You could drop the forks flush to see how it handles. Also take into account how much effort it takes to stand the bike up and to the other side. If you lean the bike in the corner you want the bike to stay on that lean with little to no input,,neither wants to stand itself up or fall further in the corner by itself. According to taste. 42psi is probably just in case you carry a passenger. Sounds like you have it worked out. I have spent alot of quality bike time just riding the same route every day just to play with the clickers and geometry. I know just enough to know I don’t know that much still learning

 

I thought about that as the start point but I think 10mm would be too much - not enough loading on the front to give feedback, even with less damping, and with less damping, it would get too imprecise and "bouncy". When I've done it the other way for faster steering on other bikes, I've never gone more than 8mm because that was a huge difference. So I tried 5mm... and I think I got lucky.

I've always run 36/42 and when the bike was new, it only had a wobble near the top speed. The S23, ageing springs (and more front and rear preload to maintain the correct sag) created some wobbles at lowers speeds - even at 135km/h or so. +5mm fork height change with no damping changes has fixed that for the time being. Leaving aside new suspension, I wonder whether tweaking this change by small amounts over time can get a better result. But of course, that will take a long time...

 

I’ve occasionally had bikes getting too high at the front gave me the opposite effect and got more unstable but mostly in a straight line on bikes with long travel suspension

 

Many scooters do that - something like 40/60 front/rear weight distribution, so the front feels light in normal use, and when a pillion sits on it, the front is very very twitchy. Add small wheels, a pivoted engine unit that heavily damps the rear wheel movement, and a double instead of triple clamp front, and it's entertaining in the wrong way. 16" wheels aren't too bad but the most common combo is 14/13 and having experienced that recently, I know to avoid it, and smaller.

This is the first motorcycle I've had that runs close to instability from the factory. I supermoto'd a XLR250R and even that was more stable than this. Is the gen 4 more stable?

 

I’ve only just worn out the tyres on my24sp and just started thinking about tyre sizes. I might try a 180 60 and just drop the forks a bit. It seems pretty much spot on handling wise for me I haven’t even turned off lift control or race mode yet. Twice only I have felt a little wobble reving it out passing a truck or something merging lanes on the highway and was worried it didn’t have enough power. It’s given a little wiggle but in a fun way. I haven’t had a race kinda mind set just taking it easy. I have had it up to 200kph ish once and hit the rev limiter for some kids going mental for attention once. So I just don’t know yet. I don’t think it needs a steering damper. It’s a awesome bike and has enough power. It’s not like my other bikes that go 130kph out of 1st gear. It’s a new kind of machine to me and maybe I just ride slow now. Working through some health problems also

 

I have a new Dunlop q4 180 60 tyre I’ll try remember after I drop the forks some. I’m going to love it no doubt

 

They're track day tires right, and you're gonna raise the rear and lower the front - stiffer springs too?

I'm going the opposite softer old springs and more rear bias...

 

I’ll do nothing first but I’m 99% sure I’ll be raising the front maybe all the way until the forks caps are flush with the top triples so I get to feel both extremes then probably set it somewhere in the middle. The rear shock on the sp has an adjustable collar I didn’t see for a while but it looks hard to adjust with the shock on the bike. I’ve been riding the bike very sedately but there are some really twisty technical roads near me that I’ve been only riding on my super motard, the reason I built that bike and it’s a 300 two stroke I’m going to retire that bike and use mt09 for that riding. The sides always wear faster than the middle, same with my old gsxr750. I haven’t ridden my hayabusa much since I started a street fighter conversation years ago so it will take over from the mt09. It has Dunlop roadsmart 4 on it still from a long time ago and they look pretty old and hard but they are probably ok. The q4 tire I have coming in the mail for the mt09 was on special and the taller profile i think my bike needs so at the moment it makes sense to turn it into a twisty bike weapon no high speed stuff. I will be looking for a grippier newer tyre for the front maybe q5 but I’ll see how I go. I’ll take some pictures in the coming weeks of tyre wear and the tight corners. It’s twisty enough that I don’t need to go much over 120kph just all corners. I just ride on road for fun no competition just lucky to live right in the middle of the twisty bits at my front door people ride a fair way to let loose every weekend. A old rider died on my road about a month ago and I’ve broken a few bones on this particular road so I try to keep the speeds down. I’m just going one step at a time now with all my bikes no competition with anyone on weekends

 

Sorry road 3 I think I’m ready for sporty tyres tires again. I have power 5 on my 300

 

I would love to have multiples bikes set up for every purpose but at the moment, this is my only one so it needs to be an all rounder.

I took my wife to work and her 50kgs (plus her 8,000kg handbag, haha), combined with a nearly empty tank and the rear preload set to 7/7, left the front feeling a little too light in traffic. Unfortunately, the rear spring needs 6/7 now to get 40mm rider sag for me alone, so 1 notch more for a pillion is not enough. When it was new, 5/7 was fine for me alone and 7/7 was okay with her too. Now, if I turn it up to 7/7 for just me, I like the ride but the instability is worse. So basically, I need a new and stiffer rear spring at least, and I doubt I'm going to be able to resolve this any other way.

Anyway, I decided I'd have to do some trial and error changes, so I dropped the clamps down the forks 10mm so 15mm is protruding above the top yoke. I immediately didn't like the turn in - the bike falls less predictably instead of turning consistently so I was much slower into corners, however, high speed stability is fine. I'll leave it like this for a week and see if I get used to it.

In the meantime, I need to find a higher rate rear spring - can anyone recommend one? Load varies between 90 and 150kgs.

 

I also have love for my little Honda mw110 scooter it’s a chunky delivery scooter I hope to make use of it sometime soon. I like all bikes

 

I think pursuant is the man to ask about springs

 

I always looked down on scooters but a friend persuaded me to try a maxi-scooter and it was so comfortable and convenient, with better weather protection, less maintenance and more storage - perfect for commuting or a quick trip to the shops. The only thing to adapt to was the left brake lever instead of a clutch, and to get a bunch of new tools for the CVT. Now I wouldn't be without one.

Anyway, for the MT-09, after looking at spring rates, I wouldn't want much higher than stock 100N/mm (571 lbs/inch) and that would depend on its exact length and preload, so I'm going to try adding a washer as extra preload for the stock shock first - remove the spring and add one M56 washer to it, perhaps with some adaptation. We'll see. I'm also going to get a new shock with remote preload adjuster and order a new spring at the same time.

 

Today, I removed the shock and compressed the spring to remove it from the damper. The tool for this was US$15 - same as this video - How to change a shock spring with a $29 tool! DIY on Ohlins Race Tech Fox OEM The only extra advice is to compress each side the same, half turn by half turn, and be aware of the tool's desire to slip round the spring. It's not a disaster if it happens - just have to unwind both tools to reposition and start again.

With the split retaining washer and spring removed, the cup washer at the other end still won't come off because of the end cap at the top of the damper section, so any extra washer has to fit onto it, not replace it, nor go under it. The split cup washer at the other end doesn't offer an easier solution, so that means to easily add preload, I needed a washer to be 52mm internal diameter to match the existing cup washer (the spring is 56.3mm internal diameter) and ideally 78mm outside diameter to match the spring. It's non-standard for metric - M52 (54mm internal diameter) is the closest but that's thicker than I wanted too.

So, I used a 3mm thick washer from a hydraulic system that is 55mmx95mm and cut it down to 80mm. Put it all back together and went for a ride - it works exactly as expected and I'm very happy at 5/7 rear preload and 7/7 should now be fine for a pillion again.

To save time, I didn't unload the spring from the compressors to measure its free length. I guess it's 160mm?