Specialized Allez 09 - Crank arm falling off!
I just upgraded my bike to a full 105 groupset and think I've broken it! Well the crankset, more specifically the arm the one without the cogs. I have a specialized Allez sport 2009 model. I bought the frame separately and have built it from scratch.
Now when it came to buying the crankset, the 105 only had one option but with different amounts of teeth etc, I went for the 54/30. The crank arm fell off the other day in mid ride and has done a few times since. I don't think there is enough of the spindle coming through for it tighten onto. So is it the bottom bracket cups, which again are 105 that are the wrong size (I could only see one size online) or is it the crank arm, or what?
Any help would be appreciated.
Thanks,
Graeme
Now when it came to buying the crankset, the 105 only had one option but with different amounts of teeth etc, I went for the 54/30. The crank arm fell off the other day in mid ride and has done a few times since. I don't think there is enough of the spindle coming through for it tighten onto. So is it the bottom bracket cups, which again are 105 that are the wrong size (I could only see one size online) or is it the crank arm, or what?
Any help would be appreciated.
Thanks,
Graeme
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Comments
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Once the arm on a Hollowtech II crank (which yours is) has come loose then it usually means the splines in the arm are knackered and it will keep falling off. A replacement arm is usually the only solution.
There are two sizes of 105 BB, British or Italian. However if you had the wrong one it wouldn't fit into the frame so I would assume you have the correct BB. Although it is worth checking what it says on the outside of the cups, should be BB5600 or BB5700.
If the BB is correct then I would guess either the bolts on the crank arm were not correctly torqued or the axle wasn't fully through when the arm was fitted.0 -
Or the 'security plate' thing in the non-drive-side crank arm isn't locked.
You can see it in this doc (marked #4):
http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FC/EV-FC-5600-2439C_v1_m56577569830646644.pdf0 -
Also 54/30 may give you trouble shifting - are you sure it's not 50/34?0
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Even if the security plate is locked, if the arm is damaged it will still work loose and wobble.0
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mister p wrote:Once the arm on a Hollowtech II crank (which yours is) has come loose then it usually means the splines in the arm are knackered and it will keep falling off. A replacement arm is usually the only solution.
There are two sizes of 105 BB, British or Italian. However if you had the wrong one it wouldn't fit into the frame so I would assume you have the correct BB. Although it is worth checking what it says on the outside of the cups, should be BB5600 or BB5700.
If the BB is correct then I would guess either the bolts on the crank arm were not correctly torqued or the axle wasn't fully through when the arm was fitted.
Thanks Mister P, it is indeed an english BB and it fits. Its the BB5700. The splines are knackered, not good seeing as I've only been on it 4 times :-(. I really think axle isn't long enough which would suggest it doesn't fit - but I've seen Specialized Allez's with the 105 groupset on so it must fit. Arrgh! I'll take a look at the tech Specs now Phy2s112 and get back to you.0 -
There shouldn't be an issue with fitting that chainset and BB to an Allez. You didn't fit any spacers between the BB and frame did you? Sometimes the arm with the rings on needs a tap with a mallet to go through the BB fully. It looks like it is fitted but a tap will move it a few more millimetres. I have fitted quite a few of these chainsets and always give the driveside arm a tap to make sure.0
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I will give it a go when I'm back later, I might post a picture as well to make sure. Thanks again.0
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Ok, so last night I had another look after what has been said in this discussion. The mallet did the trick, it really did need to go in a lot further. I had to give it quite a hard hit though :-S.
The axle still doesn't look like its long enough - does it look correct in the picture?
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Also does anyone know where I can buy single crank arms? :-P0
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that looks like it is correct now. any more and the preload cap would bottom out on the axel."Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
Parktools :?:SheldonBrown0 -
Boyesy99 wrote:Ok, so last night I had another look after what has been said in this discussion. The mallet did the trick, it really did need to go in a lot further. I had to give it quite a hard hit though :-S.
The axle still doesn't look like its long enough - does it look correct in the picture?
You are tightening the crank with the two hex bolts on the side of the crank arms, right? Not just tightening up the pre-load cap?
My apologies if I've got the terminology wrong!0 -
Yep, using the Allen bolts. I actually lost the preload cap when the peddle fell off the first time, do I'll to buy a new one. Does anyone know if you can buy crank arms separately, got a 100 miler coming up next month and need to get this sorted. Thanks for all you help so far guys, appreciate it.0
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I'd guess if you've been riding without the pre load cap then that's what the problem's been (along with the spindle not being in far enough).
Get a replacement pre load cap and it should be all ok. Don't think you'll need a new crank arm. You should be able to get a replacement cap for less than £8. Just remember when you're doing it all back up, tighten the pre load cap first (no more than hand tight) then do the allen bolts. You'll need a special tool for the cap if you don't already have one.0 -
Crikey - no wonder it was falling off!!
Here you go - i guess you're using the 105 (5700 series cranks). Worth asking in the LBS
http://www.ribblecycles.co.uk/sp/road-track-bike/Chainsets-Spares-Shimano-Crank-Arm-Fixing-Cap-each/SHIMCHSZ2300
