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Author Topic: Clip on's that fit and cheap too, courtesy our virus spreading friends  (Read 1296 times)

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Offline Sdaniels

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Fork extensions are used by many folks in the chopper conversions.  Plenty of us with VTX 13's went that route with raked triple trees with no incidents....I'm talking about 3 & 4" lengths.  Having said that though another thought just occurred to me.  Adding an extension to a C-spec to put clipons above the triple means the extension wouldn't be clamped by the triple.  I can definitely see issues with that. 
« Last Edit: June 12, 2020, 09:38:17 am by Sdaniels »
2015 C-spec

Offline srinath

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Well if you put extensions on top of the upper triple and put a clip on onto that you'd run the risk of unscrewing the cap under acceleration (left side) and braking (right side)
Crank it further than recommended torque and you run the risk of tearing out those rather fine threads in the fork leg.
You said you "can definitely" see issues with that - Sorry I thought you said you cant never mind then.

Cool.
Srinath.

Offline lunkhead

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The pinch bolt should squeeze the the fork tube out of round so it'll try to dig into the extension's threads at the split.

Try tightening a pinch bolt as much as you dare and see how much force it takes to crack the cap loose. The cap is only torqued to 17 ft-lb but it'll lock in if the fork tube deforms enough. A SS extension would start of much tighter and be less likely to yield under force. It's something that should be tested before doing.
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Offline srinath

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Yea if the leg is tightened within 6" of the cap, its likely you'd have a harder time breaking the cap free -
However we often loosen only the top triples and crack the top caps open using the lower triples's grip on the tube.
Well, I don't think upper triple being torqued down would let it spin at all, but IMHO - why even play one part of your bike against another ?
Cool.
Srinath.

Offline lunkhead

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The cap threads are pinched right at clamp, not below where it wouldn't keep the cap from loosening. If it holds up to a force higher than what will ever be exerted on it, it'll be perfectly safe with no chance of moving. Even if you happen to move it, it can't suddenly go loose as long as the pinch bolts are tight.
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Offline srinath

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Yea lunkhead, you're right I'm sure.

BTW on a C spec - It would look stupid but you could try this. Flip the upper triple upside down. That would allow you to still use the ear on the collar to clamp it on - not sure if angles etc would work. This way the handle and collar cant rotate cos its mechanically put in place.

I dunno, I like things being mechanically held including where I weld up stuff, I'd try to pin it together first.
My favorite unholy parts union - yet to try it really, to fit katana 600 risers. Those are a unique design where they don't have a pinch clamp they are bolted through the top triple. The holes on the underside of the triples in a bolt have the bracket to keep the wired organized and if you drill that blind hole through and use a longer bolt - you can still thread it in the threads already there and use a nut under it and keep the bracket in place and solve 2 irritating things in 1 swoop - bolts run upwards against gravity and closer and lower rise without dangers of pinching clamps undoing this or that.

I would have tried it already - if I had found my katana parts collection and well I have some angle and ergonomic concerns. Not to mention I am fine with the ride height, don't need it lowered.

Cool.
Srinath.

Offline lunkhead

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Assuming there's no way for the clip-ons to move under the most force they'll ever see, there's no need to over engineer it and that only leaves movement due to a crash in question. In a crash, a clip-on that's keyed in can cause more damage. You can expect a bent or broken bar, dented tank, damage to the keyed area or some combo of the three if the threads slip. With the stock setup, the clamp is directly pinching the tube so it shouldn't move even without being keyed in and the damage will be confined to the bar, tank, steering stop or no damage at. Allowing the clip-ons to rotate in a crash will only damage the tank but being raised to the top of the triple clamp might clear it.

Dannyleonard had no issues but I'd do my own testing to account for the extra force of a passenger under hard braking. However, I won't even consider fork extensions because I don't want higher bars and if I did, I'd just use hard conical bushings to accept regular handlebar clamps.
« Last Edit: June 13, 2020, 02:28:47 pm by lunkhead »
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Offline srinath

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However, I won't even consider fork extensions because I don't want higher bars and if I did, I'd just use hard conical bushings to accept regular handlebar clamps.

I don't know Danny Leonard's setup - but I also understand the merits of soft failure vs a hard failure.
But that point above +1 for sure.
Those Delrin (which are not quite "hard" - just harder) are the way to go on the risers/clamps and bars.

Cool.
Srinath.

Offline lunkhead

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Delrin is a little harder than a bowling ball and has some elasticity so it'll spring back to shape unlike aluminum which is about twice as hard and less of a problem. With Delrin, there has to be zero clearance between the posts and cones (fore and aft) so they can't move. With aluminum, the holes can be a little sloppy because they can be tightened more rigidly top to bottom for grip where Delrin would be too soft and slippery to rely on. It's a trade-off but aluminum is better overall, especially for tall bars.
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