Frame differences

teazer
Posts: 1035
Joined: Mon Mar 07, 2011 8:10 pm
Location: Chicago

Frame differences

Post by teazer »

I realize that there are some differences in frame designs and contributed some of that detail to the late Ian Sandy. What I don't know though is how the exhaust mount position changed over time.

In the shop are a set of Bassani chambers which fit really well except for the rear mounts. They are about and inch lower and half and inch forward of the frame I am using ( a 76 IIRC). I don't have any documentation with the pipes but I know that Walt Strader listed his three into 1 systems to fit K/K, L and MAB, so that's three versions. That suggests that the mounting points may have changed.

Does anyone know for sure how much the rear exhaust mounting point changed position over the years?
teazer
Posts: 1035
Joined: Mon Mar 07, 2011 8:10 pm
Location: Chicago

Re: Frame differences

Post by teazer »

I don't have a 72 or 73 frame to compare, but looking at side on pictures, it appears that J models at least had the rear exhaust mount lower than L on.

Can anyone confirm that?
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Alan H
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Location: Wombwell, Republic of South Yorkshire

Re: Frame differences

Post by Alan H »

I know they scraped very easily back in 1972, so I bought a 550 which was a bit better, and better still without the centre stand and a 19" back rim same as the 550 that Crooks Suzuki were production racing back then....... :lol:
Proof that four strokes are over complicated
teazer
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Joined: Mon Mar 07, 2011 8:10 pm
Location: Chicago

Re: Frame differences

Post by teazer »

Thanks Alan. That was exactly the information I was looking for and didn't even know it. Have a good one.

Funny that no one here has ever seen an early frame and a late frame or have any information to offer. Maybe everyone is off on summer holidays with Sir Cliff and the band.
Rubydog
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Joined: Mon Jul 13, 2015 8:19 pm
Location: Chorley, Lancs

Re: Frame differences

Post by Rubydog »

Sorry for the late reply Teazer, but you’re right I was away with Sir Cliff in bonnie Scotland, well worth a visit if you ever get over the water.
Anyway, back to the frames, I have an L & my mate has a J (with front discs but it is a J not a K) & both American imports.
Next time we’re out kettling I’ll take some pictures of them side by side to compare any differences, but can’t say when it will be though, so watch this space.
Rgds T.
teazer
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Joined: Mon Mar 07, 2011 8:10 pm
Location: Chicago

Re: Frame differences

Post by teazer »

Thanks,
I look forward to seeing the pics and your analysis/comments. I lived in Perth, went to school in Dundee and Uni in Edinburgh before I moved to the west coast and from there to other parts of the world. I managed to get back couple of years ago and took my American wife to see the Trossachs and Edinburgh and St. Andrews which was as wet and windy as it was when I was there as a kid. Some things never change. It's a rugged part of the world for sure. Glad you enjoyed it. Where did you get to?
Rubydog
Posts: 29
Joined: Mon Jul 13, 2015 8:19 pm
Location: Chorley, Lancs

Re: Frame differences

Post by Rubydog »

We went to Aberfeldy (as you know in Perthshire) & various little villages in the area, beautiful scenery, & not overcrowded like the Lake District always is. Very friendly & helpful locals, will defo be going back, we had lovely sunny weather which obviously made a massive difference to our enjoyment & overall opinion.Called at Edinburgh on the way back, have been there before, but still like it.
I’ve attached some pics of my ‘74 750L, please excuse the rust, I ride it more than I lavish paint & polish on it, in fact with the good weather at the minute, I’m using it to get to work on. I’ll give it some attention in the Winter, it’s been stood too much this year & I had a starter clutch problem which kept it off the road at the start of Summer. So I just do necessary maintenance to it at the minute, it’s just had a new chain & sprockets, but the damn fuel tap sprung a leak yesterday & the wife could smell petrol in the house, so it’s been stood outside the garage in disgrace until today - when I’ve temporary sorted it. - New tank to tap gasket on order, old one turned upside down & it’s holding for now !
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I’ll go & see my mate’s K as soon as & post those picys, are these any use though ?
Rgds T.
teazer
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Joined: Mon Mar 07, 2011 8:10 pm
Location: Chicago

Re: Frame differences

Post by teazer »

Thanks for those. Yes Aberfeldy and Dunkeld and some of the other small towns haven't changed much in hundreds of years.

Could you do one thing for me please and that's measure or eyeball where that rear mount is in relation to say the swingarm pivot and line of the swingarm on both bikes.

I suspect that the rear mount on a K is lower and slightly further forward and I need to know if that's just perspective or if they really are different. I have seem references to using the right pipes or to aftermarket exhausts for different models but the Pipes I have here were on a B model and I can't get that rear bracket to line up without applying way too much effort to lift the pipes to squeeze a bolt in. I have an M model or is it an A frame here but not a J or K so I have nothing to compare it to.

Cheers mate.
Rubydog
Posts: 29
Joined: Mon Jul 13, 2015 8:19 pm
Location: Chorley, Lancs

Re: Frame differences

Post by Rubydog »

I’ll try to visit my mate this week to get some pics of his J ( I said K in my last but it was a typo) my understanding with the frames (but don’t hold me to this ) is that the J/K frame is the same, but when they changed the exhaust from the black end cone type to the full chrome type on the L, the mountings were altered to lift the exhausts higher at the back.
Then on the M, the front link pipes were ditched to allow a tighter radius at the front, again to raise the pipes up for better ground clearance. To my knowledge the exhausts were never altered again so M,A & B’s frames should be the same in this respect & really the L should be too.
I’ll have a look at the measurements one night this week & this should partly confirm / trash the above, by you comparing them against your M/A frame.
Speak soon. T.
Rubydog
Posts: 29
Joined: Mon Jul 13, 2015 8:19 pm
Location: Chorley, Lancs

Re: Frame differences

Post by Rubydog »

Apologies for the delay, I’ve been on my hols again, but this time to St Ives in Cornwall. Another must visit again place, not been there for nearly 40 years, busier than Scotland & a different kind of scenery, & blessed with good weather which again helps.
Anyway I put a tape measure on the datum points & took pictures again of my 750L, hope these are more use. Sorry but they are a bit blurred.
I asked my mate with the J to take some as well & although he’s a decent chap they haven’t turned up as yet. He’s away on his Vincent in Spain at the minute, so I’ll have to call when he lands back in Blighty.

I think from the centre of the swinging arm nut (2nd pic) to the centre of the exhaust mount bolt (3rd pic) is 226 or 227 mm.

The 1st pic gives the overall view, showing that the footrest is separately mounted to the exhaust, I believe that some models have different rear footrest mounting points, but again I think the LMA & B’s are all the same, it’s the J & K’s which may be different, & they may even be different to each other. My mates photos may show this when I eventually get them.
Hope this helps.

Rgds T.
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