Single ring installation

trail jacker

Hi Guys,

Becoming a bit of a regular in this forum unfortunately!!

Basically I'm installing a single ring and running 1X9 gearing. I have installed the hollowtech II BB and have just pushed my cranks through the BB, but there is a gap of about 8mm between the driveside cup and the crank. Should the crank be right up against the cup or is a bit of distance (and exposed axle) ok?

Thanks!

Greer_

As far as I know there shouldn't (edit ) be a gap (i'm about to install the same things tomorrow). Just preload the bearings (finger tight) and tighten the non driveside arm.

trail jacker

Cool, I cant get the cranks to budge further along so it will have to do! Cheers

1mancity2

The crank arm should be almost flush to the BB cup,
Have you fitted the spacers on the BB?

trail jacker

Yeah, 1 X 2.5mm spacer between the frame and cup.

1mancity2

trail jacker wrote:

Yeah, 1 X 2.5mm spacer between the frame and cup.

73mm shell?

delcol

is there any play in it with that gap?.

what size bb shell is the bike frame and how many spacer did you fit?

i must learn to type faster... :oops:

trail jacker

Yup, 73mm shell. Just gave it a big push and its now pretty much flush! No play at all now. Cheers for the responses

1mancity2

trail jacker wrote:

Yup, 73mm shell. Just gave it a big push and its now pretty much flush! No play at all now. Cheers for the responses

Nice one.

nicklouse

there should be NO gap with shimano BBs.

Greer_

nicklouse wrote:

there should be NO gap with shimano BBs.

I won't make that mistake tomorrow its amazing the amount of contradicting info on the internet :shock: I may never sound smart because of it

nicklouse

Greer_ wrote:

nicklouse wrote:

there should be NO gap with shimano BBs.

I won't make that mistake tomorrow its amazing the amount of contradicting info on the internet :shock: I may never sound smart because of it

if you go to the makers pages you can get the correct manuals for everything.

but then there is also the issue that you may not have the right manual.

trail jacker

Greer_ wrote:

nicklouse wrote:

there should be NO gap with shimano BBs.

I won't make that mistake tomorrow its amazing the amount of contradicting info on the internet :shock: I may never sound smart because of it

Tell me about it! Ha

Greer_

nicklouse wrote:

if you go to the makers pages you can get the correct manuals for everything.

but then there is also the issue that you may not have the right manual.

I always look, but whether you get a comprehensive manual or not is another thing. The manual for the cranks I've bought (M590) is found here http://techdocs.shimano.com/media/techd ... 677251.PDF with no mention of gaps or sitting flush.

I also can't make head or tail of the bb width and spacers.

I haven't measured my bb shell yet, but a 73mm shell needs a 2.5mm spacer on the driveside, correct?

What does a 68mm shell need?

I assume mine is 73mm as it's most common but I just want to check. Band type/bracket type/chaincase stay type means bugger all to me in that tech doc. At a guess, bracket type is something to do with mounting a plate for a chain device?

nicklouse

Greer_ wrote:

nicklouse wrote:

if you go to the makers pages you can get the correct manuals for everything.

but then there is also the issue that you may not have the right manual.

I always look, but whether you get a comprehensive manual or not is another thing. The manual for the cranks I've bought (M590) is found here http://techdocs.shimano.com/media/techd ... 677251.PDF with no mention of gaps or sitting flush.

I also can't make head or tail of the bb width and spacers.

I haven't measured my bb shell yet, but a 73mm shell needs a 2.5mm spacer on the driveside, correct?

What does a 68mm shell need?

I assume mine is 73mm as it's most common but I just want to check. Band type/bracket type/chaincase stay type means bugger all to me in that tech doc. At a guess, bracket type is something to do with mounting a plate for a chain device?

have a read of the manual or Parktools both tell you.

and re the gap it is not mentioned as it does not matter. if the system preloads the bearings there can not be a gap.

if the system does not rquire the bearings to be preloaded there has to be a gap.

it comes down to the bearings used.

Greer_

nicklouse wrote:

have a read of the manual or Parktools both tell you.

and re the gap it is not mentioned as it does not matter. if the system preloads the bearings there can not be a gap.

if the system does not rquire the bearings to be preloaded there has to be a gap.

it comes down to the bearings used.

Thanks, makes sense. The only bb i've seen before is a truvativ powerspline with a built in axle. The built in axle being the reason the bearings don't need preloaded and there's a gap between the bb and crank?

The Rookie

Yes.....

For a 68mm shell it's 2 spacers on the drive side and one on the non drive side!