Triumphrat

n578md · 05-30-2006

Last saturday, I collected a nail in the rear tire (or tyre) of my Bonnie. As a matter of course, I rode 10 miles before I realized that it wasn't my crappy riding skills making the motorcycle unstable but a flat rear tire. The tube is minced to fine shreds and the tire is burned and broken, literally, so I needed new stuff. The rim was unscathed, however. I had a hard time finding a replacement rear tire but the dealer I bought the Bonneville from came up with a Metzeler MEZ2 in 130/80R17. OK no big deal, it's supposedly a fairly good tire except for the fact that this tire is a radial but my front (stock) tire is a Bridgestone BT45 which is a bias-belted type. Two mechanics there told me that on this bike, since it is tube-type rather than tubeless and the fact that I won't be going very fast (less than 100 MPH) that the difference in type and construction tire doesn't matter. OK, that's 2 opinions, what do you guys think about mixing radials and bias-belted? What about mismatched tires? (Two different manufacturer/model front to rear)? I haven't put the wheel back on the Bonnie yet so I have no idea how it rides. Your responses are appreciated.

[ This message was edited by: n578md on 2006-05-30 14:38 ]

PAAS · 05-30-2006

For what it's worth, since Triumph themselves started to fit Metzelers to the T100 and Thruxton, they have been fitting a cross-ply (bias) ME33 (now Lasertec) to the front and an MEZ2 radial to the rear. The only issue with fitting a tubeless radial appears to be the requirement for a tube rated for use with a radial tyre - apparently not all tubes are suitable for use with radials.

Can't your dealer supply a Lasertec rear, which is Metzeler's bias-belt recommendation for the Bonnie? Then when you replace the front you can get the matching Lasertec front. Apparently they work well on the Bonnie and I shall probably fit them when my current Metzelers are shot.

P.S. I believe the business about not mixing radials and bias-ply tyres comes from not mixing them on the same axle (of a car, truck, etc...), obviously not something you could do on a bike!

[ This message was edited by: PAAS on 2006-05-30 15:16 ]

n578md · 05-30-2006

Thanks for the reply Paul. I hadn't thought about the inner tube. The one fitted presently is a Kenda N1709, which is a standard tube. There is no mention of it being able to handle the rigors of a tubeless radial tire. I just called the dealer with the tidbit of info and they told me they have done this a lot in the past without any sort of problems. They also told me that if I didn't feel comfortable with this setup that they would replace it immediatly with something that I am confident with. (Afterall, it's my arse out there, huh?) So, I am going back to the stock BT45 tomorrow morning. It is the fastest way to get back to riding since this tire is available at another dealer. I've only been a motorcyclist since May 17th this year so I am unwilling to push my luck. Thanks again for the reply.

Copper · 05-30-2006

When my stock Bridgestone on the back wore out, I replaced it with an Avon. It was fine, handled all right, not as good as a match but not unsafe.

I have since replaced both with with matching Avons, handles much better.

sooo.....I think you can get by with it no problem, but its better to match.

CarlS · 05-30-2006

I have been running that same combination for 4K miles. No problems and no ill effects. I will replace the front tire with a Laseertec when replacement time comes.

n578md · 05-30-2006

Thanks for the reply Copper and CarlS. Yeah, the mechanic told me he's been doing the same for a while on his 99 Tiger. He even hits the track with that combo every once in a while and he's never had a single problem. He told me he wouldn't let me out on the street if it wasn't safe. (Liability and all.) But, Copper, you mentioned handling not being quite as good without a matched pair. That's what I'm worried about. I know, I know, I'm a big wuss. You guys obviously can handle a small variation in handling and are probably seasoned veterans compared to me. I only have 900 miles and 2 1/2 weeks' riding experience under my belt and... Yep, I'm a wuss. The mechanic who worked on my bike told me this would stay in the back of my mind and make the ride quite a bit less enjoyable, and he thought that part wasn't acceptable. So, a swap it is. I'm sure a year from now, I'll laugh at how lame and overly cautious I've been. :blush:

mecscc · 05-30-2006

I don't think you are either lame or over cautious. You CAN mix and match, but I will never do it. Replace it with a matching Bridgestone. If the dealer doesn't have one buy one from Dennis Kirk or Chaperelle and have the dealer install it. And get a new tube that is compatible with a BT45 while you are at it. It won't cost you any more and you will know you have a set of tires that were designed to be ridden together.

Monte

n578md · 05-30-2006

You mentioned a compatible tube and speaking of tube sizing, what is (are) the correct tube(s) for the BT45 setup. (Front and rear)? The kenda N1907 I have now is a 4.50-5.10 -17" tube, is that too big for a 3.50" wheel and 130/80 tire combo?

And yes, you're right, I will be putting a new and matching 130/80-17 BT45 on the wheel tomorrow.

[ This message was edited by: n578md on 2006-05-30 17:57 ]

mecscc · 05-30-2006

Your dealer will have a tube/wheel matching chart. If not, he shouldn't be a dealer. You can also get the info from the Bridgestone web site, from Denniskirk.com or any large internet tire sales outlet. If you fit a tube that is too large you run the risk of a pinched tube and a flat, or worse, and more likely, a blowout.

If your bike has stock wheels, your rear tire is a 130/80-17. Your rim is 3.5X17. Get a tube designed for THAT size rim --- and one that is also compatible with spoked wheels. (tubes fit a narrow range of rims, eg: 3.5/4.0, etc.)

Also: be sure the tube protector strip around the wheel next to the spokes was not ruined and also replace that if it is damaged.

Don't accept cobbed up combinations and don't take the verbal word of some mechanic who will tell you anything to get you out the door. He will forget he ever said it if it comes down to it.

Monte

n578md · 05-30-2006

Good deal. Thanks for the info. I'll look that up before I go pickup the tire. I'll get the correct tube and protector while I'm at it.