Dyna air shocks : V-Twin Forum: Harley Davidson Forums

dep47 · 06-02-2008, 05:42 PM

I am considering putting a pair of Ultra Glide standard air shoocks on my 2006 Street Bob . I ride two up with bags and gear, and the bike is bottoming with the shocks set on the highest preload setting. I think the air shocks from and Ultra Glide can handle the weight better and improve my ride. Any comments or suggestions would be appreciated.

84FXRP · 06-02-2008, 10:20 PM

Quote:

Originally Posted by dep47

I am considering putting a pair of Ultra Glide standard air shoocks on my 2006 Street Bob . I ride two up with bags and gear, and the bike is bottoming with the shocks set on the highest preload setting. I think the air shocks from and Ultra Glide can handle the weight better and improve my ride. Any comments or suggestions would be appreciated.

Welcome to the Forum!

You might also consider Works Performance. They make your shocks especially for you - to reflect your riding style, weight, passenger, luggage, etc. They have a dual rate shock setup that is very comfortable on the road. I'm pleased with mine on my '05.

http://www.worksperformance.com/

As to the use of FLT type air shocks, on a dresser (I believe) the shock is attached to the END of the swing arm. On a Dyna the shock is attached MID WAY along the swing arm. For a given "bump-in-the-road", a Dyna shock will be compressed less because it is closer to the pivot point of the swing arm. The FLT shock, being mounted at the end of the swing arm, will be compressed more. Because of this difference in mounting locations, I don't think the FLT shock will give you the ride you're looking for.

spinning wheels · 06-02-2008, 11:09 PM

From what I was told by a Progressive suspension tech. The Dyna's put a lot of bind on the shock. A shock designed for any other H-D, will not put up with the demands that the Dyna chassis will put on it. If you want air shocks, you should put on a pair designed for the Dyna chassis. Hope this info helps.

Pikeslayer · 06-03-2008, 07:35 AM

I heard some guys having the rear shock mounting bolts break. Just an FYI.

dep47 · 06-03-2008, 12:18 PM

Thanks for the information, I will look at the fit and position more closely. I have looked at several brands of air shocks, and am sure many of them will do the job, but I really wanted to experiment with the Ultra shocks, and no one seems to have made this modification yet. The position on the swinging arm could present a problem with movement and create a harsher ride then I anticipated, but I guess I cn't understand the binding part as the shocks would be more up right on the dyna then the Ultra and to my mind that would reduce the binding.

84FXRP · 06-04-2008, 04:27 AM

Quote:

Originally Posted by dep47

... but I guess I cn't understand the binding part as the shocks would be more up right on the dyna then the Ultra and to my mind that would reduce the binding.

It isn't "binding" per se but the travel distance the shock works over.

Travel over any irregularity in the road surface (a bump) is dampened by the action of the shock absorber. The rear fork moves in an arc determined by where the fork is attached to the frame (pivot point) and the length of the rear fork itself. When you hit a bump in the road, the rear tire (and the rear fork) is deflected upward.

For any given bump-in-the-road the fork will be deflected by a specific angle. The far end of the swing arm will sweep out the longest arc for any given deflection. Points closer to the pivot point will sweep out smaller arcs even though the angle of deflection is the same.

Now contrast a Dresser with a Dyna. The Dresser rear shock is attached to the END of the rear fork - The Dresser shock absorber therefore is sprung to dampen "bumps" over a long arc.

A Dyna shock is attached mid-way on the rear fork. Dyna shocks are designed to absorb "bumps" with a much smaller shock absorber travel.

Because the design parameters of the shock absorbers are so different (long travel vs short travel), a dresser shock on a Dyna (or vice versa) will probably not give you the ride you want.

dep47 · 06-04-2008, 08:56 AM

Thanks, and I see what you mean. I have the shocks and will give them a try to see how they ride ,and let you know.

dep47 · 06-10-2008, 08:40 AM

Mounted the shocks with no problem, and with about 30# of air in the shocks my ride height with two up is up about one inch. No more bottoming, all seems fine. I added sperate air valves in each shock, and used a pressure regulated air compressor to fill the shocks to get them even. So for great, the ride is better.