tubeless tires

[Rob S.]

Yep, cast wheels came first, but they still had tubes.Tubes continued in a few models a little longer -- the 1982-83 GS1100E used tubes.

Correct on all counts. But I think the invention of cast wheels had different priorities than simply a route to tubeless. I think looks, and strength were the selling points of the new cast ('mag') wheels, then somebody realized that with the right cast wheels, tubes could be eliminated.

 

[Guest]

It'd be interesting to know what came first. There was no need for tubeless motorcycle wheels if there were no tubeless motorcycle tires.

There are significant safety benefits and performance improvements from tubeless wheels/tires. I expect those are what drove the development of both wheels and tires towards tubeless design.

Yep, cast wheels came first, but they still had tubes.
there were even a few models with one tube and one tubeless tire.

My 82 1100E has a rear wheel designated with the 'MT' marking and is marked 'Tubeless" while the front is not and does not have the internal shoulders intended for tubeless tire use.

I think looks, and strength were the selling points of the new cast ('mag') wheels

It has to be a styling issue because spoked rims are much, much tougher than cast ones. Off road bikes still use spokes for good reason.


Mark

 

[Rob S.]

It has to be a styling issue because spoked rims are much, much tougher than cast ones. Off road bikes still use spokes for good reason.

I'd call them more pliable. They bend, mags break.

 

[grcamna2]

Have any of you ever measured the weight difference between spoked or mag GS wheels ?

 

[rphillips]

The "78" GS1000C spoked wheels had alum. rims W/ steel spokes & weighed less than the cast "E" wheels, not a lot, but less. I'm thinking the GS750's & smaller had steel rims & spokes. I never weighed the wheels but just guessing from memory the alum spoked probably between 2lb. & 3lb. less than the cast.

 

[Guest]

Have any of you ever measured the weight difference between spoked or mag GS wheels ?

I haven't weighed GS spoked wheels, but I doubt there is much difference and the spoked ones might even be a touch lighter. Those old mag wheels were cast with old techniques that made them very heavy. Modern mag wheels are significantly lighter than spoked, but we aren't talking about those here.


Mark

 

[bwringer]

I'd call them more pliable. They bend, mags break.

I haven't weighed GS spoked wheels, but I doubt there is much difference and the spoked ones might even be a touch lighter. Those old mag wheels were cast with old techniques that made them very heavy. Modern mag wheels are significantly lighter than spoked, but we aren't talking about those here.


Mark

I don't think I've ever even heard of a cast GS wheel breaking, unless it was a serious sort of incident that did far more serious damage to the rider and the rest of the bike. Yeah, they're unbelievably heavy compared to the wheels on modern bikes, but they're also incredibly strong. Plus they're wearing high-profile tires.

Cast wheels on modern bikes are much lighter, but they are very fragile. Bent front wheels are quite common.

Many modern "adventure" bikes come with spoked wheels that are tubeless. You get the best of both worlds in these; some of the resilience of spokes without the disadvantages of tubes.

Of course, many dual-sport bikes still come with spoked wheels and tubes. I was highly disappointed to learn that the Yamaha Tenere 700 comes with tubes.


When you change and balance tires, it's also quite noticeable that modern wheels are far better balanced; it's fairly rare that the heavy spot isn't at the valve stem on a modern motorcycle wheel, but it's common on GS wheels. I put a little silver paint dot on my GS wheels to mark the true heavy spot.

 

[Guest]

So the used front wheel I ordered arrived. Compared to my existing wheel it appears identical except the sidewall stamp indicates TUBELESS:
N19 x MT 1.85 DOT TUBELESS TIRE APPLICABLE

There is a stem already on the wheel which indicates to me it last had a tubeless tire mounted.

I noted the date code on my original is 1178 and the used one I bought is 1080. I guess the 2 year difference saw wider spread of tubeless tires!

I'm going to proceed with my plan to mount the BT46 tire without tube and see how things go

1980 Wheel rim:

https://www.flickr.com

1980 Wheel Profile:

https://www.flickr.com

 

[Guest]

so, looking for some new tires, it seems the 90/90-19 front tire i needs is fairly rare, and expensive.

is it possible to fit a 100/90-19 on the rim instead?

 

[Guest]

Hey SkyfangR:

Someone with direct knowledge of your machine will probably post but I can offer the following.

I did a quick Googly and it seems to indicate your model had stock tire size:
Front tire: 3.60in wide - 19in wheel (3.60-19)
Rear tire: 4.60 in wide - 16in wheel (4.60-16)

These would convert directly to metric size:
Front tire: 91.44mm wide x 100% tall - 19in wheel (so approx. 90/100-19)
Rear tire: 116.84mm wide x 100% tall - 16in wheel (so approx. 120/100-16)

On another thread I posted this:
"This link seems to make sense for fitting tires to rim size (check on your wheel rim for a listed size: probably 1.85-19 and 2.5-17?):
https://dropbears.com/motorcycles/utilities/tyrerim.htm "

The manufacturer website for the tire you choose may also list acceptable wheel width for the tire size they offer if you wanted to be sure.

Your wheel rim width is probably 1.85 (check on the rim sidewall) and so yes, I would expect a 100mm x 90% - 19in (100/90-19) tire will be just the ticket!

 

[Guest]

so, looking for some new tires, it seems the 90/90-19 front tire i needs is fairly rare, and expensive.

is it possible to fit a 100/90-19 on the rim instead?

I'm running a 100/90 Shinko 230 on the 1.85" rim on my 1100E. It is a bit pinched, but it works fine.


Mark

 

[Grimly]

Hey SkyfangR:

Someone with direct knowledge of your machine will probably post but I can offer the following.

I did a quick Googly and it seems to indicate your model had stock tire size:
Front tire: 3.60in wide - 19in wheel (3.60-19)
Rear tire: 4.60 in wide - 16in wheel (4.60-16)

These would convert directly to metric size:
Front tire: 91.44mm wide x 100% tall - 19in wheel (so approx. 90/100-19)
Rear tire: 116.84mm wide x 100% tall - 16in wheel (so approx. 120/100-16)

On another thread I posted this:
"This link seems to make sense for fitting tires to rim size (check on your wheel rim for a listed size: probably 1.85-19 and 2.5-17?):
https://dropbears.com/motorcycles/utilities/tyrerim.htm "

The manufacturer website for the tire you choose may also list acceptable wheel width for the tire size they offer if you wanted to be sure.

Your wheel rim width is probably 1.85 (check on the rim sidewall) and so yes, I would expect a 100mm x 90% - 19in (100/90-19) tire will be just the ticket!

Question is; were the original inch spec tyres 100% aspect ratio?
I don't think they'd been 100% since the 1940s, but possibly later for motorcycle tyres. I seem to recall they were about 90% in the later decades of inch size designation.

 

[Guest]

well, more PO weirdness on my bike
the current tires are IRC g-11 tires, which the internet tells me only come in tube type
the valve stems currently on the bike however, are bolt on's, meaning there cant be a tube on these rims.
did this guy mount tube type tires with no tubes?
what the hell.

and i guess ill have to spring for a 90/90-19 front tire, because a 100/90 wont fit with the front fender on. good news is the rear 120/90-16 seems to be plentiful, so shouldnt have any problems with that one

 

[rphillips]

The tubes on motorcycles have bolt in valve stems also. I don't remember being able to tell if tubeless or tube installed, from looking the outside.

 

[Guest]

The tubes on motorcycles have bolt in valve stems also. I don't remember being able to tell if tubeless or tube installed, from looking the outside.

oh. this i did not know. my only real experience with tire tubes comes from my bicycling days. none of the tubes i ever used or saw had bolt/nuts on them.

 

[Guest]

well, more PO weirdness on my bike
did this guy mount tube type tires with no tubes?

As noted, motorcycle tube valve stems can be clamped into the rim. Post a picture or two and I am sure we can sort it out. Or take the tire off and see what you find.


Mark

 

[Guest]

I wanted to finally post again and update on my tube/tubeless saga. Life intervened for the past couple months and I finally managed to get the poor suffering GS850 back together and out for a road test.

Keep in mind most of this stuff is new to me and I'm doing the best I can...

What I did:
Replaced fork seals and reinstalled forks.
Replaced rear shocks with EMGO Classics.
Replaced bearings on front/rear rims (no comment on bearing brand!
Mounted BT-46s on original front/rear rims with NO TUBES
Balanced both wheels on manual rotation balancer.
Put everything back together.

Problems:
Rear wheel would not turn AT ALL after remounting. After confirming things were put back in the correct order I developed a theory that I hadn't set the bearings in fully because I was scared to bash them and it was binding when the axle was torqued. Took it apart, set bearings in to bearing seat shoulder. Success.

Front tire did not seat symmetrically all around bead and had slight leak. I tried releasing pressure and rolled the bike around to see if it would squish things into place. No. Inflated to high pressure to see if it would force bead seat into place. No. Developed theory that the cold rubber had developed a misshapen 'set' in that part of the tire and figured heating it with a good ride on the highway and a few of our local highway bumps would shake things into place when warm. Oddly?, success! After about 15 kilometers the vibrations stopped and following examination revealed the tire now symmetrically set on the rim. I'm sure this approach will not be the most recommended but I did ease up to speed with the intention of calling things off if the vibrations got out of hand.

Summary:
Doing all of the above myself was an interesting experience and I feel like I learned a lot. After the front tire finally calmed down, the ride felt smooth as silk and much better than before I began. I had a great run out for a couple hours to an outlying community and will post some pics in the GS Stories board.

Peace, out.

2 Months ago. Poor GS.

https://www.flickr.com

Things balance out.

https://www.flickr.com

 

[rphillips]

Good to hear you got it sorted out.