auto tires on ST1100

[91blkst]

Does anyone run or know anyone running auto tire on ST1100? What size auto tire? Need to know because I do a lot of hi-way riding. Would us another rim for the auto and have the reg. motorcycle tire on another so swapping is no problem . Let me know, thanks, HH
P>S> also need to know about the stoc stickers

 

[sirepair]

You will need to swap the rear wheel to a GL1500 one. George has more info...

 

[owl]

I have ridden my Triumph Rocket III on a car tyre - a Toyo235/50 for the last 4 years and for about 30,000 miles.
Haven't fitted the ST1300 with one as yet - I've only had it a month and want to see what sort of mileage I get from the tyres first.

On the Rocket I've increased my rear tyre replacements from around 3500 miles to around 14,000 miles.

Cornering ability is no better, no worse. If you want proof I can post up a picture of my ground out footpegs, and they're higher rearsets, not the standard set up.

Payback is that you need a more positive countersteer effort (which I enjoy) and it tracks worse over rough ground/tar snakes.

If you are an experienced biker you will have no problems, I imagine.

What you will get (and have already got) is a lot of crticism from people who have never tried it and therefore can only speak, not from experience, but from prejudice born out of either ignorance or a closed mind.

Have a look at http://mcdarksiders.forumotion.com/ and speak to some like minded people who have actually been there, done that.

 

[STPaulK]

Technical arguments aside, would your insurance cover a wreck if they found out you were running auto tires? I suppose the policies don't specifically word it to disqualify coverage.

 

[JZH]

Technical arguments aside, would your insurance cover a wreck if they found out you were running auto tires? I suppose the policies don't specifically word it to disqualify coverage.

LOL, if he thinks fellow riders are closed-minded and judgmental, just wait until he meets a UK insurance adjuster... :

In the UK, it is the responsibility of the policy holder to inform the insurer of ANY potentially relevant facts, and swapping a motorcycle tyre for a car tyre would certainly have to be disclosed on that basis. I've heard of UK insurers refusing to adjust a policy to cover such "mods" as heated grips! I'd be very interested to hear which UK insurers had agreed to insure a motorcycle modified in this way.

Ciao,

 

[owl]

I'd be very interested to hear which UK insurers had agreed to insure a motorcycle modified in this way.

Carole Nash.

In writing, on an 'Agreed Value' policy.

And just as an aside, I'm an Accident Investigator by profession.

 

[JZH]

Carole Nash.

In writing, on an 'Agreed Value' policy.

I'm duly shocked. What, exactly, did you tell them?

Ciao,

 

[owl]

I'm duly shocked. What, exactly, did you tell them?

Ciao,

Along with a long list of modifications (my Rocket is a LONG way from standard) gave them in writing that I was running a Toyo Proxes 235/50 ZR16 95W non standard rear tyre.

They OK'd and agreed all of my mods in writing (as they have done for the last 3 years).

I really don't see this as a big deal - I've been runing a car tyre on the back for years, as have quite a few others in the Rocket fraternity. In a lot of ways it is far superior to the standard m/c tyre. Ask anyone who has actually tried it (as opposed to all those who haven't, who hold a strong opinion that they try to pass off as actual experience)

If the Pan rear doesn't live up to expectations I shall run one on that as well.

 

[owl]

You do not have less of a footprint with a car tyre fitted to a bike.

You would if you ran at the recommended pressure for the m/c tyre, but you run typically at between 28 and 35 psi dependant on your weight and whether you carry a passenger, so that the sidewall deforms into a large contact patch.

This sounds alarming, but in practice it's not.

Thousands upon thousands of miles over many many years by numerous riders prove this. Not one single failure that I've ever heard of - can't say that for motorcycle tyres. There is also a plethora of video evidence with camcorders mounted towards the tyre so you can actually see this in practice.

And it doesn't save a little money, it saves A LOT of money. At ?175 GBP a time ($283 USD) for 3500 miles average, I was sometimes having to change a tyre every two or three weeks - do the maths.

Yes, you have to use positive countersteering, I've already mentioned that. I don't see that as a problem, personally, and in actual fact I rather like the more involving input.

Did I also mention that it is far superior in the wet?

And that you can launch a hell of a lot quicker without spinning up the rear (although I guess that is not what ST1300 riding is all about).

 

[Gene]

Don't stop now this is getting good , are there are real documented facts that we will DIE if we run a car tire !!! There are lots and lots being used can anyone show a documented case where the car tire was to blame for a accident ???? Most of us can't ride well enough to use most of a M/C tire anyway the proof is we almost allways wear out only the middle .

 

[owl]

All I can offer is my own experience.

30 years in Kent Police followed by 3 years so far in accident investigation for a leading firm of solicitors.

Never had occasion to investigate a single accident involving a m/c on a car tyre. That's never.

Add to that the fact that I've been using a car tyre on the rear for about 30,000 miles over 3 or 4 years on an 150 bhp Rocket.

Add to that a mate of mine who has covered nigh on 60,000 miles with a car tyre on the back of his Rocket, including many Iron Butt runs in all weathers including deep snow.

I personally know and have ridden with around 10 other riders using car tyres, predominantly Toyos, on their Rockets.

I do not personally know of one single rider who has tried it and has not liked it and stuck to it, although in a spirit of fairness, there are two Americans on the R3 forum who tried, disliked and changed back. That's two out of about 60 riders that I know of.

I realise that it won't be to everyones taste, that there are fors and againsts, and I don't advocate the use of a car tyre per se, it's just that I get a bit peeved when sanctimonious commentators come on and give their judgemental opinions without any experience whatsoever.

It takes a pair of balls these days to 'own up' - must be like coming out of the closet

 

[owl]

I can see what you're getting at, but "one day it's gonna give" hasn't happened to me in the last 30,000 miles, and to many of my co 'Darksiders' in what must be collectively in the hundreds of thousands of miles.

How much more testing do you think it needs?

I can cite you examples of several motorcycle tyre total failures in that time. Does that make them dangerous?

I appreciate your concern is well meant, but it is misplaced.

 

[STPaulK]

I guess I can see how it would work on a Rocket or other similar bike. But I couldn't see this working on a CBR, or other extreme lean angle bike (and I really want water grooves at the hard angles). I put the ST in the category of being able to lean it way over. Do any darksiders have them installed on a sportbike? Note that I am only asking thoughtful questions here.

 

[sirepair]

Do any darksiders have them installed on a sportbike? Note that I am only asking thoughtful questions here.

There seems to be several people running C/Ts on FJRs. I'm really considering trying to do it on my 1100.

If you've ever watched video of front tires on cars, you will quickly note the amount of side-wall flex that a tire has to deal with (by design) Here's a video showing a car tire being tested.
[video=youtube;nmo_dkNZIHM]http://www.youtube.com/watch?v=nmo_dkNZIHM[/video]

I for one would be willing to give it a try. I don't understand how tire mfgs can make tires that last 40-60K miles for cars, yet only 10K miles (or less) for bikes. Obviously they COULD make tires last longer, but then they wouldn't sell as many of them (though M/C tire production numbers are much lower than C/T numbers). They stick with the "they have to be soft and wear quickly so they will be sticky" line, all the while knowing that's not the truth.

There are many variables to consider when a tire is being designed, and things like compound, profile, contact patch, block size and shape, sieping, etc. all play in to how the finished tire will perform. We understand that there are trade offs with tire design, but there really haven't been any major changes in m/c tires in 25 year (when radials came out). We know the tire mfgs make good m/c tires (for the most part!), we just want them to make the tires last longer. If they made m/c tires that performed well and lasted 20K+ miles, no one would be looking at C/Ts to replace them with.

If the market pushed for longer lasting M/C tires, sooner or later the mfgs will make them. But as long as we continue to show up at the tire store every 8-10K miles with our wallet wide open there won't be much changed with the existing tires. The more bikes that go DarkSide, the sooner the mfgs will realize they need to react.

 

[owl]

Good points from the last 2 posters.

I take the point about extreme lean angle sports bikes. I haven't got a car tyre fitted to my Street Triple, for instance.

Although don't be fooled into thinking you can't lean way over on a car tyre - I have rearsets fitted quite high on my Rocket, and am on my second pair as I wore the others clean through.

One thing that really surprised me though - when it was time to replace the Toyo, it was because the side 1/3 of the tread on each side was worn smooth - the middle section still had plenty of tread left - the exact opposite of m/c tyres.

There are plenty of vids out there of car tyre side wall flex when used on bikes - you just have to get used to looking at what's on the road as opposed to what's in the air, which can look quite alarming.

I can only talk about what I've experienced, and there is very little to convince me to change back, on the Rocket, at least.

 

[Gene]

There are few ST1300 going to Moonshine this week on car tires , I look forward to the ride reports after a few thousand miles in mixed weather . This 5-6k per rear tire really eats in to the travel funds when you go tru 3 or 4 rears per season .

 

[owl]

Could you report back, Gene?

I'd be interested in their reports.

 

[Gene]

Not me yet, but I know a few are and I'm hoping they tell us about it after they give it a real world try .

 

[owl]

It's not a well known list because of the armchair experts with no real world experience offering opinions with no value. Sometimes it's best to allow the collective to "know" whats best while doing your own thing... until they outlaw it at least.

That's basically what has been happening in the UK. More like an underground movement.

 

[Mellow]

It's not a well known list because of the armchair experts with no real world experience offering opinions with no value. Sometimes it's best to allow the collective to "know" whats best while doing your own thing... until they outlaw it at least.

Collective... LOL.. you Trekkies have a way with words.

I think a lot of us first cringe when we thing about car tires on a MC but there are many that do it. I wouldn't mind giving it a try just to see what it was like, and gain more applicable experience... not sure if I'd like it or not but would be good to at least say I tried. I can understand those that won't even try and those that see a great deal of benefit from one.

If it works for ya... why not.