How far into the dropouts?

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I've recently started to run an 18-tooth freewheel on the flip-flop side of my 20-tooth fixed.

For various reasons(all bad) I shortened the chain when putting it onto the 18-tooth side and now that it's fixed again, the rear axle is only just going back far enough into the jaws of the (forward-facing) dropouts for me to get a decent pinch on the wheelnuts.

I've pootled about on it and it seems OK.

I'm looking for assurances here (and will of course sue if I am misled) that I'll be able to descend at 30+mph with the axle very near the open end of the dropouts without risking the sudden and unexpected loss of my wheel - and my dignity and perhaps some skin.

With dropouts, is it a matter of "If it's staying in place, it's far enough in"?

Or... as with many other components (quill stems etc) is there a sort of invisible 'foolishness marker' beyond which it would not be wise to go?

I can't get the wheel any further back (the chain plays a nice High G as it is). It all looks OK, but I've never put the wheel so far forward and so far along the dropouts.

Any general wisdoms available?
 

Rob3rt

Man or Moose!
Location
Manchester
I would say that if the whole track nut is in contact with the dropout you "should" be fine. BUT, personally speaking I would want a little bit of safety margin on it and would like at least 5mm extra, probably a bit more to alleviate any nerves, a cm or more would be good.
 
Location
Edinburgh
I had a similar problem when I was running a 18/20 fixed/fixed hub but as I has rear facing track ends I found that the chain completely bound up if I tried to go from 18 to 20 without adding a link or was only half in if I went from 20 to 18 without removing a link. Not only that the brake blocks (yes I use rear brakes on a fixed) needed to be adjusted.

The answer: have 2 chains for the bike, leaving one hanging up in the shed when not in use. After all, it was not as if I changed the gearing while on the road, it was always done in anticipation of the planned ride the night before.
 

hoski

Veteran
Location
Oxford, UK
Got any nut tugs?

Is it just me, or is the combination of 'tug' and 'nuts' highly amusing?

When I use my 16T sprocket rather than the 14T, my axle is quite near the entry to the dropouts. It sounds like yours is a little further, but if the majority of the nut is in contact with the frame I doubt there would be any problems.

Is it a new chain? If so, it will obviously stretch a little as well
 
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Boris Bajic

Boris Bajic

Guest
Is it just me, or is the combination of 'tug' and 'nuts' highly amusing?

When I use my 16T sprocket rather than the 14T, my axle is quite near the entry to the dropouts. It sounds like yours is a little further, but if the majority of the nut is in contact with the frame I doubt there would be any problems.

Is it a new chain? If so, it will obviously stretch a little as well

Not a new chain... Quite the reverse. It's near the 'change' limit on my funny measurer that looks like a tuning fork gone wrong.

I am massively tight, so I wait until the gauge say I have to change...

In fact, I wait for it to write to me by recorded delivery insisting that I replace the bloody thing or face a summons.
 
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Boris Bajic

Boris Bajic

Guest
You should just be able to see the end of the dropout ahead of the nut for safety, also, make sure you are using a serrated washer.

Oops!

Dropout extends beyond axle, but not entirely beyond nut...

Serrated washer check! (Integral with the nut, but it is serrated).

Took it out for a 30-mile freezathon today (sunny and dry, but like the Arctic) and it stood up OK.

I stopped every 8 or so miles to check the rear wheel (for safety, not exhaustion) and it was still there every time.

I do like that bicycle, but I think I ought to swallow hard and cough up for a chain.

I was descending at 30+mph and that's not when you really want to be thinking about how secure your rear wheel is.

Winter foodfest has caught up with me. I pushed like mad and didn't get cadence over 145 even on a mad hill. Usually I'm easily in the high 160s.
 

HovR

Über Member
Location
Plymouth
I ran a chain single speed like this for a while. The end of the nut was just about hanging off the edge of the dropout, however even if I was able to move it back this section of the nut would have been over the cutout for the dropout rather than adding any extra security.

The first time I went out on it I'd only tightened the rear wheel up by hand and it slipped. Commence epic long skid as the wheel hits the chain stay, and a short walk to the nearest person I knew with a spanner to tighten it back up.

After that I tightened it back up with a torque wrench to ensure I was reaching 40nm, and I had no issues after that. I'd suggest that as long as you're making sure you're tightening up the wheel nuts enough it should be fine.
 
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Boris Bajic

Boris Bajic

Guest
Any reason you can't just buy a few extra links?

I boshed a couple of links out of it to allow the smaller sprocket on the freewheel side, then went back to the (larger) fixed sprocket.

I am really treading water until I replace the chain.

Yes, a couple of links would be the obvious solution.

Sadly, I last did the obvious or clever thing in about 1987.

I've done 150-ish miles on it since this thread started and am still alive, so I've passed it for compliance with the relevant regulations.

Thanks for the replies.
 
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