Rear derallier into wheel carnage

[Justinslow]

Tonight I had a major mishap climbing a hill shifting into the biggest cog (23) on the back still in the 53 on the front, the derallier collided with the rear wheel.
No idea how this happened as I've had the bike over a year and things have been fine.
I had just put a "mich pro 4 service course" on and this was the first proper out the seat climbing id done in that gear (thinking about it, I probably haven't ridden in that gear since changing the tyre.
This tyre has a more "pointy" profile apparently, could this have caused my rear wheel to "flex" or move about more, enough to touch the mech?
Anyway, whatever happened it's got to be sorted, the sora rear derallier is trashed, I rather fancy a 105 one to replace, how do I know what cage size I need? And would this be ok with 9 speed? I currently run 9 speed sora with Ultegra 11-23 cassette and Ultegra 53/39 crank. Cheers!

 

[uclown2002]

And yet you were advised on a previous thread not to use the big-big combo............................

 

[Justinslow]

And yet you were advised on a previous thread not to use the big-big combo............................

Yep, but had no problems up to now, is this inherently a wrong thing to do?

 

[Spoked Wheels]

Tonight I had a major mishap climbing a hill shifting into the biggest cog (23) on the back still in the 53 on the front, the derallier collided with the rear wheel.
No idea how this happened as I've had the bike over a year and things have been fine.
I had just put a "mich pro 4 service course" on and this was the first proper out the seat climbing id done in that gear (thinking about it, I probably haven't ridden in that gear since changing the tyre.
This tyre has a more "pointy" profile apparently, could this have caused my rear wheel to "flex" or move about more, enough to touch the mech?
Anyway, whatever happened it's got to be sorted, the sora rear derallier is trashed, I rather fancy a 105 one to replace, how do I know what cage size I need? And would this be ok with 9 speed? I currently run 9 speed sora with Ultegra 11-23 cassette and Ultegra 53/39 crank. Cheers!

You will need a small cage derailleur and if you can find a 10 spd then you are sorted.

 

[gavintc]

Yep, but had no problems up to now, is this inherently a wrong thing to do?

Yep, not a good thing. However whether it put the derailleur into the spokes is a moot point. The strain of the chain line may have twisted it. But, more likely is that the hangar was bent slightly.

 

[screenman]

Out of interest, when did you last check things like rear mech alignment?

Big to big is not a good idea, and you know why.

 

[Justinslow]

Out of interest, when did you last check things like rear mech alignment?

Big to big is not a good idea, and you know why.

I know the chain alignment is bad, but does this mean that combo of gears cannot ever be used?
I haven't checked mech alignment, to my knowledge the rear derallier had loads of clearance......

 

[Justinslow]

Yep, not a good thing. However whether it put the derailleur into the spokes is a moot point. The strain of the chain line may have twisted it. But, more likely is that the hangar was bent slightly.

So in future I must change into the 39 ring? I do TT's and I don't think I've ever changed into the 39, maybe I've twisted it? I didn't think that part of the chain line was under much stress, thought it was above the cogs so to speak?

 

[Smurfy]

It's worth inspecting the spokes for damage.

 

[screenman]

I know the chain alignment is bad, but does this mean that combo of gears cannot ever be used?
I haven't checked mech alignment, to my knowledge the rear derallier had loads of clearance......

If you have not checked it that is a poor show.

The straighter the chain runs the more efficiently it works, big to big is like asking it to work around corners.

Out of interest what are your times like, you may be losing time by being over geared at times, many people do the same.

 

[Ajay]

With respect, just take your bike to your lbs and get them to fit and set up a new derailleur. Maybe ask theme of show you how to set the limits.
If you think that a "pointy" tyre caused the problem then I'd leave it to the bike shop to sort it out if I were you!

 

[The_Weekend_Report_Guy]

Been there... Done that..

Sorry no idea about the cage... Ask your LBS if not good answers here?

Good luck..!

 

[Justinslow]

It's worth inspecting the spokes for damage.

Wheel was lucky, couple of spokes slightly bent and the wheel only slightly out of true.

 

[screenman]

Out of true and out of round maybe. Hopefully just the former, not that you would notice the latter on our roads. You would notice out of round on a turbo sometimes as it shows up as chopiness, as the pressure on the roller changes.

 

[Justinslow]

If you have not checked it that is a poor show.

The straighter the chain runs the more efficiently it works, big to big is like asking it to work around corners.

Out of interest what are your times like, you may be losing time by being over geared at times, many people do the same.

It's easy to say that now, maybe that's something I need to do then more regularly.
My times are ok, just won my club TT points championship, based on improvements in time over the year. But I'm not the fastest by any means, my 10 was 33 minutes last August, this August I'm down to 24.29 on the same course (record is 22 I think).
I bought the 53/39 as I felt I was losing speed down the hills (and everyone runs a standard!)