Author Topic: In-line handlebar top triple tree / top yoke  (Read 527 times)

Offline AnthonyA

  • Moving Up
  • **
  • Join Date: Oct 2019
  • Posts: 22
  • Karma: 0
In-line handlebar top triple tree / top yoke
« on: 12.12. 2019 18:38 »
Hello my friends,

In order to streamline the machine, in want my handlebars to be attached just above the fork tubes, aligning the whole thing when you look from the side.
Because with the standard top yoke, the handlebar is attached way back, and IMO, it's not very pretty. It didn't notice it on a full stock bike, but I want to change the handlebar (something a tad more high, with more curves), and... that's just plain ugly now.

So, I was wondering if some of you know about top yokes that fit in place of the standard one.

Some guy said it had already done such thing, but it was a Triumph one a friend of him had laying around and thus don't know where it comes from.
I just want it to work, doesn't matter if not BSA.
A10 Road Rocket (swing-arm)

Online Klaus

  • Valued Contributor
  • ****
  • Join Date: Jun 2015
  • Posts: 363
  • Karma: 10


If you think, everything is under control, you are not fast enought.

Offline AnthonyA

  • Moving Up
  • **
  • Join Date: Oct 2019
  • Posts: 22
  • Karma: 0
Re: In-line handlebar top triple tree / top yoke
« Reply #2 on: 12.12. 2019 21:21 »
Nice yoke but that's if you want clip-on handlebars.
I'm search for something that you'd find on any standard bike, but apparently not on BSA's ; mounting points for the handlebar in the middle of the top triple tree, not at the back.
A10 Road Rocket (swing-arm)

Online morris

  • Wise & Enlightened
  • *
  • Join Date: Aug 2012
  • Posts: 1538
  • Karma: 22
  • Antwerp, Belgium
Re: In-line handlebar top triple tree / top yoke
« Reply #3 on: 13.12. 2019 15:00 »
Not much options I guess.
Either modifying an original yoke ( Make sure that it’s well done. You wouldn’t want it to snap at 250 mph  *smile* ) or else making another front fork to fit. Has been done by a forum member I think. If the old memory don’t let me down I think it was a Suzuki fork with disc brake and all...
'58 BSA A 10 SA
'52 BSA A 10 Plunger
'55 MORRIS ISIS
The world looks better from a motorbike
Belgium

Online RDfella

  • Resident Legend
  • *****
  • Join Date: Aug 2017
  • Posts: 634
  • Karma: 5
Re: In-line handlebar top triple tree / top yoke
« Reply #4 on: 13.12. 2019 15:41 »
morris - you mean 'the project'? I used the Suzi top & bottom yokes and made cupped sleeves to take the Suzi tapered headstock brgs. Then there's Suzi fork shrouds to modify (BSA won't fit) etc. Lot of work if you just want want to move the bars. I'd cut and weld if I was doing it. Or even bolt up some lugs from underneath as my Yamaha / Weslake is, though i'd feel more comfortable with weld.
'49 B31, '49 M21, '53 DOT, '58 Flash, '00 Firestorm, Weslake sprint bike.

Offline duTch

  • Ricketty Rocketty Golden Flashback
  • Wise & Enlightened
  • *
  • Join Date: Oct 2011
  • Posts: 4540
  • Karma: 41
Re: In-line handlebar top triple tree / top yoke
« Reply #5 on: 13.12. 2019 15:53 »

 '71-'73 OIF/Conical fork yokes might have what you be looking for....depends what legs and wheel/axle you use though with regard to diameter and distance between centres. I think they are 1,3/8" dia. I have one my Plunger (complete set)
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline AnthonyA

  • Moving Up
  • **
  • Join Date: Oct 2019
  • Posts: 22
  • Karma: 0
Re: In-line handlebar top triple tree / top yoke
« Reply #6 on: 13.12. 2019 18:42 »
For those interested in the matter, someone on the French forum told me 1st gen A65 top yoke do the trick.
If someone has one laying around...
A10 Road Rocket (swing-arm)

Online muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8073
  • Karma: 106
  • Lake Conjola NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: In-line handlebar top triple tree / top yoke
« Reply #7 on: 13.12. 2019 19:12 »
G'day Ant.
I was just looking at one of those here https://tinyurl.com/ttzxqks. I think one problem is the distance between top and bottom yoke so the fork shrouds won't fit. It also uses shorter stanchions.
Cheers
'51 A7 plunger, '57 A7SS now A10CR, '76 XT500, '77 AG175 '83 CB1100F, '81 CB900F project.
Australia
Muskys Plunger A7

Online morris

  • Wise & Enlightened
  • *
  • Join Date: Aug 2012
  • Posts: 1538
  • Karma: 22
  • Antwerp, Belgium
Re: In-line handlebar top triple tree / top yoke
« Reply #8 on: 13.12. 2019 19:21 »
morris - you mean 'the project'? I used the Suzi top & bottom yokes and made cupped sleeves to take the Suzi tapered headstock brgs.
May well be. I knew it was something  recently mentioned  but didn’t have the time to look it up.
I am currently looking out for an A10 or A65 frame with engine. Feel a bit bored lately so I’m thinking about building some kind of street scrambler with modern forks. That’s why I remembered.
We’ll see what comes up.
'58 BSA A 10 SA
'52 BSA A 10 Plunger
'55 MORRIS ISIS
The world looks better from a motorbike
Belgium

Offline duTch

  • Ricketty Rocketty Golden Flashback
  • Wise & Enlightened
  • *
  • Join Date: Oct 2011
  • Posts: 4540
  • Karma: 41
Re: In-line handlebar top triple tree / top yoke
« Reply #9 on: 13.12. 2019 23:10 »

 I *think* that BSA have a different taper on the top of the tubes to Trihards , but may be wrong....
 That example of muskys looks like what you're after - I've a spare OIF set I can take a pic of when I find them, for comparison
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline AnthonyA

  • Moving Up
  • **
  • Join Date: Oct 2019
  • Posts: 22
  • Karma: 0
Re: In-line handlebar top triple tree / top yoke
« Reply #10 on: 14.12. 2019 10:48 »
Thank you guys for the pictures and knowledge !

I don't mind cutting into the fork shrouds for them to fit, they're no concours parts anymore. I want to keep them though.

So, if I do this (top yoke A65 but stock bottom and steering + cutting into the shrouds), it will work ?
Cause I found one used online, and I don't know if I buy it or not...  *conf*
A10 Road Rocket (swing-arm)

Online RDfella

  • Resident Legend
  • *****
  • Join Date: Aug 2017
  • Posts: 634
  • Karma: 5
Re: In-line handlebar top triple tree / top yoke
« Reply #11 on: 14.12. 2019 11:53 »
Anthony - sounds a neat way of achieving what you want - but be sure to check the distance between tubes, tube diameter and taper at top are the same. I've no idea, but someone else may be able to confirm / deny. Good luck.
'49 B31, '49 M21, '53 DOT, '58 Flash, '00 Firestorm, Weslake sprint bike.

Offline AnthonyA

  • Moving Up
  • **
  • Join Date: Oct 2019
  • Posts: 22
  • Karma: 0
Re: In-line handlebar top triple tree / top yoke
« Reply #12 on: 14.12. 2019 17:10 »
Anyone can do said measurement ? I have no way to tell myself, and it would be of tremendous help.  *respect*
A10 Road Rocket (swing-arm)

Offline duTch

  • Ricketty Rocketty Golden Flashback
  • Wise & Enlightened
  • *
  • Join Date: Oct 2011
  • Posts: 4540
  • Karma: 41
Re: In-line handlebar top triple tree / top yoke
« Reply #13 on: 14.12. 2019 19:29 »

 
Quote
Anyone can do said measurement ? I have no way to tell myself, and it would be of tremendous help.  *respect*
 

 Easy enough- Unless I'm reading you wrong, just measure outside to outside and inside to inside and split the difference (subtract inner measurement from outer)
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Online Sluggo

  • Serial Hoarder, or Eccentric Collector depending on viewpoint
  • Resident Legend
  • *****
  • Join Date: Jun 2017
  • Posts: 639
  • Karma: 11
Re: In-line handlebar top triple tree / top yoke
« Reply #14 on: 14.12. 2019 23:21 »
I can send you pictures and measurements tonight. (Been off line due to surgery, but up & walking again)
last summer I sorted and organized the land O' forks and trees in storage. (Motorcycle hoarder).

BSA stuff gave me fits and massive confusion. Still have a few mystery parts, but I narrowed 98% of it down for years-makes-models.

Here is the quick version, be happy to post up a BSA Tree tech post for ID.

Based off the top of my head here is what I found:

BSA Preunit singles some years were narrower than the twins,. # part numbers pending

BSA Preunit twins there was some variables for compy models but most were pretty std (Lugs, steering locks, speedo/tach mount and taper for the forks

BSA Unit Singles are their own animal by them selves but are tell tale with a reverse pitch risers,

BSA unit twins. there is 3.5 variants.  # part numbers pending.   There is a variation similar to the Preunit twins but 2 versions of fork locks.  There is an early casting number, a Dual part number, THEN there is the oddball 64-65 Mustache trees (pictured above in this discussion)  These are harder to find and I am not clear what all the models they used them on. (Parts books sometimes show for all models, sometimes only certain ones like Hornet)  Then Inexplicably they went back to the Preunit style trees again with a variation in fork locks.  And finally was the head scratcher that took a lot of investigation.  There was some mystery trees and what they are is somewhat resembling the preunit style but had small details different in their castings top and bottom trees.  What I discovered is these are factory service replacement trees intended to be one size fits all for unit Twins.

Then  ** Some fork parts interchanged with Triumphs for 68-70 with the 2LS brakes, and the noticable difference on the fork legs is the Fork oil seal holder/Spring abutment is LONGER on the BSA and Shorter for Triumph but the top trees differ between Triumph-BSA as well as wider to accomodate the 2LS brake after the first year. (late 67-early 68 trees are oddballs).   Also, the brake actuator levers on the brakes differ between BSA-Triumph but the brake plate is the same for TLS.

OIF 1971->  Smaller stem and different spacing and does away with the BSA fork tube taper.   Also steering locks

Triples- BSA & Triumph, look similar to the 68-70 trees but have tell tale tabs for brake lines.

OIF unit singles-  These are alloy and similar but not exactly the same as Cerrani-Betors.  The forks are the same but generally longer on scramblers, but same length on roadsters as OIF Twins.  But the forks and trees were largely copied from Cerrani and similar forks.  (Quite good actually if you switch to progressive springs)

**I spent HOURS accumulating part numbers and measuring, lots of study of many years parts books.

I also have a vintage bike magazine review-interview of early Rickmans with Bud & Dave Ekins of LA fame. They set up a lot of these (For McQueen and James Garner, as well as quite a few others)  So they took BSA Trees, and modified them, cut the fork tube holes, machined out the tapers and welded on pinch bolts to allow the forks to be slid up or down into the trees to set up the bike for off road, the reason was in some cases a nose down attitude was helpful.  Its also reprinted in a cycle world compilation.  Ill post the dates, & if interest I can scan the article.

** As noted, the fork ears for units were a different length than Preunits, and some variations in that as well.  Might be easier to just ALSO use the matching fork ears for the trees being used.

*** I am also matching trees up to projects (Triumph-BSA-Norton) and will be selling off extras soon.

In the interim, enjoy these pix of some Rickman bodywork pinstriped by the famous Von Dutch (Kenny Howard) who often was at Ekins shop. ( ** I have been exchanging emails with a former local club member who was a regular down at their shop and has some interesting pictures and stories)
Remember that any advice received on a free internet forum is generally worth about 1/2 of what you paid for it.
We overcharge every 3rd customer to pass the savings onto you.
You can have High Quality, Low price, and fast turnaround. Pick any 2, Never all 3 at the same time.