Sports touring tyres on a sports bike - what adjustments are needed

I've just put Michelin Pilot Road 3's on my Triumph Daytona 955i.

Now the bike has always been firm, it's a sportsbike, but it's always felt supple with a quality ride too.

I've changed the tyres for something that probably has a much stiffer carcass.

On country lanes and small B roads the bike now has my forearms and shoulders bouncing up and down like I'm using a jackhammer, with the occasion boot in the backside as well, and you can feel the wheels skipping over bumps, to he extent that it's actually blurring my vision of the road ahead, and forcing me to keep my speed down as going faster gives the suspension more to deal with and makes it worse.

I want to make it a bit more supple and forgiving and soak up the bumps better, whilst still maintaining decent damping control and not going soft and spongy or wallow when the road is smooth and I want to push on in corners. I will take it to a suspension specialist to be properly set up, but not until I have finished loosing weight, I have more than a stone and a half to go.

So what do I adjust?

Tyre pressures, currently at 42 rear, 36 front as per Triumph recommendations

Front and rear bouncy bits are adjustable for Pre-load, Compression, and Rebound

Thanks

[timwilky]

The obvious from your description is you may need to tweek your rebound damping, personally I would increase it a tad and see the effect.

The problem is suspension for the road is always a compromise

[flymo]

rather than rebound it sounds like you have the compression damping set too high. If its never been done before I would be looking to set the preload, static and rider sag within optimal ranges first, then if still a little harsh over the bumps back off the compression dampers little by little until you are happy with it.

Have a read through this guide.... http://www.gostar-racing.com/informa...ion_set-up.htm

[timwilky]

I would have assumed basics would have been set when new. Even if the OP has lost a bit of weight. Yes it could be too hard in compression, but I personally would have only looked at that once I had looked at the rebound.

The real art is starting from a known position, document change and effect and being prepared to roll back a change and try something else.

Thanks guys, I'll try static sag first, then I'll try compression and rebound separately setting it back to how it was after each change. I would like to get is compliant within the next two weeks as I'm going to Rep of Ireland on 20th May and the roads can be horrendous I'm told.

PS: Tim, roll back a change, you are slipping into ITIL speak

[timwilky]

Flipping heck Ralph It gets worse, my boss told me on Monday to buy a book on change management. ITIL only says you must have a change management process. I get the feeling I am in for some more theoretical business carp followed by yet another exam.

Seems obvious to me ... main problem is your weight! If you're losing a lot of lbs then it will affect the suspension (rebound, compression, everything). The tyres will feel different anyway but you probably have less 'body cushioning' (if you know what I mean so you'll get a more direct feel through the seat.

My advice is to start with rear shock pre-load and compression, but one step at a time and not bother with full suspension set-up until you stop (or slow) your weight loss as you'll have to continue making finely tuned adjustments as you lose weight.

I weigh 14.5 stone and my SV forks were way too soft so I've got Hyperpro's in the front and thicker oil. If I lost a stone or more, having put the Hyperpro's on, I'm sure the front would feel quite hard in comparison.

Nah, I'm riding the bike regularly and have to do bumpy country lanes to leave and retun home. I only loose about 2 lb per week. The tyre change is what has made the biggest difference, they are brand new and yesterday was the first time I rode on them and noticed such a harshness.

Will leave the expert advice to the experts then, but just read somewhere that change to a different make of tyre can affect geometry of the bike and handling due to difference in spec/profile.

One guy said he had to change by as much as 10mm front and significant change in the rear (preload).

Obviously tyre temp needs to be right and then preload sorted before compression/rebound. What tyre were you running before? Maybe the experts can elaborate on the effect on geometry?

Or have a look at this site - http://www.mistermotero.com/tireinfo1.htm

Your weight will make a difference for sure, well set up suspension will include having the correct spring rate front and rear for your weight. Loosing a lot of weight will undoubtedly make the ride harsher. You need to search the Triumph forums and see what spring rates are recommended for your new weight. Damping and preload obviously affect things drastically but a too hard rear spring will always feel harsh.