Question of clearance For those with a rear drum brake...

[UKPR1]

I have a 130 size rear tire on my 550 and noted that I only have about a 1/2" clearance between the brake torque bar and the widest part of the tire. Is that generally considered to be "enough" or should I be looking at a 120 size tire to gain more clearance?

Thanks in advance.

Geoff

 

[fastbysuzuki]

Seems ample to me.

 

[sharpy]

dont need any bigger than a 120 on a 550. Unless you believe bigger is better.

 

[Brendan W]

If it's not enough you could put air in the tyre

 

[Steve]

Even 1/4" would be 'enough' clearance, but I would be more concerned that the 130 tire is too much for the rim width. If you have a stock wheel, the parts manual says it's a 2.15 width. The stock tire was a 3.75H18. If you do the math, that would be a 95mm width, likely a 100 in today's sizes. Most people would run a 110, but even a 120 would be pushing the limits. I think a 130 is a bit too much.

Contrary to common thought, a wider tire probably won't put more rubber on the road. Because it is pulled into a tighter radius to fit the narrow rim, you are actually putting less rubber on the road. If you want the look that involves having a larger tire, please consider getting a wider rim to mount it to.

.

 

[GSXR7ED]

Looking at my rear drum "T", it is 130/90-17. The clearance on the swingarm is about 1/2 inch but the torque bar attached to the drum hub and the frame has tight clearance.

Interesting topic and Technical advice from Steve as always.


Ed

 

[sharpy]

Even on my 550 Race bike we only ran a 120. Same as i would have on the road

 

[UKPR1]

Gents,

As always...thanks a million! Wanted a vintage type of tread pattern on my tires for this build and I'm having a devil of a time sourcing such in a 120 tire. The bike came with a 130 and I agree that it looks way to much, but my options for a 120 with classic tread are quite non-existant!

Cheers,

Geoff

 

[Steve]

Wanted a vintage type of tread pattern on my tires for this build and I'm having a devil of a time sourcing such in a 120 tire.

Like most others here, I enjoy the quest for a certain "look" for my own bike. As it often happens, my choice for a "look" doesn't exactly agree with what others think might be a proper "look".

However, in the case of something as important as tires, unless you are going to park the bike as a permanent showpiece, would you rather have a "look" or something that actually works? :-k

What are you looking for in a "classic tread"? Do you want the tread to look like the original tires or some other performance tire that was available "back in the day"? Give us some hints what you are looking for, we can focus our efforts.

.

 

[UKPR1]

Steve,

Sound thought in your inquiry. Initially, I was looking for the parallel tread look of the Coker/Firestone/Continental. Then, faced with the frustration of finding a 120/4.60 size, I softened but actually started to prefer the look of say the IRC RS-310 line. To put into words what I'm looking for...I guess its a high density tread look reminiscent of early bikes, just not the modern, diagonal slits of a Katana type tire. Make sense? Is performance a goal...not really, although I do want to be safe. This will be a bike ridden on Sundays, rallys, and such.

Thanks in advance,

Geoff

 

[bwringer]

Personally, I think worrying about what a tire looks like makes as much sense as considering its flavor or scent.

Modern rubber works ridiculously well compared to anything available in the '70s. Unless you're going to hang the bike from the ceiling over the breakfast table, why not take advantage of the fantastic modern tires available now?


Anyhoo, you can get an IRC that is pretty much the same look as stock. I think the GS-11 or something very like it actually was the stock tire on many GS models.
http://tiresunlimited.com/ALL TIRES/Irc/IRC_allweather_gs11.htm
Comes in a 4.00-18, which I suppose is close enough to the stock 3.75-18.

The IRC Durotour is their more modern tire, and it looks like it's available in the "close enough" correct sizes:
http://tiresunlimited.com/ALL TIRES/Irc/Irc_Durotour.htm
I don't have a lot of experience with these, but I've used them and they work well.


American Moto Tire's website lets you locate tires by size, so it's also well worth a try:
https://www.americanmototire.com/street-tires/

The Bridgestone BT-45 might be a good middle ground. It's a fantastic, modern tire that works very well, but the tread is sort of more "busy" than some other later tires, so maybe it won't be as offensive to your eyes? Again, I honestly don't quite understand why this bugs you, so this might or might not be what you have in mind.
https://www.americanmototire.com/st...attlax-bt45-110-90-18-61h-rear-066222-mc.html
https://www.americanmototire.com/st...attlax-bt45-120-90-18-65v-rear-072621-mc.html


Also, Metzeler still makes "Lasertec" tires. They were popular starting in the late '80s, so perhaps they have a "close-to-period" look you can live with. However, they're dreadful, short-lived, and rather expensive. The tire world has definitely moved on since then.

 

[Steve]

I know what you are looking for, but can not find anything like that. You might have to change what you want. The Dunlop 404 has a somewhat "classic" tread. It's not a whole lot different than the K291 tires I had on my '79 KZ1300, so the look has not changed much. The tire itself is not one we tend to recommend, though, as it does not last long and its performance degrades rather steadily from the first mile. The Shinko 230 Tour Master might be an acceptable compromise for you. Not quite the in-line ribs you are looking for, but also not the swoopy diagonals you are trying to avoid. It's a very inexpensive tire that happens to last at least an average number of miles and gives decent, if not good, performance during its entire life.

.

 

[UKPR1]

BW and Steve:

Thank you for your suggestions. I think the Durotours are something that appeal to me, and I can get them in the sizes that I need (my 19" x 1.85" front wheel is killing me...).

Thanks once again, gentlemen!

Best Regards,

Geoff​

 

[Steve]

... (my 19" x 1.85" front wheel is killing me...).

Would it be any consolation at all that the '82/'83 GS1100GL uses the same size wheel? :-k

The non-"L" version uses a 2.15 front wheel, but even that large a bike still uses the same size wheel.

.

 

[UKPR1]

Actually...that makes me feel a great deal better to hear that! As my parents say "Misery loves company"!

All the best and thank you.

Geoff