PR3 rear PR2 front

[johnnyYTED]

  I have ridden on Michelin Macadams for years but they stopped them.my last rear was a battlleax which wore unevenly, so this week I got a Pilot Road 3 160/60ZR17 on the rear and a Pilot road 2 110/80ZR18 on the front.  Sydney City Motorcycles Campbelltown,told me they cant get a PR3 for the front ,, is this true?
I tow my trailer a lot so I'm hoping to get good milage from the rear,, I'll be  riding to Grey Gum cafe RTE tomorrow (without trailer) on them and see how they feel on my 98, ST1100.
  I'm  wondering how the difference between 160/70 to 160/60 rear and 120/80  to 110/80 will affect the ride, as the blokes at SCM couldnt really explain it.   the 160/60 as oppossed to 160/70, will lower the rear 1 cm...   
as earlier ST11's had 110/60's front then went to 120/60's  I dont see the front acting too differently, with a 110. 
Any views on this,anyone? thoughts appreciated..thanx

[Streak]

Tyres are like buying shoes, everyone likes something different, I am on my second set of battle axes on my  and I could not be happier, my first set I covered the better part of 18,000km from them, with alot of two up work.

Be careful with tyre sizes, as it makes a large difference getting the bike on the centre stand also....

[saaz]

All standard ST1100 and earlier ABS models used the 110/80-18 front tyre.  Later model ABS ST1100 (from 1996) use a 120/70-18 front tyre - the front rim is wider to take that size.  Rear tyres on all ST1100s are the 160/70-17.

As Streak mentions, the 160/60-17 rear will make the bike sit a bit lower, make it more upright on the sidestand, harder to get on the centre stand and lead to a few more revs at the same speed (this might suit towing).

I have used 170/60-17 and 160/70-17 rears with no issues on a standard model.  While I prefer the standard 110/80-18 front if possible, a 120/70-18 front works just fine.  Riding on new tyres makes more of a difference than what size they are - I just put on a new set and the bike felt like it was 100kg lighter with sensitive steering again.

     

[alans1100]

All standard ST1100 and earlier ABS models used the 110/80-18 front tyre.  Later model ABS ST1100 (from 1996) use a 120/70-18 front tyre - the front rim is wider to take that size.  Rear tyres on all ST1100s are the 160/70-17.

As Streak mentions, the 160/60-17 rear will make the bike sit a bit lower, make it more upright on the sidestand, harder to get on the centre stand and lead to a few more revs at the same speed (this might suit towing).

I have used 170/60-17 and 160/70-17 rears with no issues on a standard model.  While I prefer the standard 110/80-18 front if possible, a 120/70-18 front works just fine.  Riding on new tyres makes more of a difference than what size they are - I just put on a new set and the bike felt like it was 100kg lighter with sensitive steering again.

   

I think you will find that the rims on both standard and ABS models are the same at 3"x18"

I'd stay away from the 160/60-17. It will fit but the load index of 69 (325kg) is below the 73 (365kg) spec tyre 1100. The 170/60-17 is a better option having a load index of 72 (355kg). You may be ok if you ride on your own, but add the weight of your pillion, and any gear you might carry or tow you may very well exceed the weight limit on the rear tyre.

Now, if you have ABS a different spec tyre from standard might upset the ABS computer as the sensors monitor wheel rotation.

[johnnyYTED]

a further question for me is about the 'V' and ZR bit in the size,,  is that then the load rating code or what..
Alan I also thought the rim size remained the same. I was originally told my old 120 om the front was more something x police bikes like mine has.
I'll have to be aware of my loading when towing.. I dont go 2up often or load a great deal in my trailer. just stick to essentials.   
no abs on mine

[alans1100]

a further question for me is about the 'V' and ZR bit in the size,,  is that then the load rating code or what..
Alan I also thought the rim size remained the same. I was originally told my old 120 om the front was more something x police bikes like mine has.
I'll have to be aware of my loading when towing.. I dont go 2up often or load a great deal in my trailer. just stick to essentials.   
no abs on mine

If your trailer is loaded right you shouldn't get more than 10-15kg on the tow ball.

I just went to check what the ZR meant myself. It seems tyres used to go from V to Z in terms of speed ratting but recently W and Y were added.

V -- 240km/h or 149mph

W(ZR) -- 270km/h or 168mph

Y(ZR) -- 300km/h or 186mph

ZR -- Above 300km/h or 186mph

The tyre size required for your 1100 is under the seat.

I remember a dealer in Perth telling me that the ABS took a 110/80 tyre. No way would he have it that it took a 120/70 until I showed him the tyre info under the seat.

On the side of the tyre you will the tyre size (120/70ZR18 e.g.) and also next it (59W e.g.) The 59 is the load rating and W is the speed rating. The confusing thing is that the W and the ZR in tyre size mean the same but looks as if it's not.

2013_0906tyre0001 by Alan, on Flickr

Load rating of 59 e.g. is a mystery if you don't know what it is but also on the tyre is the weight rating @ the tyre pressure

2013_0906tyre0002 by Alan, on Flickr

[Rodd]

I saw all the comments about how the bike will sit more upright (and to be careful when putting the bike on the side stand) and the gearing will be effected due to the lower radius of the 170/60 tyre I have found that I feel little if an difference after fitting the new Verge on the rear of my bike. I need to keep in mind that a worn 160/70 tyre will only have a difference of about 4mm over the worn old tyre (I have found that car tyres can vary greatly in diameter/radius between brands for the same sized tyre.. not sure about bikes). I have found no problems at all so far with going to the 170/60 rear tyre over the 160/70.
With regards to gearing I found that with the CX range of bikes I was often looking for an extra gear, but not so with the ST1100.. sometimes I even check to see if I have put it in top gear! LOL

[johnnyYTED]

 
ZR68 W ON REAR AND 59W ON THE FRONT..  270 KP/H WOW...    i lost my  'HOON'  traits along with too many points.
 a long long time ago..
I'll have to hold back my trusty STeed to stop him getting the giddups,, wearing new shoes.  

[alans1100]

With regards to gearing I found that with the CX range of bikes I was often looking for an extra gear, but not so with the ST1100.. sometimes I even check to see if I have put it in top gear! LOL

When I first got my 1100 I kept looking for the extra gear (6th) as 3500 rpm seemed to much at 110kph.

I've just put my first 170/60 on the rear and there's just enough difference in the gearing to stay in 2nd gear where I would have changed to 1st with the 160/70 tyre.

[saaz]

The earlier ABS and all standard bikes share the same front rim (3.0" x 18). The 1996 on abs bikes have the 3.5" x 18 rim to suit the 120/70-18 tyre.  The later model abs rim can be used on other ST1100, but be aware that the front rim bearings differ for pre-96 and 96 on.

http://www.st-owners.com/forums/showthread.php?120321-ST1100-Front-wheel-swap

[saaz]

I have absent mindedly left the ST1100 in 4th gear after going through a town and just pressed resume on the McCruise.  After a while I realised it was not in 5th.

I saw all the comments about how the bike will sit more upright (and to be careful when putting the bike on the side stand) and the gearing will be effected due to the lower radius of the 170/60 tyre I have found that I feel little if an difference after fitting the new Verge on the rear of my bike. I need to keep in mind that a worn 160/70 tyre will only have a difference of about 4mm over the worn old tyre (I have found that car tyres can vary greatly in diameter/radius between brands for the same sized tyre.. not sure about bikes). I have found no problems at all so far with going to the 170/60 rear tyre over the 160/70.
With regards to gearing I found that with the CX range of bikes I was often looking for an extra gear, but not so with the ST1100.. sometimes I even check to see if I have put it in top gear! LOL

[alans1100]

The earlier ABS and all standard bikes share the same front rim (3.0" x 18). The 1996 on abs bikes have the 3.5" x 18 rim to suit the 120/70-18 tyre.  The later model abs rim can be used on other ST1100, but be aware that the front rim bearings differ for pre-96 and 96 on.

http://www.st-owners.com/forums/showthread.php?120321-ST1100-Front-wheel-swap

Thanks John, those wheel sizes never seem to make it into the manual (well not the one I have) and they just mention tyre sizes.

The only info I could find suggested they were the same size http://www.foreven.com/motorcycles/Tyres/HoST1100.htm

General Comments

For the 1996 model year, along with some other minor changes, the stock front tyre size on the ST1100 was changed so that the bike could use radials.  The rim sizes were unchanged.  This means that there is no reason not to run an earlier-model ST1100 on radials -- all that changed was the tyre specification, not the rim.  The 3" front rim is wide enough for the vast majority of 120/70 radials.  So here, despite there being an apparent difference between pre-96 and 96-on models, I'll treat them as the same.
One known problem with the ST1100 is the tendency for headshake under deceleration.  The radials I've selected below (especially the ME-Z4) should minimise that tendency.

 

[saaz]

Alan, the manual does not list the wheel rim specifications, but over the years I have remembered that owners have mentioned what the specifications of the wheels were (they are embossed into the wheel) as the issue of using later model ABS rims on the front has come up.  For most owners, getting the right wheel bearing size is probably the more important issue, as 120/70-18 front tyres seem to work ok on the narrower rim, but probably not ideal.

The earlier ABS and all standard bikes share the same front rim (3.0" x 18). The 1996 on abs bikes have the 3.5" x 18 rim to suit the 120/70-18 tyre.  The later model abs rim can be used on other ST1100, but be aware that the front rim bearings differ for pre-96 and 96 on.

http://www.st-owners.com/forums/showthread.php?120321-ST1100-Front-wheel-swap

Thanks John, those wheel sizes never seem to make it into the manual (well not the one I have) and they just mention tyre sizes.

The only info I could find suggested they were the same size http://www.foreven.com/motorcycles/Tyres/HoST1100.htm

General Comments

For the 1996 model year, along with some other minor changes, the stock front tyre size on the ST1100 was changed so that the bike could use radials.  The rim sizes were unchanged.  This means that there is no reason not to run an earlier-model ST1100 on radials -- all that changed was the tyre specification, not the rim.  The 3" front rim is wide enough for the vast majority of 120/70 radials.  So here, despite there being an apparent difference between pre-96 and 96-on models, I'll treat them as the same.
One known problem with the ST1100 is the tendency for headshake under deceleration.  The radials I've selected below (especially the ME-Z4) should minimise that tendency.