast iron kit topped out at 48 mph this Athena kit seems to just be getting primed to go. Now that it’s fairly well broken in the power on top end is unreal for a motorized bicycle.

When it gets to about 42-45 mph the pipe is hitting and it just keeps climbing hard. The problem I’m having is it slips the clutch at about 46..47..48-49 mph. I have the clutch spring tightened all the down, I’m running 10 RDM hard pads, and 5 of the white CG upgrade pads. It’s time for a better clutch if I intend to run it up. It holds well as long as I don’t hold it open above 45 mph.

I have no doubt once the clutch issue is solved this thing will be capable of going way in to the 50mph range easily. I’m not sure I have the cajonnes to hold it pinned. This is on a 38T sprocket. I think the engine can handle a 36T with no problem.

I was looking for a little more power and Cannonball3 sort of put me on this Athena kit. It’s way more than I expected. I doubt I look for more. I can no longer say I’m under powered. The engine is a little monster now. 😁
I’m curious to see how Cannonball3’s kit like this performs when it’s broken in.
I’ve gotten a lot of advice from Cannonball and cherry picked threads throughout this site on performance builds.
You need a 3 spring clutch plate. Similar to how a motorcycle clutch pack is.
 
Here a couple pics of my clutch pads. It appears the slip occurs on the back side. On the base plate and not on the outer plate.
I guess this would be typical for any slipping clutch… the slip happens inside?

The inside of the pads is cooked well done. The side facing out looks fine.

I wonder if flipping the pads will buy a few more miles where it bites better… OR..are they already well done?

The slip only happens when I put a WOT load on the clutch. This happens above 45mph.
Maybe the clutch is talking to me. It’s telling me to chill. No need to go that fast. If I’m smart I’ll listen to it.
Rough up your back plate with 100 grit sand paper, then rough up pads with 80grit sandpaper, reassemble & test. Will get you by for a while. Till you make a 3 spring clutch which is easy to do.
 
The other thing I've read, is to use a v-belt or flat belt for your clutch pads. They are super grippy thou, & you lose some clutch slipping ability. But the v-belt/flat-belt clutch pads holds power really well without slipping.
 
The pads I have havent slipped yet. When I ran the Zeda 40mm crank the pipe hit pretty hard, harder than the 38mm and there was no slip. As I mentioned the pads I have look like automotive brake lining. Tan hard material with wire. Not saying its not gonna slip but hasnt so far. I have the 3spring ready to go even cut a cover for it. I know folks cut brake material from disc brake pads, might give that a try.
 
I am running the RDM hard pads. I ordered them the same day Cannonball posted he ordered the RDM head.
You get 10 in the pack. I put all 10 in and used 5 of the CDH pads shown above.
It holds well until the pipe hits pretty good.
I’d guess it begins somewhere around 40+ mph or 7,500-8,000 rpm’s. When it starts slipping it’ll keep on until I back off. Every time it happened I back off immediately.

Maybe I’ll try the belt pads.

I watched the vids on making the 3 spring clutch. It does not seem overly complicated except for sourcing the springs.

Even trying a stiffer preload spring… sourcing the correct spring isn’t all that easy
 
So finally got a bit more ride time in. Went ahead and let it band for a bit. Nick is right, life begins at 40. The engine is super sweet in all ranges. Pulls a 38t easily as low as 13 mph on our crappy gravel road. Good mid range after you hit the needle from 20 or so til it bands at 40. In fact 40 is a sweet spot for extended cruise, feels like it would go all day.
Once you venture past forty hang on. This top end at least on my build is never snappy. It build power fast but not with a snap like the cast iron top. In fact for whatever reason, it never breaks the clutch. Dont know why but Im not complaning. The idle is low and consistant, in fact it idles so low you just know its gonna quit, but it never does.

So for a quick ticket to the 50+mph club this is it. The Athena, properly built with a good balanced crank(Smoliks is great),
good bearings , a cheap modded jog exhaust, a VM20(mines a good clone and has run perfect)and a bit of case matching. You are there.
 

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So I will add the band was still climbing, dont know for how long but it wasnt all in. I backed out thinking what might happen to these aged bones if something on the bike gave up. The mental picture wasnt pretty, especially in sandals and shorts!
 
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