suspension tuning, raising the rear?

[Privateer]

So today I was at a charity ride and the RaceTech support van was there doing suspension setups.  I've been dicking with mine for a while and it's never been quite right so I figure the $20 was worth it to have someone look at it. 

My main complaint is that on the highway the concrete seams beat the crap out of me.  So the guy got it all measured and adjusted the front.  He starts working on the rear and calls me over.  His diagnosis is that the rear is too low, so it's sitting back and feeling unbalanced.  His suggestion is that I add two full turns of preload to the rear to raise it up and even the weight distribution from front to back.

I'm a little skeptical about fixing the suspension with that approach, but I wanted to poll you folks to see what you think.   Would it be more beneficial to spring for the adjustable ride height rod or is cranking down the preload a good-enough solution? 

Note:  I ride 100% street, mostly 'touring' type rides.  I do ride canyons, but not as much.

Thanks for your input.

[battlecry]

Can you reduce the compression damping and/or fork oil height on your bike?

Seems to me that will reduce the jarring somewhat. 

[DarkStaR]

Do you not have an adjustable ride hight rod?

I'd get that first, if you don't have it already.

[Privateer]

Do you not have an adjustable ride hight rod?

I'd get that first, if you don't have it already.

no, the 620's have a solid rod.

[Mr Earl]

The 748 adjustable rod will bolt right up.

[hackers2r]

To me, that seems a little counter-intuitive.  If you are complaining of a harsh ride, I don't see how making it stiffer would help.  I can however understand rebalancing the bike.  In my opinion though, I think it would be wiser to go for the adjustable ride height rod in order to maintain the correct spring characteristics.

[Howie]

There just isn't enough information here to answer your question.  What year and model is your bike?  Is the sag correct?  Is the spring correct for your weight?  Do you have an adjustable link?  If so, is the base setting correct?  You might want to visit Speeddog.

[Privateer]

There just isn't enough information here to answer your question.  What year and model is your bike? 2004 620 Is the sag correct?  it is now.  Is the spring correct for your weight?  According to nick it is and when I gave the Race Tech guy the spring weights he agreed they're correct.  Do you have an adjustable link?  No.  If so, is the base setting correct?  You might want to visit Speeddog.

you're right.  I left a lot to assumptions.  see above.

[Howie]

I would say re check your sag and adjust preload as needed to get the rear up to proper height, then see how it feels.  I don't see how this will help with those expansion joints, but the bike should handle better.  If not happy, try backing off on compression a couple of clicks.  Oh, how many miles on the shock oil?  May be ready for a change.  My experience is those expansion joints are pretty horrible in about anything but a Lincoln Town Car.   

[Turf]

Properly set suspension is witchcraft

dont argue with those who understand it grasshoppa

adj rod is a good idea however

[ducpainter]

I'm no expert, but from experience it is damping that makes a ride harsh or plush, not the spring.

When my monster was stock any 'sharp' bump would rattle my teeth...expansion joints, manhole covers, etc. I had the springs changed front and rear and the forks re-valved. I also went with an Ohlins. The springs installed were stiffer at both ends.

The bike eats up expansion joints with no harshness now.

I don't think adding preload will solve your problem.

[Langanobob]

no, the 620's have a solid rod.

Actually the 140mph 620 Capirex's do have an adjustable rod.  The standard 620's do not.

[Privateer]

Actually the 140mph 620 Capirex's do have an adjustable rod.  The standard 620's do not.

thanks for the clarification.


as for an adjustable rod, I found this reasonably priced one on ebay
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=250728107581&ssPageName=ADME:X:RTQ:MOTORS:1123

I other ones I found didn't look like they were adjustable while on the bike.  nor were they this nice looking.  Motowheels had a really nice one, but at $340, out of my budget.

I wouldn't mind spending a little more to support a sponsor, but didn't find one in my searching their sites.  Any suggestions other than the one above?

thanks.

[stopintime]

The ebay listing is for a lowering link/rod. Not exactly what you need?

If it's true, as posted above, that a 748 rod is adjustable and will bolt on - keep looking for that.

If your Monster suspension gives you a harsh ride, the advice you got might help - despite the more normal raise-by-rod approach. Adding preload is often needed to get the right sag numbers, it's done to get the most out of what you've got. Remember that it will also raise the rear to a geometry where weight is moved forward, which might make the front suspension perform better (not bouncing quite as much).

So, first get the numbers as close as you can - then maybe add an adjustable rod if still needed.
I have learned enough about suspension to know that it is best to get professional help. If you can afford an hour work at a good suspension shop, you will not regret it.

[DarkStaR]

Someone correct me if I'm wrong, but I though the SBK adj. rod was of a diffenent length!?! (lower or higher)?

A stock one from any of the bigger monsters will fit sans 696/796/1100, and thry ARE adjustable while installed...it's just not fun to adjust.  Even with some of the fancier pieces, it's still a pain to get to the lock nuts on either end, but possible.