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Re: Technology used by only a small number of manufacturers
Posted: Wed Mar 31, 2021 1:51 pm
by Rockburner
KungFooBob wrote: Wed Mar 31, 2021 1:50 pm
Rockburner wrote: Wed Mar 31, 2021 1:47 pm
KungFooBob wrote: Wed Mar 31, 2021 1:45 pm
The Tele on my K1200RS, the top yoke is defo on some kind of ball joint.
That's very interesting and I am perfectly happy to be corrected.
I've never taken out both of the fork tubes at the same time before - so I thought the top-yoke was simply on a bearing. It does make a lot of sense for it to be a ball joint though.
I've added a link to the parts fiche on realoem, if you drill through the part number you can see it's the exact same part number as the lower ball joint.
Very very interesting!! Thanks for that!
Re: Technology used by only a small number of manufacturers
Posted: Wed Mar 31, 2021 1:58 pm
by Nidge
Le_Fromage_Grande wrote: Wed Mar 31, 2021 1:39 pm
Desmo type valve gear was used on the Honda CB450 Black Bomber in the 1960s, it probably copies the Ducati set up of the time.
Did Honda not use a torsion bar assembly?
Re: Technology used by only a small number of manufacturers
Posted: Wed Mar 31, 2021 2:04 pm
by Mr. Dazzle
Rockburner wrote:
That's very interesting and I am perfectly happy to be corrected.
I've never taken out both of the fork tubes at the same time before - so I thought the top-yoke was simply on a bearing. It does make a lot of sense for it to be a ball joint though.
I think it has to be a ball joint for it to work. The end of the main telelever moves in an arc, so the 'fork tubes' need to he able to steepen/relax a little bit as the wheel moves up and down. If the top joint wasn't a ball it would all just lock solid?
EDIT: Here you go, quick bit of PowerPoint engineering to show you why it's a ball at the top. The red and green lines are exactly the same length and represent the telelever. You can see that when the wheel bounces the fact the arm moves in an arc means the 'fork' angle changes, hence why you need a ball at the top.
Re: Technology used by only a small number of manufacturers
Posted: Wed Mar 31, 2021 2:13 pm
by Le_Fromage_Grande
Nidge wrote: Wed Mar 31, 2021 1:58 pm
Le_Fromage_Grande wrote: Wed Mar 31, 2021 1:39 pm
Desmo type valve gear was used on the Honda CB450 Black Bomber in the 1960s, it probably copies the Ducati set up of the time.
Did Honda not use a torsion bar assembly?
Possibly
Re: Technology used by only a small number of manufacturers
Posted: Wed Mar 31, 2021 2:38 pm
by Dickyboy
Combustion chambers in the pistons a la Moto Morini with the heron headed pistons? Also had the weird cambelt & pushrod arrangement.
Re: Technology used by only a small number of manufacturers
Posted: Wed Mar 31, 2021 2:55 pm
by Rockburner
Mr. Dazzle wrote: Wed Mar 31, 2021 2:04 pm
Rockburner wrote:
That's very interesting and I am perfectly happy to be corrected.
I've never taken out both of the fork tubes at the same time before - so I thought the top-yoke was simply on a bearing. It does make a lot of sense for it to be a ball joint though.
I think it has to be a ball joint for it to work. The end of the main telelever moves in an arc, so the 'fork tubes' need to he able to steepen/relax a little bit as the wheel moves up and down. If the top joint wasn't a ball it would all just lock solid?
EDIT: Here you go, quick bit of PowerPoint engineering to show you why it's a ball at the top. The red and green lines are exactly the same length and represent the telelever. You can see that when the wheel bounces the fact the arm moves in an arc means the 'fork' angle changes, hence why you need a ball at the top.
Yep.
I was possibly confused initially by the fact that the fork tubes bolt into the top yoke via a rubberised joint (basically a thick rubber grommet in the top-yoke). I thought that that rubberised joint would provide enough movement of the fork tubes as they rotate about their top end. You certainly don't feel any movement of the top yoke as the suspension moves: you'd think you'd feel the bars moving (as they are the end of the lever that pivots at the top-yoke ball), but there's no movement there at all.
Re: Technology used by only a small number of manufacturers
Posted: Wed Mar 31, 2021 2:56 pm
by Rockburner
Dickyboy wrote: Wed Mar 31, 2021 2:38 pm
Also had the weird cambelt & pushrod arrangement.
cambelt driving an offset camshaft which in turn drives pushrods to overhead rockers?
The BMW R1100/1150 engine does that too.
(albeit with a pair of cam chains instead).
Re: Technology used by only a small number of manufacturers
Posted: Wed Mar 31, 2021 3:12 pm
by Hairybiker84
BMW seem determined to use technology no-one else does, 'reinventing the wheel', crappy fuel strip sensor that I have spent the last 1 1/2 days doing away with being a case in point. I've worked on lots of motorcycles over the years and my GS seems to be put together in the most convoluted way possible
I must be a glutton for punishment, the Daytona 955i I had before it had enough quirks too!
Re: Technology used by only a small number of manufacturers
Posted: Wed Mar 31, 2021 4:08 pm
by Rockburner
Hairybiker84 wrote: Wed Mar 31, 2021 3:12 pm
BMW seem determined to use technology no-one else does, 'reinventing the wheel',
First to use hydraulically damped telescoping spring forks too....
Re: Technology used by only a small number of manufacturers
Posted: Wed Mar 31, 2021 4:09 pm
by Yorick
Only 1 company tried 8 valves per cylinder AFAIK.
Re: Technology used by only a small number of manufacturers
Posted: Wed Mar 31, 2021 4:26 pm
by Horse
Rockburner wrote: Wed Mar 31, 2021 2:56 pm
Dickyboy wrote: Wed Mar 31, 2021 2:38 pm
Also had the weird cambelt & pushrod arrangement.
cambelt driving an offset camshaft which in turn drives pushrods to overhead rockers?
The BMW R1100/1150 engine does that too.
(albeit with a pair of cam chains instead).
Knock Knock!
Who's there?
CX500. Cams (1 per cyclinder) & chain, then pushrods.
Although not 'technology', I suppose, the CX had the cylinder heads twisted about 15 degrees, so that the carbs were inboard from the rider's knees.