Cost/Benefit/Payback of a car tire conversion

Discussion in 'Hacks' started by BMWzenrider, Jun 10, 2012.

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Replying in a new thread since it is a bit off topic from where the question was originally asked:

Just glancing at your mileage/cost numbers I can't really tell, so I did the math.

And as I said, my pushers last 15,000 - 18,000 miles depending upon compound and riding conditions (3-5x as long).
My last pusher tire cost me \$64.00 installed and that was the most expensive one so far.
And you need to remember that I have a MUCH heavier rig and tend to enjoy power-sliding in the tight twisties.
So I don't think my tire life is typical of what you would see. But I used those numbers anyway.

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On your Ural you are using 2.2 - 3.4 tires per year using your figures.
Or \$167-257 per year on pusher tires.

If you got at least my mileage out of a car tire conversion (and most people seem to get more), then you would only be using 0.56 - 0.80 tires per year, or \$36-51/year for tires with an automotive tire conversion.

That is a savings of \$116-221 per year in dollar savings alone.
Not to mention the time/convenience factor of not having to change your tire as often. Especially when on a long trip.

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Since I have actually sold a couple of the tire conversions that I designed, we can use that number if you would like, even though I have no idea what a conversion for your bike might end up costing, and also I have actually given the design away to other inmates who have had one made on their own. So they have saved money on the cost of the conversion.
I know how much it cost me to put the first one together, and it didn't equal 2 of the radial sport-touring tires that my Beemer uses on the stock wheel. And that includes the cost of having both the wheel and adapter anodized.

going by the 'retail' price, the payback time using the above numbers would be in the range of 2.7 - 5 years.

So, if you were doing nothing but minimum miles,
and getting worst possible wear from the car tire
and always get maximum wear from the bike type tire,
and the prices don't change.
Then yes, it could take up to 5 years to pay for the conversion.

But that is alot of worst/best case conditions. In reality it would take you about 4 years at your average mileage using my tire wear rate for a car tire.

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And how many total miles do you have on it?
How many tires has that been?
What happens to all those old tires that had to be scrapped after you wore them out?
What about the time you have spent on tire maintenance? (is there a value on your time?)

And one other thing you can do with a car tire conversion is drop your overall gear ratio by going to a smaller diamter tire. Good for rock-climbing or taking off heavily loaded. That is certainly worth something in my book.

It is not all about the \$\$\$, there are other intangible benefits.
Like not needing to carry a stack of tires and stop to mount them on a long tour...
If you only ride locally, that may not be as much of an issue, but for me changing tires so often on my Airhead rigs had gotten to be a bit old and was a driving factor in my decision to do the car tire conversion on this rig.
(It also helped that the bike came to me with a huge chunk missing from the stock rear wheel from where the PO had slid it into a guard-rail post. So I didn't have a 'perfectly fine' wheel to start with...)

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IIRC, you have somewhere around 69,000km on your rig, right? (~43,000 miles)
That would be around 10-12 tires, or \$750-900 at \$75 each. Assuming you never replaced the tube...

In the same number of miles you would have only used up 2-3 car tires for a cost of \$130-190 dollars and quite a few less waste tires to dispose of.

You would have already paid for a retail conversion kit, and mine was paid for long before I wore out my first car tire. (of course, radial sport-touring bike tires do cost quite a bit more. When I priced them in 2008 they were already \$175 each.)

And going back to my primary reasons for doing the conversion, I was able to drop my gearing for better matching of my powerband to speed, and don't have to worry about sourcing or replacing a tire if I take a long trip.
For me personally, that is worth alot, maybe more than the cost savings...

YMMV
2. windmillLong timer

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Personally I doubt it would be worth the time and effort to do the conversion even if I could.

It only takes me about 20-30 minutes to change out a tire start to finish, and I can do it all myself.

Put the bike up on the center stand, back off the brake adjuster, loosen pinch bolt, remove nut, pull axle, remove wheel, swap tire, and put it back together. No need to remove bike parts, use special lifts, take wheel somewhere to have tire dismounted and mounted. Quick easy and cheap. I would like it if I could find a tire that lasted longer, but it isn't worth it for me to take it beyond that.

What I see as the only thing that really counts is that we have both found answers that suit our needs and budgets, so really neither is right or wrong, just different.

If you think about it, thats the jist of what I have been saying all along, you can't judge what is right for others by your standards.
3. EaglebeakAll roads rider, West Oz.

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My TUBELESS car tyre a 205/50-17 fits straight onto the stock Suzuki GSX1400 rim.
(I love tubeless tyres)

I currently have 18,000 kms on that tyre and expect to get another 2000-3000 kms more before I replace it.

I would be lucky to get 8,000 kms out of the stock bike tyre with the outfit.

At \$240 Australian for the car tyre, a good quality radial, compared to a bike tyre at \$300 (stock tyre 190/50-17) it's a no brainer.

Remember, the car tyre fits on the stock bike rim.

Picture taken when new, from my build thread.

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Yup, that is basically just how it worked for me I don't know how many times on my old Airheads.... I could probably remove/replace an Airhead rear wheel with my eyes closed. At one point when I was young and rich and good looking I had 4 of them at one time. And of course with the various Airheads that I had attached to sidecars I got a fair amount of practice with swaping wheels. On my last rig I eventually got a second set of wheels so that I could have a set of long-distance touring rubber, and one set with knobbies for winter and when I wanted to go have fun.

I still change the front tire of this rig myself, just haven't tried to on the rear wheel of this rig. Maybe I should, but buying my pusher tires from TireRack.com I get it shipped to a local Ford dealer who installs them for free!

And for your purposes, you can get knobbies that are much more agressive for some of the more serious stuff that you do, than any car tire which would fit into that space.
It is all about what is the right solution for you. I have been saying that for years.

Suiting budgets is a major factor as well, definitely.
If I had not been able to design and fabricate my own conversion hub, I doubt that I could have absorbed the up-front cost of it either. But in my case it was actually less expensive to design/build the conversion than it would have been to buy a used stock wheel. :huh

Stroker's wheels are pretty, and reports are that they work well. But the cost of entry for one of those is very steep.
I have actually worked out a simple solution to going darkside on my R1150R (baby GS for bad knees.) but have not done it yet because I don't know that I put enough miles on that bike anymore to justify even my low cost of entry.
And I have refrained from showing off the concept to avoid stepping on anyone's toes....

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Yes, it is nice when the stock wheel will directly mount a car tire, and there is space/clearance when installed.
The really beefy single-sided swingarm on the more recent Beemers makes it hard to find a tire which won't rub the swingarm.
One inmate did it recently on his Beemer, but it required offsetting the wheel with spacers to finally get the second size tire he tried to fit.

When you can directly fit a car tire, especially on a sidecar tug, it truely is a no-brainer!
6. Wolfgang55Long timer

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This make getting a sidecar for your BMW actually cheaper when considering the full packsge.
All the builders offer the car wheel conversion but never talk about an actual car tire fitting on the stock drive wheel.

Much thanks guys.
7. karitokiBeen here awhile

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I have a 1980 GL1100. I believe it has a 17" rim. Does anyone know off the top of their head if a car tire will fit on the GL1100 rim?
8. DirtyDRDana

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I will say that I thought long and hard before sending my money to Stroker but it is the most cost effective mod I have done. On the trip to the sidecar national at Tahoe I used up three, \$145.00 MC tires. I get around 3,500 miles out of a MC tire on the GS rig. On the Labrador trip I used one \$65.00 Nexen SB802 and that tire lasted for 14,000 miles before I swapped it out. I run between 10,000 and 14,000 miles a year on the GS so it didn't take long for that wheel to pay for itself. The other nice thing is that there are quite a few choices in 15 inch tires that will fit on the wheel for all conditions.
9. halfliveBeen here awhile

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Even for the BMW there is a car alternative.
The Continental VancoContact 185/60 R17C and the Bridgestone Potenza (175/55/R17)
Narrow enough to clear the swing and at least double the mileage of a motorcycle tire. For about the same price.

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Ahhh... but you are forgetting that Europe gets to buy lots of tires that are unavailable here in the colonies...

I would love it if there were more of the SmartCar tires available here for the 15" wheel/tire conversions, but we just can't get them.

Another advantage, for me, of the 15" wheel conversion is that I can drop in at ANY local service or tire shop and they will work with my wheel.
Trying to find a shop which will mount a car tire to a bike wheel is getting harder due to liability fears.
I can get any local dude to patch or replace my 15" car tire/wheel for me.

You can also vary the gearing through a wider selection of 15" tire sizes if desired.

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Oh, I completely agree that any of the conversion kits are a cost-effective mod on the modern bikes which use expensive radials or the big adventure bikes which can really chew up the costly dual-sport compounds.
And from everything I have heard, Stroker is very good to deal with.

For seasonal tire swaps, I actually have two rear wheels for my rig now so that I can leave my summer & winter compound tires mounted and just swap the entire wheel quickly and easily.

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Here is a link to the thread where one of the other inmates mounted a high performance 17" car tire to the stock BMW rear rim.

He did first try the 205 wide Potenza, and it rubbed the swingarm.
He eventually settled on a 195/45R17 Yohahoma S-Drive tire and a couple of wheel spacers with longer bolts.

Here is the direct link to the post where he discusses the mounting issues.

Could be a less expensive way to go than a full-on automotive wheel conversion if a high performance summer tire is suitable to your driving conditions and you are not looking to monkey around with the gearing much.
14. windmillLong timer

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One real nice benefit of a Ural and some others running MC tires is the spare, when you gash a sidewall many miles from civilization on a logging road in a snow storm, it's nothing more than a 15 minute inconvenience. Used my shovel to keep the jack from sinking in the snow.
15. oppozitBanned

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Same can be done with car wheels, even on a Ural. ;-)

16. windmillLong timer

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The irony is that while it is obvious that any type of wheel/tire combo can be carried as a spare, those who do run car tires typically say a spare is an unnecessary burden because they are tubeless and most flats can be plugged.

I have seen Urals with car tire conversions before, but that is beyond my ability or budget, that would be no small project with a 2WD rig, and I suspect it would fall behind on the curve of diminishing returns for my use.
17. oppozitBanned

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You originally said "Gnash a sidewall" not generally damage suitable for a plug. Even with tubeless tyres, I'd prefer to do a repair at home in a nice warm garage especially if there's that funny white stuff around and the thermometer is reading minus anything!
18. EaglebeakAll roads rider, West Oz.

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What size is the stock bike tyre ?
The Suzuki is 190/50-17. I found a tubelss car tyre that is 205/50-17.

Because of the wider tyre with the 50% profile it meant my rolling circumference was about 4% greater from memory. That lifted my gearing slightly but it's not noticeable and the beuaty of chain and sprockets is that you can change your gearing if you feel the need.
(I haven't bothered)

So, the car tyre is 15 millimetres wider overall, ~7.5 each side. You just have to see that it fits inside the swingarm.

Andrew.
19. windmillLong timer

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Thats kinda what I was saying, most folks who run car tires don't carry a spare because they can be plugged, but a gashed sidewall can't be repaired, so those of us who carry a spare because MC tires on standard spoke rims can't be plugged can have an advantage under some circumstances.

I just expressed myself poorly, and just took it for granted people would understand what I was saying, my bad.