Fitting out audax - question on gears & wheels

star_rover

I always connect the cable before adjusting the limit screws, then test the shifting/limits by pulling the cable by hand.
Have you checked the parktools website for instructions? They are normally pretty easy to follow.

GOMbeen

Star rover,

thanks for the tip. After last night's post I gave it 'one last go', and achieved success at the rear mech. I think the issue was leaving too much slack in the cable on initial connection - something not very well covered in the Campy instructions or books (it is mentioned on 1 of the Utube vids to be fair, just took me a while to pick - there are a lot of variables to consider).

I think tweaking the limits on the front mech in the way you describe will bring success there too - currently I am reaching the inner and middle rings fine, just the outer to go - actually prob need to check initial tension on this one too. :oops:

On the front mech, at the risk of 'going on about this' - has anyone else found the limit screws (esp the L one) to be really poor quality ?

HAGW Eoin the GOMbeen

GOMbeen

Greetings,

the Audax (Thorn Mk 3) frame is about done now, I have been giving road-trials last week or so. Today, a disaster befell the fledgling bike.

Riding along in middle chain-ring, largest rear sprocket, ambling at slow speed. Next thing, resounding bang, crash, bike ground to halt, rear wheel completely locked up.

Looked down, found chain off the rear sprocket and inside the sprockets. Replaced it, rode on gingerly, found freewheel apparently not working. Dismounted after few 100 yds, found that actually 2 spokes broken at hub end.

Not clear to me if ... spoke(s) broke, causing chain to move off rear sprocket OR chain moved off rear sprocket (why ? - had not any problem before ? ) and smashed rear spokes.

Now need :

1) Send back to wheel builders (Hewitt Cycles, as recommended on this forum) for investigation and rebuild (as if wheel faulty they should take responsibility).

OR

2) Bring to lbs (AW Cycles, Caversham) and ask them to rebuild (as will be cheaper and less hassle).

AND

3) Try to understand root cause here ? This was the most alarming failure I've ever had on a bike. Can't understand why chain should slip off as it hadn't before (despite shifting under load going uphill etc).

Any remarks welcomed, apparent from this the bike has been excellent - very stable in steering while also responsive up the hill.

Eoin GOMbeen

giant_man

I can't think of a time where a wheel built by Hewitt failed, indeed all of mine have been excellent, strong and light and a real quality build.

Have a word with Paul Hewitt if I were you, or maybe it would be something you have done set up wise. Nothing springs to mind, kinda hard to get wrong really. Strange.

GOMbeen

Hi Giant MANCP,

after a period of reflection (as the politicians would have it), I think this is an incident of 'extreme chain suck' caused by my failing to set the H limit on the rear derailleur properly. Pretty sure that Hewitt's wheel build can be absolved of blame.

Puzzling because the derailleur had seemed to function entirely properly up to then (albeit not many miles), and was being ridden not exactly under load at the time of the incident. Fortunately the chain and derailleur themselves seem to be OK, so I think the best course of action is to take it along to the lbs to re-build the wheel (looks like at least one of the unbroken spokes got some collateral damage, as well as the two that are completely mangled). ANyone got any ideas on what can expect to pay for this ? Am hoping will be basically a labour charge with spokes not costing much, so £20 ish - will that be ballpark ?

If I'd known the chain-suck could have such consequences would have taken even more care with the H/L settings - never seen anything like this before and the impact could have been much worse (e.g. if riding in traffic or at any speed).

Kind Regards

Eoin GOMbeen

robbarker

Sounds very much like you've shifted beyond the big cog and shoved the chain into the spokes. It takes quite a lot of committment to snap the spokes this way but it does happen. New spokes in a new wheel don't spontaneously break at the elbow; that's a sign of fatigue in old spokes in an undertensioned wheel.

Take it to the LBS snd get them to sort it out for you.

GOMbeen

Well, I was going about 8 mph up a very gentle incline, so the devastating extent of the damage is really amazing. Thinking about it, maybe as I lost traction, I did 'step' on the pedals somewhat, but I'm no Mark Cavendish !

I note that Evans cycles does a retrue service at £15 + £1 for each spoke, so hopefully my lbs will be comparable and can restore my wheel for £20 or so.

Then it will be a very careful set-up of the rear mech, to avoid a re-occurrence.

Cheers Guys

Eoin the GOMBeen

acorn_user

I think you would be well advised to have someone experienced with those mechs to give the bike a once over and make sure it doesn't happen again. I managed to break my wife's wheel the same way; overshifting into the rear. This was with mtb parts. Humph.