916 forks into early 900 Monster

[Nottsbiker]

Hi All,

I'm slowly getting my backside into gear and getting all the mods done on my pile of parts prior to sending stuff off for coating.

I already have the legs from a 916 that I'm going to fit to my early 900 and want to get the top yoke bored and purchase some shims for the bottom yoke. I will also need to source the correct spindle / bearing configuration as I currently have the original spindle which I know will not work. Could anyone suggest any answers to my problems;

1. Where to get my yoke bored as I have no local contacts in engineering
2. Where to buy some shims for the bottom yoke
3. What size bearings I need to purchase to run the 900 wheel with the 916 spindle
4. Does anyone have a 916 spindle / spacers for sale

As I'm going to be converting over to fat bars I'm hoping that by fitting the converters into the standard bar risers I'll be able to avoid the issue of the 916 forks being longer than the stock 900's - is this realistic, or will the 916 forks still make contact with my higher / fatter bars?

Many thanks,

Ben

[Dukedesmo]

I have done it.

As you say; bore the top, shim the bottom, I got a local engineer to do the work.

916 has 25mm axle so needs the correct 916, 25mm spindle & nut, 6005-2RS (25mm id, 47mm od, 12mm thick) bearings (assuming wheels are 47mm hole?) and you'll also need the spacer that goes between the bearings.

If you're using a mechanical speedo you'll need the 25mm drive and there may be a mismatch on the ratio so speedo would read different? I have an electronic speedo from rear wheel so have a (30mm) spacer to replace the speedo drive.

For the bars, you'll need to fit higher risers to clear the fork tops (unless the bars curve up very quickly), I fitted +30mm risers and then used flat bars to get roughly the same height as standard bars.

More info here; http://www.ukmonster.co.uk/monster/showthread.php?t=43562

Give us a shout if you want any more info, I'm not far from Nottingham so you could pop over for a look if you want. :thumbsup:

[Nottsbiker]

Cheers for the post.

Looks like I'll need a complete 916 front spindle then so I'll post up a wanted ad shortly.

Need to measure my own wheels as well so I can match up with your dimensions.

Am off 2 weeks over Xmas so could drop by :)

[Martin C]

I don't know whereabouts you are in Notts, but I do know that 'SEP' in Kegworth are a good automotive engineering firm.

[Nottsbiker]

Hi Martin,

Yes I've used SEP when rebuilding a friends KX250 engine a year or so back and know that they are very good. I was looking to see if there was an existing supplier for the lower yoke shims as I'm guessing SEP making them as a 1 off will be expensive which would mean I'd have been better off going with IMA custom made items (cant afford this right now).

Thanks,

[utopia]

Ben, I would have offered to make you some by now but they would be an absolute bitch to machine because they're so thin ... only 0.5mm if I remember correctly.
But I do have a couple of suggestions.

Have you considered cutting some shims out of flat sheet material ?
It might sound a bit Mickey Mouse at first sight but it would function perfectly.
In fact, unless tubular shims were machined particularly well, the flat sheet might be more accurate (in terms of being a constant thickness throughout).
I once bought a sheet of ally from B&Q, which was intended as flue backplate for fitting gas fires.
That was exactly 0.5mm thick and I can remember thinking at the time that it would make ideal fork shim material.
You could probably achieve a neat finish if you assembled a larger piece of sheet in the yoke with a dummy fork tube, then marked and trimmed it.
And even if not as the long term solution, it might be a way of dry-building the bike in the shorter term ?

The other option is (and its only just occurred to me so I'm still mulling it) ....
The only sensible way to consider machining some would be if I made a few pairs, rather than just one set for you.
That way it might make economic sense to make the necessary tooling (I'm thinking some sort of taper arbour or mandrel, maybe an expanding one even).
And then there would be a few on the shelf for future club members who go this route (there will surely be some).
You'll have to leave me to ponder that a while longer though.
And I doubt I could do it very soon ... I already have 2 or 3 outstanding bits of work to do for various peeps.
I'll ponder a little more.
It would be interesting if you could get a quote from someone.

Don't think I can bore the other yoke accurately enough with my equipment ... and anyway the lathe is too small to swing it.

[Darkness]

Have you considered cutting some shims out of flat sheet material ?
It might sound a bit Mickey Mouse at first sight but it would function perfectly.
In fact, unless tubular shims were machined particularly well, the flat sheet might be more accurate (in terms of being a constant thickness throughout).
I once bought a sheet of ally from B&Q, which was intended as flue backplate for fitting gas fires........

I've cut ally shims from the sides of Coke cans in the past to shim exhaust pipe joints (Other makes of cleaning fluid are available). They give a useful flat rectangle of ally, you can cut it with a decent pair of scissors, and it even has the start of a curve on it if you don't flatten it out fully. The advantage of ally shims in exhausts is that they are "sticky" when clamped, but can be separated later: should suit forks too?

[Darren69]

I've seen somewhere selling such shims on the web recently, but I'll be damned if I can find them again now. Have you tried Kamna?

[Dukedesmo]

I've seen somewhere selling such shims on the web recently

Motowheels; http://motowheels.com/i-8121511-corse-dynamics-lower-triple-clamp-conversion-shims.html

[Nottsbiker]

Sweet!

Obviously I'd prefer to put some money utopias way where possible but at least I've got an equally good back up plan here too.

[Albie]

Sweet!

Obviously I'd prefer to put some money utopias way where possible but at least I've got an equally good back up plan here too.

I would simply copy them. As you can see they dont even need to be completly wrapped around. I would cut them 2mm short of circumference. I would also probably use the tabs in just 3 places. These can be cut simply with shears and then wrapped around a leg with a jubilee clip to get shape and then removed and then squashed a tad more with fingers. Can you imagine how much metal you would have to machine to produce 2 and making a mandrel to turn the final diameter to stop it collapsing in. They would still need slitting to clamp properly.
Its just my opinion btw.

[utopia]

re. the machining ... I was considering it a proviso that I could acquire some suitably sized ally tube to make them from.
Then its just skim the bore, face the end and cut off to length.
Then skim the outside as a separate operation, off the aforementioned arbour/mandrel, peg thingy.
Fairly simple .... once you've made the tooling, which is half a days work on its own, plus materials (a big bit) and maybe postage on that too.

But, anyway ... wow, I followed Dukedesmo's link expecting to see split tubes with flanges, but they're actually just sheet ally.
And there's me thinking I was being a cheapskate.
I don't like the tabs though.
And they're surely only there as an assembly aid anyway.
But they look like a water catcher to me, with corrosive consequences.
And for the same reason, I would cut the shims to stand just a fraction proud of the top surface of the yoke, just to be certain not to leave any chances of an annular hollow to hold water.
I guess the bottom edge could be flush with the yoke, but I'd still probably leave a tad if it were me doing it.
I'm even starting to wonder, as I'm typing, whether you might even fettle the shims neatly, lining up the split nicely with that in the yoke, and getting the length perfect, then er .. glue them into the yokes (obviously taking great care to have a super-thin and even spread of your chosen adhesive.
How about one of the more permanent types of Loctite ?
But then again, they're not going to be in and out on a regular basis, are they ... no cancel that thought, I think.
If you pre-formed the tubular shape well, you might end up with enough spring in them to hold them well enough.

To fit them, I think I'd be inclined to get the leg in the yoke but with a little way still to go, then feed the shim in ....?
Maybe a plastic wedge holding the split in the yoke open a bit, for a tad more clearance ...?

[utopia]

And re. the coke can shim ....
You have read Zen and the art of .... haven't you ? :)

[Darkness]

And re. the coke can shim ....
You have read Zen and the art of .... haven't you ? :)

Yes, but not for some forty years. I can still remember the plot, but a lot of the details escape me..?

[utopia]

It was one of the very first things.
His mate was disparaging of his coke can shim to tighten the loose bar clamps on his BMW.
..... because it was a BMW, he'd paid the ticket price, it shouldn't go wrong and if it did he was going to have it fixed by a proper BMW dealer (ie not immediately) and would expect a "proper" piece of shim steel to be used .... because that was proper.
Neglecting the delay to their road trip, and more specifically the perfect suitability of the soft, super-thin, ally can, which wouldn't cause galvanic corrosion from dissimilar metals in contact, unlike the "proper" shim steel .
...... is how I remember it.

[Darkness]

A great book: must dig out my old paperback copy.
I do remember the BMW equivalent to Trigger's broom: same one for twenty years, with only seventeen new heads and fourteen new handles......
It does question the validity of an identity of a bunch of replaceable parts (And v5s)?

[Dukedesmo]

Mine were machined already to size/shape;

http://ducatiforum.co.uk/data/photos/l/5/5511-1427652209-ad373ea67cacb3f9d50ebe1b33dd323e.jpg

This way they stay on the fork tube easily. I did make a cut through them before fitting so that they would grip.

[Nottsbiker]

Did you machine those yourself or did you pay an engineer to produce them for you?

[Dukedesmo]

Local engineer did them, along with boring the top and several other bike related jobs.

[Nottsbiker]

They up for extra work or was it a one off mates rates type of deal?

[Dukedesmo]

He's a one-man band, an excellent engineer, can make anything but turnaround is not very quick.

[Nottsbiker]

I'm in no rush as weather terrible and finances limited so happy to poddle along with my build until say easter

[Dukedesmo]

You didn't say which Easter... ;)

[utopia]

Ha, ha. ... ain't that just the way with one-off engineering jobs.
I'm exactly the same.
There are at least three club members waiting for turned parts right now.

Don't think I said which easter either. :rolleyes:

[Nottsbiker]

Lol well I've only got to get a load of painting and coating done first then start to assemble it all. I never got the bike whole so it may take a while. ..