'27 JD Cut Down Project - SWAN

[TechNoir]

Hi Steve, I am sorry to hear that you have been feeling unwell, there was a particularly nasty virus going around the UK about a month ago which sounds very much like the one you have been suffering from and it flattened loads of much younger and fitter people than me.

I cant offer any more on balancing your crank other than to offer moral support and also to add that this topic is something that I have an interest in so I will be following your progress.

John

[Steve Swan]

Thanks John for your empathy. the cold was a real bitch, flat 11 days, 1st time i been sick in about 4 years, still have a nagging cough into week 4. anyway. not too sick to find a few spare moments to get up to shop and play around a bit.

A big thank you to one Mr. Mick King, thanks to Mick, i now have a gorgeous '29 frame, a nice complete forks and 1914 front and rear fenders. fitted the left crank case to frame; some very minor dressing up of case and frame lugs and and everything fits flat making full contact. made 1/2 rear fender brackets and got one brace bent. got the skirts on the front fender, am going to attach with screws like later J's.

Wiff reweighed the rods and the S&S balancing kit does not have a bob weight that will fit the smaller flywheel crank pin taper, so he's making one up. will have some free time the first part of May, so maybe we can get the flywheel assembly balanced and trued....

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[Steve Swan]

i am using a set of Tom Faber's speedster bars on my bike; i took them in trade for mechanical work i did. the rise is only 2-1/2 inches and and draw (six inches) is such that it makes one, when siting on the bike, hunch forward and draw is such that wrists are more parallel with the bars than angled back. my question is: "Has anyone "adjusted," bent Faber's bars into a different position? i definitely do not want standard or board tracker bars. i am thinking if i could get another 1-1/2 inches (three) of rise and bring the draw of the spiral area back another inch or possibly even two inches i would be happy. another thought i have is to bend the two stems back where they meet the handlebar, this would move the bars a little further back... i have this tool, it works like a charm on 7/8" bars....

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[Steve Swan]

more progress....

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[Steve Swan]

Big moment in Northern Colorado today!!!! after 4+ years, we got my buddy James Lafler's '29 rolling down the road today! Runs strong!

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[Steve Swan]

got my fender brace rods and brackets made...... imho, i think the '14-type front and rear fenders with modern aluminum rims and tires and sport solo tanks are going to look kick-ass!

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[Steve Swan]

Steve,
I can't remember if you mentioned which flywheels you are using. OEM or Truet & Osborne. This will change the way you balance this motor.
Regardless of the wheels, the procedure for measuring the weights is the same. As you mentioned, the rods need to be horizontal when you weight each end. I think cotton posted a picture of a good tool to ensure this.
You will find that the Carrillo rods you be will much heavier than OEM rods, maybe twice the weight. Using OEM wheels will mean more work to balance them by adding or removing more weight. T&O wheels are probably heavier to start with ?
Because the Carrillo rods are heavier to start with, any discrepancies in top and bottom weight will be a bigger percentage of overall weight, if you don't get it right.

As mentioned in numerous other posts, the balance factor is very subjective. As a general rule, a lower balance factor will move the vibrations in the vertical plane, the higher balance factor will move the vibrations in the horizontal plane. This comes down to personal preference. I am surprised T&O used 60% as a balance factor for such a low revving motor. As you say, it is a bit "buzzy" over 50 mph, I would expect that on a lower balance factor motor. How is it at 100 mph?

Now to the actual balancing.
Once you have done all your measurements, and decided on what your balance factor will be, there are two ways to balance your motor.
In dynamic balancing, the total calculated bob weight, including the crank pin, is clamped to the crank pin and rotated. This is done on a dedicated machine, like a tire balance. This is typical of what the factories use. Can also be done on knife edges with a manual interpenetration of where the heavy spots are.
Doing this on a machine will tell you where to add or remove weight on the screen, probably even do this automatically, as you can see in a lot of OEM wheels.

The most common way for people to balance flywheels is the static method. This is as you described above. Setting up the flywheels with counter weights to visually identify when a flywheel will settle, regardless over where it is first placed on the knife edges. Adding or removing weight is an integral part of this process.
I don't have a copy of Uncle franks book, but it seems to me that was the best practices at the time, before we knew what factors influenced the engines feel. You may be lucky and have the parts add up to the correct bob weight.

I was taught to balance motors using the S&S system where you balance each individual flywheel.
I have found over the years that not all OEM wheels have the same density from the factory. Occasionally while drilling a hole in the wheel to add weight, I have come across an air pocket in the casting.
If the flywheel is balanced as a unit, this density difference can manifest itself as a side to side motion. This is unlikely to be, as it is probably such a small force, or felt, but it is why I prefer to balance each wheel individually. If each wheel is individually balanced, this effect it probably negligible. Once again, this is the way I know to do this.

Cheers,
Mick

Mick, my apologies for being so slow to respond to your post of the great information you shared. twas during the time i was laid low with that nasty cold... it was great to meet you in person and have you look and advise on the flywheel balancing work that needs to be done. Yes, balance each flywheel, that is what Wiff and i are going to do. i will keep posting the process as the project moves forward.

[exeric]

Your JD is looking great, Steve. I admire, and envy your project and know you are having fun finding the parts that fit your vision. Enjoy your pictures, text, and information.

[Steve Swan]

Eric, thank you for following my thread, i always appreciate any and all your comments. It's hard to not be excited about these beautiful old IoE engines and everything that goes with them! It's going to be interesting to see how the oversize inch Model T headlight and horn look as the project continues to flesh out. And, i am really married to the idea of using the Velocette fishtail silencer... A good friend of mine, i think i mentioned his name, Duane Dreesen, he was neighbors to us growing up, he had a Quonset hut full of all sorts of things, a 1904 Buick and early bikes, he also had a '48 Chief with the fishtail on it, i always gave Duane a hard time about the fishtail being on the Chief and one day in the mid-1980's when i was visiting him, he unbolted it from the Chief, handed it to me and said "Don't ever sell it!" Duane passed on to the great bike shop in the sky about 25 or so years ago, and the fishtail has been with me since as wall art. Always felt it a shame i didn't have a Velo to hang it on, and as i began this project i got the bright idea to have the fishtail go with this project. It is quite narrow, i think i can make it fit, will probably look a bit outlandish on the JD, but i want to feel Duane's smile....

[aumick10]

I must echo Eric's comments.
After watching your build thread for the 27 JD, and seeing it in person, I am looking forward to you next build.
I love the idea that you are building a period bike, using period parts that look good to your vision of what it should look like.
Cheers,
Mick

[Steve Swan]

I must echo Eric's comments.
After watching your build thread for the 27 JD, and seeing it in person, I am looking forward to you next build.
I love the idea that you are building a period bike, using period parts that look good to your vision of what it should look like.
Cheers,
Mick

Mick, THANK YOU ! the only thing that's going to be weird is that Velocette fishtail silencer.... as i said, a good friend gave it to me with the promise of never selling... so, i am going to see if i can fit it and give it a try....... i guess if i don't like it i can always take it off, but it should't look any more weird on a JD than it did on Duane's '48 o.p. blue Chief........

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[aumick10]

Steve,
That is silencer is pretty large, it fits nicely with your horn and headlight.

[Steve Swan]

Steve,
That is silencer is pretty large, it fits nicely with your horn and headlight.

yes it is..... the good part of it, it is as narrow as the '27 stock exhaust. we shall see.........

[Steve Swan]

I must echo Eric's comments.
After watching your build thread for the 27 JD, and seeing it in person, I am looking forward to you next build.
I love the idea that you are building a period bike, using period parts that look good to your vision of what it should look like.
Cheers,
Mick

Mick and Eric, i have always liked stock bikes as they come from the factory with tasteful unobtrusive modifications. So, i want to keep the JD as stock as possible using period parts. The Model T headlight and horn and to say the least that Velo muffler is a BIG step out of my comfort zone. but, what the hay...... i'm trying to save what money i can, at least on some things take the path of least resistance and i want the bike to have a look of it's own that's apart from bobbers and cut downs, so i guess it is going to be a custom of sorts.

For a frame, forks, fenders, tanks, battery box color i have had the color gray in my head, looking at the gray primer on the frame, i am thinking i am going to go with a light gray with a blue tint and some sort of red striping. Thinking the gray-blue should give nice contrast to the rest of the Parkerized parts. i am leaving the transmission in it's original Olive finish, what little remains of the Olive. Debating if i should leave the cases raw or paint them gray-blue or some other color..... Olive Green......? right now i am thinking raw, but i really like the look of painted cases. i can get aerosol cans of paint with hardener in them (push a button in the bottom of can to release hardener) kind of thinking painting them the gray-blue, but raw aluminum might be a nice contrast to the gray-blue frame..... debating leaving original finishes on horn and headlight, but the horn's pretty scratched up and the headlight looks like somebody painted it with a corn cob.

[sveger]

Steve, as being the owner / builder of the first of the four bikes in your post from 01.16. I can tell you for sure my frame is "cut down". Rear frame is altered such as the wheel is raised by one inch and the neck is raked in to give it easier handling. The front fork legs are shortened too. My bike have approx 2 inch shorter wheel base and is by using 18" wheels and frame modifications lowered close to 2 inches, for full story of "The Muroc Special"; http://www.veteran-mc.com/2018/07/th...edecessor.html Regards Sverre aka AMcN / http://www.veteran-mc.com