Dear Brains Trust,
I am running a 15" rear rim with a 165 tyre on the 85 K100Rt now. It has improved the roadholding and handling......but the other day coming home from a ride I had a slightly "spirited" moment and decided to give it some stick. There was a fairly stiff cross/head wind blowing but all I could drag out of the old girl was about 135kmh after about a kilometre along a straight. I've had her up to 155kmh indicated two up before and it felt like it had more to go.

Could it be that the rear rim and adaptor affects the amount of horsepower the bike is producing at the rear wheel ...or is it just she is getting old and tired.....?

I mean, she's only done 232,000km.
Any thoughts?

Sean.

Check if your speedo readings have been affected because of the wheel diameter.

As far as I know, the profile of the tyre, ( Which I forget off the top of my head), ends up with the same gearing as the stock set up. 4,000rpm is still 100kmh indicated as is 4,400 at 110 etc. The odometer has recently died, but as far as I know the speedo is still reading accurately? An indicated 135kmh just felt like that, no faster.

Sean.

hmm pity you didnt have a compression test to compare to seani

i wonder what fuel you are using ....lots of us mob up here use the 98 fuel ....and besides lots of banter about its merits ....i certainly notice the difference when under load and higher in the speed range , besides the mileage that we get out of the "good fuel " per tank .

i wonder if just a good tune up , (air filter replacement at least ) could help your issues mate ? as im thinking that you are more prone to be collecting dust more than many of the rest of us ....

just thinking aloud mate

Some good points Charlie.
I think you're right about the tune up. Been awhile since I even shoved a set of plugs in her. I change all the fluids religiously...but not plugs. I want to put in a new radiator I have and fan, so while I'm at it I will do plugs and air filter etc and see how it goes. I don't have the kit here to do a compression test....but I guess it's a matter of time until I should at least pull the head off and see what the rings are like etc, Then all I need to do is get Caferacer62 to modify my muffler for me and Bob's yer auntie mary! Should breathe a bit better.
Sean.

yes plugs for sure mate ....

those are the simple but proven maintenance necessities for good performance

I'll want to have her running well for the ride to Vic in December. There'll be Triumphs and Ducatis and huge R GS types and Guzzis and more....so we shall need the Brick to lend some dignity to an otherwise sordid affair.

Sean you should have turned around and went back the other way. you know the law of averages and all that. My rear wheel is 2080mm in circumference if that helps 130 x 90x17

The head wind may have had something to do with it, Sean. Our aerodynamics are worse than a 'brick': more like a thermolite block!

Saxon7 wrote:Some good points Charlie.
Then all I need to do is get Caferacer62 to modify my muffler for me and Bob's yer auntie mary! Should breathe a bit better.
Sean.

I agree with the others on fuel..plugs and air filter...can make a huge difference..

As I have found out..if you get the awesome muffler mod by caferacer you will use more fuel only because as GITH pointed out..IT SOUNDS SO GOOD!!!!!!! The bike does have much better mid and low range now. I only lost a couple of k p/ltr but well worth the gain.

Hope you find a simple fix.

Saxon,

Why don't you try to ride with a GPS to check your speed? When I compare my speedo to the GPS, at 140kms, it's off by almost 15k. I installed a smaller tire on the back, and it may have some effect on the reading.
Remember, the speedo is a tachometer translating the rpm into speed.

CF makes a good point it would be interesting to see what the differential b/t the speedo & GPS is after you do the maintence items as well.

You could always go blasting through a fixed speed camera and see what they say on the ticket. Just note what your speedo says at the time.
If it wasn't so cold just now mate I could go for a run up with a compression kit I borrow from a mate in a garage, maybe if we get a bit warmer soon I can do it.
RT

RT, it's bloody freezing here today. So cold in fact that I am heading to Canberra in the hope it's warmer! Sadly, the dog and I are going by the trusty old Falcon as we have a wedding to go to in Terrigal along the way. You're welcome here anytime though mate!

Thanks for the replies everyone and I promise to give the old girl a flash tune up when I get home. 75sta, you're right, I need to do the reverse run...otherwise it doesn't count!

Sean.

if you jump online and find a tyre size calculator and put in tyre size eg 165/80/15 and compare the rolling diametre to that of the original bike tyre eg 130/90/18 it will tell you the rolling diametre difference between the two tyres which will affect your overall gearing

Hey Sean, if you are still in the ACT, if when heading home you travel up the M7 and then M2, stop in and say hi. I work and live within 5 minutes of the intersection of both roads.
I think I sent you my phone number.
rossco

btw, do you know a Paul Camilleri? He lived in Guyra for a long while. Wife is Katherine? Nurse.
I guess he would be in his 70s now.
Wifes uncle.

|Gday Rossco,

I'll be heading home via Wellington etc. Leaving in the morning.Can only do the freeway thing once!( Even in the car) Will catch up next trip to Sydney/

Don't know Paul ......I'm not a local there....only been there 12 years. Takes 15 years to be a local....or 25 if you're from Armidale.

|Sean.

Saxon7 wrote:|I'm not a local there....only been there 12 years. Takes 15 years to be a local....or 25 if you're from Armidale.
|Sean.

lol ...good point seanii

So, in recent times I have put in a new air filter element, new radiator and fan, had a visit from Charlie and Alby and the carbtune and not to forget Bert 2.0's Zorst.



Beautiful early morning ride out of Sydney then up through Gloucester to Walcha and home. Zorst music filled my ears and those drums were definitely beating today. Sat on 120kmh all the way home with 3 squirts to 150 and another to 155 kph. ( Indicated) Each time I ran out of road, not puff...so the old fashioned "ton" is definitely within reach.

That Zorst sounds damned fine bouncing off the hills coming up the hill from Gloucester.

mmm that sounds great seanii

now youll have a little more incentive to fix those tb lower rubbers ?

go "lunch box " !!!!

How cool is that?? Having a bike named after a tupperware container!
Yes, you're right Charlie, I ought to get onto that job as well....though...it crackles marvellously backing off from 6 grand!

good to hear she going well

you might have to head a little further west nice long straights and a odd corner every 10 or so clicks the you will have top speed

warp factor 10 eqals 202 on the enterprise

i could get a sticker made for back if bella agrees she take offence saying she riding around in a lunch box

As long as the Koreans don't think she is the lunch.....