Harv748\'s ride height tool
 

Mine arrived today. A big thanks to him for going to the trouble of having them made up. I hope he sells many.

Doogalman

Mine also arrived today,very well made-lovely tight fit:),excellent value for money I reckon.Now I may be about to make a fool of myself cos either Im using the tool wrongly,or the ride height is in the wrong field!.

Look nice dont they,might leave it on.:)

Loverly tight fit...thats what we all like...eh...eh...;)

Mmmmh...does look a little on the low side mate...you got me a bit paranoid now...gonna have to go out and recheck mine!

Weight must be off the rear wheel & the measurement taken for the spindle center

mmmh...is that right? I always thought it was taken with the weight of the bike on the paddock stand as pictured, after all, that is the actual ride height when the bike is moving (no rider), with the weight of the bike included, not when it is supported?

I could be wrong?

Also, I have always seen the measurement taken from the top of the wheel nut (flat)?

At the end of the day, it doesn't matter too much, as the final ride height a rider settles for comes down to personal preferences, with the tool allowing you to measure it and record the height in an accurate way for YOUR OWN RECORDS for the future, if things are ever changed such as chain tension/sprockets etc. As long as the method is the same each time...

Looks like 210mm + 20.5mm (half the nut) + sag so probably a few mm less than I run mine

Ahhhhhh...yes...doh!

Forgot to mention (in the notes I included with the tool) to also add halve the nut. U2U to follow for all whom have purchased to date!

Its been such a long time since I measured my old 748 with a proper tool, that I had forgotten that obvious bit!

Am I right in thinking you run 242mm Kev.

This is a copy of the email I just sent to L3OONY with regard to his ill handling 748R

Hi Ian
just dug out my 916 race note book.
mine is indeed set a 242mm fully extended or 232mm under its own weight as I run 10mm of sag, this is from the centre of rge rear wheel spindle to the index mark on my ride height gauge, which is home made but a direct copy of the one we borrowed from AJR.
Also in my notes I have Craig Barkers settings, he came 2nd in Bemsee Supertwins at the time and worked for Ducati London South and therefore used the official Ducati tool, He Ran245mm extended and with the 10mm of sag 235mm under its own weight, if you are indeed using a comparitive tool then your bike at 195mm would turn like a barge and your mates like a super tanker.
Before I got a ride height tool I was told to run the tie rod at 270mm between centres of the fixing bolts, standard is 261mm.
As you look from the wheel nut side of the bike (RHS) the wheel spindle should be bellow the centre-line of the swing arm in between 6 O'clock and 9 O'clock.


Harv any chance of comparing your ride height gauge to mine
Kev

Shouldn't be a problem Kev...I probably won't be at Popham on SUnday...but I'll bring it upto Foxes next Monday if your there?

knew there was something I wanted to speak to you about today..

...my tool...:lol:

To check/set ride height with weight off rear as per Haynes ,whats the best way to support the bike.Abba type stands use the swingarm pivot,so does the ride height tool.:puzzled:

If you have solid footpegs then you can use a couple of axle stands, not recommended if you have standard folding pegs.
I usually just get somebody else to help so the back can be lifted so that the shock is topped out. Once you do it once and get a couple of readings so that you know what your sag is then adjustments become easy

...or I would imagine that with a small trolley jack, there must be somewhere under the rear of the engine casing you can raise the bike just enough to get the wheel off the ground. It only has to be there for a couple of seconds whilst you record your sag.

Is this the way to calculate the sag?.Bike on paddock stand,measure from top of spindle nut to mark on exhaust can = 422mm.
Support weight of bike so wheels hanging,measure again = 443mm Sag =21mm.
Maxton spring on shock,should sag be around 10mm.

Weight off,wheel hanging.

Yes, you got it right. Make sure your measuring stick is vertical.

Yep, and this is where it all gets a bit complicated for my small brain, but I think I'm correct now in that you should be increasing your preload until the correct sag setting is achieved.

Once this has been done, you then should do the front the same way. Once that has been done, you then need to look at the loaded sag (ie with you on it (kit included))...and obtain figures suitable for your purpose, ie road or track.

If you find you cant obtain a suitable loaded sag figure whilst still maintaining the static sag at the correct setting, then this is pointing to incorrect springs for your weight.

As with anything to do with suspension...this is probably all bollox!

Someone please correct me if I'm wrong.:puzzled:

Nope, no bollokcs, that.

Set the sag to 10mm by increasing pre-load on spring.Attach R.H.T,back wheel hanging measurement top of nut,top of tool=239mm+21mm axel centre = 260mm.Is there enough adjustment left on the tie-rod to get down to 245mm?.Or have I got this wrong.

Something doesn't sound right. I can't believe you're running a 260 mm ride height with the rod at the near shortest length.

Ride height now exactly 245mm.224mm top nut /top of tool+21mm.Tie rod at its shortest length almost,the only non standard part is the spring,which is a Maxton item as the standard spring was way too stiff for my weight.
Measuring from top of spindle nut to fixed point:-
Bike back wheel hanging =443mm
Bike on paddock stand = 433mm
Bike plus my weight = 400mm
Does that seem about right:puzzled:

Not to me it doesn't, sounds as if there is to much loaded sag, can't be sure with out checking a few figures and having a bit more info,
Do you know what spring rate the Maxton spring is, what is your body weight and was the measurement taken with you in a prone riding position.

just thinking along the lines that 33mm of sag is approximately 16.5mm of shock travel and if the spring is say 7.5kg/mm then thats a few Kilos needed to move the shock that far especially when you allow for a front to rear weight bias of around 50/50

Thanks for the comments so far,Im not sure what the spring rate is,had to wind on a fair amount of preload to get 10mm static sag. Im 71kg sat upright on bike when mesurements taken.Im confused as to calculating loaded sag,is it the difference between the static sag and rider or unloaded +static+rider,in my case:-
Static measurement433mm,+rider =400mm Loaded sag 33mm.or
Unloaded443mm,static433mm+rider=400mm Loaded sag 43mm.
Most of the web set up guides suggest 30-40mm loaded sag,am I that far out?