Chain comes off to the right, over pedal and foot...

[SatNavSaysStraightOn]

Anyone any ideas? everything looks set up OK and everything aligns OK, but if I change from middle (2) front ring to outer front ring (3) when on anything other than about 1-3 on the rear rings (in otherwords the inner ones/biggies) not doing technical today, bit tired... then the chain launches itself up and over the front bigger ring (3) and ends up hanging off my pedal and foot.

Thing is, when you do get it back on and look at the position of the front derailuer it seems spot on the middle of where it should be, its just seems to go too far and then come back again hence losing the chain...

was thinking possibly chain length, in that it seems a touch slack, but wanted thoughts first..
otherwise the gear changes all work (albeit time delayed and my frustrations at not being on my rohloff hub..) but things are not helped by the fact at my fastest point, and wanting to go faster, I find my chain wrapping itself around my foot (today at 51.8kph/32mph). couldn't go any faster since chain....

It's a triban 3 btw...

If you want photos just yell... oh bike rather than chain hanging off foot. Happening every day now and done about 300 miles on it from new.

 

[fossyant]

Adjust the limit screw

Sent from my HTC Desire using Tapatalk 2

 

[SatNavSaysStraightOn]

Adjust the limit screw

Sent from my HTC Desire using Tapatalk 2

thanks - said I was tired - forgotten evertying I knew about derauliers since 12 months of rohloff hubs! not to mention how to spell!

 

[PoweredByVeg]

With chain on big chainring/small sprocket there should be a 0.5mm gap between chain and f/mech outer plate adjust screw to achieve this

 

[screenman]

How the hell do you measure 0.5mm?

As well as the front mech, have you thought loose bottom bracket, bent chain ring.

 

[andrew_s]

Also check the height of the front mech.
The outer cage plate should be 2mm above the chainring teeth when directly above.

 

[diyduffer]

How the hell do you measure 0.5mm?

As well as the front mech, have you thought loose bottom bracket, bent chain ring.

As well as the front mech, have you thought loose bottom bracket, bent chain ring.[/quote]
Measure 0.5 easy, Feeler gauges/ Vernier gauges or from the bike shop or a bit of wires, where 8 pieces side by side = 4mm, therefore 1 piece = 1/2 mm or 0.5mm 0.02 In in imperial about a large'ish 1/64 "

 

[Sheffield_Tiger]

0.5mm is a simple measurement. It's what's known universally as a gnat's whisker (NOT to be confused with a gnat's chuff which is a technical measurement of tightness)

 

[baldycyclist]

I often use my breathe to measure unmeasurable widths - usually works
In the case of 0.5 mill I believe a nun's doodah is often a good gauge