Triumphrat

Panic Reflex · 05-20-2008

I've gone through a lot of old threads in my search results, and I keep seeing references to the necessity of running a special radial tube inside that kind of tire. No specifics on why. I ordered my Tourances from Dennis Kirk, along with tubes. The front tire is a bias ply, no problem with my new tube there.
As the rear on these sets is a radial, how bad is running a standard tube? The Kirk website has no radial tubes that fit the size for the Scrambler rear. I ordered a Metzeler tube (not cheap) that apparently is suitable to fit 10 different width/height sizes in the 17 inch range. If a tube is flexible enough to work in that many different tires, what bad thing will happen to it inside a radial?
I was so excited to be getting new tires for my bike and enjoying the handling upgrade, I did not dig far enough into the heretofore unknown minutiae of motorcycle tires. Do I have to send this tube back and find a different vendor, or will it be ok on a bike that will rarely see 85 mph?

modre · 05-21-2008

the debate is about making heat due to tire flex of the radial tire...on cars it's fairly dramatic on the footprint and cornering stresses, but on a bike I don't think it's much of an issue since the weight is minimal and the bike leans rather than scrubs.

I put the stock tube in the new radial tires without a second thought.

if you have any anxiety, run it at higher pressure to minimize deflection.
I know the spec is 33 & 37-ish, but I run mine at 30 & 33 psi with no problems.

Panic Reflex · 05-21-2008

Thank you, Modre. Relaxing now..... Ken

uzidzit · 05-21-2008

texture in a lot of radials, Biggest thing is just to make sure the changer uses enough talc between the tube and the tire. the radial tube in radial tire usually goes down when punctured like a tubeless, slow and easy under control. not the pop bang hold on for dear life like the old days.

ps DO NOT run the tourances below 36 front and 40 rear, on the paved roads, you will kill them dead real quick, I have seen a set ruined completely in 900mi (only had 50-60mi on them when he did this) by a guy that lowered the pressure to 24lb for a fire road and did not raise it back. those were on a gs 650 which is about the same weight.

I really like the tourance it is a good tire, not my choice on a bonnie but if you hit the gravel roads you will be good at 24-22psi, carry a pump!

Leeroy · 05-21-2008

What you're looking for is a heavy duty tube. Dunlop, Bridgestone, Michelin and others make them. Mine is a Michelin 140/80-17 SuperMotard tube.

Panic Reflex · 05-21-2008

Yeah, I wanted heavy-duty tubes for both tires, but Dennis Kirk didn't have those in 17" either. I got my Metzeler tube today, and am less than overjoyed that it is made for Metzeler by King tires in China. $22.99 plus shipping, thirty bucks for a pretty ordinary tube. The Michelin heavy-duty was only $24.99. Yeesh.
At least I'll have the one heavy tube out front. Should it require less topping off with air, being 4 mm thick?

uzidzit · 05-21-2008

usually leak just as much, make sure to use a metal valve stem cap with a o ring in it. that will help. I hav been using heavy kenda tubes and they have been very good to me.

ps make SURE they put in NEW rim tapes.

Really if you want to know the best change procedure,

wire wheel all the rust off the inside of the wheel (yes it will be there, more than you thought)
spray the inside of the wheel with rust converter and a coat of paint, let really dry
new rim tape
lots of talc
new tire
balance (put the heavy spot opposite the valve)
check spokes
you're done

a lot of folks skip the first two steps any more, the cleaning and paint may be overkill but your wheels will last a lot longer, but do not skip the new rim tapes,

oh and do not go below 22lbs on the tourances off road , you can spin them on the rim and tear out the valve stem (a bad thing), these rims do not have locks.