Cleats -> damage

[KenM]

This morning I put on my one-sided clipless pedals and tried my cleats for the first time. Its mostly a big improvement with a noticeable increase in stability on the pedals (obviously), better pedalling technique and an all-round better feel.

I was managing tight U-turns to the left OK but on my first one to the right, going downhill I lost it and had to get my foot out quickly. On my second tight U-turn to the right a while later coming down a pedestrian/cyclist overpass the same thing happened, but this time I wasn't quick enough getting my foot out and I partially put the bike down - on the front chain-wheel. The bigger cog was bent, enough to pick up the chain for a quarter turn each rotation when on the smaller cog or drop the chain altogether on the big cog.
As they say - "Once bitten, twice shy." I suspect that I may unclip my shoes and use the other side of the pedal in tight manoeuvres for a while, until I've got some more experience.

Fortunately there was a train station nearby and I was able to get most of the way back home that way. If I'd thought about it more I could have taken the bent cog off and ridden home with just the lower range of gears.

Is this something worth trying to straighten or just head to my bike shop for a replacement? Is there such a thing as a guard to protect the edge of the big cog and chain? I've managed to mark a door wheeling the bike to a store room when the sprockets touched it. It is also conceivable that a bit more metal may reduce the type of damage I did today.
Cheers,
-Ken

 

[tmpotter]

My experience from mountain biking would say that it is worth trying to straighten out the cog, but I would not hold my breath -- most of the time it does not really shift right afterward (sometime it can be straightened out just fine, though).

You can buy chain ring protectors for mountain bike cranksets. I don't know about road sets, though. Also, I'm not sure how much they'd help in the situation you describe -- I've mostly seen them used as protection for "clearance issues" over rock ledges and such (which is an impact perpendicular to the ring, as opposed to something from the side). They'd work for a bent bike crashing headlong into something hard though (assuming you hit chain-ring-first rather than pedal or wheel first).

--tmp

 

[KenM]

Upon closer examination the top of one of the teeth was missing so it had to go. I ended up with a fairly good 50 tooth ring instead of the 48. While I suspect the overall placing of the gears is not as good, I'm enjoying the little bit extra at the top end.

I agree that a guard would probably have done little in this incident It could make a big difference as I wheel it around into storage rooms etc in protecting doors and door frames from being spiked by the teeth if attention is not 100% on watching the manoeuvring through tight spaces. I suspect that many recumbents could benefit from something like this. I've recently seen one on a MTB but the size is too small.
Cheers,
-Ken

 

[John Tolhurst]

What I sometimes do in wheeling around is lift the back way up high. This means the whole thing moves on the front wheel and the chainring is pointing down low.

 

[marshall2389]

KenM wrote: Upon closer examination the top of one of the teeth was missing so it had to go.

By the way, many chainrings have a short tooth that acts as the gear-changing tooth. So if the tooth was just short, that might have already been there.

 

[currystomper]

KenM wrote:
Is there such a thing as a guard to protect the edge of the big cog and chain? ,
-Ken

I have been looking into chain guard and there are some for a recumbent, this page has a good summary of what is available
http://www.hostelshoppe.com/cgi-bin/search.pl?category=202700

CS