bottom steering stem

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barry g

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hi to everyone just joined xs650 com im from scotland uk used to have many xs 650 in the 90,s when the first uk club was started halco tuning days .however ive decided to build a xs1 b lookalike but ive come to my first problem trying to mate the forks up can any one tell me was there change in sizes on the bottom steering stem ??? ive got a original xs1b top clamp and ive bought a new top clamp with the bigger rubber shocks and ive put the two together and the fork holes match however when i put the forks through the bottom fork stem there to wide to meet the top i got the bottom stem from a breakers and was sold as xs2 it has the damper etc but when i put top and bottom together the holes dont match hope someone can shed so light on this
 
to give readers a better picture ive started of with a 1972 xs2 frame , i managed to get a set of xs1b 1971 forks (no steering stem or top clamp) a nice xs1b wheel and im buying bits along the way the breakers sold me xs2 steering stem and i bought the top clamp triple tree from ebay part number 256-23435-01-98 new part so i know its right and ive got a rough xs1b top tree and the parts match fork hole,s and stem , im now thinking the bottom steering stem could be a later tx650 one as there different part numbers but im not sure so im hoping so one can shed light on this were xs2 and tx650 steering stems different
 
Hey Barry,
Could be the lower may be from the newer 35mm forks, as opposed to the early 34mm forks.
Pics would probably help. And then there's the leading axle triples from other models......
 
thanks for reply no they are all 34mm holes top and bottom as well as the steering damper rod etc it just seams the holes are futher apart on bottom stem maybe 4-5 mm
it has all the looks of xs2 two hole on top front for bottom headlight mount etc
 
Yes the 70 71 drum brake triples are narrower than the 72-73 (XS2 TX650) disk brake triples. Just another heads up; in 74 the triples stay the same width but the stem gets about 1/2" longer.
 
thanks guys think ive got it now so my top triples right but the bottom stems xs2 and wont match so i need to get xs1- xs1b bottom stem to match top but the stem will still fit into my xs2 frame as the stems are the same yep. hi paul i live in coldingham near eyemouth 12 mls from northumberland berwick i know dk spares thats where most of my parts came from frame, forks,front wheel cheers barry
 
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Finally got a pic and some measurements of an XS1B UnderBracket.

The center-to-center distance is 174mm (6.850").
 

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many thanks thats great info i got my stem out and it measures 225mm across end to end compared to the xs1 in the picture which states 208mm ,ive done a wee bit home work and found xs2 and tx 650 have different part numbers also . however with the help from your self and ggggary ive now found and bought a matching part number stem for xs1 xs1b brand new again many thanks guys barry
 
barry g said:
... i got my stem out and it measures 225mm across end to end compared to the xs1 in the picture which states 208mm ,ive done a wee bit home work and found xs2 and tx 650 have different part numbers also ...
Click to expand...

225mm forktube outside width for the XS2 stem? That's noteworthy.
Can anybody else confirm this?
I'm learning about this as well.

There is a maddening list of part numbers that must've drove the Yam parts guys nuts.

256-23340-61-33 = 1970 XS1
256-23340-61-33 = 1971 XS1B
256-23340-62-33 = 1971 XS1B (superceded by 306-23340-09-33)
306-23340-09-33 = 1970 XS1 (supercedes 256-23340-62-33)
306-23340-09-33 = 1971 XS1B (supercedes 256-23340-62-33)
306-23340-60-33 = 1972 XS2
366-23340-60-33 = 1973 TX650

The superceding 306 number for the XS1 and XS1B is certainly misleading, as it implies an XS2 part.
The suffix, 09-33 versus 60-33, is the big difference.

The only significant differences that I can find in this array of UnderBrackets are:

70 XS1 UnderBracket has 2 separate/welded tabs in front for the lower headlight adjuster bracket.
71 XS1B and later has 2 threaded protrusions in the front of the casting for mounting the lower headlight adjuster bracket.
Later XS1B's have 2 unthreaded bulges at the rear of the right bracket arm, presumably in preparation for a future gadget.
72 XS2 and later UnderBracket is wider (???), and has threaded rear bulges, for mounting the front hydraulic brake line.

The right rear part of my spare 70-71 UnderBracket is straight, with no bulbous bulge.
XS1B-UnderBracket03.jpg

My two XS1Bs have 2 undrilled/unthreaded bulges.
XS1B-UnderBracket04.jpg XS1B-UnderBracket05.jpg
 
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Some random upskirt shots, images are named first 4 are 70 last 3 are 71, each shot is from a different bike.

70triplea.jpg 70tripleb.jpg

70triplec.jpg

Early 70 SN1550

70tripled.jpg

71 triplea.jpg 71 tripleb.jpg

71triplec.jpg

Note these are old barn find bikes who knows what horible things may have been done to them in the distant past. But they all are drum brake bikes.
 
one thing i have noticed is the bottom stem stops are not the same the one i have xs2? tx650? has square stops, where some on the xs1 stem look like oblongs on one side any way once my new bottom stem 256-23340-62-33 arrives from texas to bonnie scotland i will take note in both stems and post here
 
Five years later, did it all work out? I'm contemplating putting a 73 tree on my 72 and use shocks and wheel from a 75. The 73 stem height is the same as a 72, but the 73 shock mount width is about 5/8" wider than the 72. The extra width on the 73 will accommodate dual disks if necessary. Just curious!
 

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