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Discussion Starter · #1 ·
I've heard from somewhere that aftermarket 30 mm triples, such as the Ducshop ones I got, will cause the wheel to hit the radiator slightly under heavy braking, and you have to do some modifications to the radiator to avoid that....is that true?? Anyone experience this? If so, what's the fix?
 

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I read that 30's were good but 28's where questionable as far as rubbing. I could be wrong through.
I was temping to go 28's but decided on 30's after reading a couple members front rubbing.
 

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Discussion Starter · #3 ·
I read that 30's were good but 28's where questionable as far as rubbing. I could be wrong through.
I was temping to go 28's but decided on 30's after reading a couple members front rubbing.
I imagine tires matter too (different tires, different diameters). Perhaps some rub on the 30s too, and some may not even rub on the 28s?

According to my trigonometry calculations (been awhile, I struggled with this :eek:), a 6 mm difference in offset would move the wheel back by about 6.5 mm. Does that sound right? I have no idea how close my wheel gets to the radiator as is now though, stock with my current tires.
 

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You shouldn't have an issue with the 30s, unless you were running your forks dropped through a long way, or your springs were too soft.

Even 28s shouldn't touch if all else is well.

The radiator-touching issue is more with offsets back at 25 - 26, such as Bayliss or Fogarty ran sometimes, and required a small repositioning of the radiator.

Mine has never touched with 30s, and the forks dropped through the triples a little. But I still run the stock 1 kg springs (with the 25mm cartridge kit).
 

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Rake, offset, ride height and tire height, all play a role.

The 1098/1198/848 come with a rake of 24.5 degree's. If this isn't changed and the ride height is set up where it should be, you won't have any interference with the 28mm or 30mm clamps. The moment you bring that front wheel back, even that 1 degree of rake change, you can start to get into some issues. At that point, (23.5 degree rake, 28mm offset AND proper ride height), it's all down to tire height. Some of the taller profile tires from Pirelli and Dunlop can have issues. However, you really can't do anything about it on the 1098/1198/848 because the radiator overlaps the front cylinder head. So you can't "move it back" like the older bikes. The corse bikes have a cut-out there for the front tire, which gives a bit more room to breathe which is nice.

From my personal experiences, I haven't had a problem with tires hitting the radiators or cylinder head on the 848/1098/1198 series with 30mm or 28mm clamps. Just finished up a 1198 two weeks ago with Attack 28mm clamps, not a single issue.
 

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I imagine tires matter too (different tires, different diameters). Perhaps some rub on the 30s too, and some may not even rub on the 28s?

According to my trigonometry calculations (been awhile, I struggled with this :eek:), a 6 mm difference in offset would move the wheel back by about 6.5 mm. Does that sound right? I have no idea how close my wheel gets to the radiator as is now though, stock with my current tires.

yep It was the tire profile on certain brands and 28mm offset triple clamp . But both Pat and Tye agree That your good to go with the 28's or 30's. So I am good with that. Since I have the same set up as you Rub 30mm/stock tires/1198;)

Sh*t you lost me at Trigonwhatatree.Thought I knew and was good at math until Culc and trig.:ahhh:
 

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Discussion Starter · #8 ·
Ok, so for the people who have offset triples (30mm especially), what tires do you have?

I've seen differences of as much as 15 mm in diameter between tires, so that makes a huge difference.
 

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Ok, so for the people who have offset triples (30mm especially), what tires do you have?

I've seen differences of as much as 15 mm in diameter between tires, so that makes a huge difference.
Umm… I've run every single slick out there BUT Michelin's.

The Pirelli Superbikes are the tallest tire I've run, but that was with the 30mm setup. They actually barely fit under the OEM front fender. I had absolutely no problem with them fitting with the ride height setup properly with fork cap extenders. I'm sure it would have rubbed with the bike setup lower, but there was no reason to experiment.

The 1198 I just finished, he ran 28mm offset clamps (24.5 deg rake) and Dunlop's, which aren't nearly as tall. They don't have that pointy tip like the Pirelli does. Since David @ Fast Bike did the fork cartridges, I had him install the fork cap extenders so we could get more ride height on the bike, the way I always set them up. As a consequence, we never got close to touching the front under hard braking. After a day of testing, there were some marks on the fender from rubber being sprayed, but nothing to indicate the tire rubbing.

I've also run Bridgestone slicks on an 848 with 30mm clamps (I assume 24.5deg rake) a few years ago. We didn't have all the tools necessary to set the bike up at the track, so I did the best I could with the limited resources. The tire was rubbing when I got to the bike, but that's because he had the damn front down to far. I brought it up and the problem went away.
 

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I had absolutely no problem with them fitting with the ride height setup properly with fork cap extenders.
Forgive my ignorance, usually with most sports bikes having a few mm of fork leg showing above the top triple clamp, what purpose do these serve?

Is it really to push the top of the fork below the top of the top triple clamp.

Thanks
 

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Discussion Starter · #11 ·
Forgive my ignorance, usually with most sports bikes having a few mm of fork leg showing above the top triple clamp, what purpose do these serve?

Is it really to push the top of the fork below the top of the top triple clamp.

Thanks
Wondering exactly the same thing :confused:

I don't think I've never seen anyone set up the front so high that you need extenders. Highest I've seen is there the fork caps are flush with the top triple.

I'm no genius in bike setup, but I don't think the solution to a wheel rubbing is to mess up the geometry so much to gain the clearance needed.
 

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Just to add, I'm also running DucShop 28s with the radiator in the stock location. RT forks are roughly around 6-8mm above the top clamp riding on Q3 (street), and 211 GPA & GPA Pro (track). No rubbing issues so far.

Really curious to hear why fork cap extenders would be favorable, as I've never seen any of the AMA calibur 848s running those. Zemke, DiSalvo, Fong, not even our local (by way of Canada) fast 848 guy Imrie doesn't run them.
 

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If you look carefully at the AMA bikes, most guys are running the grey unpolished superbike cap with lots of holes all the way around.



Most people run those caps with the Öhlins cartridge kit and they are made in different heights depending on what the tuner wants.

Since this is a thread about tire clearance, going into a discussion about chassis geometry and ride height, kinda changes the subject a great deal. I recently wrote a novel about this stuff in another thread about Superbike geometry, you can find the answers your seeking there. :)
 

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30mm offset triples and 30mm ohlins carts with the pirelli superbike pros, does not hit my radiator but it does just touch my belly pan when on the binders really hard.
 

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Discussion Starter · #15 ·
Sorry for using the wrong part there, apparently I was wrong in that the issue is not rubbing against the radiator, but the front bottom part of the bellypan.

Christian, out of curiosity, have you ever done the old fashion "zip ties on the fork tubes" trick to see how far down your forks compress on the track? If you did, do you remember roughly the distance from the very bottom of the tube to the zip tie after a session on the track (preferably one at full pace)?
 

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Ohh... rubbing the bellypan? Depends on which pan you buy and how tight you install them. The 1198 I just built, we used Attack fairings (rider was sponsored by them) and we purposely drilled the pan to be very tight on the bike. We only got some slight splash of rubber on the belly pan and cowl.

In terms of unused fork travel, it's between 10 - 20mm. You don't want to go much less then 10mm because bottoming can lave you without the ability to absorb bumps, henceforth loosing front traction and steering in some cases. Fine tuning this is done via oil gap at the top of the fork. So if your front sag is correct and you bottom the forks out, then you need to add 10cc's worth of oil and try again. This will bring that air gap down, which causes the fork to stop dead in it's tracks. It's like having another spring within the fork, activating when the fork fully compresses.
 
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Discussion Starter · #17 ·
Yeah my bellypan is already a bit lower than it should, but i don't think it sits more forward than it should. I know this because of the countless times it dragged on the edge of the trailer/ramp when loading it in...that didn't happen with stock bodywork. Hell if it sits lower a bit, that might actually help with the clearance while on the brakes!

I know what that distance at the forks is supposed to be Tye, I'm asking him to see what HIS is so I can compare. Mine has been at around 15-17 mm at worst case, after I got the stiffer springs. I will have to do the same when I put the Ohlins forks on, as these have the springs for someone that weighs like 130 lbs.
 
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130lb springs did you buy them from a 6 grader?

Ok I got my RT's set at 6mm @ the end of gold, before cap. So I should be good. I can tell by your avatar your way faster then I am Christian.

I just scored a brand new ST CF belly pan off ebay. I hope I don't have to do any thing fancy(at all)
 

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Discussion Starter · #19 ·
130lb springs did you buy them from a 6 grader?

Ok I got my RT's set at 6mm @ the end of gold, before cap. So I should be good. I can tell by your avatar your way faster then I am Christian.

I just scored a brand new ST CF belly pan off ebay. I hope I don't have to do any thing fancy(at all)
Nope, Chinese adult! :D

Yeah, Christian's the real deal! Can't wait to lap him at MAM (or RPM I should say) this year ;)...that track will freak him out enough that he'll be running novice pace if he's like most of us :p

High Plains will be the real test as neither of us have been there before.
 
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Nice :D let me know if you get rub with a different tire. I will do the same. just to avoid that brand in the future, but sounds like were butter by Christians experience. I am tiring to get out this year(first time on bike @ track) a couple of times. Still got to pick up a couple of things. So might see you guys around the track. I'll do the school my first time out.
 
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