TheSamba.com :: View topic - 15" Radial Tires

Fri Jan 20, 2023 8:50 pm

I have a 1967 bus with a 1600 DP, RGBs and a big nut transaxle. The trans was recently rebuilt but I don’t know what the gearing is. The bus has 15” wheels instead of 14”. I have 205/75R15 tires mounted. I have reason to believe the speedometer is accurate. I generally drive around town, and don’t venture onto the freeway, so I am not concerned about how fast the car will go. What bugs me is that I am typically going about 30mph around town and the engine sounds like it wants me to shift from 3rd to 4th. I don’t have a tachometer, but it’s noisy at that speed and sounds like it’s spinning pretty fast. The owner’s manual says 3rd gear is good to 45mph. No way! If I do shift into 4th at that speed it is lugging a bit, so I just put up with it in 3rd.

Here is my question: will I notice a significant difference if I change from my current 205/75R15 tires to 215/75R15 tires? According to the calculators, the 215s turn only 16 revolutions per mile less that the 205s. Will I see any practical difference in RPMs?

Thanks.

Fri Jan 20, 2023 9:01 pm

'40's guy wrote: I have a 1967 bus with a 1600 DP, RGBs and a big nut transaxle. The trans was recently rebuilt but I don’t know what the gearing is. The bus has 15” wheels instead of 14”. I have 205/75R15 tires mounted. I have reason to believe the speedometer is accurate. I generally drive around town, and don’t venture onto the freeway, so I am not concerned about how fast the car will go. What bugs me is that I am typically going about 30mph around town and the engine sounds like it wants me to shift from 3rd to 4th. I don’t have a tachometer, but it’s noisy at that speed and sounds like it’s spinning pretty fast. The owner’s manual says 3rd gear is good to 45mph. No way! If I do shift into 4th at that speed it is lugging a bit, so I just put up with it in 3rd.

Here is my question: will I notice a significant difference if I change from my current 205/75R15 tires to 215/75R15 tires? According to the calculators, the 215s turn only 16 revolutions per mile less that the 205s. Will I see any practical difference in RPMs?

Thanks.

The short answer is no. You will likely not notice a difference in felt RPM with the change in tire size.

The big question is, do you have much VW bus experience? To some folks, they feel like they are screaming at everyday speeds. Cruising around Spokane at 35MPH in third gear will be loud, but not abnormal. If you are on flat ground headed out North Division, you can shift to 4th. If you are climbing Southeast Boulevard up to Trader Joe's, keep it in 3rd.

Fri Jan 20, 2023 9:40 pm

agreed. It just is loud. they absolutely go 45 in third. and that is without overreving it.

put a full interior in it and it will quiet down. still same revs, but it won't kill your ears anymore.
maybe the exhaust could use some help too?

if you don't go anywhere on the highway, it may make sense to use a slightly smaller tire that allows you to get in 4th.

Sat Jan 21, 2023 7:49 am

Unlikely, but it could have the 'mountain gear' ratio reduction boxes. That might effect shifting points.

Sat Jan 21, 2023 8:26 pm

I appreciate this good feedback. Thank you all for responding.

Sun Jan 22, 2023 5:39 pm

I’ve posted these before, no rubbing or issues. My SC isn’t a speed demon, but these take me everywhere.

Sat Mar 23, 2024 12:54 pm

I might as well contribute in trying to keep this thread up to date. My Cooper Discoverers in 195R15 are way past due for replacing (44th week, 2006 date code). They have been an excellent tire in that they took me everywhere and never let me down.

Not many to choose from in the US in 195R15... Linglong, Thunderer, Otani, Westlake, Cosmo. The last one I looked into a little closer. Cosmo appears to be a US family owned company that's been around since 1942. The Cosmo El Jefe Van II comes in 195R15. Curious if anyone has run them yet? They are fairly inexpensive at $82 each.

https://cosmotires.com/product/el-jefe-van-ii/

...but then I see Larmo's last post and dammit, those BFG all terrains in 215/75R15 sure do look nice...

Larmo63 wrote: I’ve posted these before, no rubbing or issues. My SC isn’t a speed demon, but these take me everywhere.

Sat Mar 23, 2024 1:59 pm

'58 Single Cab wrote: I might as well contribute in trying to keep this thread up to date. My Cooper Discoverers in 195R15 are way past due for replacing (44th week, 2006 date code). They have been an excellent tire in that they took me everywhere and never let me down.

Not many to choose from in the US in 195R15... Linglong, Thunderer, Otani, Westlake, Cosmo. The last one I looked into a little closer. Cosmo appears to be a US family owned company that's been around since 1942. The Cosmo El Jefe Van II comes in 195R15. Curious if anyone has run them yet? They are fairly inexpensive at $82 each.

https://cosmotires.com/product/el-jefe-van-ii/

If that is a current pic of your Coopers, and that is how much wear/driving time they have had since you put them on when the date codes were fresh, don't bother getting new tires. They will be fine.

If you plan to drive 10K miles on hot summer freeways, then get new ones.

Sat Mar 23, 2024 3:06 pm

That pic is from today. I put less than 1000 miles on it per year. It's stored inside a windowless garage that is typically between 60 and 80 deg F all year long. I mounted them when they were brand new.

We hear horror stories of tire failures but I agree with you. Those failures are probably missing key details of how the tires were not taken proper care of.

cdennisg wrote:
If that is a current pic of your Coopers, and that is how much wear/driving time they have had since you put them on when the date codes were fresh, don't bother getting new tires. They will be fine.

If you plan to drive 10K miles on hot summer freeways, then get new ones.

Sat Mar 23, 2024 9:03 pm

'58 Single Cab wrote: That pic is from today. I put less than 1000 miles on it per year. It's stored inside a windowless garage that is typically between 60 and 80 deg F all year long. I mounted them when they were brand new.

We hear horror stories of tire failures but I agree with you. Those failures are probably missing key details of how the tires were not taken proper care of.

cdennisg wrote:
If that is a current pic of your Coopers, and that is how much wear/driving time they have had since you put them on when the date codes were fresh, don't bother getting new tires. They will be fine.

If you plan to drive 10K miles on hot summer freeways, then get new ones.

I believe it's when the sidewalls are cracked from age and/or sun exposure.

This is really common here in AZ.

I see people with shredded tires all the time and I had a couple Coker Tire Continentals 6.40x15s rot out in a few years when my Bus was outside a lot more.

Sat Mar 23, 2024 10:19 pm

EverettB wrote: '58 Single Cab wrote: That pic is from today. I put less than 1000 miles on it per year. It's stored inside a windowless garage that is typically between 60 and 80 deg F all year long. I mounted them when they were brand new.

We hear horror stories of tire failures but I agree with you. Those failures are probably missing key details of how the tires were not taken proper care of.

cdennisg wrote:
If that is a current pic of your Coopers, and that is how much wear/driving time they have had since you put them on when the date codes were fresh, don't bother getting new tires. They will be fine.

If you plan to drive 10K miles on hot summer freeways, then get new ones.

I believe it's when the sidewalls are cracked from age and/or sun exposure.

This is really common here in AZ.

I see people with shredded tires all the time and I had a couple Coker Tire Continentals 6.40x15s rot out in a few years when my Bus was outside a lot more.

Often times a tire failure due to age cannot be seen easily. They may show no outward signs of deterioration at all. But, in this situation, knowing well these tries were made, and how little this vehicle is driven, and then with the info of how the vehicle is stored, I would have no issue continuing to drive on them for many years to come.

Wed Apr 24, 2024 1:09 pm

I was having trouble finding any tire shop to supply 205 75 15 radials for my 66 bus. Finally, I went to the tire companies, found a tire of the right size and load range (1609 pounds max), looked up the company's local contacts, and had that store order me the tires. They are Hankook Kinergy. They look OK; haven't got them mounted yet. That's the next step: finding a tire shop that will deal with 15 inch VW rims.
I had Cooper Discovers of the same size and load range that have served me well for 7 years. They probably have several thousand miles left but I am contemplating another long trip and do not want to run out of rubber while travelling.

Thu Jun 06, 2024 5:19 pm

Well ... the Hankooks have no specific sidewall stiffening. I just finished a 1000 mile trip, though, and they were quiet, very comfortable (cushy even), and handled fine. My major reservation is that they flex so much that moving around in a parked bus while camping can get the bus rocking (no, not front to back caused by bed antics but side-to-side when getting up from the table). I will see if I can actually get proper light truck tires locally and compare.

Thu Jun 06, 2024 5:41 pm

Don66bus wrote: Well ... the Hankooks have no specific sidewall stiffening. I just finished a 1000 mile trip, though, and they were quiet, very comfortable (cushy even), and handled fine. My major reservation is that they flex so much that moving around in a parked bus while camping can get the bus rocking (no, not front to back caused by bed antics but side-to-side when getting up from the table). I will see if I can actually get proper light truck tires locally and compare.

Are they a P metric size? No LT or C or D rating? If that is the case, they are essentially passenger car tires. Load rating my be OK, but those designations I listed denote reinforced sidewalls.

Also, any knowledgeable/reputable tire shop can mount 15 VW wheels. The issue is balancing with modern machines. I don't bother balancing bus wheel/tire combos and have not had an issue in over twenty years of bussin'. But, if you really want them balanced get your hands on a wide five to Chevy/Ford/Porsche adapter. With that bolted to the wheel, the center hole will fit modern balancing cones.

Thu Jun 06, 2024 7:15 pm

cdennisg wrote: Don66bus wrote: Well ... the Hankooks have no specific sidewall stiffening. I just finished a 1000 mile trip, though, and they were quiet, very comfortable (cushy even), and handled fine. My major reservation is that they flex so much that moving around in a parked bus while camping can get the bus rocking (no, not front to back caused by bed antics but side-to-side when getting up from the table). I will see if I can actually get proper light truck tires locally and compare.

Are they a P metric size? No LT or C or D rating? If that is the case, they are essentially passenger car tires. Load rating my be OK, but those designations I listed denote reinforced sidewalls.

Also, any knowledgeable/reputable tire shop can mount 15 VW wheels. The issue is balancing with modern machines. I don't bother balancing bus wheel/tire combos and have not had an issue in over twenty years of bussin'. But, if you really want them balanced get your hands on a wide five to Chevy/Ford/Porsche adapter. With that bolted to the wheel, the center hole will fit modern balancing cones.
slightly pricey, but good to have.

https://www.thesamba.com/vw/classifieds/detail.php?id=2576677

These are the 15" tires that I run on most of my buses. They feel great.
195R15 thunderer ranger r101 from simpletire.com (if the mile-long link doesn't work)
https://simpletire.com/brands/thunderer-tires/rang...amp;rad=DD

Thu Jun 06, 2024 7:25 pm

Lind wrote: cdennisg wrote: Don66bus wrote: Well ... the Hankooks have no specific sidewall stiffening. I just finished a 1000 mile trip, though, and they were quiet, very comfortable (cushy even), and handled fine. My major reservation is that they flex so much that moving around in a parked bus while camping can get the bus rocking (no, not front to back caused by bed antics but side-to-side when getting up from the table). I will see if I can actually get proper light truck tires locally and compare.

Are they a P metric size? No LT or C or D rating? If that is the case, they are essentially passenger car tires. Load rating my be OK, but those designations I listed denote reinforced sidewalls.

Also, any knowledgeable/reputable tire shop can mount 15 VW wheels. The issue is balancing with modern machines. I don't bother balancing bus wheel/tire combos and have not had an issue in over twenty years of bussin'. But, if you really want them balanced get your hands on a wide five to Chevy/Ford/Porsche adapter. With that bolted to the wheel, the center hole will fit modern balancing cones.
slightly pricey, but good to have.

https://www.thesamba.com/vw/classifieds/detail.php?id=2576677

These are the 15" tires that I run on most of my buses. They feel great.
195R15 thunderer ranger r101 from simpletire.com (if the mile-long link doesn't work)
https://simpletire.com/brands/thunderer-tires/rang...amp;rad=DD

These are way cheaper, sometimes even free...

Several years back I had a local mechanic use his vintage brake lathe to cut the braking surface and snout out of a beetle brake drum for me. I use it as an adapter for my manual tire changer, but it would work great for a balancing adapter, too. Cost me twenty bucks as I recall.

Fri Jun 07, 2024 3:46 am

Regarding passenger car tires vs. light truck tires:
- I have been running passenger car tires (load range 1600 pounds +) for fifty years now and have never had a problem with their capacity. I do distance, I carry loads, I do some back roads. They work. It may be that light truck tires work better BUT
- Up here in Canada, I cannot find any tires to fit my 15 inch rims that are in the 195/75/15 to 205/75/15 range. I go to big tire companies and say "What have you got in 205/75/15?" and they say "Nothing." So, if I can find in some obscure garage or website a tire that fits, I try it out. So far, all have been good. The most recent, Hankook Kiinergy, work well dynamically but bug me when I am camping in the bus. Maybe I will go down to standard 14 inch rims so I can tap into the range of tires sold for Vanagons.

Fri Jun 07, 2024 5:17 am

Don66bus wrote: Regarding passenger car tires vs. light truck tires:
- I have been running passenger car tires (load range 1600 pounds +) for fifty years now and have never had a problem with their capacity. I do distance, I carry loads, I do some back roads. They work. It may be that light truck tires work better BUT
- Up here in Canada, I cannot find any tires to fit my 15 inch rims that are in the 195/75/15 to 205/75/15 range. I go to big tire companies and say "What have you got in 205/75/15?" and they say "Nothing." So, if I can find in some obscure garage or website a tire that fits, I try it out. So far, all have been good. The most recent, Hankook Kiinergy, work well dynamically but bug me when I am camping in the bus. Maybe I will go down to standard 14 inch rims so I can tap into the range of tires sold for Vanagons. For many years, I could not find any 15" tires with the proper load rating. Only in the last ten years or so I have been able to find the right tires. It makes a noticeable difference in the handling. Passenger car tires are too soft, and it feels like you are driving on a marshmallow. I would recommend crossing the border and getting some of the right tires down in the states, or going with 14s to get the right tire.

The other thing for making the bus handle good is the anti sway bar. Of course this came stock on all '66-'67 buses. Anyone out there with a '55-'65 bus would do good to put an anti-sway bar on their bus. you will notice the difference. I was recommending them long before I was selling them.

Shameless plug:

https://www.thesamba.com/vw/classifieds/detail.php?id=2675822

Fri Jun 07, 2024 9:37 am

Lind wrote:
These are the 15" tires that I run on most of my buses. They feel great.
195R15 thunderer ranger r101 from simpletire.com (if the mile-long link doesn't work)
https://simpletire.com/brands/thunderer-tires/rang...amp;rad=DD
Wow, this seems a good answer.
I estimate I've driven bays an more on Vanagons about 700,000 miles in my life. Almost every bit of it on 185R-14C properly rated tires. And always more pressure in rear than front.

Tue Jul 09, 2024 5:18 pm

So I took Lind up on both of his suggestions....bought his front sway bar kit and upgraded my tires to the thunderer rangers he linked above. Holy cow did it make a difference in the handling around corners and overall feel of my bus. If you are on the fence on either of these upgrades, do it. Both will be going on any future bus I may encounter. Thanks Lind!