The truth about VTR frame and Spondon "ears"
02-08-2013, 04:55 PM
#31
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the frame itself is soft and flexible. Not the engine case. Even after all of the bracing of the frame, the race bikes would shake all over the place.
The other big problem with adding too much shock length (besides decreasing rake and trail) is that it causes too much anti-squat due to chain tension, which stiffens the rear suspension under acceleration, when you need it to be compliant.
The other big problem with adding too much shock length (besides decreasing rake and trail) is that it causes too much anti-squat due to chain tension, which stiffens the rear suspension under acceleration, when you need it to be compliant.
02-08-2013, 05:24 PM
#32
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About the ride height. The Mori forks that are on the bike in the picture are almost 1.5" longer so they could raise the front to match the rise in the rear.
RCVTR, in the Ditchfield post on the other forum he says "The only full spec Moriwaki ST3 bikes produced were two for the late Bob Hayashida formerly of Big Valley Honda in Nevada, the Revolution bike and Moriwaki's own bikes." What happened to Bob's 2 ST3 bikes and how much of them ended up in my bike?
Thanks,
Jay
RCVTR, in the Ditchfield post on the other forum he says "The only full spec Moriwaki ST3 bikes produced were two for the late Bob Hayashida formerly of Big Valley Honda in Nevada, the Revolution bike and Moriwaki's own bikes." What happened to Bob's 2 ST3 bikes and how much of them ended up in my bike?
Thanks,
Jay
02-09-2013, 04:37 PM
#33
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the rear ride height is set in order to get the proper swingarm angle. Basically the rear weight transfer is countered by the chain tension, so that the rear suspension is near its static position, with maximum compliance, when the front tire is unloaded. There's more to it than that, but that's a good starting point. Then the front geometry can be established via fork length, rake angle and triple clamp offset.
I only knew of one chassis in Bob's possession. Bob worked with Moriwaki on the chassis bracing. Some of the design was his.
Jay, yours is that bike. I believe his was a ST2 engine, built to last an entire race season, so he could keep his day job. He went to a ST3 build on his RC51, but also built it for a full season of racing. The RC51 has a true GP chassis. Roger told me that his British SB SP1s were rebuilt after every race weekend. Hence the higher horsepower numbers.
I only knew of one chassis in Bob's possession. Bob worked with Moriwaki on the chassis bracing. Some of the design was his.
Jay, yours is that bike. I believe his was a ST2 engine, built to last an entire race season, so he could keep his day job. He went to a ST3 build on his RC51, but also built it for a full season of racing. The RC51 has a true GP chassis. Roger told me that his British SB SP1s were rebuilt after every race weekend. Hence the higher horsepower numbers.
02-10-2013, 09:36 AM
#35
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So I wonder what happened to the 2 ST3 bikes Rodger referred to? I'd love one of those sexy swing arms, I bet the weigh 5 pounds less than mine and are about as stiff.
Jay
02-10-2013, 12:13 PM
#36
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Race reinforced frame with extra bracing (sans ears) as per Roger's spec
Honda VTR Firestorm, frame | eBay
Honda VTR Firestorm, frame | eBay
02-11-2013, 02:19 PM
#41
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Hence having the engine as a stress member of the frame it should stiffen the overall frame. The forks being attached to the twisty frame does cause some issues though. It seems to me more so than running a brace from the top to the bottom frame spars it needs to have some diagonal cross bracing from the left to right upper spars. The lower spars are attached to the engine and therefore are going to be pretty stiff. The upper spars have diagonal bracing to the lower spars but nothing between them. Biggest issue I see in this type of bracing is there is stuff like the air box in the way of such bracing.
02-11-2013, 04:02 PM
#42
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Hence having the engine as a stress member of the frame it should stiffen the overall frame.
MC Leather I'd like to see some pics of your mori. I shall have a search through some of your threads in a minute to see if I can find any.
I think Gilson on the UK firestorm site has one of the ST3's
(:-})
Last edited by cybercarl; 02-11-2013 at 04:18 PM.
02-11-2013, 04:40 PM
#43
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And one can feel that when putting an engine back in the frame and torquing up the mounting bolts. This is why it's important to do them all up in a particular order and to the required torques. Otherwise the engine could go back in twisted which would cause handling problems.
MC Leather I'd like to see some pics of your mori. I shall have a search through some of your threads in a minute to see if I can find any.
I think Gilson on the UK firestorm site has one of the ST3's
(:-})
MC Leather I'd like to see some pics of your mori. I shall have a search through some of your threads in a minute to see if I can find any.
I think Gilson on the UK firestorm site has one of the ST3's
(:-})
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