# Questions about mystery component and anti-rotation washers on T3 hub



## bat400 (Dec 16, 2012)

Hi,

I bought a couple of wheels of eBay for my project bike - they were previously fitted to a mountain bike. The front has a SRAM VTR drum brake hub and the rear has a SRAM T3 3 speed drum brake hub (H3125) I think. They seem like late nineties vintage - the T3 still has a pullchain and not a clickbox, but it's definitely SRAM not SACHS.

Anyway, there's a component I don't recognise. It's on both sides, just inboard of the retaining (anti-rotation) washer on the axle.









It's the extra washer (with the threaded part and nut attached, and the crescent shaped piece) which I can't identify.









It doesn't appear in any of the SRAM schematics so I was wondering if anyone knew what it was?

Also, in the SRAM installation guide, it says that the teeth on the retaining (anti-rotation) washer should face outwards at the dropout, but the picture has the teeth facing inwards (towards the dropout), and this is how they are mounted on the axle of my hub as well. I wondered if this was just an error of translation from the German, so would value any other opinions.

Thanks in advance for any help anyone can offer!

Al


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## Surly29 (Jun 8, 2009)

Looks like a chain tensioner to me. For horizontal drop-outs/track ends?


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## JimboAgain (Dec 2, 2014)

Chain Tensioner Paired FOR Mini Scooters | eBay

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## Michal777 (Feb 20, 2021)

bat400 said:


> Hi,
> 
> I bought a couple of wheels of eBay for my project bike - they were previously fitted to a mountain bike. The front has a SRAM VTR drum brake hub and the rear has a SRAM T3 3 speed drum brake hub (H3125) I think. They seem like late nineties vintage - the T3 still has a pullchain and not a clickbox, but it's definitely SRAM not SACHS.
> 
> ...


I have the same dilema now. Have you found the answer to this question ?


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## 127.0.0.1 (Nov 19, 2013)

them things keeps axle aligned by pushing against dropout
so you don't need to mash the axle bolts beyond reasonable
to keep it in place and chain tensioned


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