Re: Motobecane Stock Variator Tuning: what you need to know

The rules for stock class are bent to benefit some bikes. Like you have to use a stock variator, but you can use whatever clutch. It’s more to level the playing field for puch to hobbit since clutches are a significant wear part, especially if you’re racing and have high stall, it’s kinda rude to force people into original equipment.

Re: Motobecane Stock Variator Tuning: what you need to know

> Daniel '' Wrote:

> -------------------------------------------------------

> The rules for stock class are bent to benefit some bikes. Like you have

> to use a stock variator, but you can use whatever clutch. It’s more to

> level the playing field for puch to hobbit since clutches are a

> significant wear part, especially if you’re racing and have high stall,

> it’s kinda rude to force people into original equipment.

That interpretation is more in line with how the Moped GP stock class rules used to be written, where it had said specifically "stock variator", now it says "Trans: Stock". Which I thought was to address the fact that clutches in a non-variated bike were not included in the original restrictions, but now they are. No jammers or hammers or tomars or whatever. I read it as no aftermarket parts in your trans, including clutches. For example, the way it was written I was going to run a Tomos with Jammer clutches, but that would not fit with the current rules, so now I'll run the modded ZA50 first clutch and a modified stock second. Anything stock can be adapted, like a Peugeot SPX clutch pully onto a Moby, or Hobbit clutch arms into a Moby vario. Just no aftermarket.

Obviously there are going to be different interpretations with such purposefully vague rules. As you can see from this thread and my examples there are ways to work within the stock trans rules and still be successful. I always thought that was the main point and the spirit and fun of the stock class.

Re: Motobecane Stock Variator Tuning: what you need to know

Totally normal JBOT /

I swapped out my clutch bearing on this setup today and man, the new bearing was super tight. Difficult to get spacing right but I got it.

Also added some good bearings to the pulley.

Amazed at how much tighter everything is. Like there’s no old bearing sounds anymore.

Here’s the weird thing....

My tune got crazy after the swap. Acts like it only can variate halfway. Either too light rollers or too strong of a spring. Does swapping bearings in the transmission do that much to a tune if you previously tuned to sloppy bearings? Everything is spinning great, just like my previous tune is gone ????! Idk

And the bike was being a total moby today, just fucking with me, clips going flying and shim combos that didn’t work...

then she cut me and I was gushing blood.

This is the way of the moby and I accept this

Re: Motobecane Stock Variator Tuning: what you need to know

If everything is now super tight vs loose then maybe the resistance would make it so you need more weight to variate? Honestly that doesn't really add up correctly though. It really shouldn't be that different, but who knows. Tons of shit changes with the littlest mods.

Re: Motobecane Stock Variator Tuning: what you need to know

I'm psyched for all these mods to come together and be able to finally test it.

I went crazy with the drill and lightened the fuck outta the clutch drum. 7/8" holes in the face and 1/2" holes all around the perimeter/clutch pad area.

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All the bits of the stock variator are wayyyy heavier than they need to be so I was looking at everything like, how can I make this lighter without fucking it up?

So I also drilled out a bunch in the clutch/vario bell. Being outside of the ball or roller area, this was fair game.

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Re: Motobecane Stock Variator Tuning: what you need to know

Just some tips here for anyone who wants to do the spring mod.

Remove the pads by drilling out the heads of the rivets. Countersink the pads for machine screws with nuts on the inside of the bell.

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Cut back the pad on the tip to expose the metal, drill the appropriate hole and be sure to bevel the corners so it doesn't cut into the added spring.

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Re: Motobecane Stock Variator Tuning: what you need to know

Totally normal JBOT /

That looks awesome! You will be blown away with the engagement. Will be a whole different bike.

I figured out that indeed my tune changed a bunch after just switching from very noisy wobbly clutch and pulley bearings to new ones.

I had to go from 6 lightest varplus to 6 medium weights (never weighed them) and also switched to a weaker spring. Now it seems decent but I have to run it for a bit. Doesn’t sound like a rattly can of bolts at high rpm anymore so that’s cool.

Of course I found a ton of other bullshit I had to fix on the moby, locking up rear brake plate due to a wobbly brake arm, the press fit needle bearing retainer in the clutch hub kept popping out near the cases so I gave it 2 tack welds.

Re: Motobecane Stock Variator Tuning: what you need to know

Totally normal JBOT /

I would have made that hole at the end of the leaf spring smaller to keep the spring from wiggling around as much. They do dance around quite a bit.

Re: Motobecane Stock Variator Tuning: what you need to know

Finally got a chance to weigh out the McMaster ceramic vario balls.

4 balls is at 16.7 grams and is what I have been using.

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I also have a 3 ball guide that would bring it down to 12.5 grams.

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And just for shits, 2 balls in a 4 ball guide would be 8.3 grams. Probably wouldn't variate.

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Re: Motobecane Stock Variator Tuning: what you need to know

Finishing up the work on the clutch bell I added two more posts to contain the moving variator cheek. As someone pointed out previously, if you were to use roller weights instead of the balls, you need to stop the cheek from being able to rotate in the assembly so that it doesn't try to twist and flat spot the rollers. This could either be done by having a cheek with 2 tabs on each side to straddle the posts, or by adding a second post to each side of the bell like I have done.

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Like Jbot pointed out, I also needed to cut down the backside of the posts almost flush to clearance the moving parts on the clutch drum.

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So far I'm pretty happy with the ceramic balls for weights, but figured I should just do this modification now in case I would like to try rollers in the future.

Re: Motobecane Stock Variator Tuning: what you need to know

> weldwizard Jake Wrote:

> -------------------------------------------------------

> Finally got a chance to weigh out the McMaster ceramic vario balls.

>

> 4 balls is at 16.7 grams and is what I have been using.

>

> I also have a 3 ball guide that would bring it down to 12.5 grams.

>

> And just for shits, 2 balls in a 4 ball guide would be 8.3 grams.

> Probably wouldn't variate.

> >

I ran 9g in my roller cage, and you assumed correctly, it did not variate!

I need to do the spring mod, Ill probably give it a go tomorrow

Re: Motobecane Stock Variator Tuning: what you need to know

Totally normal JBOT /

In stock class could you use different springs?

Like a hardware store spring or a scooter contra?

Re: Motobecane Stock Variator Tuning: what you need to know

> JBOT Admin Wrote:

> -------------------------------------------------------

> In stock class could you use different springs?

>

> Like a hardware store spring or a scooter contra?

Yeah, any spring. I currently have no issues with the mousetrap spring though. Didn't want to spend money on doppler spring or make shit more complicated when what I have works.

Re: Motobecane Stock Variator Tuning: what you need to know

Totally normal JBOT /

Someone should try cutting off the hook and the whole spring mount assembly and run a scooter contra.

It’s an amazing difference.

Very easy to do, then you can use literally any compression spring, and it’s much easier to run a slightly longer belt

https://www.mopedarmy.com/forums/read.php?7,3998497,4101739,flat=1#msg-4101739 (edited)

Re: Motobecane Stock Variator Tuning: what you need to know

Totally normal JBOT /

It’s a 2 hour job max. Worth every minute.

After doing all the stock spring mods, this is double better. Sometimes a stronger spring with heavier rollers can really make a bike come to life. (edited)

Re: Motobecane Stock Variator Tuning: what you need to know

Put the clutch drum in the lathe to remove some more material and hopefully balance it a bit. Then I media blasted just to even out the look. If I was worried about it rusting or longevity I would give it a quick squirt of paint, but fuck it, shitty race bike. A lil surface rust won't matter.

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I initially installed the lightest Treats Jammer springs, wasnt even close. Then the heaviest Jammer springs, definitely needed more. Then jumped wayyy up to the red springs from the 2911326 Malossi set.

Daaaaaaaamn! Super dope.

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With all the holes drilled and taken down a bit on the lathe, the clutch drum with springs and pads installed weighs 445 grams, just under 1lb.

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Re: Motobecane Stock Variator Tuning: what you need to know

Totally normal JBOT /

Looks fantastic

Re: Motobecane Stock Variator Tuning: what you need to know

Brandon Weiss (Detective brandon to you) /

That's super cool, but i would think the red springs might prove too much for the surrounding material, since the post is right between two of the holes you made?

Re: Motobecane Stock Variator Tuning: what you need to know

Yeah that's rad

Re: Motobecane Stock Variator Tuning: what you need to know

Wow....that is awesome.

Re: Motobecane Stock Variator Tuning: what you need to know

Nice work gents. Love that Jbot is pushing the limit once again, and laughed at the this is the way of moby and I accept it comment. So true.

Jake you beat me to the drilling. I had intentions of doing all those 1/2 inch holes and the holes just outside of the roller area as well. Also thanks on the ceramic weights! I thought they were like 3.3 or something close to that. I couldnt remember.

As mentioned, most likely you can get away with using a varplus over the stock ramp plates, but its more fun to say you didnt, especially if you win.

Travis was saying he doesnt really care if one uses a doppler clutch pulley cus its the same tech as the SPX pulley, but cheaper made. While I would love to get away with that, I prefer that clutch pulleys not be allowed, as it forces us all to mod and use stock parts. If one did use a clutch pulley, youd have to lock up the stock variator as shown on page 1 I guess though, because an aftermarket variator like a doppler is a no go. The only time these parts become an issue, is if your vying for the podium, and there is a clear advantage. Say if you had a half lap on position 2 and 3. At this point in time, we gotta be doing everything we can within our reach, cus Eds derbi engages at like 9k, is ported well and is fast as shit. I got some reacts when I showed up with a LC MBK 512 cylinder last year, but I had no time to tune it, so it never mattered to most as it wasnt that fast. Again, if you win by a landslide, that's when it matters. (edited)

Re: Motobecane Stock Variator Tuning: what you need to know

and Jbot the contra mod is dope. We can use doppler spring setups however, which is easy for all of those who dont have the wizardry skills you do. they make yellow and white springs now too for lower power or lighter setups that cant quite squeeze the red.

Re: Motobecane Stock Variator Tuning: what you need to know

Yeah like, I don't really have a dog in the fight so I'm just talking out my ass, but it's kind of a bummer the rules basically class out any actual stock 'sold in america' moped and the only way you can be competitive is with one ultra rare late model derbi or by importing a bunch of late model euro parts.

I think if you're in it to win you're probably in the wrong hobby, but it would be nice if a us model av7, 103, or a35 could actually stand a chance, just for the fact that I think this kind of nerding out is part of the fun. I've done the gp200 class in ahrma and it's kinda the same thing, a few dudes have mega $$ cheater bikes and then everyone else fights it out for 7th place ... Personally I think the guys in the pack fighting it out are having more fun but I've never been up front so I can't say. Haha.

Re: Motobecane Stock Variator Tuning: what you need to know

I understand the sentiment. Ill just share my experience from being at i think 8 or 9 MopedGP events.

The amount of riders is never huge, but it has dwindled, and rotated(some leave and new come in). We usually only have around 25-50 riders in total, between all classes. Maybe one of the organizers can correct me on that, but thats what it feels like. Many of us race multiple classes, but this means only 10-20 bikes per class, usually on the low end of that number. This is one reason why there is not a true stock class. Due to the nature of what our riders consist of (moped owners), there is not a ton of racing skill or money in the sport. Most often, its the only racing they have competed in. Its for fun with friends, and overall there is usually only 3-5 people in each class that are truly competitive both in mindset and skill level as a rider and builder. The rest are out there just to have fun, or are disillusioned about what it takes to win. Ultimately, just being there and going around the track is what its about, and as you mentioned, there is fun to be had at different positions in the race. Because of the vast difference in skill and bikes, the pack tends to spread out a bit. Last year, I slapped a puch together to race in the fixed class for my first time ever. I had more fun with my slower poorly tuned bike, trying to out ride and pass 5th 4th and 3rd, then hearing a real bad noise, then having to try all over again. So did all those riders. After the race we were all super jacked and reliving the moments of battling each other. If you have watched a true stock bike race (we did it in cali once) its slow as shit, and boring. In the end, I find that most people that get salty about the few guys pushing the limits of the stock class and finding fun in that, dont even show up to race, or may be more mad at the themselves for not having the money or time to be competitive. If thats the case, ya gotta keep at it, it takes dedication. I know for example Ed has been building that Derbi to be competive for like 3+ years. He also has raced for like 8 years now. Each year getting a little faster, because of all the time he puts into it.

Re: Motobecane Stock Variator Tuning: what you need to know

> Siezed Again Wrote:

> -------------------------------------------------------

I got some reacts when I showed up with

> a LC MBK 512 cylinder last year, but I had no time to tune it, so it

> never mattered to most as it wasnt that fast. Again, if you win by a

> landslide, that's when it matters.

Im running that cylinder, you are correct, its not that fast, I bet with porting that could change a bit, but I am no pro at that, mine is doing a solid 40, and is quick out of the corners, so Im happy with that

Up next is the spring mod, I had intentions to do that yesterday, but we just found out the closing date on our groups new building, so all mopeds are set aside, its moving time!

Re: Motobecane Stock Variator Tuning: what you need to know

Yeah totally, I agree 100%

I'm one of those armchair guys, I'd like to come spectate but I decided a few years ago that I just don't have the time or dedication to actually compete. The whole reason I got into moto track days and AHRMA (LO fuckin L) was because I wanted to focus on the riding skill and not the machine, then I discovered dirt which is cheap and way more fun and hurts less, and now I just enjoy mopeds for what they are and when I want to ride to ride, I grab one of my 'ready to race' orange bois.

When your time is super limited with projects, a farm, 3 kids and everything else I cram in a average summer, showing up to race and not even getting to start because your wrist pin bearing gives up after a 4 month death slog building a bike is just too soul crushing to recover from, haha.

All I'm saying is I love this spirit in this thread! It kinda bums me out to think that the climax after all of this is 'yeah, cool, nice job but just slap on a spx pulley' but I know that's not really the point here. I'm just talking trassssssssshhhhhhh!

Re: Motobecane Stock Variator Tuning: what you need to know

Totally normal JBOT /

Yes trash to gold is my goal always if possible.

Redesigning poorly designed things is the best thing ever

Re: Motobecane Stock Variator Tuning: what you need to know

See, I think it would be hilarious to putt around the track on a stock unmodified 20 mph moped, while everyone else in the class zooms past me. I'd be cackling the entire time. :D

Re: Motobecane Stock Variator Tuning: what you need to know

Totally normal JBOT /

Put the new leaf springs and shoes from treats on version 1 today

The extra thick pads don’t even help, you have to shave them down. Like 1/2way :( just to fit in the bell.

New leaf spring is weaker than stock, but after cutting the pads in the lathe and cutting sipes it really rips super hard again. I like this original modded clutch over the other one I made still. Could be it’s weight but I’ll lighten at some point.

But fuck I’ll challenge this clutch mod against any clutch pulley for how it responds.

I’m planning on trying a trick to put the spring hook on the bottom of the pad, because it sucks when the pad wears out and the spring gets eaten. But you just pop the next coil out on the spring and you’re ready to go (with new pads)

Other odd thing is that there’s a gap between the spring and the metal it rests on, Even with attaching the bolts in the same place. So I’d feel comfortable adding another rivet or bolt higher up the leaf spring to get that arc pulled back down and engagement higher with less end spring

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Re: Motobecane Stock Variator Tuning: what you need to know

Totally normal JBOT /

I cut the new pad to be like my old pads, might try a longer one next time (that’s what he said)

I also came up with a super baller idea.

I know physics, and this wire wrapped spring retainer for below the pad will work flawlessly. Won’t even deform the circles wire I bet. I tested with a rope loop on the end of the spring and standing on it and the spring extends just fine.

The wire sits much lower than the spring did, and if it gets damaged no big deal. Just add a new one.

The twisted part will live inside the spring as well which is the 2nd coolness. Behold greatness

(Can’t wait for dummies to be like, durrrr wire won’t work durrrrrrr) wire is amazing

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(edited)

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