Problem installing Shimano FC-5703 Triple Cranks

[S1m0nR]

Hello Retrobikers,

I'm hoping someone can shed some light on a problem I've got because it's preventing me from finishing a new bike build

Basically, I've bought a Shimano 5703 groupset to build up a frame that I built some time ago. Everything's come together nicely except I can't get the 5703 crank right. I've studied the installation instructions and have obeyed them but somehow the cranks are sticking out too far on the drive side which means that there's not quite enough hollowtech spindle on the non-drive side to clamp the crank arm on properly, and also the front derailleur doesn't seem to have enough travel to select the large chain-ring.

Here's the Shimano assembly instruction sheet- my cranks are set up exactly as per that, including a 6.5 mm spacer on the drive side. The BB shell is a standard 68 mm one and I've used a SM-BB5700 Bottom Bracket.

Here are some pics:

First, the half-built Bike:

IMG-20170512-WA0006 by Simon, on Flickr

The drive side, including spacer

IMAG0210 by Simon, on Flickr

The whole assembly, including 3 mm spacer that's required on the non-drive side:

IMAG0211 by Simon, on Flickr

The spindle only comes through this far on the non-drive side:

IMAG0212 by John Doe, on Flickr

That doesn't look right to me - if I remove the 3 mm spacer on the non-drive side it fits flush on the non-drive side, but I think I still have a problem with the front derailleur reach.. This is most odd because I expected this to work out of the box like every other Shimano crank that I've installed. So - What's wrong?! - I'm using the correct BB, my BB shell is within spec, it's set up as per Shimano's instructions but it doesn't fit. Or is nothing wrong?

As I say, all suggestions and help gratefully received!

 

[klunkrider]

Re:

Simple solution would seem to be to remove the 6.5mm driveside spindle spacer and fit a few 1mm bb spacers on the drive side.

Not quite 'correct' but should get the job done with no ill effect.

Edited due to being confused which spacer was which.

 

[ishaw]

Re:

6.5mm spacer sounds too big to me. I've done some googling and it does suggest that at least 1 3mm spacer is needed on the drive side depending on the bb shell width.

This pdf seems to suggest that no spacers are needed between the frame and bb shell, but some are needed outboard of the bb:

https://www.google.co.uk/url?sa=t&sourc ... AZx3n6mKxw

 

[legrandefromage]

The only 'good' thing about these external BB and chainsets is that you can adjust the chainline to fit the bike.

Rather than obey the 'roolsz', fit it to the frame rather than to the handbook. You can then space it out to suit what is required instead of pulling your hair out trying to fit it if it were the perfect combination of frame, parts and workshop.

 

[mattr]

Is the bottom bracket within spec?
think it's something like 68mm with a tolerance of plus 0,8 minus 0,4

This *looks* like it might be too wide.

Other than that, if i was doing it and i had clearance on the drive side, i'd be swapping the 6,5mm spacer for something smaller.

 

[The History Man]

The only 'good' thing about these external BB and chainsets is that you can adjust the chainline to fit the bike.

Rather than obey the 'roolsz', fit it to the frame rather than to the handbook. You can then space it out to suit what is required instead of pulling your hair out trying to fit it if it were the perfect combination of frame, parts and workshop.

+1. Done a few of these lately and worked on chainline rather than spec. All turned out fine.

 

[S1m0nR]

Re:

Thanks one and all for your answers. I've done as suggested, and fitted a 3 mm spacer on the drive side which has solved the problem. Actually, I think I may need a 3.5 mm spacer as there's the tiniest bit of play now.

Yesterday evening, I went and got a Tiagra 4603 triple crank out of the shed and tried that. It had the same 6.5 mm spacer and unsurprisingly also didn't fit. It was the 3 mm non-drive side spacer from that which I robbed to make the setup work.

The BB shell is 68 mm so that's within tolerance.

It's just odd that I've got a standard BB Shell, the correct BB installed and the crankset isn't engineered to fit out of the box.

Never mind - all sorted!

Thanks again.