How to shop tires

[Admiral Beez]

This is a metric site, but the translation is painless.

https://www.tyreleader.ie/tyres-advices/car-tyres-load-and-speed-indexes

The same load and speed ratings apply to car and bike tyres.

Thanks. I see H on the list, 210 kph. What does H-57 vs H-61 mean, as found on the seller’s website mean?

[LAB3]

Buy from a high volume dealer

Yep! I've ordered several tires from chapmoto and never got one over a year old. Some of the other sellers may be selling older tires, especially if advertised as NOS (New Old Stock) so don't be afraid to ask. Last winter I found a SMOKIN' deal on Dunlop Elite 4's that where three years old, with the number of miles I ride a year they'll probably be six years old by the time they're ready to be replaced (That wouldn't have happened without Covid keeping me in one spot this summer)

[GSDoubleDyl]

Beez, the Letter is the speed rating, the numbers are the load rating.

Speed rating (quick googly from FortNine site):

https://fortnine.ca/en/motorcycle-tire-speed-rating

Load rating (quick googly from FortNine site):

https://fortnine.ca/en/motorcycle-tire-load-capacity

I just went through what you are for my GS850. Lots of info on the web for converting inch wheel sizes to the current metric sizes.

Basically your 3.25-19 inch size = 82.5/100-19 metric. (82.5mm wide x 100%high x 19inch wheel)(19 inch wheel? what? metric??-yeah, love it)
Rear 4.25-17 = 108/100-17 metric

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 next question is whether you need tube or tubeless tires which is a whole other thread! I expect your 1982 is tubeless (I can't confirm). If they are, and you need new air stems, they may not be the same as car tires. My '79 GS 850 has 8mm bolt in motorcycle stems. Car tire are wider press in stems. Someone else comment?

So, my thoughts are these,

Front:
https://fortnine.ca/en/avon-roadride...ront-rear-tire (100/90-19) ,or
https://fortnine.ca/en/bridgestone-b...-46-front-tire (100/90-19)

Rear:
https://fortnine.ca/en/avon-roadride...ront-rear-tire (120/90-17) ,or
https://fortnine.ca/en/bridgestone-b...t-46-rear-tire (120/90-17)

Stems:

https://fortnine.ca/en/k-l-long-valve-stems-32-8251

If yours need tubes, the FortNine has Michelin tubes to fit.

I ordered the Bridgestone for mine and they look good but not yet installed. Check the Bridgestone and Avon sites regarding which models can take a tube if you need tubes. The Bridgestones I ordered can be tube or tubeless and I'm planning to mount without tubes though my front rim does not say "tubeless". It's interesting stuff!

Good luck!
-Dylan

[grcamna2]

Yep! I've ordered several tires from chapmoto and never got one over a year old. Some of the other sellers may be selling older tires, especially if advertised as NOS (New Old Stock) so don't be afraid to ask. Last winter I found a SMOKIN' deal on Dunlop Elite 4's that where three years old, with the number of miles I ride a year they'll probably be six years old by the time they're ready to be replaced (That wouldn't have happened without Covid keeping me in one spot this summer)

I don't like buying tires that are past a certain date(it's molded into the sidewall of every tire)and a high-volume seller is a good bet that you get a fresher tire.

[Admiral Beez]

Beez, the Letter is the speed rating, the numbers are the load rating.

Speed rating (quick googly from FortNine site):

https://fortnine.ca/en/motorcycle-tire-speed-rating

Load rating (quick googly from FortNine site):

https://fortnine.ca/en/motorcycle-tire-load-capacity

I just went through what you are for my GS850. Lots of info on the web for converting inch wheel sizes to the current metric sizes.

Basically your 3.25-19 inch size = 82.5/100-19 metric. (82.5mm wide x 100%high x 19inch wheel)(19 inch wheel? what? metric??-yeah, love it)
Rear 4.25-17 = 108/100-17 metric

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 next question is whether you need tube or tubeless tires which is a whole other thread! I expect your 1982 is tubeless (I can't confirm). If they are, and you need new air stems, they may not be the same as car tires. My '79 GS 850 has 8mm bolt in motorcycle stems. Car tire are wider press in stems. Someone else comment?

So, my thoughts are these,

Front:
https://fortnine.ca/en/avon-roadride...ront-rear-tire (100/90-19) ,or
https://fortnine.ca/en/bridgestone-b...-46-front-tire (100/90-19)

Rear:
https://fortnine.ca/en/avon-roadride...ront-rear-tire (120/90-19) ,or
https://fortnine.ca/en/bridgestone-b...t-46-rear-tire (120/90-19)

Stems:

https://fortnine.ca/en/k-l-long-valve-stems-32-8251

If yours need tubes, the FortNine has Michelin tubes to fit.

I ordered the Bridgestone for mine and they look good but not yet installed. Check the Bridgestone and Avon sites regarding which models can take a tube if you need tubes. The Bridgestones I ordered can be tube or tubeless and I'm planning to mount without tubes though my front rim does not say "tubeless". It's interesting stuff!

Good luck!
-Dylan

Thanks Dylan, that helped a lot. Tubeless. Do you need new stems when you change tires? My rear is 17 not 19.

[GSDoubleDyl]

Sorry Beez, I cut and pasted the tire size for the rear and didn't change it properly. Those Avons and Bridgestones do list 120/90-17 as well. The Avons are listed as Front AND Rear use while the Bridgestones are specific to Front OR Rear use. Make sure you don't put a Front tire on the rear rim just because the size fits, the rubber structures are different and would affect handling and longevity.

Something I noticed when researching the manufacturer websites is the "H57" rated tires tend to be bias-ply types geared towards classic and/or slower machines. Faster rated tires tend to be radial-ply geared for sport oriented bikes. The bias ply are good for my riding and are usually cheaper. 100/90R19 and 120/90R17 (instead of -19 & -17) would indicate radial ply tires which would also work.

Rule of thumb seems to indicate motorcycle tires expire within 7 to 8 years of manufacture. There is a 4 digit date code stamped on the sidewall that is the week and year of manufacture (ex: 1220 = 12th week of 2020). I don't have a whole lot of experience with tires but so far I've had Metzelers that don't seem to last very long before the sidewalls are all cracked dry rot and Bridgestones and Shinkos that seem to last forever. Others likely have different experiences.

You *might* not need stems but I would do it so you know they are fresh. Like tires, the rubber degrades and may no longer provide a good seal. I've seen comments that people never change them unless they have frequent pressure loss and other people who change them every tire change. It's a judgement call. I figure I'll change mine every 2nd tire change. Maybe. BTW I ordered those ones from FortNine as I believe they are correct but I haven't received them yet to confirm they fit. I expect them in next couple days so will confirm when received.
- Dylan

[Admiral Beez]

So, my thoughts are these,
Front: https://fortnine.ca/en/bridgestone-b...-46-front-tire (100/90-19)
Rear: https://fortnine.ca/en/bridgestone-b...t-46-rear-tire (120/90-19)

Was 120/90-19 on the rear a typo? Mine's 120/90-17.

[Nessism]

Thanks Dylan, now that the seasons done I’ve ordered the Bridgestone BT-46 in 100/90-19 and 120/90-19. I believe my stems are new from 2019 so I’ll not order them, but my mechanic will have them if needed.

Hope the highlighted diameter is a typo

[Admiral Beez]

Hope the highlighted diameter is a typo

It was a typo. I checked the order and did the correct sizes.

Bridgestone Battlax BT-46 Front Tire 100/90-19
Bridgestone Battlax BT-46 Rear Tire 120/90-17

[GSDoubleDyl]

It's been a while since I've been back to the forum, been flat out since the middle of August. Got the youngster to university a couple of provinces away for first year. Got in a grand motorcycle tour from Newfoundland across Labrador, through Quebec then back around to Newfoundland (12 days, on the weeStrom, not GS . Had a successful moose hunt to stock the freezer back up. Phew. There were a couple weeks of work work in there too. Now it's back to the grind for another few months until retirement.

Beez: Glad you got the tires ordered. I finally got mine (BT-46s) on the rims and they look great! Back tire seems to be holding pressure just fine (it was tubeless before) but the front is causing me some concern (it previously was mounted with tube but I did go tubeless The stems I mentioned above that I ordered worked fine but only have one nut to keep it on. I tried to add a second nut to lock things up but then the exposed stem was too short for the valve cap to seat fully. I just used one nut. It's all so much fun. Ha.

The weather has been very ugly (cold rain, mist, fog) here for the last few weeks but I'm finally getting back to bike maintenance before the snow flies any day now.

I bought a wheel balance stand to balance the new tires for the GS. It seemed to work out pretty well. I should get the forks (seals replaced) and wheels back on today before I go to work and hope to get out for a spin in the next few days to check how things feel. I replaced the rear shocks with EMGO classics so want to see how they feel as well. My bike still had the originals and they feel solid but a lot of the chrome has rusted off the inside. The EMGOs look good but only offer preload adjustment. You gets what you pays for...

[Admiral Beez]

Got the new Battlaxe tires on today. They look sooo much better than the oversized 130 Shinko I had on the rear. Also had some maintenance done:



1) Tire install and balance (incl. check that speedo cable drive off front wheel is aligned and tight)

2) Molly 77 grease to drive shaft joint hub

3) Intake manifold o-ring replacement (old ones were hard as plastic and causing poor idle and stalls)

4) Oil and filter change (changed to 15w50 semi synthetic instead of the usual 10w40 to see if oil burn reduced)

5) Check/clean air filter

6) Check brakes (hoses, pads, etc) including function of brake lights

7) Change fuel filter

All this, not including the cost of the actual tires cost me CAD$600 including tax. #3 was the big job.

[GSDoubleDyl]

Beez: You have managed to get a bunch of things done too. Sounds great. I hope you get out for a good run to check things out. And post some pics!

I posted some comments on my new tires elsewhere but I agree they sure look a lot better. I also had a 130/90 (Bridgestone Spitfire) on previously and the new 120 width just looks right. They BT46s feel great on the road.