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Old 09-08-2012, 11:23 PM   #115
Dubbious Adventurer
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Joined: Aug 2001
Location: San Francisco
Oddometer: 5,022
Originally Posted by AntonLargiader View Post
OK. Dunno if the 4354 has a different axle offset (I sort of doubt it's significant) but the last diagrams I see in his design thread show 35mm offset and the clamps are made to 38mm, so clearly there was some more work done.

Anyway, you sort of confirm my suspicion that this clamp may not be optimized for my wants. I'll just have to do a bunch of figuring and see where the trail ends up on an R100GS.
Anton, if you are still paying attention this may help your understanding.

I finally got around to reading this thread and though I would chime in on the subject of offset. It's all fairly controversial, and probably less significant in the performance than we all think it is. After all, the airhead has tremendous rake by modern standards. When I saw other airhead fork adaptations, including HPN, were using clamps with very small offsets, this just didn't make sense, unless one was willing to steepen the head angle in order to use them.

The design intent was to produce a clamp that would work with standard rake. I also assumed that if the front were raised for more travel, the rear would be raised an equal amount. Now having said that, I can't remember exactly how I ended up with 38mm of offset. There was plenty of discussion in the design thread at the time. Ultimately, I believe the offset was bumped to 38 in an effort to sharpen steering given that a better suspension doesn't need quite as much trail to behave well. The stock offset numbers are easy to come by also.

According to my measurements the WP4357 and the 4860 both have 36mm at the axle. So, the total is offset is 74.
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