Improved Rear Wheel Chain Adjuster

Glenn

Bonneville T100
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I just saw this but for the life of me I cannot figure out how it works. Can somebody help me on this before I buy 2 of them? The part that I cannot figure out is that since it is totally covered how do you keep the tab in place on the end of the swing arm that the adjuster bolt fits in to tighten the wheel which tightens and loosens the chain or in my case on my '79 T140 the rear drive belt. One thing I may be wrong on (since I have never seen one of these new improved ? versions) is that it may be covered on 3 sides and the bottom is open.

 
Last edited:

Rudie

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since it is totally covered
new improved ? versions
What do you mean by "totally covered"? Afaict, the CBS advert shows the cheap bent tin chain adjuster Triumph and BSA fitted for years.

Or post a picture of what's on your bike, in case they're something non-standard?
 

Glenn

Bonneville T100
Riding for 62 Years
Local time
Today, 20:39
Joined
Aug 13, 2010
Messages
450
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47
Age
78
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Gibsonville
First Name
Glenn
My Ride
1979 Triumph Bonneville
[/QUOTE]


What do you mean by "totally covered"? Afaict, the CBS advert shows the cheap bent tin chain adjuster Triumph and BSA fitted for years.

Or post a picture of what's on your bike, in case they're something non-standard?
The type that is on my bike (which is the original part) looks like this.

1594333162504.png

The one on the CBS (Classic British Spares) looks like this.

1594332715854.png

The description of this one says that it is a new design.

New Triumph rear wheel chain adjuster. Chain adjuster is made in England by L.F. Harris to replace Triumph and BSA part number 37-3742 and W3742. Hole measures 5/8"... suited for both conical and rear disc brake models. Fits Triumph 650 and 750 models from 1971-1979. Also fits BSA 650 (A65) models from 1971-1972. Check your parts book to ensure the best fitment.



My point and question is how do you adjust the tension on the bolt where it makes contact on the end of the frame.
 

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Rudie

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You are still not making any sense.

... is a standard 37-3742 pictured from above;

... is a standard 37-3742 pictured from the side;

... afaict, the two images in your post #4 are of exactly the same part, just the images have been taken from different angles.

The description of this one says that it is a new design.
You are definitely confused:-

. the only place the text editor can find the word "design" is in something you have written;

. otoh, the editor finds the word "New" at the beginning of the text from the CBS you have quoted;
New Triumph rear wheel chain adjuster. Chain adjuster is made in England by L.F. Harris to replace Triumph and BSA part number 37-3742 and W3742. Hole measures 5/8"... suited for both conical and rear disc brake models. Fits Triumph 650 and 750 models from 1971-1979. Also fits BSA 650 (A65) models from 1971-1972. Check your parts book to ensure the best fitment.
. i.e. CBS is not saying it is "new design", it is simply new stock newly-arrived at CBS's premises;

. i.e. what CBS is advertising is a new stock of chain adjusters as fitted as standard by both Triumph and BSA between from the '71 to the '79 model years inclusive (in fact, they were fitted only to the OIF and T160; '71-'74 T150's and T100's continued with the more substantial chain adjusters that had also been fitted to pre-OIF 650's).

My point and question is how do you adjust the tension on the bolt where it makes contact on the end of the frame.
The image of "The type that is on my bike (which is the original part)" shows a nut - usually spot-welded to the chain adjuster - at the 'closed' end of the chain adjuster. A bolt and another nut ('79 parts book, "REAR WHEEL" pages, parts #17 and #18) screw through the spot-welded nut.

When the threaded end of the bolt contacts the end of the swinging arm, if the bolt is turned clockwise, the chain adjuster will pull the wheel spindle rearward, to increase chain (normally, belt on your bike) tension and/or align the rear wheel with the front wheel. If rear wheel alignment or chain/belt tension requires the spindle to be moved forward in the swinging arm, the bolt in the chain adjuster must be turned anti-clockwise and, separately, the spindle pushed forward until the end of the bolt through the adjuster contacts the swinging arm again.

When the chain/belt is tensioned correctly and the rear wheel is aligned with the front wheel, the bolts through the chain adjusters can be secured in position by tightening the the loose nut on each bolt against the chain adjuster.

Afaict, the CBS chain adjuster - being exactly the same - is used in exactly the same way; the spot-welded nut in CBS's image is not visible directly; however, the nut's shadow can be seen if the image is enlarged.

If you are still unclear, why not 'phone or e-mail CBS?
 

Glenn

Bonneville T100
Riding for 62 Years
Local time
Today, 20:39
Joined
Aug 13, 2010
Messages
450
Points
47
Age
78
Location
Gibsonville
First Name
Glenn
My Ride
1979 Triumph Bonneville
You are still not making any sense.


... is a standard 37-3742 pictured from above;


... is a standard 37-3742 pictured from the side;

... afaict, the two images in your post #4 are of exactly the same part, just the images have been taken from different angles.


You are definitely confused:-

. the only place the text editor can find the word "design" is in something you have written;

. otoh, the editor finds the word "New" at the beginning of the text from the CBS you have quoted;

. i.e. CBS is not saying it is "new design", it is simply new stock newly-arrived at CBS's premises;

. i.e. what CBS is advertising is a new stock of chain adjusters as fitted as standard by both Triumph and BSA between from the '71 to the '79 model years inclusive (in fact, they were fitted only to the OIF and T160; '71-'74 T150's and T100's continued with the more substantial chain adjusters that had also been fitted to pre-OIF 650's).


The image of "The type that is on my bike (which is the original part)" shows a nut - usually spot-welded to the chain adjuster - at the 'closed' end of the chain adjuster. A bolt and another nut ('79 parts book, "REAR WHEEL" pages, parts #17 and #18) screw through the spot-welded nut.

When the threaded end of the bolt contacts the end of the swinging arm, if the bolt is turned clockwise, the chain adjuster will pull the wheel spindle rearward, to increase chain (normally, belt on your bike) tension and/or align the rear wheel with the front wheel. If rear wheel alignment or chain/belt tension requires the spindle to be moved forward in the swinging arm, the bolt in the chain adjuster must be turned anti-clockwise and, separately, the spindle pushed forward until the end of the bolt through the adjuster contacts the swinging arm again.

When the chain/belt is tensioned correctly and the rear wheel is aligned with the front wheel, the bolts through the chain adjusters can be secured in position by tightening the the loose nut on each bolt against the chain adjuster.

Afaict, the CBS chain adjuster - being exactly the same - is used in exactly the same way; the spot-welded nut in CBS's image is not visible directly; however, the nut's shadow can be seen if the image is enlarged.

If you are still unclear, why not 'phone or e-mail CBS?
Rudie, When I looked at the CBS photo in a larger view I see that they are the same part. I think the dull looking material created an obstacle illusion in the smaller part photo in which it made it seem as if there was no open side. That the open side looked like it was covered with a piece of dull looking material which gave it a boxed in looking effect. BTW my adjuster nut that fits inside the frame is not welded in. It is actually wedged in so that it does not move and can be tightened to secure the bolt in place. BTW I know how to adjust the part to secure the tension. That has never been an issue. Just because something does not make any sense to you does not mean it does not make any sense to me or other people.
 
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