Can you SuMo a CRF80?

[The Snowman]

Just picked up a 2004 CRF80 as a pit bike and wondered where to start looking for SuMo wheels/tires for it. Just don't want the dirt tires on the bike at the track.



I'm also intending on teaching my son how to ride with this bike. Should be interesting.

[hondarider102]

Wirelessly posted

Just get some street tires in the stock size, I wouldn't spend the money getting aftermarket wheels for it.

[The Snowman]

Isn't the front tire on a SuMo wider and smaller than if I went with a tire to fit the stock front rim?

[hondarider102]

Wirelessly posted

Isn't the front tire on a SuMo wider and smaller than if I went with a tire to fit the stock front rim?

Are you racing it? If your just using it as a pit bike I really don't think it matters

[Kurlon]

The CRF80's front wheel is what most of the CRF100 guys opt for when sumoing the 80's big brother. I think it's a Bridgestone 16" number they shove on and race the piss out of, so I'd say no worries running that wheel as is. Dunno what to suggest in back though.

[Chippertheripper]

I'd just leave it as is myself. You aren't racing it, just cruising around the pits it really isn't worth it.
Preteen is still going to win the pitbike race with that cheater bike anyway.

[Kurlon]

I'd just leave it as is myself. You aren't racing it, just cruising around the pits it really isn't worth it.
Preteen is still going to win the pitbike race with that cheater bike anyway.

Tell me more about the pitbike race and his cheater...

[The Snowman]

I'll probably put street road tires on it, since I have no intention of ever riding it off-road. And if I do decide to do he pit bike race this year, I won't have to worry about grip.

Not that I'd ever take the pit bike race as seriously as Christian did last year. I'd just be having fun.

[The Snowman]

BTW, the cheater bike was a vintage street bike and Christian pretty much lapped the entire field, at least once.

[csmutty]

I'll probably put street road tires on it, since I have no intention of ever riding it off-road. And if I do decide to do he pit bike race this year, I won't have to worry about grip.

Not that I'd ever take the pit bike race as seriously as Christian did last year. I'd just be having fun.

But I WAS having fun...

[Chippertheripper]

Your definition of vintage streetbike and mine are really different.
I thought that thing was just a ttr125 geared to the moon.

[csmutty]

Your definition of vintage streetbike and mine are really different.
I thought that thing was just a ttr125 geared to the moon.

It had a high compression piston, cam, carb, air filter, exhaust, ss lines, woodcraft clipons, sun rims?, vintage roadrace rubber, etc.

[klp]

Wirelessly posted

Just get some street tires in the stock size, I wouldn't spend the money getting aftermarket wheels for it.

+1

From what you intend to do it is not worth the time and $ of new wheels. You can get street tires in those stock wheel sizes - I have an xr80 that I have raced at C128 Masters of Mini for a few years now. The front is a 16' and has pretty limited selection of tires, the rear at 14" has more. I think my front is a moped tire, the back I don't remember. I could go check what I am running if you want. I went the cheapest route and ended up with some tires that are pretty skinny so it looks a little wonky.



If you want more and better tire selections you should run a set of xr100 wheels at 16/19. You could also run a 100 rear if you have your heart set on the Sumo look.

[The Snowman]

Well, my rim sizes are 16"x2.5" front, 14"x3.6" rear. Same as the XR above. Finding tires to fit the rim width is proving to be difficult.

I have searched and found that some use a 100/80-16 front, but I haven't found information on the rear.

Pirelli makes Diablo scooter tires and I could get a pair for about $100.

The issue is the rear. I'm not sure if even a 120 could fit on it. I am thinking that a 120 would be the biggest tire I could fit. But the 120/80-14 or 120/70-14 are both also front tires.

The same is true with most other brands. The 120/X-14 are usually front tires.

Does it really matter??

[Kurlon]

Ignore the suggested rim widths, especially given you're not racing. Same goes for front vs rear fitment, if you're fitting a tire on the wrong end of the bike, run it 'backwards'.

[Doc]

Just get an entire front end with a 14 inch front off ebay... you know you are going to.

'Oh and listen to Kurlon, he is one of the mini experts on here (in more ways than one)

[The Snowman]

MY intention is not to spend a fortune. I Just wanted to put some street rubber on it.

Oh, and can you do street tires with tubes?

The Diablo scooter tires look like the right choice, but they're tubeless.

@Doc, I didn't swap the front end on my race bike (but considered it at one time), why would I do it to my pit bike?

[Kurlon]

Yup, you can run tubes. What Diablos are you looking at? The SL26? are available in a wide range of sizes but are HEAVY.

[The Snowman]

http://www.phatperformanceparts.com/...RELLI-DBLOSCTR

[Chippertheripper]

I have tubes in my tubeless race tires. On my motard.

I don't know you too well beyond forum banter, and talking smack around the pits c-lo, but I think you're way over analyzing this. If I'm wrong, I'm sorry. Get em, and some good tire irons (me likey motion pro) watch some YouTube videos on changing dirtbike tires, and you'll be in the money. Ps: get some ridiculous sprockets and smoke preteen too.

[Kurlon]

Lube the beads of the tires before you try to mount them. Lube them A LOT. Like, dripping all over the place lubed. Windex works, 50/50 mix of dish detergent and water, I know people that use medical hand soap because it has alcohol and evaporates nicely. You're going to fight both the beads and the tube cramming a 120 onto narrow rims but it is doable. Once on, wind the pressure up, like 90psi or so and let them sit in the sun for the day to fully seat the bead all the way around. These tires have a nasty habit of not seating in one spot making for a bit of a wobble. Once seated, drop the pressure to say, 25 and experiment from there.

[The Snowman]

I have tubes in my tubeless race tires. On my motard.

I don't know you too well beyond forum banter, and talking smack around the pits c-lo, but I think you're way over analyzing this. If I'm wrong, I'm sorry. Get em, and some good tire irons (me likey motion pro) watch some YouTube videos on changing dirtbike tires, and you'll be in the money. Ps: get some ridiculous sprockets and smoke preteen too.

You're probably right. I over-analyze everything. I'm just looking for smoother tires, in case I do the pit bike race. It also makes tooling around the pits much nicer.

Lube the beads of the tires before you try to mount them. Lube them A LOT. Like, dripping all over the place lubed. Windex works, 50/50 mix of dish detergent and water, I know people that use medical hand soap because it has alcohol and evaporates nicely. You're going to fight both the beads and the tube cramming a 120 onto narrow rims but it is doable. Once on, wind the pressure up, like 90psi or so and let them sit in the sun for the day to fully seat the bead all the way around. These tires have a nasty habit of not seating in one spot making for a bit of a wobble. Once seated, drop the pressure to say, 25 and experiment from there.

Good info. I would grab a 110 rear (or front to put in the rear) if I could find a 110/80-14. No one seems to make one though.

I'd love to go 100/80-16 in the front and 110/80-14 (maybe 110/70-14) in the rear. But like I said, pickins are slim or non-existant for the rear.

[csmutty]

http://www.irc-tire.com/mce/
For the rear...


And for the front...
http://www.avonmoto.com/products/classic/roadrunner
1675019 AM9 MT90-16 TT 74H 3.00D 2.50 - 3.50 139 5.5 645 25.4 8.0 518 828.8

[The Snowman]

Was hopeful, but can't seem to find a distributor who sells the 110/70-14 NR77. (in the US anyway)

[The Snowman]

Found a site, but will be mixed types.

I actually compared tire sizing to my street bike rims & tires and it looks like I would need:

Front - 80/80-16
Rear - 100/90-14

If I went wider, it would be bulging beyond belief. I measured the rims and they're only:

Front - 2.125" at the bead (54mm wide)
Rear - 2.5 "at the bead (63.5mm wide)

Yep, over-analyzing once again.