Norton Bonneville Tires

Hey all! Currently building a 750 C'do to run at Bonneville next year. Having trouble locating speed rated tires to work for the project. Looking at the SCTA rulebook I need to have ZR,ZR-W, or Track Day tires for the 750 M-PG(F) class record. Looked into alot of different brands, rim sizes, ect but no such luck. Even considered swing arm modifications to accept bigger tires due to limits on tire width.

Any info is greatly appreciated! I've been scratching my head on this one for months at this point.

This is my bike as I ran it in the 750 M-PF class at the Bonneville Motorcycle Speed Trials (AMA sanctioned) in 2019 (the last time I ran). I used Shinko Tourmaster tires, which are V rated (good up to 149 mph). I had Yamaha wheels on it, and ran a 120/90-18 on the back and 100/90-18 on the rear. Note that AMA does not have a specific speed rating requirement for tires, but say that tire choice is the responsibility of the rider. From your concern over ratings, I assume you are planning to run in one of the SCTA/BNI events, which do have speed rating requirements, requiring the tires to have a speed rating above that for the existing records in the class. The current records in the 750 M-PG and 750 M-PF classes are only 137.872 mph and 138.491 mph, resp., so V rated tires should be fine.

I had previously run it at Bonneville with the same wheels and Bridgestone Battlax V rated tires, but I don't recall the sizes. I may have also run it once at either Bonneville or El Mirage with these wheels and radial tires, but I haven't been able to dig up any info on that. I'll keep looking, and post anything I find.



Ken

Ken,

Very nice looking machine! Yes the current plan is to run in the SCTA/BNI event but I haven't committed just yet. V rated tires definitely would be adequate for the existing record, but if my math is right the build will be able to push 150+mph (Probably wishful thinking but I can hope) so I'd like to have tires rated higher than that. Should I run in the AMA event the 750 M-PG record is 159.9mph I believe and even though the AMA leaves tire selection up to the rider I would still like to play it safe. Had two tire failures on the streets in the past and DO NOT want to have that same experience at 130+mph. No need to tempt the salt demons more than necessary.

Well, there's no drawback to using higher rated tires than required. About that 159.9 mph record. I think it might be unbeatable in reality. When Tom Mellor set it with his Triumph Trident in 2008 he was able to use aero features that he had developed over several years, but that were prohibited in future years by a re-interpretation of the class rules by AMA/BMST. But the 750 M-PF records look fairly easy to break, with a good bike and a trouble-free attempt. Unfortunately, I wasn't able to manage that.

Ken

There's an account of Tom's records in 2008 on this site.


It shows the bike with full streamlining for the MPS class. For the MP class he kept the tail section but removed the fairing. That tail section design is no longer allowed in the unstreamlined MP classes. Tom is quite the interesting guy, and has put a lot of effort into setting multiple records with his triples.

He draws a lot of attention with his British tow vehicle. This is a shot one of our pit crew took of it at Bonneville in 2009.



Not wanting to hijack your thread, but if you're interested, here are a couple of pictures of Tom's bike in fully streamlined MPS class configuration that one of our pit crew took at Bonneville in 2008, when Tom set the 159.9 mph record in the MP class. In the 750 MPS-PG configuration shown here, he set the class record that year at 180.317 mph.

In 2011 he swapped in a bored and stroked engine and set the 1000 MPS-PG record at 191.752 mph.





Ken

lcrken said:

Well, there's no drawback to using higher rated tires than required. About that 159.9 mph record. I think it might be unbeatable in reality. When Tom Mellor set it with his Triumph Trident in 2008 he was able to use aero features that he had developed over several years, but that were prohibited in future years by a re-interpretation of the class rules by AMA/BMST. But the 750 M-PF records look fairly easy to break, with a good bike and a trouble-free attempt. Unfortunately, I wasn't able to manage that.

Ken

Click to expand...

We are running a bike this year in the 750 M-PG class at BNI running V rated tires. You never said what size rim/wheel you are looking to find tire for. If you are looking for higher rated than V rated tires then most likely you will need to widen pun intended your wheel selection. Many of the higher rated tires are for small rim diameters. Getting down to 17 and 18 open up a lot of options. Also, look at some of motorcycles that have used the Goodyear drag tire for a front wheel.

lcrken said:

There's an account of Tom's records in 2008 on this site.

Tom Mellor’s record-breaking 1969 Triumph Trident T150 - Motorcycle Classics

It’s not every day you see a 1950 Rolls-Royce Silver Dawn sailing along the high desert highway. But it was this unlikely rig that brought Tom Mellor, his wife, Diane, and their 1969 Triumph Trident T150 to the Bonneville Salt Flats last summer, where the Canadian rider set four new World Speed...

www.motorcycleclassics.com

It shows the bike with full streamlining for the MPS class. For the MP class he kept the tail section but removed the fairing. That tail section design is no longer allowed in the unstreamlined MP classes. Tom is quite the interesting guy, and has put a lot of effort into setting multiple records with his triples.

He draws a lot of attention with his British tow vehicle. This is a shot one of our pit crew took of it at Bonneville in 2009.

View attachment 95044

Not wanting to hijack your thread, but if you're interested, here are a couple of pictures of Tom's bike in fully streamlined MPS class configuration that one of our pit crew took at Bonneville in 2008, when Tom set the 159.9 mph record in the MP class. In the 750 MPS-PG configuration shown here, he set the class record that year at 180.317 mph.

In 2011 he swapped in a bored and stroked engine and set the 1000 MPS-PG record at 191.752 mph.

View attachment 95049

View attachment 95050

Ken

Click to expand...

Love the TOW vehicle.....

City Garage said:

We are running a bike this year in the 750 M-PG class at BNI running V rated tires. You never said what size rim/wheel you are looking to find tire for. If you are looking for higher rated than V rated tires then most likely you will need to widen pun intended your wheel selection. Many of the higher rated tires are for small rim diameters. Getting down to 17 and 18 open up a lot of options. Also, look at some of motorcycles that have used the Goodyear drag tire for a front wheel.

Click to expand...

The tire selection will pretty much determine where I go with rims. I know the 19" are pretty much out for higher speed ratings in the rear. I'm open to go all the way down to 17". I tried looking into the Goodyear drag front and that's definitely a good option. The fronts are easier to find. Rear tires on the other hand are the problem. I may just go with V rated tires for this run and see how things go.

Hopefully I'll see you when I run next year!

lcrken said:

There's an account of Tom's records in 2008 on this site.

Tom Mellor’s record-breaking 1969 Triumph Trident T150 - Motorcycle Classics

It’s not every day you see a 1950 Rolls-Royce Silver Dawn sailing along the high desert highway. But it was this unlikely rig that brought Tom Mellor, his wife, Diane, and their 1969 Triumph Trident T150 to the Bonneville Salt Flats last summer, where the Canadian rider set four new World Speed...

www.motorcycleclassics.com

It shows the bike with full streamlining for the MPS class. For the MP class he kept the tail section but removed the fairing. That tail section design is no longer allowed in the unstreamlined MP classes. Tom is quite the interesting guy, and has put a lot of effort into setting multiple records with his triples.

He draws a lot of attention with his British tow vehicle. This is a shot one of our pit crew took of it at Bonneville in 2009.

View attachment 95044

Not wanting to hijack your thread, but if you're interested, here are a couple of pictures of Tom's bike in fully streamlined MPS class configuration that one of our pit crew took at Bonneville in 2008, when Tom set the 159.9 mph record in the MP class. In the 750 MPS-PG configuration shown here, he set the class record that year at 180.317 mph.

In 2011 he swapped in a bored and stroked engine and set the 1000 MPS-PG record at 191.752 mph.

View attachment 95049

View attachment 95050

Ken

Click to expand...

Yea that definitely would be considered aero/streamlining with that tail section even from my lack of experience. Maybe one of us can break that 159.9 some day. Seems a little unfair/odd to essentially "lock" that record with a rule change like that. But hey, that's the way it rolls and I don't make the rules and reg. Haha