How tight should a pair of wheels be to the B2B gauge?

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zebedeesknees
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Re: How tight should a pair of wheels be to the B2B gauge?

Postby zebedeesknees » Thu Jan 05, 2017 10:13 pm

If you work your way round the circuference of almost any pair of wheels, it will likely be the case that there will be spots that are tighter than others. This is often only a slight variation, and with feel the back to back can be set to average out the error. If in any place the gauge can be held up by the wheels, or any 'knock' can be sensed, they need work..
(A purists' purist)

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Tim V
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Re: How tight should a pair of wheels be to the B2B gauge?

Postby Tim V » Fri Jan 06, 2017 7:56 pm

Treat yourself to the Sisson's back to back gauge (is it still in stores?).

This can very accurately set your back to back, much better than the standard gauge.
Tim V
(Not all railways in Somerset went to Dorset)

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Tim V
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Re: How tight should a pair of wheels be to the B2B gauge?

Postby Tim V » Sat Jan 07, 2017 5:25 pm

Just checked, and yes it's still listed "Gravity Back to Back" - another of those Very Useful Tools.
Tim V
(Not all railways in Somerset went to Dorset)

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James Moorhouse
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Re: How tight should a pair of wheels be to the B2B gauge?

Postby James Moorhouse » Thu Jan 12, 2017 6:13 pm

Using a back-to-back gauge effectively is dependent on the user appreciating the right feel of the gauge between two wheels. This feel is difficult to convey in words or pictures – perhaps there’s call for a video on the subject? In order to appreciate the right feel, why not measure your gauge with a micrometer and see what values you get for differing degrees of tightness?

BB measuring.jpg
The micrometer reads 17.75mm (the upper limit for the P4 BB setting) and the gauge can still be slid between the micrometer’s anvil and spindle.

JBS back-to-back gauge notes.jpeg
Is this useful set of notes still included with back-to-back gauges sold by the Stores?
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