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Vintage in spirit if not year of manufacture

1433 Views 8 Replies 6 Participants Last post by  BH121869
Hello. I just joined. My bike is a custom made by Bartel's Harley in SoCal. The bike is one of 10 made in 1993-94. Engine is a 883 Sportster bumped up to 1200cc and is cradled in a specially made Champion frame. Forks are inverted Buells. Single Mikuni, 41mm. XR-750 glass tail section and aluminum XR-750 tank. Frame is 4130 chrome-moly tubing. Wheels are 18" Sun rims, front and rear. Dry weight is 430 pounds. The bike is pure street tracker. Bought it two years ago. I raced Sportsman Class C back in the early 1970's and fell in love with this when I saw it. I hope I'm not too out of place on this forum.

I tried to upload a photo from a picture hosting site but it said I could not until I had made 15 posts. Maybe someone knows the secret handshake and they can tell me, otherwise - photos later!
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OK, all 15 posts made. Here's a photo of my bike.

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Nice! :D
That is a cool looking sporty! I don't know if I like yours or bsporty's Sportster better.
Well, I guess I'm in good company then.
Probably a dumb question but...what's inverted about the forks? the triple tree or what?
The whole fork is "upside down" compared with most other forks. Look real close you can see the inner fork tube is the one that moves up and down compared to the outer fork tube.

Found this on a BMW F650 fork page

Why are Inverted Forks Better?
Flash #412, 07-Oct-01

When the bigger tube is the longer tube, the fork is stiffer. Stiffer means that it flexes less. If it flexes less, you have a better sense of control and in fact DO have better control.
There is also something called the sprung to un-sprung weight ratio (sometimes just called un-sprung weight ratio). This refers to the weight of the vehicle mechanically located below the suspension to the weight of the vehicle mechanically located on top of the suspension.
Considering the engineering extreme will help you understand why this is important:
If your bike and you weighed 1000 pounds and your wheels, fork lowers and swing-arms weighed nothing, when you hit either a dip or a bump in the road, the attitude of the bike would not change. The ride would be super-smooth. Conversely, if your wheels and stuff weighed 1000 pounds and you and your bike weighed 200 pounds, every dip or bump in the road would throw you up or down with the wheels, no matter how great the suspension.
Inverted forks put the heavier bits in the sprung category, which improves suspension action compared to the identical parts installed conventionally. The lighter the bike, the more noticeable this effect.
And that is why inverted forks are better.
Very nice bike.
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