Hollowtech 2 Gap?

[djb1971]

Are you sure it's a compact fitted and not a triple with the inner chainring removed. How many teeth has the large chainring got and can you see any holes on the back of the drive side crank arm where it looks like another ring should be?

 

[Thomk]

It's definitely a compact - it's this one - http://www.evanscycles.com/products/shimano/fc-3550-sora-9-speed-compact-chainset-ec041355

 

[djb1971]

It must be the shell width then. Take it back to the shop that fitted it and ask them to fit a spacer. If you ve got the tools it easy, 5 minutes. The arm has got to meet the bb otherwise it'll slide from side to side and ruin the axle and bearings much faster than normal.

Have you done the chain thing I mentioned a few posts ago?

 

[Thomk]

I'll have a go in a bit. I've got tools but no spacer.

 

[Thomk]

Does the spacer need to go between the frame and the bearings?

 

[djb1971]

The metal spacers go between the bb and the frame. They can go on either side of the shell, check the chain line to see if its in line, centred okay and put it on that side if the chain isn't running in line along the cassette . You may be able to get a plastic spacer, like the one in the photo above that's used on a triple that fits behind the non drive arm.

Without seeing the frame etc. we're all guessing the problem. Take it back to the shop and explain the problem. They shouldn't charge you, it's their mistake.

Turn the bike over and measure in mm the width of the bb shell

 

[Andrew_P]

Have to agree I am pretty sure there should not be a gap as big as that, they crank axle will be able to move left to right.

The reason I know this is that I strip it down every now and then clear gunk. Now when I did it around Christmas I reckon I left a gap like yours and a month or so went by and it felt like my cleat/pedal were loose as they had lateral movement never thought it could be the crank arm. Then after a quite a while having replaced the cleat I got used to it then out on a Sunday I was up and out the saddle when I ended up with both crank arms at 6 o'clock! It had chewed up the spindles on the non drive side.

When I fitted the new chainset I noticed a gap like yours so I took the pre loader off loosened off the bolts and did as above hit the chainset from the driveside put the non drive on kept one hand on the drive crank and hit the non drive so it looks flush up against the BB. If you look at the hollotech BB the rubber bit protrudes a little to stop the crank arm rubbing on the bit that screws in BB shell

 

[Thomk]

This is what it looks like with the non drive side crank on and off. It looks to me like I should be able to push the crank further onto the axle but I can't. Should I give it a hefty thump with a mallet?

 

[djb1971]

Put the arm back on and push it as hard as you can it should meet the black plastic seal on the bb. The black spacer between the bolts on the arm itself should lock into the axle. Don't force it on.
If the gap hasn't gone, now with the arm on hit it hard with your palm and it will push through the drive side. This shouldn't happen because there shouldn't be a gap. See now?

Is there a ring on the bb I can see? On the axle?

 

[djb1971]

Look at part number 5

http://techdocs.shimano.com/media/t.../FC/EV-FC-3550-3413_v1_m56577569830799977.pdf

Do you have these fitted and does the arm push up against this then they in turn psh up against the bb plastic seal?

 

[Thomk]

Is there a ring on the bb I can see? On the axle?

Yep that's it I think! I just realised when I had a closer look that there were 2 O rings instead of one. One of them was nicely nestled in the recess in the crank arm as it should be and the other just getting in the f...ing way.

 

[djb1971]

So you don't have a gap, you have spacers

As long as the arm pushes them against the bb seal you're okay. Put the arm on, tighten the crank arm adjuster cap finger tight. I push with a big finger in the hole and turn until it hurts then a bit more or lightly with the the ht2 tool . You need something like 2-3 nm. Then fasten the two arm bolts alternately to 13nm.

Edit
According to tech docs you should have one each side, check there's one on the drive side before you fasten it all up.

 

[BSRU]

Y-1GF 11000 3mm spacer is required for triples.

 

[Thomk]

So you don't have a gap, you have spacers

As long as the arm pushes them against the bb seal you're okay. Put the arm on, tighten the crank arm adjuster cap finger tight. I push with a big finger in the hole and turn until it hurts then a bit more or lightly with the the ht2 tool . You need something like 2-3 nm. Then fasten the two arm bolts alternately to 13nm.

Edit
According to tech docs you should have one each side, check there's one on the drive side before you fasten it all up.

All done. I don't have a torque wrench but assume that 13nm is pretty tight.
The drive side had an O ring so I assume the spare one came off the old crank and was just left there.
Big thanks chap

 

[djb1971]

Glad it's fixed