I have a 2005 FLHTC. I am planning on making some upgrades to the bike rather than getting a new bike. I recognize that these bikes are not sport bikes, but I think that much could be done to make the bikes handle better. My plans are to add the Ohlins to the rear of the bike and am seriously considering Howard's new inverted forks for the touring bikes. Has anyone seen them, tried them? They are $1900ish on his site. I don't think anyone else has an upgrade this comprehensive for the front end of the bike.

 

 

Inverted forks and radial mounted calipers, that is some serious quality right there. If you were a serious performance oriented rider with curved or mountain roads as part of your daily riding the i would think its a great upgrade. If most of your riding is straight, no curves and flat highway riding then it would not be beneficial to spend the money.

 

the advantage of an inverted fork is less unsprung weight.

but when the percentage of weight unsprung is the difference between 10% and 5% of the bike's weight, I don't think it is worth the cost.

on a sport bike the percentages might be more like 20% and 10%

handling is more affected on the FLHTC by the batwing fairing which unloads the front end at speed ( above 85 ish wind speed), or can catch updrafts in canyon riding, which translates to steering input.

maybe a sharknose conversion...?

mike

 

With the inverted forks, at least you can take it off before selling it. Cheaper route is the Progressive cartridge...

 

I went with Traxxion dynamics ak 20 cartridges. Made a huge difference

 

Howard,

Does your setup change the fork location or suspension geometry? If so, what changes does it make to handling?

DOM

 

Given the overall bike, I do not see how one could push things far enough to make a inverded system worthwhile.

The progressive monotube system or the Ricor intiminators (inertia valves) would be a better fit. (I went with the Ricors + additional .25" preload, major reduction in front end dive).

 

Some of the reason why you put an inverted fork on a bagger is a much improved plush ride as well as performance. The ID is larger in an inverted fork thus you can actually put a real cartridge inside of the fork tube, not a small cartridge without external compression & rebound as well as spring pre-load. On my own bike which, the green one is not (for you sports fans out there, you would recognize him & yes he puts up to 40K miles/year on his off season), I have 30mm Ohlins externally adjustable compression and rebound w/spring pre-load. The ride is no where the same or even in the same class as the aforementioned products.

If you do not have the funds than just say so and do the best you can for what you can do. If you are saying what is best for all than you clearly do not know how these things work nor do you know the difference between the products and have not had the experience to talk about the subject. The aforementioned products above are not in the same league as real suspension.

Go to the track where there are professional people who make a living at riding and actually know what they are talking about. Ask their opinion or let them ride your bike for their opinion on what your bike feels like. All of the riders already know what every option is available. The road and the track are basically the same as far as your suspension goes. Settings and values change for the application.

Fork Tube Rigidity:
The slider is the part that strengthens the fork. There is typically 7" of fork tube showing between the axle clamp and slider. The slider is very sturdy and prevents the forks from deflecting. watch how your own crap 41mm fork bends while traveling at speed by duck taping a few LED flashlights onto the forks and report what you see. When your forks are deflecting they can not ride in the bushings very well and control is sacrificed.

Top Triple tree connection:
The top triple tree on a 1986 & above does not have a positive connection. The top of the fork is held in to the top tree by a slip fit bolt that passes through the top tree. The bolt pulls up the fork tube only and never clamps it. Travel very slow, like a mile or two, turn the handlebars to 45ş and lock the brake while watching the top tree deflect from alignment of the bottom tree. What do you think happens at speed? Does the tail wag the dog on high speed wobbles? Most certainly does not help and an explanation of why after a bagger brace is installed the wobbel is still there.

An improvement over this HD Bagger system is clamping the top tree to the fork tube like a real motorcycle does.

41mm (Really a 1 5/8" (-) 0.001" /there was no metric makers when the original 1948 Hydroglide was designed and offered for sale in 1949 on HD's. These forks deflect due to the small diameter and were the staple until the 49mm V-Rods & 2006 Dynas. Weight could be reduced on the 41mm fork tube from 0.165" wall tubing to 0.100" by making a larger diameter (49mm) fork tube from deflection through strength gained by something called cross-section.

Bushing system comparison:
The Showa fork on your Harley uses a bushing system of the top bushing is captivated in the slider and the fork tube rides/slides on the bushing. The bottom bushing is captivated on the fork tube and slides up and down on the aluminum slider.

The better inverted forks have bushings that are captivated in the slider and the fork tube slides in the bushing almost at the top of fork tube when fully extended and at the bottom of the slider where the fork seal is. The spacing is much longer than the Showa slider system so the support of the fork tube is better. This means less stiction so the suspension can work better.

Springs:
The springs rub constantly against the inside of the captivating fork tube constantly causing small metal particles that contaminate the fork oil. These particles than mix with the oil than wear the Teflon coating of of the bushings and wear the hard chrome off of the fork tubes. 2 weeks ago I rebuilt a set of forks off of a Roadking with 20K miles and the bushings on both top and bottom were worn out and the fork tubes had the hard chrome rubbed off. This is very typical.

A cartridge system has the springs on the cartridge body and at the end of the damper rod. A quality system has a spring guide inside of the spring to provide support and aid in kink prevention.

Rake and Trail:
Rake: The FL's use large amount of rake which wear the top portion of bushing on the Slider bushing (top of slider) and bottom busing on the Guide bushing (captivated on the fork tube). The fork tubes do not slide as well as a bike with less rake therefor the suspension do not work as well.
Trail: The FL's have between 6.6" & 6.9" of trail. Great for going straight and poor for maneuvering. If you wish to near unconscious while riding, a longer trail requires less input.

 

You have that all wrong! A heavy bike needs high quality suspension, even to ride in a straight line, if the riders are to enjoy a high quality ride. I just wish we could change the minds of riders who think only sports bikes should have good quality suspension.

Next time you hit a pothole and brace yourself, think how much nicer the experience would have been if your suspension was 21st century and you had just bumped gently over it, like a $20k+ bike should.

I have ridden the bike you see in my sigpic many thousands of miles in the USA and Canada as well as East and West Europe and the worst roads I have suffered are those in USA. You chaps are in the greatest need of decent suspension, believe me!

The sooner you all wake up to that the better off we Harley owners will be. And the factory might just respond and upgrade their bikes - something that is long overdue!