Derailleur hanger extension.

[ANTONISH]

I've just been reading the latest "Arrivee" the Audax UK magazine.
One article being "Because it's there" about Alice Thompson's "Everesting" exploit - which involved her climbing Naish Hill near Bristol 89 times in one session breaking the women's "Everest" record.
I don't know the hill myself but it seems the sort of hill that once would be enough for me
However she had a 40t rear sprocket for which she was able to use a 105 changer enabled by a gear hanger extension.
I realise that this was a special situation - but is a gear hanger extension a viable proposition in general to enable that fitting of large rear sprockets ?
Gear hangers do fail occasionally and I feel that the stresses on the hanger would be considerably increased.

[foxyrider]

I have wondered this myself, afterall due to the vagaries of frame designs the mounting position varies a bit between bikes anyhow.

How much extra drop would be required, 5mm, 10mm? Maybe a longer drop but a short cage RD?

[Brucey]

these are a wolf tooth 'roadlink' hanger extenders (you can get knock-offs on ebay for peanuts BTW)



The short one is about 20mm long. In terms of capacity each 2mm is 'worth' about 1T on the sprocket so it gives an approximately 10T increase in capacity. In terms of bending loads on the hanger yes they are increased but

a) it is only 10 or 20% and
b) hangers fail in accidents, not normal use, by and large.

I'm not sure it is any longer available but you could buy devices to increase the total capacity of shimano 'road' 11s RDs eg



This picture is interesting because it shows the special top pulley that is (IME) required to get the most out of hanger extenders, with longer teeth than normal, to give extra traction during shifting. Shimano fitted pulleys similar to these to many of their long cage versions of first generation road 11s mechs and more of the second gen 11s road mechs seem to have them regardless of cage length.

BTW the first time I saw one of these hanger extenders being fitted to an 11s system I was sceptical that it would provide even half-way decent shifting, but it did; in fact it worked bloomin' well. In general terms I don't think the move to 11s has really improved the lot of the cyclist very greatly, but for whatever reason the long-held trend for n+1 (better, slicker shifting, together with a service life that isn't completely hopeless) is maintained. So a longer distance from pulley to sprocket (than I'd be happy with) appears to be tolerated with an 11s system, at least with new parts; whether the shift quality is maintained in the long run I'm not so sure about.

cheers

[roubaixtuesday]

I've just been reading the latest "Arrivee" the Audax UK magazine.
One article being "Because it's there" about Alice Thompson's "Everesting" exploit - which involved her climbing Naish Hill near Bristol 89 times in one session breaking the women's "Everest" record.
I don't know the hill myself but it seems the sort of hill that once would be enough for me
However she had a 40t rear sprocket for which she was able to use a 105 changer enabled by a gear hanger extension.
I realise that this was a special situation - but is a gear hanger extension a viable proposition in general to enable that fitting of large rear sprockets ?
Gear hangers do fail occasionally and I feel that the stresses on the hanger would be considerably increased.

I fitted one of these to enable a rather brutal short Welsh tour on a 36 rather than 32 rear. I would guess that a 40 was possible.

Never had any problem in use, but recently couldn't index the gears properly and replaced the hanger (not visibly bent) which solved the problem. I think the bike falling over in the garage bent the hanger slightly. I would guess that the extender both made the hanger more vulnerable (bigger bending moment if derailleur impacted) and more sensitive (smaller deformation to hanger gives bigger impact to shifting) but this is just guessing.

[hamster]

I fitted a Roadlink last year to allow me to run a 12-27 with a 1996 Campag Chorus rear mech. It all works very nicely.

[MikeDee]

I think I'd be inclined to buy a new derailleur instead of the hanger extension. Seems like the top pulley would be too far from the smaller cogs for optimal shifting.

[foxyrider]

I think I'd be inclined to buy a new derailleur instead of the hanger extension. Seems like the top pulley would be too far from the smaller cogs for optimal shifting.

Not necessarily an option and certainly not if you are running current Campag. As soon as you put in bigger sprocket jumps the 'optimal' is lost and given that optimal isn't likely on anything running wide gear ranges of the sort we are talking it's hardly a big issue.
Not only that, but an extender would be somewhat cheaper than a new mech, especially if like me you ride exotica costing three figures!

[DavidFreeman]

Talking about the Roadlink, I was wondering if it would solve my problem of replacing a 6 speed freewheel from 14-24 to a 14-28 on my vintage bike with DuraAce 7200EX groupset. I'm guessing (reference RD7400 Shimano archives) that the total capacity must be at least 26, 12 min 26 max at the back ,13T max difference at the front. I plan to change the front from 52/42 to 48/39 the smallest possible. These changes would give a total capacity of 23 but would exceed the 26T max at the rear. So in theory (?) the Roadlink should work.
Wolftooth have declined to recommend the Roadlink as they don't know if it would work in this case.
Anyone have any thoughts or has tried the Roadlink to improve the gearing on their vintage bikes?