Replacement top yoke g/s

oldnfat

oldnfat

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Hi all, I am due to take the old girl on a backroads trip through the Pyrannes later this year where about 70% is off road...mainly fire trails but some more technical stuff.

I have replaced the fork valves with emulators and the improvement is considerable. However, I want to replace the OEM pressed steel top yoke with s something more substantial....any recommendations as I a. Having trouble sourcing a replacement?

Cheers
 
A common mod back in the day (and which I have on my G/S) is to take a G/S bottom yoke, remove the stem, flip it over and use that. You will have to get it run through a mill to flatten the (now) top surface but other than that its a failry easy swap, looks OEM and is very good.

Alternatively dig very very deep into your wallet and get a bespoke billet top yoke from Toaster Tan (based in USA I believe)- I think maybe one or two of the German suppliers might offer something as well now (Motoren-israel, Boxxerworks, Seibenrock???)
 
I wouldn’t have thought this conversion was necessary unless you intended to do some serious, high speed, off road competition. Thousands of miles of off-road travelling must have been accomplished with the standard top yoke without drama.
 
scooter paul said:
I wouldn’t have thought this conversion was necessary unless you intended to do some serious, high speed, off road competition. Thousands of miles of off-road travelling must have been accomplished with the standard top yoke without drama.
Click to expand...

Of course it isn't necessary, but it does improve matters significantly. In my actual experience.
 
These flat plates are now almost 40 years old , and some are simply stuffed, particularly if they get further than Safeway's car park for a photo shoot.
The holes usually elongate first, then thay bend and twist and flex so much that the top nut slackens off all the time

San Jose make a reasonably priced one for 36 mm tubes which they usually have on Ebay.

It is not G/S specific , but a little work with a hacksaw and file will soon have it fitting.

Indicators fit OK if simply flipped over to the other side and the tab bent over. I have a large cable tie from the bars to the indicators to stop them bouncing around- off road vibration just kills them and new brackets are expensive.

I fitted a SJ style tubular brace from Flatracer at the same time, and their short guard.The brace holds my well worn unbushed slders a bit tighter on the tubes as I deliberately set it to pull them over. Stock one just clears a 21 " wheel - I dont do mud!
Looks good, and from being able to watch the forks twist when I was moving it around the shed they are now considerably stiffer than the 42 mm forks on my F650 GS.
Fork action is better too, as with a billet triple fork alignment is a doddle and it stays that way.

Toaster Tan also do a special SS top nut, around the same price as everyone else's but designed to hold the triple a bit tighter and doesnt depend just on 96 ft/lbs to hold it in place, if you fancy a little more bling.
 
Many years ago I just cut myself a thicker one on a laser cutter I was operating, Nowdays probably better on a waterjet.
 
Well thank you all for the comments. I have experienced the loose top nut on last jaunt in the Pyrenees a couple of years ago.....seems OK on the road although I do check regularly. I like the inverted bottom yoke idea and with a friendly machine shop nearby might give that a go.

Now on the search for a bottom yoke so thanks mikeyboy or anybody else anybody with one kicking around looking for a home, let me know.

Cheers
 
If you do go the bottom yoke route, you might find that as the new top yoke has a larger footprint around the outside of the fork tubes that your lock stops might need adjusting - I have a Paris Dakar tank on my G/S and the clamp bolts in the top yoke hit the tank quite hard........just be aware before you start sawing the bars about....!
 
If you want to keep the stock geometry a lower triple used up top must be reduced in thickness on the bottom at the centre hole to match the OEM flat plate - any increase in thickness will need the fork tubes a corresponding amount further through the triples.
I dont have a mill and while my chosen machinist does the best job possible he isnt cheap, so modifying a lower wasn't for me.
And with a modified lower you still have to work out how to mount the bars, indicators, lights and stop it hitting the tank, if you have a PD.
 
Hmmmm....mine is a PD. May have to think this one through again.....although like the idea of the re used bottom. I do appreciate that I would have to drop the geometry a little as I raise the folks a bit but can’t believe this would make a massiv change to the handling and would be prepared to give it a go.

The hitting the tank thing is not good however....
 
Arkwright said:
This chap in Australia makes them at a sensible price.

http://skrunkwerks.com/skrunk/bling-2/

I've got one on mine, very good.
Click to expand...

Looks like to be just the ticket.....but £109 plus gawd knows how much for posting....I guess by the time I have faffed around with a bottom yoke the price difference may not be so big....have to think on this one....probably the way to go...thanks for the info.

Cheers
 
oldnfat said:
The hitting the tank thing is not good however....
Click to expand...

You only have to adjust your lockstops. Easy peasy. Its only a problem if you DONT adjust your lockstops! (I used a longer stainless steel cap head bolt and some washers) I only mentioned it so you dont damage your tank in the first 10 seconds of fitting it - like i did as my bars swung round. Luckily my tank was brand new and still in primer so the little dink I put in it was dealt with when the tank was painted.

BTW you will still have the same issue with the Skunkwerks one as from what I can see its even bigger around the stanchions than the BMW bottom yoke. Also you will pay customs charges, a Parcelforce handling fee, tax, and postage - I did look at this about 3 years ago and it was a showstopper (for me anyway).

As for geometry - I noticed no difference whatsoever in regard to that but the overall improvements far outweighed any "negative" impact on the geometry (not that I noticed any as I say)

And also (IMHO) whilst it looks a decent bit of kit it still looks a bit "aftermarket" and sort of a bit to modern for the G/S.

Edit

I have just looked at the Skunkwerks one again, and precisely where it is thickest (the clamping bolt area) is exactly where it will be hitting the tank, and is much thicker than the BMW bottom yoke.

Also per Beemerboffs post - once the top surface is milled the indicator stems can be fitted by flipping them over (and maybe side to side to, cant remember), the bar mounting is simply 4 holes to be drilled (you can use the old plate as a template) and yes you will need to drill 2 threaded holes in the front of the yoke to fit the binnacle brackets (which doesn't seem possible on the Skunkworks one BTW - seems much thinner there)
 
Thanks for the link to Skrunkwerks, some fabulous stuff on there, especially this salt racer .

Lake_Gairdner_BMW_Saltracer4-940x603.jpg

:beerjug:,
 
http://www.sjbmw.com/--xstore?zcid=28902#dsstore -
This works with the front bar holes cut off .

Oz postage charges are ridiculous - just about kill buying anything from here.
$ 230- to send a shock to the UK, from memory.

Yes, indicators have to go over to the other side , and upside down.

Airheads dont seem that sensitive to different tires, so they probably are not that sensitive to a little change in hieght at the front either, but most folks who makes aftermarket top triples reduces the thickness at the center nut to near OEM for whatever reason.

Dropping the front will reduce the stability a little, with the correct tires it might not be that noticeable, but we all owe each other a duty of care when suggesting modifications.

http://toastertan.com/top_brace/
Top stuff from TT including the special centre nut, and not a lot more expensive.
Tech tips are worth reading too, there is more to this than some would have you believe!

http://www.flatracer.com/#/bmw-frame-handling/4586170197
While you are at it you may as well finish the job and fit a decent brace and a guard that works.
 
I used a bottom clamp and machined it to fit a few years back on mine
A worth while mod that does make a noticeable improvement even on the road
I think one of the reasons a later GS rides a lot better is because the dropped the flexible top plate
 

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