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Discussion Starter · #1 ·
Okay, so after riding about 40 miles last night and another 10 this morning I realize I was wrong about the shocks being almost right. My lower back is telling me that the ride is too harsh! And on bumpy streets (like W. River Parkway) there are some spots where the road is rough enough that with the current setup it's hard for me to apply the brakes for how unsettled it gets. I'm not sure what I need to change but I need to soften the ride a bit. On the stock setup I rode a 700-mile day without a sore back.

I still have the stock rear shocks. The front end has Ikon progressive springs, thruxton adjusters, and 15w oil. I had 6 turns of preload (base on the thrux adjusters is ~15mm so call it 21mm) on the front, which gave me a static sag measurement of about 35mm. On the rear I had to crank the preload up to the highest level to get static sag around 40mm.

This morning I dropped preload in the front to 2 turns (call it ~17mm) and dropped the rear to the third position, but the rear was wallowing at that setting so I turned it back up to the second-highest, which seems to be a balance point between too mushy and too springy - clearly the rear is underdamped for these settings. This seemed to help a bit but it's still pretty harsh. It *handles* very well when the roads are fairly smooth, but my back hurts (after only about 50 miles!) and the issue of braking on uneven pavement is definitely there.

Theories? Is it just a matter of the fact that the rear shocks suck and need to be replaced (I can tell that they do and they do), and everything will magically be better, or do I have an issue up front that won't be resolved by switching the rears? Judging by the fact that I'm primarily feeling it in my back, I'm guessing this problem is at least primarily the ****ty rear end, but anything I can do to make it better would help.

I switched to 15w in the front because with 10w I felt too much bounce after hitting a bump, which indicated underdamping for the spring preload to me. Maybe I need a weight between 10 and 15?
 

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linsay...my advice is...change your riding postion. The more you sit straight up and down on the seat, the more your back gets pile driven by the road. Likely better shocks will help...perhaps a lot. More of a sport bike position perhaps with rearsets maybe what the doctor ordered for your dodgey back. Mine isn't always good either btw and I can't ride a cruiser very far because of it but I have very little trouble on a stock bonnie with stock preload settings at 190 lbs. The seat matters as well as it is part of the suspension. I believe between the above three factors, you will solve your back issue...that and some exercise and stretching. The Bonneville to me is one of the most forgiving bikes I have ridden for back comfort...partly due to mid controls and riding position.
Good Luck,
George
 

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I'm not telling you anything you don't know...the stock shocks are horrible. Replace them. I like the YSS shocks that bellacorse sells, but you'll do much better with any of the progressive/works/hagon/ikon offerings.

Trying to tune the front w/ the rear so whacked out is pointless...put the front end back to the proper sag measurement and then re-evaluate the oil weight/volume once you've eliminated the rear end as a major contributor of instability.

Cheers,

--Rich
 

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Yes my man - I think that you have already hit the nail on the head. The rear shocks are underdamped for you. You need a higher quality rear.

Sounds like you have the front in pretty good shape - I would leave that alone for the time being until you do something with the back end.

I've watched you ride so I already know you have good posture (not that I was checking you out or anything :D). The seat is always possible - I need to loan you that Corbing to try.

Anyway, I reckon better rears will help a bunch. Then reset the sag, and adjust again from there.

You may well find that you prefer a sag setting a bit off optimal - that's why I decided not adjust my spring tension when we did the measurements - I want to get a few miles in first so In know what I am comparing against.

And with the Ohlins and Ikons - it's feeling GOOOOOOOOOOOOOOD!

I reckon a nice pair of Ikons on the rear will be a cost effective excellent upgrade for ya.
 

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Isn't the sag supposed to be 30% of total travel? In the front the total is 120mm, I believe, but in the rear its only 100mm. So your sag should be set at 30mm, not 40mm. Its been awhile so we're dealing with my memory here. Not what it used to be (kids...).
 

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I think that's right - but I think the big problem here is that he can't achieve that anyway, and then the damping is insufficient.

That's how I understand it anyway.
 

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Here's my experience on comfort.

My current bike is a 2007 black America bought 06/2007.

I'm 6'2" and 230 lbs. I ride two up a lot with my wife.

Been riding bikes for over 42 years (I'm 58).

I love this bike but I was not happy with comfort & safety (I will explain)

First: I did not like the way the BA nose dived on hard braking. Thats the safety issue I was referring to. Answer: New Progressive Suspension progressive front fork springs. Best mod ever for the price, ride and control much better.

Second: Original rear shocks on these bikes are terrible. Answer: Progressive Suspension HD412 (Heavy Duty Springs) shocks. Wow what a difference. (412s are best bang for the buck)

Third: I know there are some who like the original seat but at 230 lbs I could not go very far before monkey butt (numb behind) set in.
Answer: A new Corbin solo and passenger seat. Now thats so much better for me and my wife. You either like Corbin or you don't according to research on seats, at 230 I love it.

There is many different combonations of these three things but I wanted to share mine. I love the way it rides now no matter how many miles I plan. Wayne
 

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Discussion Starter · #8 ·
Good points all, I suppose I really just need to deal with the rear end before I can get it any better. Wonder how I'll convince the wife that I need to spend another $300 on the bike? :D
 
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