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Had a bit of a mechanical a fair way from home - left hand crank arm fell off whilst pedaling. 5800 11 speed 105.. closer examination led me to the conclusion the pinch bolts had slackened and the crank had slipped off its spines just enough for me to strip the arm (I think) partially.
Got home with the age old method of 'pre load with a brick' and it seems to be staying put but I'm not sure I trust it. Can I buy just a left hand 5800 crank? Is it worth the risk, and instead I should replace the chain set? Having another look at home I cant quite get the plastic plug / preload thingy in place, so I might have knackered it in bodging home anyway :-/ - in my defence it was 12 miles over 200m of climbing back so I wanted to be sure it stayed on 😀
Cheers!
Any shop with a Madison account can get you one. £44.95
Part numbers...
Y1PH98010 Left Hand Crank Arm 165 mm (Black) B
Y1PH98020 Left Hand Crank Arm 165 mm (Silver) B
Y1PH98030 Left Hand Crank Arm 170 mm (Black) B
Y1PH98040 Left Hand Crank Arm 170 mm (Silver) B
Y1PH98050 Left Hand Crank Arm 172.5 mm (Black) B
Y1PH98060 Left Hand Crank Arm 172.5 mm (Silver) B
Y1PH98070 Left Hand Crank Arm 175 mm (Black) B
Y1PH98080 Left Hand Crank Arm 175 mm (Silver)
I suspect it'll be fine. Just keep an eye on it for the next couple rides.
Thanks Simon, only had a cursory glance online and wasn't coming up with anything - LBS was on for tomorrow, part number saves them a job - appreciated 🙂
cyclistm - I did hit it pretty hard. I reckon getting it off might be a chore now 🙂
Mmm, might you have killed the axle as well with the initial stripping/slipping? Might be worth pricing up new and flogging the rings off it to make it less painful????
I'm sure the online bike companies will sort you out for not a great deal of cash and then eBay for the rings.
Just thinking like!
Tim
As above, if its that bad i reckon you'll end up needing the axle side too. I would try a wanted ad here before buying new
cranks are the thing you stand on and generate torque from; if you've used a rock to put it back together on the roadside I would flog the rings and get a fresh one.
That was my concern. Going to clean up and degrease both parts and see how it looks first of course, but first inspections (in a hail storm, brick in hand) looked like the crank had slid off the splines then stripped as there was insufficient engagement.. but haven't had a really good look at the axle yet.
Any others to look at beyond 105 / Ultegra for 11 speed?
I stripped an xt crank arm, bought a replacement arm and it worked fine for a long time (still using it now, tho it appears to be creaking a little nowadays, it has had a long hard life tho)
afaik the axle is steel so should be harder to damage the splines on there.
Axle will be fine.