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Old 08-02-05, 09:24 AM   #1
bkennedype
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Rake and geometry question...Cannondale

I have removed the headshok from my Cannondale road bike and have a new headset. It appears that I am going to lose about 1.5 inches by removing the suspension...so I wanted to calculate the rake required for the new fork to get me back to approximately the same trail...not sure if I'm understanding this, but here it goes....

If the front end is dropping a bit and everything else stays constant, in theory that makes for more aggressive steering. Like it to putting a 650 wheel on the front end. To compensate for this I require want a fork with more rake to provide less aggressive steering and this will compensate. Of couse I could have my logic backwards, never was very good in geometry.

The rake on the busted fork that is the root of this insaneness was 43. Would I add a fork with a rake of higher or lower than 43? and should I be able to calculate the best scenario?

Thanks.
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Old 08-02-05, 10:00 AM   #2
galen_52657
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I don't think you will be able to duplicate the old geometry if you are dropping the front of the bike 1.5 inches. You will end up with a very steep head angle. Can you have a 1.5" spacer constructed to raise the bottom headset race?

In any event, you would want less rake on the fork as the head angle gets steeper to keep the trail constant. I would think if you go through with this, you will need a custom fork or a track fork with very little rake. You will have a very short wheelbase and may have toe/front wheel overlap issues.

What is wrong with replacing the busted fork with original equipment?
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Old 08-02-05, 10:51 AM   #3
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Quote:
Originally Posted by galen_52657
What is wrong with replacing the busted fork with original equipment?
That is still an option, albeit an expensive one. Closest Cannondale dealer is 3 hour drive. I didn't know anything about headshoks until a month ago, or I would not have purchased the frame. An original fork from Cannondale, shipped to Canada, a three hour drive to drop the bike off and another 3 hour trip to pick it up, plus the bike shops costs...that's a lot more than I have into the entire frame, but quite a bit. A rookie mistake.

I have another bike and was building up the Cannondale for the fun of it. But I may have created a problem that I will have to pass on fixing and take my lumps if the "geometry" issue will prevent me from riding safely.

Thanks for your input.
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Old 08-02-05, 11:00 AM   #4
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I kind of feel like I need to apologize for mentioning that reducer. I have heard of them being used on mtn.bikes so that std. 1-1/8" steered tubed forks would work. But you'd just be replacing a headshok with a regular suspension fork, so wouldn't have that difference for which to compensate. But a road bike would be a different animal. Seems like Cannondale has ya on the road bike headshok fork. And I do apologize for causing all of this confusion.
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