Minimum wall thickness for triple clamps...
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Minimum wall thickness for triple clamps...
I know it's a tricky question, but my Spondon lower triples are for a 54mm fork tube (USD) and I want to fit a 56mm fork. Of course I've thought of just getting them machined out by 1mm but I don't want to risk my neck in the process.
Current wall thickness is 7mm, so they'd end up at 6mm. (That'd be a 6mm strip of aluminium running around the fork leg, by 31mm high).
The triples on the RWU fork on the '90 EXUP are 4mm bevelled to 5mm in the middle, but of course the fork is flexier and may??? as such exert less stress on the triple, but still, that suggests there's room for manouver.
Your opinions are eagerly anticipated.
Current wall thickness is 7mm, so they'd end up at 6mm. (That'd be a 6mm strip of aluminium running around the fork leg, by 31mm high).
The triples on the RWU fork on the '90 EXUP are 4mm bevelled to 5mm in the middle, but of course the fork is flexier and may??? as such exert less stress on the triple, but still, that suggests there's room for manouver.
Your opinions are eagerly anticipated.
If you're going to take a shot at me let me know so I can duck...!
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Thanks Hooli,
Yeah, 7mm at the thinnest point (the bit that actually wraps around the fork leg), which would, after machining, end up at 6mm.
My guess is that the attacks will be something similar... 7mm. The height muct affect things too, more material, so if you could measure the thickness and the height so I've got more comparisons.
Would someone measure the standard YZF or later FZR USD lower triple too please?
Thanks
John
Yeah, 7mm at the thinnest point (the bit that actually wraps around the fork leg), which would, after machining, end up at 6mm.
My guess is that the attacks will be something similar... 7mm. The height muct affect things too, more material, so if you could measure the thickness and the height so I've got more comparisons.
Would someone measure the standard YZF or later FZR USD lower triple too please?
Thanks
John
If you're going to take a shot at me let me know so I can duck...!
ok, measurements as promised. these were taken with a set of digital calipers, so should be pretty darn accurate.
stock yzf750 lower triple clamp
height: 36mm
thickness: 7mm in the center that tapers to 5mm at the top and bottom of the clamp. it's cast that way with a rough parting line right at the center of that lower clamp.
attack performance lower triple clamp
height: 56.5mm
thickness: 5.5mm at the thinnest point
the attack also uses a three pinch bolt arrangement on the lower, the stock uses two.
let me know if you need anything else.
stock yzf750 lower triple clamp
height: 36mm
thickness: 7mm in the center that tapers to 5mm at the top and bottom of the clamp. it's cast that way with a rough parting line right at the center of that lower clamp.
attack performance lower triple clamp
height: 56.5mm
thickness: 5.5mm at the thinnest point
the attack also uses a three pinch bolt arrangement on the lower, the stock uses two.
let me know if you need anything else.
Jason, aka: Hooligan
1994 YZF750-R
1996 YZF750-R
2003 Bonneville T100
1994 YZF750-R
1996 YZF750-R
2003 Bonneville T100
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6ml will be tons... and would hold them literally. Being spondon they would be billet? Chord more so than thickness is the major determinate... they won't flex so much where the fork is (clamped) attached, it will be mainly between there and the spigot, so what you have will not be greatly affected, if that makes any sense?
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4.48am Hooli.... you need to spend less time in the shed!
Funny how after all these years I still get caught out by the 'international'ness of the 'hood. Wonder what time it was for you when you posted that?
Anyway, back to the important stuff...
Thanks for the info!
Nice to know the Attacks are thinner still, but they are nearly twice the height and I wonder how much that affects the strength?
Right now I think I am going to get them bored out.
Spook, you've been on the beer again? 6ml you say... you want me to melt the triples before I measure them? but what you say makes sense, and your ideas are always more than welcome (if open to ridicule!)!!! Yeah, the Spondons are billet, but only 31mm high (read: thick)....
Cheers all,
John
Funny how after all these years I still get caught out by the 'international'ness of the 'hood. Wonder what time it was for you when you posted that?
Anyway, back to the important stuff...
Thanks for the info!
Nice to know the Attacks are thinner still, but they are nearly twice the height and I wonder how much that affects the strength?
Right now I think I am going to get them bored out.
Spook, you've been on the beer again? 6ml you say... you want me to melt the triples before I measure them? but what you say makes sense, and your ideas are always more than welcome (if open to ridicule!)!!! Yeah, the Spondons are billet, but only 31mm high (read: thick)....
Cheers all,
John
If you're going to take a shot at me let me know so I can duck...!
ha! it was shortly after 11:00 EDT here in the states. i'm a night-owl anyhow, and i spent the earlier part of the night getting some maintenance items taken care of on the bonnie.
the attacks are very tall, which i think compensates for the slightly thinner walls. i guess it depends on the engineer doing the design, i have seen many aftermarket triples that use a shorter/thicker lower, a taller/thinner lower, and some that use an upper/lower combo that look identical in height.
i think you'll be a-ok milling out the spondons, they make great stuff to begin with.
the attacks are very tall, which i think compensates for the slightly thinner walls. i guess it depends on the engineer doing the design, i have seen many aftermarket triples that use a shorter/thicker lower, a taller/thinner lower, and some that use an upper/lower combo that look identical in height.
i think you'll be a-ok milling out the spondons, they make great stuff to begin with.
Jason, aka: Hooligan
1994 YZF750-R
1996 YZF750-R
2003 Bonneville T100
1994 YZF750-R
1996 YZF750-R
2003 Bonneville T100