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Old 11-11-2012, 05:18 AM   #1 (permalink)
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Questions About Lowering My FXR.... Yeah Yeah

So, as you may have followed my thread that turned from rare FXR's into how tall my forks were on my bike, you know that you all were right and my front forks were 27".

Well, I bought the standard 25" tubes, put all new progressive springs and spacers in it and replaced all bushings/seal etc.

So My short ass can touch the ground much better, not as low as I would like, however. I think an inch should be pretty decent. I am looking at the Progressive 11.5" 412 shocks. I don't want too low, but I want to have close-to flat feet.

These are my questions:

1) Tell me how low you have dropped the rear (also your front fork height) and if you have any scrapping issues. I am buying a custom made exhaust for the bike that is short and tilts upward a bit, therefore I'm not too worried about my pipes scraping.

2.) Do you suggest cutting one of the front fork spring spacers an inch if I decide to drop the rear an inch as well as to not mess up factory "trail?" Or will the change in handling be literally insignificant with only a 1" rear drop and leaving the front the 25" height?

Thank you!
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1985 FXRS: Dyna 2000 ICM, Twin Tec II Single Fire, Mikuni HSR 42mm carb, S&S intake, Progressive 11.5" rear springs, progressive front sprigs, SPF Lightningheader exhaust and bars, rebuilt front forks with brace (lowered back to 25.5"), Arlen Ness fairing, all new electrical, shyt-ton of powder coating etc. etc.

Last edited by Krowbar; 11-11-2012 at 05:22 AM.
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Old 11-11-2012, 10:38 AM   #2 (permalink)
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The shorter you make the forks, the more twitchy (for lack of a better word) it will get. It shortens the wheel base which makes it steer quicker. FXR's are already quick steering, and any quicker makes them a little nervous. It not a big difference, and you might not really notice it on a scooter that you hadn't ridden before. But switching from a very long fork scooter to a very short fork will be noticeable.

Mechanically, you need to check the primary for clearance on top of the belt. Some will rub when lowered. If yours is too close, make sure the rubber mounts aren't sagging and then just make the opining larger.

IIRC, you can do a 10 inch forward mount strut without moving the fender. 10 inch shocks wont work.
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Old 11-11-2012, 11:20 AM   #3 (permalink)
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Someone before me put +2" forks in the front from factory. My bike is a SP so it came with the 25 1/4" front forks factory. I replace the aftermarket 27" ones with the factory 25 1/4" ones. I was just curious about lowering the back from 12.5" to 11.5" and its effects on trail (withouth lowering front 1" too" and potential clearance issues.
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1985 FXRS: Dyna 2000 ICM, Twin Tec II Single Fire, Mikuni HSR 42mm carb, S&S intake, Progressive 11.5" rear springs, progressive front sprigs, SPF Lightningheader exhaust and bars, rebuilt front forks with brace (lowered back to 25.5"), Arlen Ness fairing, all new electrical, shyt-ton of powder coating etc. etc.
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Old 11-11-2012, 09:21 PM   #4 (permalink)
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I don't understand why you're so hung up on affecting trail. The minimal changes you're making to geometry will not be noticeable.
Think of it this way : during the Shovelhead years, all 4 speed big twins were built on the same frame/same rake. FLs had really short forks with short 16in wheel and tire. Superglides had 1in longer forks and taller 19in wheel/tire. FXB Lowriders had 2in longer forks and FXWG had 4in over forks and even taller 21in wheel and tire. People didn't have any problems with all those options. All those bikes were capable of the same thing ....
I'm willing to bet whatever changes you make by lowering, you'll get used to in first 50 miles and won't even remember what the bike handled like before.
Unless you're a seasoned roadracer and REALLY understand motorcycle suspension and geometry, you will not be able be able to notice any difference except MAYBE ground clearance.
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Old 11-12-2012, 02:04 AM   #5 (permalink)
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Originally Posted by ALAY191 View Post
I don't understand why you're so hung up on affecting trail. The minimal changes you're making to geometry will not be noticeable.
Think of it this way : during the Shovelhead years, all 4 speed big twins were built on the same frame/same rake. FLs had really short forks with short 16in wheel and tire. Superglides had 1in longer forks and taller 19in wheel/tire. FXB Lowriders had 2in longer forks and FXWG had 4in over forks and even taller 21in wheel and tire. People didn't have any problems with all those options. All those bikes were capable of the same thing ....
I'm willing to bet whatever changes you make by lowering, you'll get used to in first 50 miles and won't even remember what the bike handled like before.
Unless you're a seasoned roadracer and REALLY understand motorcycle suspension and geometry, you will not be able be able to notice any difference except MAYBE ground clearance.
I tend to agree with Al. My FXRS-CON has the same length forks as you, with 12" shocks. That was how the bike was when I bought it so I don't know it any differently. I don't race the bike, and only occasionaly scrape the kickstand.

On paper I'm sure it's the wrong thing to do, but not something you'll have problems living with in the real world.

I think the problems you are going to feel is the loss of travel, the hard ride or bottoming out with the short shocks. Personally, I'm waiting for that good deal on a set of 13.5 shocks for my bike.

I noticed your other 2 bikes have pretty small seats so you must be happy with them. If you are a short guy I would change that big Mustang seat out for something smaller before I'd change the shocks. It might just lower it enough for you.

I don't know if you have bike nights in your area, but if you do it's a good place to watch for other FXR's to get ideas. It's nice to ask questions on the forum, but to see another FXR in person and talk to the owner and possibly sit on another FXR that has been modified is invaluable. Unfortunatly FXR's seem to be few and far between so you might not see many.

I've had mine now for about 11 months and pretty much know all the FXR's in my area. Probably half of them have aftermarket seats and shorter shocks.

~Pete
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Old 11-12-2012, 05:11 AM   #6 (permalink)
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If you put 25.25" fork tubes on your bike but are running 12.5" shocks then you are still not running stock. That length fork matches with 13" or 13.5" shocks. If you drop your fork tubes down to 23.25" you will have a stock match with the 12.5" shocks. That's what I would do. 27" fork tubes were really 4 inches over for most FXR's. At this point if you want a bit lower then try a LePera bare bones seat or similar. I would certainly not go with 11.5" shocks with 25.25" forks as this will too low in the rear as well as the lower shocks will have less travel.
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Old 11-12-2012, 09:15 AM   #7 (permalink)
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The center/center length of the OEM shocks from my '92 FXRS Lowrider is 13" ....
Pete mentioned that he's waiting for some 13 1/2" shocks ...... this is the OEM shock length on the FXRS-SP ....
It has 12 1/2" Progressives on it now. Wouldn't want it any lower ..... I'm 170 lbs.

Last edited by lucille; 11-12-2012 at 09:20 AM.
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Old 11-12-2012, 10:45 AM   #8 (permalink)
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Quote:
Originally Posted by Krowbar View Post
Someone before me put +2" forks in the front from factory. My bike is a SP so it came with the 25 1/4" front forks factory. I replace the aftermarket 27" ones with the factory 25 1/4" ones. I was just curious about lowering the back from 12.5" to 11.5" and its effects on trail (withouth lowering front 1" too" and potential clearance issues.

Trail is just something that can be measured on paper. What you are changing is caster and steering axis inclination.

Leaning the top of the fork back (longer forks or shorter shocks) adds caster and increases the axis incline. The added caster makes it naturally run straight. as does the gained wheel base from longer tubes. But the additional axis angle makes it turn worse. It forces you to rotate the steering head which then adds excessive camber as it rotates/yaws the wheel.

Ever notice that most of the late 60 early 70 extended fork choppers had no front brakes. It was because of the yaw issue. Look at a sport scooter, notice how straight up and down the forks look

What ever you do, it's nothing you won't get used to right away. My 84 is very low and it's a little twitchy. I notice it after getting off of the other scooters. But after a few miles I'm used to it again. The FLTRX is actually just the opposite and as such more of an issue. It's lazy and late to rotate, so I tend to run a little deeper into the turns at first. Same deal, after a few miles I adjust without even thinking about it.

Put your scooter on the jack and level it up, then pull the shocks and fork caps. Let it down to where you like it and take some measurements and check your clearances. Compare the measurements you end up with to the ones you started with and there your changes are.

Shocks come in all sorts of lengths and you can cut/remove the spacers on the forks.
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Old 11-13-2012, 04:25 PM   #9 (permalink)
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Quote:
Originally Posted by yogin View Post
If you put 25.25" fork tubes on your bike but are running 12.5" shocks then you are still not running stock. That length fork matches with 13" or 13.5" shocks. If you drop your fork tubes down to 23.25" you will have a stock match with the 12.5" shocks. That's what I would do. 27" fork tubes were really 4 inches over for most FXR's. At this point if you want a bit lower then try a LePera bare bones seat or similar. I would certainly not go with 11.5" shocks with 25.25" forks as this will too low in the rear as well as the lower shocks will have less travel.
Early Year FXR's had 12.5" rear shocks eye-to-eye. Some FXR's came with 23.25" or 25.25" front forks. When I bought the bike, it had 2" over front forks at 27.25" So I am running a factory height set-up at this time.

My rear shocks sag down to 11.5" with the weight of the bike on it anyways. I went ahead and bought the Heavy Duty Progressive 412's (Black) as I think (hope) they will only sag about .5" with the weight of the bike. The half inch will render me close to flat footed. I only weight 150lbs and am 5'4". I really just bought them to get black ones and the small drop will be nice.

Thanks for the replies, gentleman.
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1985 FXRS: Dyna 2000 ICM, Twin Tec II Single Fire, Mikuni HSR 42mm carb, S&S intake, Progressive 11.5" rear springs, progressive front sprigs, SPF Lightningheader exhaust and bars, rebuilt front forks with brace (lowered back to 25.5"), Arlen Ness fairing, all new electrical, shyt-ton of powder coating etc. etc.
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Old 11-13-2012, 04:30 PM   #10 (permalink)
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I lowered mine about 1-1/2" using blocks in the back, and pushed my forks up through the trees about 1". I am totally flat footed when stopped. I am between 5'8" and 5'9". I guess you could get a custom Corbin seat made that helps you sit lower in the saddle. All of those combined should help with reaching the ground.
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Old 11-13-2012, 05:23 PM   #11 (permalink)
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I have the 35mm set-up so you can't push the forks through. I like the looks of taller forks, but not the 27" ones, just want to drop the butt a little. Should only drop it a half inch or so from factory though.

I also have a new really thin seat that helped out a bunch too.
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1985 FXRS: Dyna 2000 ICM, Twin Tec II Single Fire, Mikuni HSR 42mm carb, S&S intake, Progressive 11.5" rear springs, progressive front sprigs, SPF Lightningheader exhaust and bars, rebuilt front forks with brace (lowered back to 25.5"), Arlen Ness fairing, all new electrical, shyt-ton of powder coating etc. etc.
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Old 11-13-2012, 05:42 PM   #12 (permalink)
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From the parts dept. .....
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Old 11-13-2012, 05:54 PM   #13 (permalink)
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Originally Posted by Krowbar View Post
I have the 35mm set-up so you can't push the forks through. I like the looks of taller forks, but not the 27" ones, just want to drop the butt a little. Should only drop it a half inch or so from factory though.

I also have a new really thin seat that helped out a bunch too.
Sounds like you need to update your FXR picture.

Let's see the changes!
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Old 11-14-2012, 03:10 AM   #14 (permalink)
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Dirty garage pic. The bikes not starting. I got the Mikuni new, but not in the box new. Been out and on a shelf. Looks flawless, but I am not too good with them It will fire and idle for about 1 sec and die, no matter how much throttle you give it. I did do a lot to it at one time before checking everything after individual install (twin-tec single fire, Dyna 2000 ICM and carb.

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1985 FXRS: Dyna 2000 ICM, Twin Tec II Single Fire, Mikuni HSR 42mm carb, S&S intake, Progressive 11.5" rear springs, progressive front sprigs, SPF Lightningheader exhaust and bars, rebuilt front forks with brace (lowered back to 25.5"), Arlen Ness fairing, all new electrical, shyt-ton of powder coating etc. etc.
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Old 11-14-2012, 08:08 AM   #15 (permalink)
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Originally Posted by Krowbar View Post
I have the 35mm set-up so you can't push the forks through. I like the looks of taller forks, but not the 27" ones, just want to drop the butt a little. Should only drop it a half inch or so from factory though.
I also have a new really thin seat that helped out a bunch too.
Looks like pretty short shocks already. What do you mean when you say it will only drop it a half inch or so from the factory?

Shouldn't your stock shocks be 13"-13.5"?

~Pete
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