Triple tree

[gabbyjon]

Please explain the differences in the early top tree.I have 1 tree with the 4 mounting tabs in front but the stem hole is not offset enough to line up with the fork tubes holes on the lower tree casting #45707-52A.Another top tree has the correct offset but only 2 mounting tabs.What casting # should the lower tree have to line up with my upper 4 tab upper tree?What years did they use this shorter offset tree on?Does anyone have the correct lower tree to sell?

[JerrryR]

Hi Gabbyjon,
Sorry to take so long to reply to your request. You need to use a bottom tree with a casting number ending in -52, your -52A bottom tree goes with a later version of the 4 tab top tree that I believe started with VIN 2250 in 1954 (see the picture from the parts book). If your two tab top tree is steel I believe it started with the 59 model year and does go with your -52A bottom tree. If it is aluminum I think it started in 62 and goes with your -52A bottom tree. I'm not sure on when the change from steel to aluminum took place but I'm sure someone will clarify this for us. Is your bike pre or post VIN 2250 in 1954?
Have a great Holiday
JerryR

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On a side note someone please tell me what I do with the choke when the bike is cold. I give up on that question.

[EKHKHK56]

Jerry is there another -54 top tree with the "welds" by the stem hole? I have some like that...I think close the choke might work

[JerrryR]

Hi Erik
Harley didn't throw anything away. When they changed the tree profile at VIN 2250 in 1954 they reworked the early top and bottom trees to match the newer profile. They cut and welded the early top trees and bottom trees.

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[hennesse]

Please explain the differences in the early top tree.

Most old Harleys used frames with a 30-degree rake. While this varied a little with different models and years, 30-degrees seemed to be the right amount. The triple trees had the fork stem parallel with the fork tubes. Some of the big twins had "adjustable offset triple trees" so you could change the trail for sidecar use.

When they designed the K, they came up with a lot of innovations (19" wheels, aluminum brake shoes, wacko steering geometry, etc.) most of which didn't work out too well, and were subsequently changed.

The 1952-1953 K frames had a much smaller rake. To compensate, they "raked" the triple trees - the fork stem is not parallel with the fork tubes, and the front wheel is kicked forward an inch or more. "Raked" is not the correct technical term - the "raked" triple trees changed the "trail", not the "rake". But the result is pretty much the same. The lower tree has a -52 casting number. I don't think any of the top trees have a casting number.

In 1954, they decided to increase the rake on the frame. They did this by cutting 1952-1953 frames, increasing the rake, and welding it back together. The result looks like a born-again chopper, but it's factory. (See Jerry's article in Technical : Frames). They continued to use the "raked" triple trees.

At 54 KH 2250, they introduced a new frame with a newly-designed head casting, and (I think) a little more rake. At the same time, they decided use normal, parallel, triple trees. (The lower tree has a -52A casting number) However, in their infinite frugality, Harley cut and re-welded the 1952-1953 triple trees too. This might have been done starting with 2250, or maybe they ran out of the new ones after awhile - I don't think anyone knows for sure. Jerry? But these born-again lower trees will still have the -52 casting number.

In 1959, they stopped using the two ignition/light switches, so they only needed two tabs - for the speedometer to mount to. Then as Jerry mentions, around 1962 they changed to aluminum top trees.

The parts books are all fouled up - they give some impossible combinations. The "raked" trees have -52, 52A, PART numbers. The "parallel" trees have -54, 54A PART numbers. Some of the parts books show a -54 lower tree being used with a -52 top tree, and vice-versa - impossible combinations. I went through all the parts books for a technical article I never quite finished, and parts books are amazingly fouled-up. Now that the weather is getting cold, I'll have to dig that out and finish the article.

The constant changes in the steering geometry are amazing. 1952 had small rake, raked trees, and 19" wheels. 1953 had small rake, raked trees, and either 19" or 18" wheels. The size of the wheels affects the "trail", so a bike with 19" wheels would handle differently than one with 18" wheels. 1954 bikes had more rake, raked-trees, and 19" or 18" wheels, so they handled differently from the 1953s. Late 1954 and 1955 had slightly more rake (I think) and parallel triple trees. So they handled differently. But I think by then the 19" wheels were no longer. There was a short-lived 1955 frame with a -55 casting number on the head - not sure what that did. The 1956 frame was lowered to the ground considerably. So no two K-models will handle quite the same!

I think sales of the K-models were much lower than expected. This was supposed to be Harley's answer to the British Invasion, but it didn't go as expected. They knew they had to make improvements, but with lagging sales, they decided to rework old frames and triple trees until they ran out, rather than trashing the old stock and making the investments in the new designs right away. Things like the aluminum brake shoes were expensive to make - so they reverted to the tried-and-true designs they had used, and continued to use, on their big bikes. Where did the 19" wheels come from? I suspect some of the Brit bikes used them, and Harley thought that might be a good idea. I think that's why the lightweight 125cc and 165cc "Hummers" used 19" wheels from 1948 through 1955.

Ramble ramble. Hope this helps understand the crazy triple trees and frames.
Dave

[gabbyjon]

Thanks for the great information this does explain a lot about the trees.I do have the upper tree with the welds by the hole,was wondering about that.

[gabbyjon]

Does anyone have the lower tree with part #45707-52 cast # for sale?

[sportsterpaul]

I've got one I can sell. I will list it on eBay tonight. I will do it as an auction, and I promise not to price it at $399, like that other guy. I will put a 50 buck reserve. It looks like the little vertical flanges between the stem and cross beam and have been expertly welded, I assume this one hit a tree. My instinct is to start it at $3.50 in honor of the South Park where Chef's parents gave the Loch Ness Monster three dollars and fifty cents.

I have an upper as well, as well as a tree and clamp for later models. I also have an ultra-rare cad-plated front end I will list. This might take a day or two-- its what my friend calls The Chain of Dependencies. First I have to unpack and set up the light box I just bought. To do that I have clean off the Ultrasonic cleaner that I am trying to fix for another chain of dependencies-- rebuilding 5 carbs. Then its trying to figure out the new camera, and why it is haunted and has a mind of its own.

Paul

[JerrryR]

Hi Dave & Gabbyjon,
I believe that there were only two frame rake changes between 52 and 69 even though there were a number of different neck castings. I contend the only frame rake change due to a re-worked neck castings took place with the introduction of the 54K model. I haven't yet nailed down when in 54 Harley introduced the new -52A neck casting but I am pretty sure it was not with the 2250 VIN tree change in 54. It may have been before or after, the earliest frame I am aware of with a -52A neck casting has a J3 frame date code. I am convinced Harley used the cut & welded reraked -52 neck castings not only for all of the 54 model year along with the later introduced -52A casting but also used the reworked -52 neck castings for some of the early 55Ks. I have an "i4" date coded frame with the reworked neck with the 3/8th fine thread bosses for the coil that started with the 55 model year. The trail topic as you mention was all over the place with those K frames. What I found interesting was what took place with it in the 54 model year. With the start of the 54 model year the trail was affected not only by the greater degree neck rake but also up until VIN 2250 they had the early tree combination that some folks refer to as the "raked trees". As you mention at VIN 2250 the trees put the forks parallel with the stem reducing the trail some. I am curious how the early 54Ks handle compared to the post VIN 2250 bikes.

Gabbyjon I am a little puzzled by something you said about your trees. You indicated you have a bottom tree with a -52A casting and said your top tree would not line up. I think in one of your last post you mention that your top tree has been welded/reworked? If you have an early tree that has been cut, welded and reworked to have the same profile as the later trees it should line up with your bottom -52A casting tree?
Jerry

[hennesse]

If your two tab top tree is steel I believe it started with the 59 model year and does go with your -52A bottom tree. If it is aluminum I think it started in 62 and goes with your -52A bottom tree. I'm not sure on when the change from steel to aluminum took place but I'm sure someone will clarify this for us.

Jerry,

The first mention of the 45738-62 aluminum top triple tree is in the 1963 Parts Catalog. It shows the -59 for 1959-Early 1962, and the -62 for Late 1962-1963.
The 1962 Supplement was dated Sept 1, 1961, right at the beginning of the 1962 model year. The 1963 Catalog was issued November 15, 1962, 2-1/2 months into the 1963 model year, so there's no clue as to when in 1962 the change occurred.

While we're picking nits, there's some oddities on the bottom triple tree which started in 1967. The 1967 Parts Catalog shows the 45702-57 for late 1954 to 1966 all, and 1967 XLCH. Then there's the 45702[u-]67[/u] which fits only the 1967 XLH. The 1968 Supplement shows the 45702-57A for Late-1954 to 1968. The 1969 Supplement shows the 45702-57B for Late-1954 to 1969. I have no idea what's going on with those late models, but it looks like the 45702-67 was a one-year-only.

Dave