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gxsr front conversion question
- donthekawguy
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Post edited by: donthekawguy, at: 2007/09/06 03:22
Rathdrum Idaho
1971 Kawasaki g3ss
1972 Yamaha R5 350
1965 Suzuki Hillbilly
1964 Yamaha 125
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- StreetfighterKz
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Later, Doug
1978 z1000 Streetfighter
1976 z900 Stripfighter (work in progress)
1983 Gpz750 Resto-Mod
1989 Vmax
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- steell
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I am using a GSX front end and cutting the stem at an angle so I can put a round bar inside it and weld it back together 1/8" longer. Then it will be chucked in the lathe and turned back down to stock diameter.
By cutting the stem at a diagonal, it allows me to lay a much longer weld and retain the strength. The stem should actually be stronger than stock when I get done.
KD9JUR
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- mark1122
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- Keep twisting it
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i have a 02 zx12 front end for sale if interested.
76 KZ, frame gusset work,1200CC.Ported by Larry Cavanaugh, 1.5mm.over intakes, Carron Pipe, ZRX12 rear end, and seat,96zx9 front end.
01 CBR600F4i Track bike.
Cobourg, Ont. Can.
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- StreetfighterKz
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All the weight is on the lower clamp, so I think machining it is a bad idea, if you are determined to machine one of the clamps do the top one.
The way I figure it is the stem has two kinds of stress; tension and shear. There's also bending but tension and shear will most likely fail before bending would.
Machining the lower clamp to move the stem further in doesn't change the two stresses. The stem is still going to have the same tension and it's still going to have the same area that shear stress is working against.
The solid blue line in the image is the current recess for the stem while the dotted blue line shows the future recess of the stem.
Later, Doug
Post edited by: StreetfighterKz, at: 2007/09/05 12:19
1978 z1000 Streetfighter
1976 z900 Stripfighter (work in progress)
1983 Gpz750 Resto-Mod
1989 Vmax
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- Fossil
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- steell
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I agree about the stresses encountered by the stem, but my concern is the lower clamp. It's my opinion that Suzuki has done everything they can to lighten the GSXR series, including using finite analysis to determine the minimum amount of metal they can use in that clamp and still do the job safely. And KZ's weigh more than the GSXR's, thus putting more stress on that clamp.
Consider the stresses involved when you hit a bump hard or drop the front end after a wheelie (I know, no one does wheelies )
I just hate to even think about the lower clamp breaking :woohoo:
My concern may be totally baseless, but I think it's worth thinking about.
KD9JUR
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- mark1122
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- Keep twisting it
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76 KZ, frame gusset work,1200CC.Ported by Larry Cavanaugh, 1.5mm.over intakes, Carron Pipe, ZRX12 rear end, and seat,96zx9 front end.
01 CBR600F4i Track bike.
Cobourg, Ont. Can.
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~ (k) / (z)
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- donthekawguy
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Rathdrum Idaho
1971 Kawasaki g3ss
1972 Yamaha R5 350
1965 Suzuki Hillbilly
1964 Yamaha 125
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- StreetfighterKz
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I wasn't trying to argue. If that's the way it came across then I'm sorry. I've mocked up the front end and have enough threads for one of the two nuts Suzuki calls for on the stem. I figure 1/8" should be enough to get the proper thread engagement without weakening the lower too much. The bike is going to be used 95-98% on the dragstrip so I don't have to worry about Ohio's notorious potholes.
Later, Doug
1978 z1000 Streetfighter
1976 z900 Stripfighter (work in progress)
1983 Gpz750 Resto-Mod
1989 Vmax
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- steell
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My memory is not what it once was, but I seem to recall reading somewhere that stunters were breaking the GSXR front ends much more often than any other bikes, and this was assumed to be because Suzuki had lightened the front ends as much as possible. That makes me a little concerned about removing any metal from it, hence my decision to add a little metal (and strength) by cutting it at a diagonal and welding it back together with a bar inside it to lengthen it. I'm using a GSX front end, and I'm not sure if the GSX and GSXR front ends are the same.
I do tend to worry (perhaps to much) about the safety of my modifications, if a 1/8" thickness will do, then I'll use 3/8" just to make sure
My brother is even worse, he can't just nail new pieces of wood together, he has to use glue, and then add metal strapping for additional support in addition to the nails.
KD9JUR
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