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Discussion Starter · #1 ·
Does anyone happen to know the size of this bolt (diameter & length)? It appears to have a 19mm head.

The TBS in question is going to be fitted with a sidecar and the bolt will need to be replaced with a longer one in order to attach the sub frame. Just trying to get all of our ducks in a row.

Thanks in advance,

Nina
 

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Okay - the swing arm pivot and centerstand pivot are two different things. The latter also forms a pivot for the rear suspension.

But, you need to know this - neither are just a bolt - both are safety critical. The suspension pivot has a smooth bearing surface and just happens to resemble a bolt. I'm not sure if the swing arm pivot is hardened but like the suspension pivot it will have high loads and be carefully engineered.

For safety's sake I would strongly advise you not to mess with either but rather bolt or weld to the main frame member / rear engine mount horns instead (as denny has done on his sidecar project). IIRC last time I bought one of the suspension pivots it was over $50.
 

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Discussion Starter · #3 ·
Thanks, Mick. I've passed your words on to my better half. I'm just the go between at this point so I may have written things down wrong. I've asked him to clarify.

I do admit that, at times, when he gets to talking about the bike all I hear is "blah blah blah bolts" :)

Nina
 

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Discussion Starter · #4 ·
sometimes...I swear...

OK, I've gotten my husband to translate (and break out the hand puppets for me). He was asking about the centerstand bolt & the swingarm pivot because they appear to be the same size (diameter) and he's not certain of which one he'll have to replace in order to mount the sub frame until the sub frame arrives.

Best thing would be to get hold of an exploded parts diagram for the TBS. Or call a Triumph dealer.

sigh.

Nina
 

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As I said - neither are just a "bolt"

exploded diagrams can be seen on the bikebandit website though it will not give you sizes, nor will a dealer - over and above measuring the thread.

You are likely going to have to get an engineering shop to evaluate what you need and make a longer one to the same specs and material if you have to go this route. Personally I would not ride any bike or rig that had been modified in this way unless I knew it had been done by a very competent engineer.
 

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Discussion Starter · #6 ·
Mick, thanks again. I think we'll just have to wait until the sub frame arrives & see how it's supposed to go on...then panic :). My question may very well end up as having been unnecessary.

Nina
 

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bolt

if the subframe is similar to the Watsonian one Ihave, the bolt you speak of will be M12 by 150mm long. I got a high tensile cap head screw for mine since I had problems fitting a hex head due to a tight clearance at the far right hand edge of the frame.
IF you can get it, it would be a smart move to get an M12 fine pitch instead of the ISO metric coarse that I ended up with. Not that it has ever come loose, being fitted with a Nyloc nut, but fine pitch seems to be the way to go for frame/motor connectors.
Hope this helps.
 

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Your husband's a lucky man - hand puppets have been banned in my house ever since the anniversary "incident".:D
 

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Discussion Starter · #9 ·
if the subframe is similar to the Watsonian one Ihave, the bolt you speak of will be M12 by 150mm long. I got a high tensile cap head screw for mine since I had problems fitting a hex head due to a tight clearance at the far right hand edge of the frame.
IF you can get it, it would be a smart move to get an M12 fine pitch instead of the ISO metric coarse that I ended up with. Not that it has ever come loose, being fitted with a Nyloc nut, but fine pitch seems to be the way to go for frame/motor connectors.
Hope this helps.
2 wheels, it helps a ton! Now, your Watsonian is fitted to a Tbird, right? Do you know if Tbirds & TBS both have the same frames? I'm asking because it was a friend with a Tbird/velorex combo that mentioned the need for a longer bolt to connect the sub frame but when we spoke to Doug Bingham at Side Strider (who has a TBS combo) he said that the bike to sub frame fit was very straight forward.

Your husband's a lucky man - hand puppets have been banned in my house ever since the anniversary "incident".:D
Next time try jewelry ;).

Nina
 

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bolt again

just been to check my outfit, yes the bolt is M12x150. Metric fine pitch is 1.25, mine is metric coarse which is 1.75 pitch. you will NOT need to get this specially made, unless you cannot access standard metric fittings. A reputable engineer's merchant should be able to supply this.

If it really falls into a sack of poo, mail me and I will send you one from the UK at cost price plus postage.

One thought to bear in mind, there is always a possibility that a 1/2" UNF will fit, might be worth trying this before we get into a trans-Atlantic trade in fastenings!

If you haven't done it before, fitting a sidecar is not difficult, providing you follow some guidance from experts, easily available on the web, and you remember to follow good engineering practice.
It isn't difficult, folk have been fitting sidecars at home for a century.

Lean-in dimension is critical, toe in ditto; position the sidecar so that the sidecar wheel leads the rear bike wheel by approx 20-25% of the bike's wheelbase (this isn't critical, and depends on the make of sidecar-some US sidecars are designed for the side wheel to be in line with the bike rear wheel, whereas most Euro sidecars are designed for the sidecar passenger to sit level with the bike's rider).

If you have more queries, I'll be glad to answer them to the best of my ability- I am a professional engineer of 30+ years experience, and have been biking for 37 years, not some Johnny-come-lately!
 

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pics

2 wheels, it helps a ton! Now, your Watsonian is fitted to a Tbird, right? Do you know if Tbirds & TBS both have the same frames? I'm asking because it was a friend with a Tbird/velorex combo that mentioned the need for a longer bolt to connect the sub frame but when we spoke to Doug Bingham at Side Strider (who has a TBS combo) he said that the bike to sub frame fit was very straight forward.

Yes, Watsonian GP700 on a T'bird which now has a 1200 motor.
TB and TBS frames are the same, at least, the front bit is.
If Doug says you don't need to worry about the bolt, I am sure he is right.
I did need a longer one, though. All us lads say that though!

Which make of subframe are you fitting?
I will gladly mail you pics of my outfit, don't want to post any on the forum until the 1200 motor swap is complete cosmetically though.
 

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Discussion Starter · #13 ·
2 wheels,
Getting our hands on the correct bolt shouldn't be a problem. there's actually a manufacturer nearby that makes nothing but metric bolts. Now if you have any way to get us Panther parts we can talk about trans atlantic shipping :D.


Yes, Watsonian GP700 on a T'bird which now has a 1200 motor.
TB and TBS frames are the same, at least, the front bit is.
If Doug says you don't need to worry about the bolt, I am sure he is right.
I did need a longer one, though. All us lads say that though!
Maybe to somebody like Doug swapping out the bolt qualifies as straightforward?

The sidecar is actually a Side Strider Mark 1 and the sub frame is being built per Doug's specs, by the guy that he sold all of his TBS sub frame tooling to. I can't remember his name but he's somewhere in Iowa, I think. Or Idaho. One of the I states.

Of course I'd love to see pictures of your outfit! I can wait until it's fit for public consumption, though. I wouldn't worry about cosmetics. I posted a link to pics of the TBS with it's hideous, sluglike Tbird seat stapled onto a Tbird pan & I haven't been driven off of the list with burning torches (yet).

Thanks so much for your help!

Nina
 

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just been to check my outfit, yes the bolt is M12x150. Metric fine pitch is 1.25, mine is metric coarse which is 1.75 pitch. you will NOT need to get this specially made, unless you cannot access standard metric fittings. A reputable engineer's merchant should be able to supply this.
This sounds like you are describing the subframe attachment bolts rather than the swing arm pivot or suspension pivot.

If this is the case it all makes much more sense - and yes you just need a regular though decent grade metric fine bolt.
 
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