Steering head bearings and nut

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jabcb
Moto GP
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Joined: Mon Dec 13, 2010 4:32 pm
Country: USA
Suzuki 2-Strokes: 69 T350 thru 75 GT750
Location: southwestern Pennsylvania

Re: Steering head bearings and nut

Post by jabcb »

I asked about this on the GS forum & got a useful response.

For the top use bearing 99-3509 (25x48x13mm). For the bottom use bearing 99-3515 (30x48x12mm).
Take the lower triple tree & bearing to a machine shop. Have them make a shim that provides the proper interference fit, and assemble it.

Using the standard All-Balls kit & grinding 2.5mm off of both bearings is a total PITA way to save 5mm.
This solution is more expensive but is a straight forward way to save 4mm.

Any thoughts?
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
sportston
Expert racer
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Joined: Wed Jul 10, 2013 12:04 pm
Country: England, UK
Suzuki 2-Strokes: FZ50, GP100, RG125 Gamma, GT380, Bandit 1200S

Re: Steering head bearings and nut

Post by sportston »

That sounds like a great idea!
User avatar
jabcb
Moto GP
Posts: 4240
Joined: Mon Dec 13, 2010 4:32 pm
Country: USA
Suzuki 2-Strokes: 69 T350 thru 75 GT750
Location: southwestern Pennsylvania

Re: Steering head bearings and nut

Post by jabcb »

One more issue worth noting…

The stock dust seal for the top bearing, part # 51643-30000, is intended for the stock ball bearings.
The center section is too thick for use with tapered roller bearings. I remember someone commenting that they needed to retighten the steering stem nut — that may be due to the use of the stock dust seal.

Suzuki switched to tapered roller bearings after the two strokes were discontinued.
The redesigned dust seal is part # 51643-49002. It fit just fine on my GT550. But I sanded down the top lip just a smidgen to give a little more clearance.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
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