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955i Suspension -- Fork bottom-out measurement?

11K views 7 replies 3 participants last post by  gonzojournalist  
#1 ·
Trying to make the best of the stock suspension on my 2004 Speed Triple by getting the settings dialed in for my weight and riding style. I've been monitoring my fork dive ala' a zip-tie on the forks and have found that with aggressive riding and a stoppie or two in for good measure, I seem to max out at 10mm of chrome showing at the factory preload setting (5 rings showing). Does anyone know what the bottom out measurement is for these forks? I want to get about 1cm of clearance from my harshest dive to the fork bottom out measurement, but I'm not sure of where that point is, or if I'm already hitting it (which would be BAD).

I haven't touched the rear preload yet, but it seems like I could do for a pinch more there, but I don't want to make any changes there until the front is close to ideal.
 
#4 ·
Yeah,

120 is pretty much standard, there are a few that aren't (like a 675).


Either way, rider sag should be set roughly 30mm-35mm like pretty much everything else. Its hard to find data on the Speed Triple/Daytona, but there is a SHITLOAD out there for the CBR900, and its the same showa fork.
 
#6 ·
Try this it is a good and cheap way to help fix you up.

Remove the oil and replace with 7.5wt and air gap of 110mm/105mm lowering the fork leg 5mm through the triples will help the bike turn in, but you will lose travel and the guard will hit the under side of the triple clamp under hard braking. Use the air gap to control the travel.
Turn the comp all the way in and then out half a turn on both legs and rebound turn all the way in then out one full turn on both legs.

Wind the preload all the way in and then back four turns.

Run a 190/55 rear of a 180 rear tyre and you will be a lot faster........
 
#7 ·
racecomp said:
Try this it is a good and cheap way to help fix you up.

Remove the oil and replace with 7.5wt and air gap of 110mm/105mm lowering the fork leg 5mm through the triples will help the bike turn in, but you will lose travel and the guard will hit the under side of the triple clamp under hard braking. Use the air gap to control the travel.
Turn the comp all the way in and then out half a turn on both legs and rebound turn all the way in then out one full turn on both legs.

Wind the preload all the way in and then back four turns.

Run a 190/55 rear of a 180 rear tyre and you will be a lot faster........
Questions:

The stock weight is 10wt as I understand, wouldn't the 7.5wt increase the rate of change for the dampening? Too thick of a fluid or too much dampening is bad because it can cause packing, leading to bottoming out, but going too far the other way seems like it'd make dampening too light, causing the opposite affect. I've never dabbled with weights though in forks, so it may not be nearly as dramatic as I am making it out to be with only a 2.5wt change. Actually, this would be in affect similar to new valves as more fluid would flow correct? So as long as my springs were sized appropriately, it wouldn't be bad at all.

The stock air spring is 120mm correct?

Current suspension settings:

FRONT:
Preload - 4 marker lines exposed (about 10-12 turns out from all the way in).
Rebound - .75 (out from hard)
Compression - .50 (out from hard)

REAR:
Preload - Stock (middle of collar)
Rebound - 1.5 (out from hard)
Compression - 1.5 (out from hard)

I am running Dunlop Qualifier 2 tires (120/70/17 front, 180/55/17 rear) -- I originally ran Battlax BT016's with a 190 rear and noted better turn in with the narrower tire. What benefit would the 190 offer over the 180 besides a slightly larger contact patch? (I'm buying tires tomorrow). I'll likely stick to the Q2's as they work well and the price is right (plus I already have a new front that has been in the closet for the last 7 months). I'd like to try a sport-touring tire like the Pirelli Diablo Supersport or the Dunlop Roadsmarts but I think that will have to wait for my next tire change.

Just pulled my wheels tonight and noted normal wear on the rear but the front is completely destroyed... not sure if it is just because I ran it longer than it's intended life, but there was bad cupping (possibly related to low tire pressure as I ran 32lbs cold up front) and on the partial-lean section, there were large flat spots that had developed on both sides. Is it possible my forks could be slightly mis-aligned; causing odd wear?

This has turned into a rather interesting conversation.
 
#8 ·
Correction.

The stock air spring is 78mm for the 2002-2004 Speed Triples. The later models with USD forks have a 120mm measurement. I set my airspring to 68mm and it feels okay, firmer than before, but a bit too much gets transferred through the forks. My RB/CP/PL haven't been adjusted much to compensate for the level change -- so my opinion may change. At present I am looking at backing the fluid off 5mm, to a final measurement of 73mm -- at least until I decide to respring properly.