any mathmaticians on the forum able to give me an idear how much lean angle i will gain on my 2010 iron by increasing my spring lengths by 1", 2"?
as i recall i am at 29* now.
notice i said spring lengths, as the spring is not mounted vertically the ride height should increase by a little less than the increase in spring length.


also, as a new rider, i am unfamiliar with different bikes and their lean angles. anyone know what a decent/average lean angle would be on your non-HD cruiser?

 

the ride hight increases by more than the spring length. this is because the axle is behind the shock mount. if you move the shock mount forward you'll get more ride height.

13" springs will give you a noticeable improvement in lean angles. but, i'm not sure how much more. i'll put an angle finder on the tank and lean it over this weekend.

 

Don't you know they all ride Bimmers......LOL

 

WOW your thinking to much into things. The Iron has 11" rear shocks stock and I have no idea why people buy them and then want to lift them up? If you wanted crazy lean angle then you should have got a sport bike, not trying to be an A** just saying. I mean ig you get 13" shocks then you should get alot more lean angle, but just how much I don't know.

 

because most people don't take into account the amount of peg-dragging they'll be doing on a lowered bike. in fact, these lowered bikes are designed to draw new buyers, and those buyers are not likely to understand how the bikes perform.

and its not that people want crazy lean angles. they want usable lean angles. 29 degrees is insanely limited to anyone who enjoys riding.

after a bit of riding experience you have to decide which you like most: looking cool
riding for fun

a compromise is usually in order: fit longer shocks.

 

thanks! you summed it up perfectly. i did not know i was buying "a lowered bike". AS A NEW RIDER i had no idea how limited the lean of the iron was. the more i progress in my riding, the harder i tend to hit the corners, and the more i grind my mufflers.

i figured while i am changing out the shocks/springs with Progressive 412s i could find that happy medium between the current height and something high enough to turn without hanging off the bike.

as far as ride height goes... i see your point about the axle being behind the shock... but i think my idea still applies to the forks and the height of the fork-spring spacers? though, i may have the whole thing mixed up.

 

you wont get much more out of your front. there are two front ends for the newer sportsters. one has standard-length forks. the other is the short fork. the iron has the short fork.

if you dont change the fork tubes/damping rods to the longer version, springs and spacers will only net you a small fraction of an inch in ride height.

dont let this discourage you. 13 inch rear shocks coupled with standard short-forks will get you enough lean angle. you'll also get a decrease in rake, which will make steering a little quicker. and trail will also decrease, making transitions a bit faster too.

i haven't got to put a sportster on a scale yet, but i know that raising the rear puts more weight on the front. superbikes are slightly biased (weight-wise) to the front. i think it gives balance under a hard acceleration, keeping the bike from going wide in turns. this is just a guess i'm no engineer.

the ideal setup, in my mind, would be standard-length forks pushed up into the trees to get the right about of weight bias. the rears would be 13 inches. all springs would be matched (let the suspensions guys do this they're experts) and i'd want cartidge emulators in the front forks and some sort of adjustable damping on the rears.

clear as mud?

 

i appreciate your comments and help very much!

i follow.... i figured i'd grab progressives for the rear in XX" height and drop the progressive fork springs in with enough preload to keep the forks a bit higher while loaded. would that be considered 'matched'?

if i went with a 12.5 in the rear i may be able to gain a bit of front end height by loosening the fork tubes and sliding them down (per reading in the forum here).
though i would not gain as much steering advantage that you noted, i still might be able to lean a bit further and still get my feet down flat with my 30" legs.

its almost always all about comprimise, no?

 

This should also help . Just google

Rubbermount_EVO The second 7 pages of suspension from XLXR

 

I went from 11" shocks to 13.5" ones on my Custom and the difference was HUGE. There is plenty of lean angle available now for "spirited" rides where as before it would scrape pretty easy. The steering response has sharpened up dramatically. And as an added bonus, the ride quality is much better since I'm not bottoming out all of the time. It was easily the best thing I've done to my bike.

W/ your bike and the shorter forks I would look at 12-12.5" shocks. If you go too much the trail gets to be a bit too short. There are a lot of people on the XL forum complaining of high speed wobble from this. My Custom doesn't suffer from it but I believe it has the longer forks as well as a taller front tire (increasing trail). A 12.5" shock should net you plenty of lean angle w/o compromising stability.

As far as the amount of lean gained: it's simple right triangle trig. Measure from the tire contact patch out horizontally to where your "contact point" is when you drag. Then measure up to that point. Plot those on a piece of paper and draw a line from the contact patch to the drag point and form a right triangle. The calculate it from there. Hopefully this drawing will explain it OK.
Please excuse the crude drawing: