seat post issues

just took delivery of a t-bar and seat post for a saddle i have. t-bars fine, but the seat post doesn't fit in the frame? it was advertised for a pan/shovel. so i though it's a good 'un. but it's too wide for the tube on the frame. seat post is 30mm diameter and internal frame tube is 28mm diameter. it's an fl frame, number is 70fl blah blah.

i'm thinking i can have it turned down a couple of mill' so it'll fit, but whats going on. have i got one off a 45 or somehting? anyone wanna swop for corretc one maybe?

i'm concerned i might have bush issues now. the frame hasn't got one fitted and i've one on order. thinking that'll be too wide aswell and have to be modified?

how do the bushes fit. any special tools needed, hope not? i'm thinking they sit at the bottom of the frame tube and the post rests upon it allowing the spring to compress etc. the top solid part is simply greased and slides within the tube. but i'm wondering how the bush is locked iside the frame downtube. it it just pressed in, am i thinking correctly?

sorry for all the quesitons, but i'm abit confused and doing it all abit blind really.

thanks in advance for any advice/info.

j.

[Kiwi]

1980 they changed the frame tube diameters

the seat posts used to be 1 1/4". but after 1980 they were 1"

you could get it turned down or modified but a 45 seat post is an inch and should fit ok

[kevscrivener]

I have a seat post from a 77 FLH; PM me if you're interested.

Just been out and measured it; unfortunately it looks to be the larger size! It definitely fits my frame though. Graeme, perhaps the change-over was a few years earlier where the seat posts are concerned?

o.k, thats enlightened me. but it's all abit odd. my frame indicates that it's a later tube 80+ from it's internal diameter, but the frame number indicates a 70.

i've now got horrible thoughts that the frames been cut and welded about. if it has it's been done exceptionally well. and isn't problematic, except for little surprises like this. so maybe i shouldn't be too concerned about it?

i suppose it's possible to weld an early head stock to a later frame to keep the year if the original got bent?

mmmm, well off to the local machine shop then.

regards, j.

[Kiwi]

Originally Posted by kevscrivener

, perhaps the change-over was a few years earlier where the seat posts are concerned?

could be but a 72 seat post definitely didn't fit my 82 frame, i was told it was 80 teh change over could be ealier as the factory made a load of changes around 77 when they changed the gearbox and the workshop manuals are different ie specify 78 onwards

[Kiwi]

Originally Posted by jzk

i suppose it's possible to weld an early head stock to a later frame to keep the year if the original got bent?

.

factory sell replacement frames with no numbers and stamp your old numbers on the new frame and destroy the old frame (aledgedly)

I have a brand new 82 frame factory fresh with no numbers

your frame could be a later one stamped with early numbers ????

[Simon_Y]

I've had a look through my parts manual and the plunger for the seat post for the 81 onwards flh is the same as that for the 41-80 model part # 51626-36. The frame bushings were fitted between 58 & early 81 (Part # 47094-58).

br

Simon

right well i think it'll be easier for me to get this fatter post turned down rather than try and track a later 'skinny' post?

regarding the actual bushing, can anyone throw some light on the actual fitting of said item, and any tips on doing it.

thanks in advance.

[bazereid]

Hi J
I have the advantage of just having fitted a seat post about 3 weeks ago, so possibly I may be of some assistance.
I have a Generator Shovel but it all hangs roud a mid 70s frame.
The seat post hole is one and five sixteenth inch.
The bushes have an internal diameter of a fraction over one and three sixteenth inch.
The post has a diameter of one and three sixteenth inch.
The post assembly is listed as part number 903340 in the Motorcycle Storehouse catalogue to fit FL/FX frames with machined castings. No cut of year mentioned.

The bushes (2 of) simply press into the hole, one flush with the top and the other half way down. you will need a long length of 8mm threaded stud and nuts (from your local hardware store) and assorted spacers, big washers etc. Drop the stud down the hole and out through the bottom (there should be a hole there to secure the post rod) and fit the nuts and suitable spacers to pull the bushes into the post hole carefully or you will distort them.

The seat post and all its component parts if they are all there (you dont say if its allready assembled or in bits?) can be put together a couple of different ways and still work some shape. It can be tuned to give different ride heights and spring preload. As the right way of assembling it is too long winded to describe on here leave me your contact number if you want for further info.

PS If you turn that 30mm post down to fit a 28mm hole allowing for any bushes you will probably be seeing daylight through it.

hi baz, thanks for that.

my post was assembled, but i've taken it apart to see how it works, and can see about fitting the damper springs in varoius orders to give different ride heights.

i also see that no way can i machine the seat-post tube, just ain't enough metal, bummer.

the internal diameter of the frame tube is 27.9-28mm. no way will a 1.3/16 inch bush fit. no chance?

also the frame tube is just that a tube. it's not blanked off with a smaller hole for the seat-post rod to locate in, if you know what i mean. so even if bushes were fitted it'd just slip through.

before you said how it all goes together i thought a bush would fit at the bottom of the frame tube and the post would rest on it.

obviously there's somehting strange going on. especially when you say there is no date specific items. wonder if the down tube has been replaced with just a tube. maybe it had a siezed post in one time and had to be cut out?

well i've got an inch diamter piece of tube and i'm going to fabricate my own post with a spring on the outside of the post, so i wont need to block off the frame tube. i can sort some bushes otu of some description. i've got support springs on the rear of the saddle and i'm thinking of a suitably sized valve spring for the post itself.

all good fun, if a little frustrating. well thanks for the info anyway.

laters.