Can you SuMo a CRF80?

[Kurlon]

Pssst.... didn't I say to ignore the suggested rim widths?

For the front, get a BT45, the smallest 16 they offer. There are tons of people RACING on them on these narrow rims, for podunking around the paddoc they'll do fine. In back, that Diablo you posted is neither an SL26 or GTS26/36, it'll be fine.

[The Snowman]

Pssst.... didn't I say to ignore the suggested rim widths?

For the front, get a BT45, the smallest 16 they offer. There are tons of people RACING on them on these narrow rims, for podunking around the paddoc they'll do fine. In back, that Diablo you posted is neither an SL26 or GTS26/36, it'll be fine.

Well, you ARE the small bike racing expert. Guess I should listen, eh?

[Kurlon]

Heh, the trick to putting fatty tires on narrow rims is to get tall sidewalls. A 120/70 on a 2.15" rim looks ridiculous, you can't use the anything close to the whole tire. A 128/80 on the other hand presents a usable profile.

Useless:

Useable:

Head over to the WERA forum, they've got a freshly minted mini section with a bunch of XR100 enthusiasts who can give you hands on advice also.

[The Snowman]

Ah, seeing is believing.

So...
100/80-16 front: http://www.motorcycle-superstore.com...ront-Tire.aspx

120/80/14 rear: http://www.motorcycle-superstore.com...oter-Tire.aspx

And run the tire for the rear backwards, since it is a front tire.

I also want to replace the tubes, since I have no idea how old or worn they are. What sizing should I order? Stock sizes for the dirt tires, according to Ron Ayer's fiche are:

front: 2.25" or 2.5"
rear: 3.0" or 3.6"

[Kurlon]

You go by tire size to choose tube size, I don't have my metric to ye olde tire size conversion chart handy but I *think* in front you're closer to a 3 or 3.25, in back a 4 to 4.25?

[The Snowman]

Is this because the tires are larger?

[Kurlon]

Ayup, bigger tires mean you've got more volume to fill up inside with that tube.

[The Snowman]

OK, so I ordered the Pirellis and some spoons. Just waiting for a response over at the Wera board for a second opinion on tube sizing.

Looks like we're in business.

[The Snowman]

Reply from WERA forums shows Josh is correct.

3.00/3.25-16 front
4.00/4.60-14 rear

Chart they posted is here, if anyone wants a reference:

http://www.cb450stuff.com/tires/

[Kurlon]

That chart is MUCH better than the one I've been using from a Tucker Rocky catalog, score!

[Kitt]

OK, so I ordered the Pirellis and some spoons. Just waiting for a response over at the Wera board for a second opinion on tube sizing.

Looks like we're in business.

could be tough with spoons for those tires and diameters. If you have close access to a machine, it may save you some rim carnage.

[Kurlon]

Small bites, take your time.

[The Snowman]

could be tough with spoons for those tires and diameters. If you have close access to a machine, it may save you some rim carnage.

I was thinking this as well. We'll see what happens when the stuff comes in.

[The Snowman]

could be tough with spoons for those tires and diameters. If you have close access to a machine, it may save you some rim carnage.

As Kitt mentioned, it was a battle. But I was persistent and managed to get both tires off with minimal swearing.

Now I'm waiting on one tire and tubes for both:



While the wheels are off, I'm also replacing the brakes. They look a little thin.

[Chippertheripper]

Way to take the bull by the horns.

[Kurlon]

Back the nut on that rimlock off all the way, you only need the nut on there a few threads to keep it from pulling through while you're working.

Small bites with the tire irons, and be conscious of 'biting' the tube with the irons while you work. Pinch flats suck.

[The Snowman]

Way to take the bull by the horns.

That 14" rear was a real bitch. I came close to throwing the spoons more than once. I will remember that a 3rd may come in handy just at the start.

Since this is the first dirt bike I have ever owned, I have a question on something I found installed on the inside of the rear rim. It's a piece of rubber with a bolt that screws in from the outside of the rim. (see photo) Is it for wheel balance? This was one of the biggest reasons I had issues pulling the tire off this rim.

[The Snowman]

Back the nut on that rimlock off all the way, you only need the nut on there a few threads to keep it from pulling through while you're working.

Small bites with the tire irons, and be conscious of 'biting' the tube with the irons while you work. Pinch flats suck.

Guess my previous question was just answered.

[The Snowman]

I also watched a few YouTube videos on how to remove/install tires. I saw in a few that they used talcum power, instead of a liquid, citing that it doesn't leave the residue that liquids to.

Anyone ever try it?

[Chippertheripper]

Powder the tube when putting the new one in. That's what it's intended for.

And then use windex for the lube to put the sneaker on. The windex evaporates much faster than dish soap.

[The Snowman]

Small bites with the tire irons, and be conscious of 'biting' the tube with the irons while you work. Pinch flats suck.

CRAP! My first pinch flat. It was on the last part, 2" of bead to flip into the rim. The tube was a tiny bit outside the bead and caught as I flipped it in. I instantly heard the telltale psssst of air releasing.

Looks like I now need to grab a tube patching kit. Grrrrrrr.

[Chippertheripper]

forget the patch, new tube. bettencourts should have the stock size on hand, which really should be fine for your application.

[The Snowman]

forget the patch, new tube. bettencourts should have the stock size on hand, which really should be fine for your application.

Bettencourt's is quite a haul for a tube. I did the patch and it's holding. Both rims are getting some sun.

If it doesn't hold, I'll grab a new tube. I did head to MTR in Woonsocket, but as usual, they didn't have what I needed.

[Kitt]

good work. I'm much more afraid of irons on anodized or PC'd rims... But I realize not everyone can have a tire changer in the garage to use twice a year (duh, bought it and then took a break from racing). There are a few tricks to keep the shiny stuff shiny though when using irons.

[The Snowman]

good work. I'm much more afraid of irons on anodized or PC'd rims... But I realize not everyone can have a tire changer in the garage to use twice a year (duh, bought it and then took a break from racing). There are a few tricks to keep the shiny stuff shiny though when using irons.

Believe me, if these weren't stock chrome dirt rims, I would have had someone with a machine do them for me.