F650 Tire FAQ

by David #476
Please read the Disclaimer before attempting any work in this FAQ.
Updated 23 June 2004 by Scott, ID #1244

My tires are about shot. What should I replace them with?

That depends on what you do or intend to do with your bike. If you intend to ride on pavement only, you're in luck. Every tire manufacturer makes several types of tire in sizes to fit the F650. The choices range from sticky sport-oriented tires to harder, long wearing, touring type tires which will last much longer at some small deficit to the handling.

If you intend to ride off-pavement there are more variables to consider. Do you ride a mix of 75 road/25 off-road or the other way round? Is the percentage more lopsided one way or the other? Off-road tires can be grouped into two types as well. You have your dual-sports and your off-road MX/Enduro types.

While some Inmates are quite pleased with the Bridgestone Trailwings that came on their bike, reporting good longevity, most inmates who have tried nearly any other tire report that handling and confidence are greatly improved by abandoning the Bridgerocks. Michelin T66 and Metzeler Tourance tires are two of the favorites for those who favor highway over dirt in their dual-sport percentage mix. Avon Gripsters are another offering with vocal aficionados who tend to have a slightly higher dirt percentage than the previous two.

Dual-Sport tires can be further sub-grouped into two groups: Block tread designs which are more oriented towards the highway side of things, (The Bridgestone Trail Wings or Metzeler Tourances that came with your bike are of this type), and knobby type more towards the off-road side of things. The characteristic they both share is that they are DOT rated. This is important if you plan on spending hours on end at highway speeds because the manufacturer has certified with the DOT that these tires will do this without coming apart. Examples of the knobby type are the Metzeler MCE Karoo and the Continental TKC-80 Twinduro, or Metzeler Sahara. All these tires come in a size that will fit the F650, although sometimes not in the suggested 100/90-19 or 130/80-17 size.

When we move to MX/Enduro tires things get a little sticky (pardon the pun). The F650 and GS come with wheel sizes (most notably the 19" front) that are somewhat less common for off-road bikes and most tire manufacturers only make this type of tire in 21" front sizes. (If you have a Dakar, you're in luck!).

There are several remedies for this. Some members have replaced the entire front ends from off-road bikes (the benefit of which is greater ground clearance and suspension travel, as well as a 21" front tire). Others have had the rim and spokes replaced with a 21" Excel and re-laced by Buchanans Wheel. (Benefit here is a much stronger rim, but stock hub uses stock brake and Speedo set up) Another option is to use 100/90-19 REAR tires mounted backwards on the rim. I personally have used this option and it is the best solution for "off-road" with a stock bike I've found. It required cutting the outermost knobs down about 1/2" with a sharp knife to clear the fender, but it went like stink in the dirt. While the rear 17" is easier to fit, a greater variety of off-road tires are available in 18" size. This requires the new rim option and care must be taken to assure clearance of the tire against the swingarm. This can be accomplished by adding a link to the chain and moving the chain adjuster towards the rear off the bike or by buying a smaller diameter tire. Both have ramifications in handling and gearing, so consider this carefully.

The down side to using this type of tire is that it is NOT DOT rated. Use at your own risk! Another bummer is that they are LOUD on the street, because the knobs are pointed (when new) instead of flat like the DOT knobbies and the designers waste no time on making them quiet as they do with all street and dual-sport tires. Although I found the handling to be acceptable, be careful. Riding on dry pavement with an off-road knobby is like riding on dirt with a street tire. You need to increase your braking distance and reduce your lean angles.

Q. OK. So, I realize that there are a lot of variables of course, but would a high-mileage touring tire have at least as good wet and dry grip on pavement as something like the Tourance? Michael #941

A. The short answer would be no, Michael. All other things being equal, the mileage that you can get out of modern tires has a lot to do with how soft and sticky is their rubber compound. A soft sticky tire tread will grip the pavement better, but leave more of itself behind as you ride along. Where things get complicated is how the construction, flexibility, design (radial, bias-ply, bias-belted), aspect ratio, diameter, width, tread profile, rain grooves and other factors enter into the equation. To make matters worse, many high-mileage tires are designed for much larger and heavier bikes than the F650 and are also designed to be mounted on tubeless wheels. Installing a tube in a tubeless tire will cause the tire to run hotter than the tire engineers planned on and a hotter tire will usually wear faster and have a lower maximum speed rating. What all this means is that you pretty much have to go by word-of-mouth to find a tire that works well on our bikes while also providing good mileage. Richard #230

My bike has a bias ply tire on the front and a radial on the rear, do I need to keep this configuration?

BMW recommends a bias ply front and a radial rear tire. I'm sure there is a valid reason for this, but it severely limits the choices of rubber for your bike. While many street tires and a few dual-sport tires (mostly of the block tread design), are available in Bias Front/Radial Rear types, most aggressive Dual-Sport and all MX/Enduro tires are bias ply. If at all possible, I would try to pick tires that meet your needs as well as follow the recommendations of BMW, but don't let it be a limiting factor. Many of us have run bias rear tires such as a Michelin Sirac with no detrimental effects. A radial Dual-Sport tire will disappoint if most of your riding is off-road, especially in loose material.

What tire pressure should I use?

They are many answers to this question, and just about everyone has a different one. Many folks on the list have experienced better tire longevity on some brands at higher pressures than the ones recommended in the owner's manual (and on the sicker on the swingarm). The best rule of thumb is that your hot tire pressure should be between five and ten percent higher than the cold pressure. That is if you inflate the tires to 36 psi when cold, when the tire is hot it should be 38 to 40psi. Any more or less and the tire is over or under-inflated. This rule also takes into account the varying loads you could put on your bike.

See the Tire Opinion FAQ for comments on tire inflation.

My tires say tubeless, but they have inner tubes. What's up with that?

There are several answers for this one. One has to do with the style of the rims. For whatever reason, probably cost, the tubeless type of wire spoke rims as used on the R/GS series were not used on the F's. Because the spoke nipples are inside the bead of the tire much care and considerable luck would be needed to keep air inside the tires, one reason for the tube. Others have to do with riding off road. With the low pressures used for off road riding, it would be very easy for a tubeless tire to pop it's bead off the rim, and having a tube inside gives a little extra insurance against punctures. The plus side of this is that should a puncture ever happen, a simple fix of the tube gets you back on your way. Many off roaders carry "Slime" or some other puncture repair along with some way to re-inflate the tire, either CO2 cartridges or a pump. If a flat happens, you're back on your way relatively quickly. With a tubeless tire, while emergency plugs are available, they are just that and a puncture pretty much dictates a new tire for safety reasons.

It is fine to put tubes in tubeless tires. In fact all tubeless motorcycle tires say, either on the tire or in the manufacturer's literature words to the effect, "Install tube when used on tube-type rim."

Just what is a tube-type tyre, anyway?

Q. What is a tube-type tire? Benefits/drawbacks? Differences vs. tubeless? Manolo

A. Tube-type tires are always bias-ply tires (usually marked with a tubeless/tube-type designation on the sidewall). They supposedly have a slightly different bead configuration than do "pure" tubeless tires and are specifically designed to accommodate the installation of tubes. My guess is that the design is more resistant to heat build-up, due to the weight and friction of the tube, and may not have the same air-proof coatings inside the tire and stiff sidewalls as a tubeless or radial tire may have. This may be why the tubeless radial tires that BMW specifies for the rear wheel of our bikes are so difficult to break the beads loose from the rim. The front tires, which are not radial in design, seem to come off more easily than the rear tires. In my experience, both types of tires hold air and seem to work OK. Richard #230

What do those numbers on my tyre mean?

Would you believe just about everything you need to know about a tire, including when it was made, is contained in the article: What's in a tire besides air? De-mystifying the black art of tire designations ? This comes from the American Motorcyclist Association. Will in CA

Can I mix different tires?

Q. A KLR riding friend of mine and I have been discussing and debating various tire choices. My friend is a big proponent of putting an Avon Gripster (provided they are really being produced) on the back and a Sahara on the front - he says there's no adverse affect to mixing tires like that.
However, in the MSF class I took last weekend, the instructor was vehemently against mixing tires. Opinions? Seacuke#1214
A. MSF has a strict party line about many things. Like using all four fingers on the front brake. They won't support mixing tires. As long as you don't mix drastically types, you should be fine. I've used mixed high performance radials to good advantage. Even the carcass type isn't all that important, if you look at the Classic. It came from the factory with one radial and one bias ply, if memory serves. Your friend's combo for dual sport riding sounds like a good one. Harl#380
A. All bias ply or all radial are best choice. Some combinations are actually illegal in the UK. The manufacturer and style of tread should make no difference if they are both approved, but you may notice a different feel. Andy#982
A. This is a legal liability issue here, not a technical question. As long as it fits, doesn't get in the way of anything, and you do the job right, you can mount anything you want. Flash#412
A. I concur with BMW's recommendations. You can run radial tires at both the front and rear, but you need to use a higher pressure in the front tire to keep the bike from understeering around corners (which can cause other problems). Their recommendation to use a radial rear and a bias ply tire for the front is the best combination, in my experience. Richard#230

Can I use oversized tyres?

Q. Has anyone ever stuffed a 160/60-17 onto the rear rim of a Classic F650? I happen to have a pretty decent tire handy. Will it fit? It really looks wide, but I had to check. Someone here must have tried! Andy
A. It fits fine but needs a wider rim. 4.5" is the correct size. Chainsuk

A. Anyone considering using non-homologated tires on their bike, particularly those doing a super motard conversion might be interested in consulting this Rim Width/Tire Size Chart  Flash #412

What about knobbies and a low fender?

Q. Does anyone have experience with running knobbies (Conti TKC80 for example) with the low TT [Touratech] fender? How much room is in there? Bike in question is a 03 Dakar. Rene

A. Apples and Oranges, I know, but on my '99, TKC's fit fine with the OEM fender (small square knobs) but real-off road knobs (Maxxis with tall pointy knobs) needed a trim on the outside row of knobs, and still grabbed rocks and threw them up against the fender and eventually broke my fender extender. I wouldn't think you would have clearance problems, but if you do, a serrated knife makes short work of the offending knobs. David #476

A. With street tires, the big concern is caking up the tire with mud, then locking the wheel when the mud fills up the clearance between the tire and fender. Not sure if "knobbies" can cake up in the same way or not. Marty #436

A. I put some 1/2" chrome plated spacers under my TT fork brace to raise the fender a little after a mud-cake problem. I forget the name of the company that makes chrome plated fasteners, but I got them from the local hardware store. You'll need longer fork brace bolts too. RodP

Can I change my own tires?

Short answer: Yes. Big Picture: While changing tires on many bikes is a relatively easy process, the design of the F650 rims with very little drop center, particularly in the rear wheel, make this a very difficult and patience-testing ordeal. Many an old pro has returned to the list whimpering about bent tire irons and scratched rims and vowing never again. It IS do-able, there's no magic involved. And if you ever plan on repairing a puncture in the field, a bit of advanced practice in the garage is well worth the time. Breaking the bead loose on the rear will require either a bead breaker tool, running it over with a car (just the tire, not the wheel), using a jack or some other artifice. Once the bead is broken extracting the tube for repair is difficult. Reinstalling the valve stem through the rim will flat hurt your hands and try your resolve. But, take heart, it can be done.

As always: YMMV

Tyre Installation

Check your tires are installed the correct way around!

"The F is somewhat unusual in that the drive chain is on the right side of the bike. Pointing this out to the service department, and maybe putting a piece of masking tape on the rim with an arrow showing the direction of travel, may help prevent the tire from being mounted bass-ackwards on the rim. If they're a Japanese shop, they're probably accustomed to the drive chain on the left and may not realize the F is different unless you point it out. Also cause of Wobble, Poor grip etc." James #523 CT.

Q. It appears that I may possibly have a bent rim after having a new tire installed. Could it be something else and how do I check?
A. "...you wrote 'When the bike is on the center stand and running in first gear, you can see a significant wobble back and forth of the tire'. What's more important is whether the rim wobbles. You need to check that out, 'cos it's possible that the tyre is not properly seated on the rim, with the tyre-walls not sitting correctly against the rim flanges. You can check for rim wobble, just by laying a pencil on the swing-arm, close to one point on the rim, then rotating the wheel by hand. If that's ok then it's likely you'll need to re-visit your tyre dealer, (or whoever did the job), to get the job done properly.
Just to make it a bit clearer after re-reading my previous post - Sometimes when a tyre is fitted the tyre bead does not slide up hard against the rim flange, but the side-wall folds over and it *looks* like it's up against the flange. Sometimes there is a thin raised line of rubber on the side-wall, which should run close to and parallel to the rim to indicate that the tyre is fitted correctly. Close inspection should reveal whether or not that's correct in your case.
...you wrote 'The thin rubber line on the tire next to the rim wanders toward and away from the rim noticeably on one side.' That may well be it. Once when it happened to me the tyre fitters had to put around 100psi in the tube before the tyre popped into place correctly, even though they lubricated the bead and rim thoroughly. Once it was in place they obviously reduced the pressure (I was stood well away when I saw the pressure gauge going round the dial)." (Trevor #999)

Fixing Flat Tyres and Related Advice

Some Q&A on Fixing Flats at Home and on the Road

Q. How can I learn to change my own tires?
A. "Check the tire companies' web sites. Some of them have an FAQ for tire changing. You might also check out this site: http://www.clarity.net/~adam/tire-changing-doc.html " (Richard #230)

Q. Any advice on using tire irons, especially on the road?

Q. How do I change the tires myself? Any good advice?

Q. Got my first flat, pulled a huge pin out of my rear tire and have some Questions. What's the deal with slime, can I use it? Will it help my situation now? The tire thread is fairly worn (about 7K on the bike). Should I just get a new tire and tube?

Q. What about using dish-soap or other lubricant to aid in mounting a tire?

 

Q. Will not be going far off road in near future but have been to places where cell-phone has no signal and wondered whether I should be carrying gear to repair a tube. Can't find much in FAQ? (you can now!)

Q. How do I get the valve stem back through the rim?

Q. Any advice on not pinching the tube when reinstalling the tire?

Q. What options are there for inflating a tire after a repair?

A. The Tyre Pump section of the Tools FAQ says it all.

Q. What options for Tools are there for Breaking the Bead?

1. Tire Wizard - http://www.ctm-design.com/prolevr/

Here are some photos of the Tire Wizard in action.

2. Tyreplier - http://www.extremeoutback.com

3. C-Clamp

4. Manual Tire Changer

I recently got the Harbor Freight tire-changing device (parts 34542 & 42927), and I've spent the night trying to figure out how to use it. The instructions are horrendous. I haven't seen the Tire Wizard's instructions, but I bet these would rival those... it's like they omitted about 80% of what needs to be done. So I gave up and took my tires to a dirt shop. Here are some pictures of my shabby operation: the whole operation; the top half, i.e. the Motorcycle Tire Attachment; the bottom half.

  Seacuke #1214

5. Kowa Tools Bead Breaker

6. Tire Irons

Studding Motorcycle tires

Written by Chppdlvvr 17 feb 2003

Studding motorcycle tires is a BAD IDEA. Do not install studded tires on a motorcycle unless you are prepared to crash. Prepare or update your last will and testament and tape or otherwise securely fasten a waterproof copy of your emergency contact information to your bike AND your helmet before rolling an inch on studded tires. This is no joke.

Tire Selection
The most important part of this process is the tire. The knobbier a tire is, the better it will do in fresh snow and slush. On the other hand, dirt specific tires have less of a contact patch and will not stop as well as a more street oriented tire on dry pavement and will also have less traction than a tire with more studs and surface area on compact snow. I decided to go with a 90/10 Kenda Trakmaster II DOT knobby. Mainly I got those tires because they were cheap and they were one of the few sets of matched knobbies I could buy. I also tried a 50/50 tire, but the casing was too hard to accept the stud. Some tires just won’t take studs.

 

Mileage
In nearly 1000 miles, my tires show minimal rolling wear and the edges of the front tire are slightly rounded on one side from braking. This is due to the metal spikes sticking out of the tire- they relieve the individual knobs of a significant amount of pressure but also decrease the size of your contact patch and reduce traction on bare pavement. Keep in mind that reduced contact patch = extended braking distances and less overall traction, especially when cornering.

 

Studs
The studs I used for my tires are 13mm automobile studs. They are inserted using a stud gun attached to an air compressor. This is expensive equipment and I was able to get my tires done at the local tire shop instead for $10/tire. You may have to search for a tire shop willing to work with you. This is a generally easy project but it can be difficult to find the right dimensions for the studs to seat right. I took each tire in 3 different times for test studs before drilling all of the holes. My shop also used some kind of lubricant to help seat the studs that reduced the amount of knobs that had cracks around the edges of the holes. Using glue is not necessary.

Pattern
I decided to stud about half of the knobs on my front tire to make it perform better on dry/wet pavement. I haven’t noticed any problems with this setup but my minimum braking distance still increased about 30 percent from the original Bridgestone Trailwings. I studded every knob on the rear tire except for the outside edges. I figured if I ever got that far over on snow I was going down anyway and I might as well have the extra traction for emergency manoeuvres on dry/wet pavement. So far the outside knobs still look new.

Drilling
The diameter of the stud is just under 3/16”. I used a 3/16” all-purpose drill bit with a locking collar for the front tire and I wrapped the bit in duct tape for the rear tire after losing the set screw for the collar. I preferred the duct tape, but it’s harder to set up. When drilling the front tire, the collar slipped once and the bit went straight through the tire. I repaired the hole with a string patch and trimmed it flush with a knife on both sides.
If you drill a hole completely through the tire, do not try to stud it. It could rip the casing and ruin your tire.

 

I found that the perfect depth was exactly the length of the stud- from base to tip. This may differ from tire to tire but it’s a good place to start. The rear tire was a harder compound than the front and required a little more time per hole and I had to stop the drill and roll the bit around to loosen up the rubber. To date I still have every stud; none have fallen out. The only way to remove a stud once it’s in your tire is with a good pair of pliers. I decided that it’s better to drill a little deeper and then do a couple hundred miles of pavement to seat all of the studs and wear the rubber down to the proper depth- just poking the tip out of the rubber.

 

Performance
These tire have worked out much better than I’d hoped. The handling is definitely different due to the shape of the new tires and the studs track badly in rain grooves, but I can straight-line accelerate in the snow nearly as fast as I can on dry pavement in snow up to 2" deep. I have ridden in snow up to 10” deep with no problems at all. I actually prefer deeper snow to well-traveled snow. Traction is still shaky on compact snow but on ice, fresh snow, slush, and bare pavement the tires have performed beautifully.


 

Opinions on studding tires

Photos:

Metzler Karoo