Cyclo dropout for Benelux - info/advice please

I’ve just bought (on Gumtree) a pretty Viking Ian Steel Model. (Separate thread later)

It’s the first bike I’ve owned with the Cyclo dropout intact - have a Hetchins where a previous owner had hack(saw)ed the derailleur attachment part…

No doubt because the cranked hanger meant that rear mechs, available at the time of butchering, wouldn’t have reached the lowest gear cog.

I presume ‘modern’ mechs for 8 or more gears would have enough movement(?)

However, the threading on the dropout is 1950’s (British only?) and not the current (universal?) standard.

I could go for hours of endless fun of trying to persuade the Mark 7 to work with a 6 speed block and shift to a 28t sprocket.

Or repurpose the hanger.

So question is, should I try to tap the existing thread to the correct one or drill out and add “Rear Dropout Saver Insert Nut Problem Solver Replaces Stripped Threads”?

Was surprised not to be able to find any Cyclo thread info on the internet, but I’m sure there are people here who know!

Thanks.

If you have enough meat for a 12mm drill it might work. Whether the geometry of the drop out works with a modern set up, who knows.

https://www.sjscycles.co.uk/accesso...ed-insert-fits-into-rear-mech-hanger/?geoc=US

I'm not sure what you're trying to do. Are you wanting to go from the 5-speed on there to a 6-speed with a 28T lowest gear? If so, I agree, it looks like the Mk7 will be reluctant to do that.

Guinessisgoodforyou said:

If you have enough meat for a 12mm drill it might work. Whether the geometry of the drop out works with a modern set up, who knows.

https://www.sjscycles.co.uk/accesso...ed-insert-fits-into-rear-mech-hanger/?geoc=US

Click to expand...

Thanks

Yes, suspect that’s what I’ll do

Jonny69 said:

I'm not sure what you're trying to do. Are you wanting to go from the 5-speed on there to a 6-speed with a 28T lowest gear? If so, I agree, it looks like the Mk7 will be reluctant to do that.

Click to expand...

Not sure either (apart from producing a bike I’ll like riding)

All part of the dilemma!

Mech is original and seems in good nick

48/22 just not ‘sensible’ (I don’t live anywhere ‘flat’!)

I do have a 40t ring that would fit (and other chainsets).

Forks not original (no sign of damage to frame). Wheels not original either so it’s not about preservation or restoration to some variety of original.

Viking catalogues show several options for each model and sold framesets, so no chance of ‘as sold originally’.

AHA

Inspiration

Was thinking

Old bikes, old threads

Old bikes, old bicycle threads

Turns out same thread/diameter as ‘pre Shimano’ axles!!

More options without altering the frame at all.

Dropout gear extension with ‘modern’ thread.

So almost any mech and number of gears and size of sprockets.

Yes, frame is 120 OLN, but can easily be ‘cold set’.

My recent experience of restoring a Viking Hosteller with the original 5spd Mk7 Benelux led to 2 days of frustrating adjustment to get it to shift reliably across the original 5 speed block. Still wasn't happy with it but it worked (sort of). I wouldn't attempt trying a 6 speed block!

3wheeler7 said:

My recent experience of restoring a Viking Hosteller with the original 5spd Mk7 Benelux led to 2 days of frustrating adjustment to get it to shift reliably across the original 5 speed block. Still wasn't happy with it but it worked (sort of). I wouldn't attempt trying a 6 speed block!

Click to expand...

Thanks

Sounds like sound advice…

I’ll retire the mech now I’ve worked out other options!

I tried a Mark 8 Tourist 5 speed on my 1953 Holdsworth.
I've got SunTour New Winner ultra 6 13 - ??? freewheel on it so I could try 5 or 6 speed and 28 or 32 big cog.

It would just handle 6 cogs but was only just managing and wasn't happy.
With 5 cogs it shifted fine (13-15-17-20-28-18 "Ultra 5").
That did need a 1950s Simplex DT shifter to get enough cable pull.
It worked but it was quite hard work shifting.



I'm currently using SunTour Cyclone Mk1 GT + Simplex retrofriction shifter + SunTour New Winner Ultra 6 13-32.
It's working fine in all 12 gears and is much easier to shift.

FYI the Mark 7/8 hanger (M02) is a Cyclo part and is in the parts diagrams, for Cyclone you can use a standard SunTour hanger (Ebay).

Mark 7 diagram


Edit:
FYI - Cyclo Benelux mark 7 suicide shifter will handle 18 or 20 cog difference on the front and it works quite well.
So I don't mind hills: 13-32 + 50/32.

Thanks for all that.

Think it confirms I’ll try more ‘modern’ things.