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04-04-2001, 10:15am
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Joker
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Member # 454
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posted 04-03-2001 08:48 AM
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Sounds to me that the steering head bearings need tightened. I had to tigheten them on my old 7 that I had, generally caused by to many wheelies. hahaha
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Posts: 14 | From: Kokomo, In, US | Registered: Jan 2001 | IP: Logged
Busa@11K
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Member # 217
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posted 04-03-2001 01:07 PM
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I tried to pin-point the noise again last night, but need to do it with a helper so I can crawl over the front end while the clunking is going on.
I thought it might be the brake pads clunking in the calipers (with brakes on), but discovered that it would still make the noise if the front end was pushed down without using the front brake at all.
I'm back to thinking it is the steering stem bearings, even though I can not feel any play in them. Maybe the bearings are just loose enough to make noise, but not loose enough to detect movement (seems strange).
If anyone else has any info, please let me know.
Thanks!
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Posts: 685 | From: Busa, WA (USA) | Registered: Dec 2000 | IP: Logged
Dave
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Member # 332
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posted 04-03-2001 04:06 PM
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In our Vmax club, it was always the stem bearings. Couldn't see the play, but it was there in the clunkers.
Vmaxes are notorious for a front end wobble on sweepers. The fix was to install a heavy duty fork brace, replace the RUBBER washer between the crown nuts with a steel or aluminum one, and tighten the primary crownnut to anywhere from 15 to 25 ft lbs (the manual said 4 ft lbs).
I found that the higher torque range worked best for me to eliminate wobble and clunk. Make-and-break the primary crown nut at least three times to really draw everything together, then torque to at least 15 ft-lbs. The effect on the Vmax was almost that of a steering dampener (the bike doesn't have one). Another Vmax member pointed out that timpken bearings will take quite a bit more load than what normal steering functions create, so as long as you are not restricting the rotation of the head, then tight is good.
TMH pointed out that the head bearings lack sufficient grease from the factory, so maybe a quick teardown is in order before you start torquing things tighter.
I haven't checked my busa's steering bearings, or changed the crown nut torque (yet). This stuff is just what I learned from tweaking my Vmax.
If it ain't the bearings, then maybe its the cartridge. Again, I haven't studied the busa front suspension yet, but basically all cartridge systems work on a light-load/heavy-load basis. Under light load, fork oil flows through Restriction A. Under heavy load, the cartridge guts slide shut, closing off part of the flow area, forcing oil to flow thorugh a tighter Restriction B (hence stiffer). If the suspension is not set up properly, the transition from 'A' to 'B' occurs too soon, or under too light of a load. Basically, the cartdidge slams shut at the slightest load, and that can make a clunk. Such bikes are basically riding around all the time on the 'B' level, and would be a pretty stiff ride. The transition should require something more than normal load on the suspension, and should be smooth. Not something you notice every time you hit a bump -- clunk! Adjustable variables are the fork adjustment settings, fork oil weight (viscosity), and different rate fork springs.
I'm talking out my ass a little here, but unless the front suspension on the busa is radically different than other stuff, the theory should apply.
Maybe I'll read a little in the manual tonight.
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Posts: 100 | From: | Registered: Dec 2000 | IP: Logged
Joker
NEW MEMBER
Member # 454
Rate Member
posted 04-03-2001 08:48 AM
--------------------------------------------------------------------------------
Sounds to me that the steering head bearings need tightened. I had to tigheten them on my old 7 that I had, generally caused by to many wheelies. hahaha
--------------------------------------------------------------------------------
Posts: 14 | From: Kokomo, In, US | Registered: Jan 2001 | IP: Logged
Busa@11K
SENIOR MEMBER
Member # 217
Member Rated:
posted 04-03-2001 01:07 PM
--------------------------------------------------------------------------------
I tried to pin-point the noise again last night, but need to do it with a helper so I can crawl over the front end while the clunking is going on.
I thought it might be the brake pads clunking in the calipers (with brakes on), but discovered that it would still make the noise if the front end was pushed down without using the front brake at all.
I'm back to thinking it is the steering stem bearings, even though I can not feel any play in them. Maybe the bearings are just loose enough to make noise, but not loose enough to detect movement (seems strange).
If anyone else has any info, please let me know.
Thanks!
--------------------------------------------------------------------------------
Posts: 685 | From: Busa, WA (USA) | Registered: Dec 2000 | IP: Logged
Dave
NEW MEMBER
Member # 332
Rate Member
posted 04-03-2001 04:06 PM
--------------------------------------------------------------------------------
In our Vmax club, it was always the stem bearings. Couldn't see the play, but it was there in the clunkers.
Vmaxes are notorious for a front end wobble on sweepers. The fix was to install a heavy duty fork brace, replace the RUBBER washer between the crown nuts with a steel or aluminum one, and tighten the primary crownnut to anywhere from 15 to 25 ft lbs (the manual said 4 ft lbs).
I found that the higher torque range worked best for me to eliminate wobble and clunk. Make-and-break the primary crown nut at least three times to really draw everything together, then torque to at least 15 ft-lbs. The effect on the Vmax was almost that of a steering dampener (the bike doesn't have one). Another Vmax member pointed out that timpken bearings will take quite a bit more load than what normal steering functions create, so as long as you are not restricting the rotation of the head, then tight is good.
TMH pointed out that the head bearings lack sufficient grease from the factory, so maybe a quick teardown is in order before you start torquing things tighter.
I haven't checked my busa's steering bearings, or changed the crown nut torque (yet). This stuff is just what I learned from tweaking my Vmax.
If it ain't the bearings, then maybe its the cartridge. Again, I haven't studied the busa front suspension yet, but basically all cartridge systems work on a light-load/heavy-load basis. Under light load, fork oil flows through Restriction A. Under heavy load, the cartridge guts slide shut, closing off part of the flow area, forcing oil to flow thorugh a tighter Restriction B (hence stiffer). If the suspension is not set up properly, the transition from 'A' to 'B' occurs too soon, or under too light of a load. Basically, the cartdidge slams shut at the slightest load, and that can make a clunk. Such bikes are basically riding around all the time on the 'B' level, and would be a pretty stiff ride. The transition should require something more than normal load on the suspension, and should be smooth. Not something you notice every time you hit a bump -- clunk! Adjustable variables are the fork adjustment settings, fork oil weight (viscosity), and different rate fork springs.
I'm talking out my ass a little here, but unless the front suspension on the busa is radically different than other stuff, the theory should apply.
Maybe I'll read a little in the manual tonight.
--------------------------------------------------------------------------------
Posts: 100 | From: | Registered: Dec 2000 | IP: Logged