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Discussion Starter · #1 ·
I have an 08 and never been a fan of the generalized suspension tables found in owners manuals. I much prefer to adjust using the sag measurement method. My question is what is the recommend sag front and rear?

Pardon me if this has already been discussed, I did do a search and could find this information.
 

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If you input suspension settings in the search window you should get at least six pages listing individual threads.

Bottom line is that there is no recommend sag. It is an individual thing based on your preferences and requirements. Different riders need/are more comfortable with different amounts of sag.

If you tell us your weight (kitted up) and riding style, one of the suspension gurus can make a starting point recommendation. Then you can ride, evaluate the settings, and tailor them to your needs.
 

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Discussion Starter · #3 ·
Thanks, and yes I'm well aware of the process of dialing in a customized (personal reference) suspension setup which is why I asked the question.

Most of the bikes I've owned, there is a factory recommended starting point for sag measurement suspension setup method. This is just a starting point for dialing in the suspension to meet ones preferences. For example on my Buell 1125R it's 35mm front and 25mm rear. The generic tables in the Buell manual are shooting for 30mm front and rear. As you can see the sag method starting point is shifting a bit of weight toward the front compared the generic tables in the manual. This made the bike much more responsive during turn in. I think it's also safe to say that Buell is assuming if you want to manual setup sag and dial in your suspension that you are looking for a bit more aggressive riding style starting point than the generic tables in the manual.

To answer your questions, I'm about 180lbs with gear on. I live near and spend a lot of time riding in the NC Mountains and prefer a little bit more performance oriented setup than most would like for street use. By that I mean I'm not an overly aggressive riding style, but prefer a suspension that is a bit firmer than the average street setup as I spend a good bit of my riding in some fairly nice twisties. I'm not going to be knee dragging on the Sprint though as I'd take the Buell to the track for that.

Currently I'm finding the front grip less than confidence inspiring. The back seems firmly planted in high speed full lean, but the rear tends to step out in low speed full leans. The low speed grip loss may however be just me getting use to the throttle response. I like pulling strong in the turns and still have a bit more slack in the throttle than I'd like. So as you can see, I'm still learning and bonding with the bike and just trying to adjust and move the setup a little more in the direction that will suit the riding that I do.

Any suggestion would be welcome.
 

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As OnD said so very much depends on......everything that we don't know about you.

Here's a good link.
http://www.racetech.com/articles/SuspensionAndSprings.htm

What you describe can be attributed to many things like tires, tire pressures, current settings etc., etc., etc.

For instance you mentioned front vagueness and the rear stepping out. What TP are you running? Too high a pressure can cause both of these symptoms as well as too stiff a compression especially in the rear.

Many confuse stiff with performance. Not so good on the street. Our local professional racer, two time AMA super bike champ, Daytona, currently Macao and IOMTT sets his front at 41mm sag.

Currently my setup is:
Misch. Pilot Road II's TP 34 front 36 rear
Front has a higher viscosity oil with 10ml more volume. 31.5 sag.
Rear is set at 26.5 sag.

I'm 200lbs fully kitted up and these setting I'm finding may be a bit stiff for the conditions I ride on and will probably loosen them up some.

Tires/tyres make a Huge difference in handling as well as the pressures.
Cranking in preload at the front is not a good idea either, this is why I opted for heavier oil and a bit more of it. With this I can run less preload and still keep the front planted and compliant.
Many are concerned about front end dive. Me less so, as long as I am not bottoming out. The more weight I have up there during cornering and braking the more I like it.

A lot of perceived front end problems can be traced to the rear. (I think you are too stiff back there either TP/preload or both) I'd also venture that you are running too much tp and or preload in the front too.

Here's a link to a thread showing my new PR2's. About all my riding in done in the mountains on fairly bad logging roads so keeping things planted is very important to me.
http://www.triumphrat.net/sprint-forum/113942-i-m-gonna-be-scarce.html

So far she's tracking straight in the low and high speed stuff up and down hill and handling the transitions quite well. I recently made some major changes in tires and setting both front and rear and still twiddling with it a bit.

Don
 

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Discussion Starter · #5 ·
Thanks, there's a lot of good information in there and you have given me at least a starting point on the front and rear sag. I agree with your assessment as far as the rear probably being too stiff on my setup. I had already suspected that was probably the culprit. I at least have some reference points now to start working from. I'll post up later what I learn and results.
 

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What a nice informative thread:)

I am not absolutely certain because two racing budds of mine I ride with set up my bikes for me................I just sit there while they do all the work!:D

But I think mine is very similar to Don's set up and it is firm but I weigh more than Donski, I'd say a good 30 -40lbs lbs heavier (I am about 225lbs nekkid).

AFAIK my sag is about 30 at the front also running heavier oil and more volume in the tubes.
I think it is about 25 at the rear, my rear shock was rebuilt though, re-valved etc but stock spring with 5mm spacer.

I am running Pilot Power 2CT's with 33psi fnt and 36psi rear
(For solo riding) for pillion I stick 1- 2 more pounds in the back tyre.

My riding is probably very similar to Don's, almost all back roads and mountain corners.

When lighter peeps ride my Sprint they complain at how hard everything is, and it is very firm but it suits what I do nicely.

DaveM:)
 

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Discussion Starter · #11 ·
When I got home today, I checked all the suspension settings as a baseline and to confirm they were at the factory settings.

Don - suspicions confirmed! The front was at 10mm, but the rear was 21 and 1.75. TP is 34-36. I went ahead and set it back to 25 & 1.5. I know from experience working with the suspension clinics at track days, that you should only make one change at a time so you can gauge the effect. So for now I'm going to start with the factory default settings, take some sag measurements and ride it a couple days to see what it feels like now. Next change will most likely be TP.

On another note. According to the owners manual the rear damping adjustment is supposed to be on the right. It was not, it's on the left (same side as the preload). Is my rear shock base rotated 180 out or is the manual a miss print?
 

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Yep, miss-print. You are absolutely right one change at a time, though I would see if you could get a friend or two and set your sag all at once to an intermediate setting and then go from there. It just takes a couple. You fully kitted out, one or two to do the lifting and one to do the measuring and adjusting.

Last time we revised things after the tire change Jerry did the lifting, Clint did the measuring and twiddling with an on-looker's input (very welcome considering who it was) while I conferred and sat there scratching myself. We had it done in 5 minutes.

One thing to consider might be to drain the fork oil and try the next higher viscosity of the same brand if you can. This essentially changes the valving which effects both compression and rebound slowing them down some. Also, 5-10 ml more than standard helps. My experience and I think DaveM feels the same way is that this enables you to run less pre-load giving more compliance and more stable and controllable fork travel.

Don
 

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I sent you a PM shortly after the first couple of posts to save cluttering the board with a long post.....

For the rest of you, I weigh 250 butt naked and white.... now try and sleep with that visual burned into your poor sickened minds! :p

I have my front set @ 5.9mm and the rear .5 RD and 18clicks.... tires 33 F 36 R - Michelin Road 2s
 

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The 5.9mm really has nothing to do with the sag measurement that would be correct for the OP. That just has to do with how far you have the top pre-load screw screwed in. The sag measurement is the important one. Same thing with the clicks in the back.

Pardon but I'm seeing a whole lotta pre-load in the front and very soft in the rear. I'd be surprised if you weren't running wide accelerating out of a corner. Unless you had the rear re-sprung.

This for the OP's 180lbs. would be pretty much out of the ball park.


I sent you a PM shortly after the first couple of posts to save cluttering the board with a long post.....

For the rest of you, I weigh 250 butt naked and white.... now try and sleep with that visual burned into your poor sickened minds! :p

I have my front set @ 5.9mm and the rear .5 RD and 18clicks.... tires 33 F 36 R - Michelin Road 2s
 

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Hi Dolson, I have no issue with your comments and I appreciate you sharing them, but perhaps I should clarify my intent (I wrote a MUCH more extensive PM to the chap as stated)... My settings were shared there just as an example of a personal setting, NOT with the intent that they be 'right' or copied by someone else.

I did have 'sag' set by the race shop and the bike handled in a frightening manner (they also informed me I was too heavy for the stock suspension and it needed to be upgraded both ends).

Whilst my setting IS weird (and that is why I shared it), I have arrived at that by a process of trial and error, adjusting one setting once each week (or putting it back) before riding some of the same roads on each weekly ride; until I got the bike transformed from something that picked up on every snake or crack in the road, wanted to change lanes with the slightest gust of wind and was very unstable; into a beastie that I love riding, that is steady as a rock, drops into corners nicely and feels 'safe and steady'. I can now corner bends that were scary at 45 @ 85 and feel good... *That is relative of course, the front of the bike still does not feel 'good', especially on bumper surfaces compared to others I have owned and the front dives like mad at any application of the brake, but it is the best I can get it until I can afford to upgrade the forks with new springs, racetech valves, etc...

All along I have bitched with the store about the front end being too soft (I bottom the forks out on a regular basis - I did the old 'cable tie trick' to find out how much travel I had left after reading the suspension stuff on here, and discovered the answer was 'none') - so I don't know whether my forks are softer than most for some reason (seems unlikely, but your comments and my settings seem to suggest something), but this is what works.

If I have the front any stiffer it feels like wood, any softer it wants to tank slap (once you get quite a bit softer, it just heads that way)... and I discovered that the stiffer I made the back (I started experiments with it at '5', the race shop had it dialled all the way in), the more twitchy and unstable the bike felt, I just adjusted it down until I went past the point of feeling 'its best' and then put it back... the front I tried everywhere from all the way in to about 15mm out before ending up here - so I really don't know what else to share - strange I know, appears to go against some of the 'known wisdom' - but it works for me on this particular bike - and that is the reason I was sharing, to demonstrate that 'personal aspect thing. :)
 

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Sag? What sag? :D

Just put on my new Ohlins rear and I get about 18mm total rider sag. I was concerned about it - but after riding it for a few weeks. WOO HOO.
 

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Discussion Starter · #18 · (Edited)
Here's a video on the Sprint ST Suspension from Dave Moss with Catalyst. I've done a suspension clinic with Dave before and he knows his stuff. That being said I couldn't glen too much on tuning the Sprint suspension from this video other than if your outside the range of 145 - 190 (geared up), it will probably need to be re-sprung.

http://www.youtube.com/watch?v=OU2Fz02HPvk
 
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