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Getting ride height geometry correct?

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Old Oct 8, 2011 | 06:36 PM
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Default Getting ride height geometry correct?

Ok, I know there is a ton of info out there to be searched, but I don't feel like looking through endless amounts of threads for incorrect information. I wasn't planning on adding wheels before more power to my 2011 Ultra Limited, but a friend cut me a del too good to pass up.

I do take long rides and like the feel of the bike as is now, I know the handling will change some and that's fine, but I want to keep the ride as close to stock feel as possible with the new wheels. If I go to a set of PM Gatlin's with a 21" front and 17" rear how much do I need to lower my bike to get the same geometry as stock? The stock wheels on my FLHTK are 17" up front and 16" out back. I know I will have to drill my stock fender but I just want to know how much the bike needs to be lowered front and rear to have the same ride as stock.

Thanks
 

Last edited by Fire-Medic; Oct 9, 2011 at 09:19 PM.
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Old Oct 10, 2011 | 10:33 PM
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Anyone? Most people say only need to drop the front 1", but on the HD website it specifically states if you use the 1" front end lowering kit you need to have the 12" low shocks out back......
 
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Old Oct 11, 2011 | 12:13 AM
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1.) depends on selected tire profile- total distance from ground to center of the axle

2.) you can generally "lengthen" the front forks ( dropping the rear, leaving the front the same as alluded to in the HD lit you reference, or even extending the forks- this make for nice stable high speed ride, little hard to steer at low speeds.

reversing that makes for very unstable bike at low speeds.

when a 21 goes on the front you are essentially lengthening the front, which is OK.


you need to retain stock or over, rake vs trail


BUT if the forks are dropped to bring the front back down ( even if correct rake/ trail) you may have a problem with the fender smacking the triple tree on a big bump- which is kinda big surprise.

lots of guys have 21's looks awesome, I dunno how much they actually ride them- like bar hopping ok, but maybe not riding to Sturgis

Mike
 
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Old Oct 11, 2011 | 04:24 AM
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Originally Posted by mkguitar
1.) depends on selected tire profile- total distance from ground to center of the axle

2.) you can generally "lengthen" the front forks ( dropping the rear, leaving the front the same as alluded to in the HD lit you reference, or even extending the forks- this make for nice stable high speed ride, little hard to steer at low speeds.

reversing that makes for very unstable bike at low speeds.

when a 21 goes on the front you are essentially lengthening the front, which is OK.


you need to retain stock or over, rake vs trail


BUT if the forks are dropped to bring the front back down ( even if correct rake/ trail) you may have a problem with the fender smacking the triple tree on a big bump- which is kinda big surprise.

lots of guys have 21's looks awesome, I dunno how much they actually ride them- like bar hopping ok, but maybe not riding to Sturgis

Mike


I will find out the tire profile. So are you saying its better to drop the rear and leave the front alone vs the opposite?
 
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Old Oct 11, 2011 | 12:15 PM
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Streetglide rear already lowered 1" stock. Lowered front 1". Never hit the fender and have lots of trips. Bar hopping for me and my group is a short 300 mile day. 20k+ miles on the current setup on a wide variety of roads from perfect interstate to caliche (dirt and gravel). You feel a little more of the road (not in a good way) due to the low profile tires. Very slow speed handling is a little heavier. Once you're moving you probably won't notice any handling issues in high speed, twisties, two up fully loaded. You will probably carry more than me plus the Ultra is a bit heavier to start. Lots of guys have voiced concerns over exceeding the load rating of the 21' tire. You may want to check into that.
 
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Old Oct 13, 2011 | 11:28 AM
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Is the 1" front lowering kit changing the internal fork tube guts? And is that a garage mechanic job or a dealer job? I am looking to put a 21" on the front of Electra Glide Classic but don't want to change fork tubes, nor do I think now that I wannna lower the rear.

If adding about an 1 1/2" height from the 21" wheel, and lowering it 1" , does that bring the bike closer to stock and handling closer to stock and opposed to being "tippy" at low speeds? Or just the fact that the tire is more narrow make a diff?
 

Last edited by Harleybike; Oct 13, 2011 at 11:46 AM.
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Old Oct 13, 2011 | 11:49 AM
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Originally Posted by Harleybike
Is the 1" front lowering kit changing the internal fork tube guts? And is that a garage mechanic job or a dealer job?

OK, scratch this part, just looked it up at the HD site, 150 clams for the kit, and for me...Dealer job. Lol. So how long at the dealer? Labor cost.

Also, I read on the kit description, that this:

"Must only be installed on vehicles equipped with Profile® Low Touring Shocks P/N 54635-09"

So is that a "must" or is this HD just wanting to sell more?
 
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