ok, well after learning that my lil f3 won't make it thru a 4 hr without putting a whole in the radiator, and over heating. I have a ??? for all you ex f2/3 riders, ever have a problem with a 120/70 tire up front hitting the radiator? I am thinking that is what the problem is/was, but am unsure. I have heard mixed answers. Walt from michelin says that the pilots are the same overall circumfrence and diameter as the "60 series" slicks(which I ran without hitting the radiator). The only change that was done to the bike was the tires, and then it hits the radiator. I don't know how long it was before it started hitting it because I changed tires on fri. night and noticed the hole after the endurance practice, and changed radiators, and then it happened again in the race. I don't know, any opinions? or ideas?
The only way to make sure you won't have a problem when changing from one tire to another is to pull the fork springs and collapse the forks, and check for clearance. Or you can compare installed circumference, or measure from bottom of the front axle to the ground and compare that measurement to the measurement you got from the same point with the tire that you know had enough clearance. Don't forget to allow a little extra for fork flex under braking. And look at the radiator after practice to check for any sign of contact, too.
First you need to get a good witch doctor and some good inscents and have a big bon-fire. You need to get the evil spirts out of your bike. The ghost of Callahand will rise from the frame and then you can beat him with a broom!!!!!
Hey Medic, we run an F3 with adjustable triple clamps as steep as they will go and haven't run into a clearance problem. What shape are your forks in? are they bottoming out? how much of the forks do you have over the top ot the triple? How are your head bearings? is the frame bent? why do birds suddenly appear? where was I...oh yeah, with a steep rake we don't hit on 120/70's michelin or dunlop. I'd look into the stuff mentioned above and eliminate things one by one. If nothing helps, i'll give you $20 for the whole bike.
ok, so it's not all f3's just my bike, GREAT!! to answer your other questions, good, don't think so, 15, 43, hut hut hike!! oops. I have 55mm of ride height from top of lower triple to middle of axle. The head bearings are in good shape and I made sure everything was nice and tight before the race. The frame has seen it's time at GMD, but hasn't been crashed since the last outting at GMD. Of course finding out what GMD has done with the bike is apparently a "trade secret" I don't know what they did to it. $20 cool, that'll get me started on the new gsxr for next year!!! heck, maybe I can get JU to start a drive to get me a new bike, and I'll have it in a weeks time. JU, how bout it? a lil help????
Hey Medic, I've seen that problem on F3's before and in some cases it was because the forks were bent and others because the steering head was bent. It doesn't sound like that's the case since it's been to Computrack, but might not hurt to have them double checked. When I bought my F3 back in 99 the front tire used to rub the chin of the lower and come close to the radiator and even rubbed it a little in endurance races. After a trip to Computrack all was good. They put on new forks, straightened the steering head and got everything lined back up the way it should be. Haven't had a problem since. Good luck getting it straightened out and I'll see you at Roebling.
Hey medic, How'd it do yesterday at TGP? I saw you around, but forgot that you had trouble last week. I hope it went well. Joe 117
I have heard of forks flexing so much under braking they would cause the tire to rub the radiator. I don't know if those were stock forks or aftermarket fork tubes. Maybe check your fork oil level and add some if you can to prevent the forks from bottoming out and flexing into the radiator.
Medic, We ran a 4 hour on the F3 this weekend with 120/70 pilots, and even with the front end bottomed out in practice couldn't hit the radiator. I checked for you. I like the idea of adding some fluid, or use a thicker fluid and see what that does.
ok, the latest in the SAGA. I raised the rear end and also the ride height up front, and since the rad. is already smashed up a bit on the bottom, the forks can be collapsed and not hit it. I made a few calls about getting the rad. fixed and was given the idea of cutting the last row or two off the bottom to get some extra clearance. Thru the words of Myler's(motorcycle radiator repair shop) by doing this I would raise the running temp of the engine no more than 5 deg. So I am thinking of trying that on 1 of my rad.'s and seeing what happens. That should give me the extra clearance to adjust ride height if the bike doesn't handle right. Now if I could just get the engine back and drop it in and see how it works, I just might be happy with THE BEAST!!!
Doesn't look like I get to goto Roebling, but I AM riding in the 4 hr @ VIR, and hopefully will have my bike their to do the sprints, and get some points. I gotta try to get an invite for the GNF's.
GMD can explain how to fabricate the two tabs at the bottom of the radiator. both my f3's needed this and there is no problem with tire/radiator after gmd performed this trick.
I agree - space the radiator out - do NOT cut off any rows. Race radiators have enough airflow problems with the fins getting beat up without removing even more of them. Besides, higher temps equal less performance and your bike needs all it can get
unfortuneately I will not be going to roebling. I hope to make it to VIR with my bike, but that remains to be seen. And I think I have the radiator clearance thing under control, but not sure how the bike is going to handle after the "adjustments" made to ride height and all. And thanks Derek for letting me use your impact.
