[chris brown]

why would i want a 5'' rear rim as opposed to a 4.25''. flatter cross section of tread equalling more rubber on the road? help me out guy's, i have an "05"crf coming and i want to know why i should go with the wider rim. :headscrat

 

[Nick Novice]

because you can use a wider tire and getting a larger contact patch on the ground. a 165/55 works quite well on my crf 450. it's not a flatter cross section(unless you use the same size tire as you would on a 4.25"). i don't think i would run a 5.0" on a smaller bike like a 250f. i have to install my wheel in the swingarm with the chain guide removed and no air in the tire. but i think it's worth it. whatever rim width you use, use the correct size tire. some people use too wide a tire on too narrow a rim. it messes up the profile.

 

[kpracing]

I'm using a 5'' rear but also have 4.25 the 5 seem easier to get out of the tight corners the 165 tire fit better on it.
They now have 5.5'' for the crf, not easy to get in the swing arm but it can be done
.

 

[ypvs]

Because it will gain you a lot of time on track.
Tune how much you want, without a 5" you cant use it as well as the others.
There are no reasons to buy a 4.25 today except money but that's a stupid save.
And, normally you shouldn't have to take the air and chainguide out to change wheel. It's possible to get it in with a bit of an angle.
I just came out of the same discussion on another forum btw.
http://www.monomaniacs.nl/smf/viewtopic.php?t=1381


Daniel...

 

[RichieB]

I have a 5" W rear rim on my CRF and it's feels a lot better in the turns then it did
with the 4.25.

 

[Nick Novice]

And, normally you shouldn't have to take the air and chainguide out to change wheel. It's possible to get it in with a bit of an angle.
I just came out of the same discussion on another forum btw.
http://www.monomaniacs.nl/smf/viewtopic.php?t=1381


Daniel...

well that thread never mentions a the installation and removal on a crf. i can't get mine out w/o removing air and the chain guide. it works like a champ. but is tight.

 

[RichieB]

Remove chain guide and slide brake caliper out while pulling wheel out.

 

[ypvs]

well that thread never mentions a the installation and removal on a crf. i can't get mine out w/o removing air and the chain guide. it works like a champ. but is tight.

I know but the main question to deal with here was the possible benefit with a 5" compaired to a 4.25" so I saw it relevant to the discussion.
Problems or not, if you race and don't take a second given to you for (almost) free you're a fool. I see only one other chance of getting that second, and that's loosing 5kgs either off your bike or off your belly.
I worked off a ton of weight as I started to race seriously again after a few years off coming up to this season and gained about a sec for every 5kgs lost.
Skill, physics, chassi, engine, in that order, are the most important things in SM racing. Skill and physics you get by riding, riding and riding. Nothing is as valuable as time spent on the bike. The gym has to be used with sence for a racer. Don't build where you don't need it as it makes you gain weight, where you need more strength you will feel the day after a hard day on the track. For condition run or ride bicycles.
Get a really good chassi. Suspension, wheels, brakes, see that the bike is as light as possible etc.
Then, start to work on the engine.

Mostly people go the exact other way though and as a result take 3 years more than needed to develop into fast riders. Rear wheel is a very important step, you will never win a race on a 4.25 the difference is that big.

Daniel

 

[Nick Novice]

Remove chain guide and slide brake caliper out while pulling wheel out.

that's the only way to do it. to further what ypvs said, rotating weight is the first place to start(unless you're a fat ass). this winter i'm plan to make my own tubeless kit. it can't be hard. it's only 22psi. i'm going to adapt a "stan's" bicycle type set up. that'll shave some rotating weight.

 

[Master Pain]

I got a 5.5 rear with a 155 dunlop. I get my bro's take off's. All fit nice except a little rob on the exhaust. fmf powercore.

 

[Middy]

You guys have REALLY thrown a spanner in the works for me now.

I'm just in the process of buying wheels to convert my 03 crf. Will be racing it only.

So i should get the 5.00 i take it? your the only people to tell me this!

Are tires as easy or easier to get on a 5.00?

Do i still want to be running a 3.50 up front?

Thanks all and please reply to this i really do need to know

 

[RichieB]

You guys have REALLY thrown a spanner in the works for me now.

I'm just in the process of buying wheels to convert my 03 crf. Will be racing it only.

So i should get the 5.00 i take it? your the only people to tell me this!

Are tires as easy or easier to get on a 5.00?

Do i still want to be running a 3.50 up front?

Thanks all and please reply to this i really do need to know

If your gonna race, go with the 5" :thumbup:

 

[PowerFiend]

You guys have REALLY thrown a spanner in the works for me now.

I'm just in the process of buying wheels to convert my 03 crf. Will be racing it only.

So i should get the 5.00 i take it? your the only people to tell me this!

Are tires as easy or easier to get on a 5.00?

Do i still want to be running a 3.50 up front?

Thanks all and please reply to this i really do need to know

Yes, get the 5". Some Pros are even running 5.5". Tell the other people they have been living under rocks for the last couple years. The tire selection for a 5-5.5 is also a lot better.

Maybe a bit easier.

3.50" in front, yes. But there is a choice of a 17" or 16.5". The newer trend for some is the 16.5" for racing only, due to that is the only type of tire you can get in 16.5". The road racers are running 16.5's and they have a bit better leaned over profile.

 

[Middy]

Thanks for them replies.

Well looks like the 5.00 it is then!

Cheers for that you stopped me going down the wrong road i owe you a beer or something :thumbup:

 

[Middy]

1 question i do have though...

Does it rub on the chain? If so do you need to cut a little off the tire?

Do you have to change the offset or anything like that?

Thanks :thumbup:

 

[Middy]

I just got sniped on ebay for a excel black 4.25 in the last few seconds...i think somebody is yelling buy a 5.00 at me!!!

5.00 it is!

Still woudl like to know if the offset etc is the same...do i need to mod anything to get it to fit>?

 

[outofcontrol]

= this winter i'm plan to make my own tubeless kit. it can't be hard. it's only 22psi. i'm going to adapt a "stan's" bicycle type set up. that'll shave some rotating weight.

I'm thinking the same thing (tubeless) wouldn't some rubber glue and a strip of 2 inch wide innertube do the trick?

-Kevin

 

[chris brown]

just picked up my wheels this morning, 5'' rear and 3.5'' front with silver rims and nickel hubs. i don't think i'm gonna put them on the bike though, they're to pretty. might just hang them on the wall in the house! jeff at east coast is the man, he had them waiting right there in his living room when i showed up on his day off. top quality people, just like most everyone you meet in this great sport of motorcycling. thanks jeff :thumbup: