free website stats program lowering a ultra glide classic??? | Page 2 | Harley Davidson Forums

lowering a ultra glide classic???

There are a lot of numbers on a motorcycle (price, air pressure, wheel base etc.), but only one of them will kill you "TRAIL". There is a reason HD only offers kits to lower their bikes 1" - Anything more and the trail number starts moving toward the red.

In your picture it looks like you are reaching the ground with knees bent and feet flat on the ground, so your lowering plan must be based more on looks than safety.

Lowering to extremes will cause handling problems more dangerious than parts dragging. At some unknown speed you could go into a wobble be it slight or severe.

If you use your glide for riding, I would strongly suggest you leave the ride height alone.

I was riding behind a friend when his bike went into a wobble at 115 mph and the rear wheel was leaving the ground and bouncing from side to side. He managed to get it stopped and after about 45 minutes he was calm enough to ride back home. He is now an expert on trail numbers.

You can read more about it and see diagrams about rake/trail at scootersperformance.com

Just one person's opinion.......
 
I don't dispute anything you say and in fact I agree with you but good grief, "went into a wobble at 115"? That is so far outside my speed envelope. I bought and lowered the bike to enjoy touring with my wife. We enjoy doodling along at 60 - 65. Who tours on a motorcycle because they want to get there quick? We ride so as to enjoy what's going on around us. If I wanted to experience that kind of speed I'd be in my airplane. No worries about wobble here. ;)
 
ChopperDoc said:
There are a lot of numbers on a motorcycle (price, air pressure, wheel base etc.), but only one of them will kill you "TRAIL". There is a reason HD only offers kits to lower their bikes 1" - Anything more and the trail number starts moving toward the red.
In your picture it looks like ..........
Click to expand...

How would lowering change this with nothing done to the fork, neck, tripple tree arrangement?
 
Nitro-Fish said:
How would lowering change this with nothing done to the fork, neck, tripple tree arrangement?
Click to expand...
You are changing the length of the fork tubes. If you look at the formula for calculating the trail number you will understand the effect this has.

As for my friend doing the 115 MPH. He had built a Boss Hoss and got a little carried away and thankfully he didn't actually get carried away.
 
The attached may explain rake and trail, and how one change will affect another number. It's simple, but the effects are complicated. I have been trying to really understand it for decades. Still get confused.
Forum won't allow attachment: "already been uploaded in steering angle" .
 
Last edited:
I lowered the rear end of my 07 by going to 12 1/2 Progressive 412's. I went the cheap route because it was an experiment. I left the front end alone. You wouldn't think 1/2" on one end would be a big deal and it wasn't, but it did give me just a bit better feeling while stopped at the light. The difference was subtle but noticeable, I had just a bit more weight on both feet and didn't feel like I was going to drop the bike every time I stopped.
The bike handled just fine and maybe slightly better but that is subjective and would vary from rider to rider.
I hear Progressive has a new series that is also 1/2" shorter than stock.
I ended up selling the bike, I told the new owner about the change. About 6 months later I wandered into the shop at the dealership and watched as a new tech was trying his best to pump air into the rear shocks. I gave him about two minutes before I reminded the lead tech that they had been changed.
 
You must log in or register to reply here.
Back
Top