Old pegasus rear axle

[Bike28472]

I have an old Pegasus mountain bike. My rear axle is bent. What size axle is this?

 

[Ajax Bay]

My rear axle is bent. What size axle is this?

Visit your LBS - it's a normal nutted rear axle 10mm iirc.
How do you know the axle is bent without removing it? What are the symptoms on which you've made that diagnosis?
If the tyre is rubbing one of the chainstays, drop the chain onto the small ring (or off) and adjust the axle angle to perpendicular (to the frame's plane) and secure the nuts.

 

[Bike28472]

I removed the wheel at a bike shop to fix looseness and when I spun the axle in my fingers it wobbled. Thank you again.

 

[Oldhippy]

Cones loose?

 

[Ajax Bay]

You need to have it out (NB note carefully in mm how far the lock nut is from the axle end). The freewheel can stay on (suspect it will be very keen to do so!)
Roll the axle on a flat flat surface: I'll bet it's not bent.
Clean all, maybe a set of replacement (ball) bearings (from LBS) and then reassemble (with drive side locknut within a mm of where it was); grease everywhere; and adjust so it spins and there's (just) no wobble (will need cone spanners obv). Secured with nuts means the complications of allowing for compression with a QR is not an issue.

 

[Cycleops]

Good chance to service the hub as it probably hasn't been touched since new. This should help you out:

View: https://youtu.be/ERvMQHNF8Nk

 

[Bike28472]

Will the one in the link probably work? It's 185mm long. https://allegro.pl/oferta/os-oska-pelna-piasty-tylniej-m10x185mm-ch-ji-2319-8506483001

 

[Cycleops]

Check length with existing. Doesn't matter if it's a bit too long. As Ajax says remove it first to find out if it is bent .

 

[Ajax Bay]

185mm long

Will be unnecessarily long (probably designed for BMX) and will result in ugly (imho) axle ends sticking out. You can measure how long you need, can't you? [172mm?] Except you haven't established 'need'.
https://www.sjscycles.co.uk/hub-spares/weldtite-chrome-moly-95-mm-axle-175-mm/