550 forks

[Tredown]

Are there different fork widths ? ie the the distance the fork legs are apart from each other.
this would mean there were different width yokes on different 550 models.
i ask this question as i have just bought a 1972 j model from a keith Harding in Chester, Told me it was an A1 bike he had restored, .
I only rode it 100 yards up the road and back when i picked it up.
When I rode it at home the forks were almost solid, no up and down movement.
I found the problem when i removed the front wheel (with a right and left twin leading shoe) the wheel is 20mm wider than the forks, so he has had to force the fork legs apart to get the wheel in, so the fork legs wont slide up and down.
Any Help or advice PLEASE
Tim
timselwyn1@gmail.com

[Alan H]

I believe there was a difference with the 750J and 550J fork widths, but not 20mm. Baz may know different.
What diameter are the actual forks (under the corrugated rubbers)? It may be that you have 380 forks bodged made to fit, but fairly unlikely. What spacers are there on the axle, and how wide is the distance between outer edges of the brake drums and distance between fork bottoms whete the axle goesbthrough?
I can't measure mine until next week when I get back home, but Barney has a 550J and there are 750J's and Richard's T500 with a 750J front end on out there that I know of that might do some measuring in the meantime.

By the way, it's nice for new posters to do a bit of an introduction with basic details of bikes, knowledge and general home area. We're a nosey lot on here, but there may be someone close that can pop in and actually show you what's amiss.

[PaulD738]

I know the 750J with the drum brake has different yokes to all the disc brake bikes

[barney01]

Lets back up a little and start with the basics. Frst i would ask the PO what is he thinks the problem is. Next i would strip the drum brake and make sure the thing has been assembled correctly, its easy to make a mistake on reassembly. There are obviously different parts for later disc brake models. AFAIK the actual drum brake is the same between both models but the spacers may be different.
Check here to see the correct parts https://www.partzilla.com/catalog/suzuk ... ront-wheel
I will physically measure my forks and report back
Look here at a previous post http://www.kettleclinic.co.uk/kcforum/v ... &hilit=4ls

[Tredown]

Thanks for your help Guys
Th Chap i bought it off is away until Monday, he is going to look into it for me.
He bought six j's from the states in 2016 mine was number 5 to restore, so he knows his way around them !!!
I think he has Bodged the wrong wheel on and had me over !
Between the middle of the fork tubes at the top and bottom is 175mm
across the flats at the bottom of the forks is 155 mm
the spindle i think is the right one for the forks, as the thread will just protrude out the end of the nut when you offer it up to the forks
the length of the spindle to the coller is 190mm
the wheel width is 175mm so when you put the spindle through the wheel and put the nut on it only catches by a couple of threads.
Feel like the forks are right, is the wheel of an early 750?

Bit of background , i buy and sell secondhand Landrovers in Devon, ride an 2016 Africa Twin on the road, got a 1972 Bonny, always fancied a 550 , gone off them the last couple of days!
Thank for your help

[canaletto5]

Is that a Daffodil Ladies sweatshirt you've got on there Barney ?

[Alan H]

Regards tbe hub. The axle goes through the centre with tbe brake plates each side, and the axle nut on the end of the axle. Obviously, I hear you all say.
Then the complete wheel assembly is offered to the fork bases (without the captivating half collars) so that the axle goes into the machined half round cutouts in the fork leg bases and the speedo drive on the left facing rearwards and up a bit.
Then fit the two half collars and washers/nuts to hold them. Nip up both sides and Robert is your ma's brother.
I don't understand how the forks were angled inwards at the bottoms to cause the forks to jam. There's summat just not right there.
I emailed the same guy ages ago about his 550s and he wasn't very knowledgeable about them at the time and I didn't buy one off him as some things didn't seem right.
Bear in mind I had my first 550 in 1972 (for about 5 years) and several recently over the last 7 years, so I reckon to know a bit about them too.

[barney01]

Without offering the wheel to the forks just assemble the hubs on the axle and then how much thread sticks out? There should be ample the bolt down onto.
Here are some videos I have done which may help
https://youtu.be/lc5XIT0TpT4
https://youtu.be/mC4l7jHIIo0
https://youtu.be/oOHbhaJwrc0
Having looked at your picture of the whole bike it looks to me that the drums are not flush to the wheel. Wrong shoes fitted? The front shoes are unique and are nothing like the back ones.
This is how it should look

[barney01]

Is that a Daffodil Ladies sweatshirt you've got on there Barney ?

I'm keeping in touch with my feminine side Kev!

[teazer]

I thought that, all 750 forks are 140mm between legs or 175 center to center but I read on this thread http://www.kettleclinic.co.uk/kcforum/v ... ple+clamps that GT750J models had wider set fork legs and the hub has spacers.

The 4LS front brake I have here is for a GT550K and it measures up at 155mm across the brake plates. It slides in perfectly between a set of 550 fork legs in a set of K on GT750 triple clamps.

I don't have a 750 brake assembly to measure, but if yours is 175mm across the plates, it would need wider triple clamps than disk brake models.

So it looks like the 750 drum brake is wider than the 550, suggesting that whoever built that bike fitted a 750 wheel and bodged it big time. It also looks like 550 drum brake forks are the same legs as a 750 but 175mm on centers the same as disk braked 750s. I don't know what 550 disk brake model fork dimensions are but I suspect that they are the same as drum brake 550s and disk braked 750s.

It might be useful to have this data posted somewhere as a sticky if it isn't already. There have been a few threads about fork/brake combos. Might be time to summarize that data.