Should I move the shim over to the non drive side.

[Cycleops]

Don't know where you got that from @wafter but listed as spares there are no separate bearings for road or MTB BBs.
I've swapped Hollowtech cranksets between road and MTB with no probs.

 

[Deleted member 121159]

Don't know where you got that from @wafter but listed as spares there are no separate bearings for road or MTB BBs.
I've swapped Hollowtech cranksets between road and MTB with no probs.

View attachment 720362

Not separate bearings, but the sleeves are different lengths, the bearing bits should be interchangeable.

 

[Cycleops]

Not separate bearings, but the sleeves are different lengths, the bearing bits should be interchangeable.

Nope, the plastic sleeve slides inside the bearings so doesn't need to be a different length. Read the included items on the listing again.

 

[wafter]

Nope, the plastic sleeve slides inside the bearings so doesn't need to be a different length. Read the included items on the listing again.

The plastic sleeve sits inside the BB shell between the bearing cups; and hence its length is determined by the spacing between the cups. Broad-strokes it seems that:

Road groupset: For 68mm shell, short sleeve, no spacers included
MTB groupset: For 73mm shell (bare) or 68mm shell (with 2x2.5mm spacers), longer sleeve, spacers included

Also, if you search for images of road and mtb BBs you can see that the sleeve is longer in the MTB items..

 

[Gillstay]

The plastic sleeve sits inside the BB shell between the bearing cups; and hence its length is determined by the spacing between the cups. Broad-strokes it seems that:

Road groupset: For 68mm shell, short sleeve, no spacers included
MTB groupset: For 73mm shell (bare) or 68mm shell (with 2x2.5mm spacers), longer sleeve, spacers included

Also, if you search for images of road and mtb BBs you can see that the sleeve is longer in the MTB items..

I have been through this a bit already and I think your correct its just the sleeve. Glad I am not the only one who has had a bit of trouble checking this as I was starting to feel stupid. I thought I read somewhere that the original set up on this frame was exactly as I have done it
, but cannot find that now. I have copied it on to a bit of paper but did i make a mistake ? No way of knowing as cannot find it on my browsing history.
i might just try it in the morning as i have time with just one spacer each side and check it over carefully. Thanks for all your time and thoughts.

Very helpful. Ta.

 

[fossyant]

Hold on, it's a Shimano MT800 BB - look here - 68/73mm - the plastic shell isn't the issue

https://bike.shimano.com/en-EU/product/component/deorext-t8000/BB-MT800.html

 

[Deleted member 121159]

Hold on, it's a Shimano MT800 BB - look here - 68/73mm - the plastic shell isn't the issue

https://bike.shimano.com/en-EU/product/component/deorext-t8000/BB-MT800.html

68/73mm as in it fits 68mm shells with spacers, but the sleeve still longer than road BBs

 

[fossyant]

68/73mm as in it fits 68mm shells with spacers, but the sleeve still longer than road BBs

It is, but if there isn't enough spline showing on the non-drive side OP is in a world of trouble. Easy way is to check this first.

Do we also have the bike's shell width ?

I'm more bothered about what's showing on the non drive side. Then you can remove a spacer, see if it still fits, or the plastic shell fowls it when tightened. If it does, remove shell and test without shell. If enough spline is there then a new shell is needed. But before splashing out, all these checks need to be done. Also need to see if it's a triple front mech and there is enough movement in it.

BB cups are BB cups, they will fit either.

 

[wafter]

I have been through this a bit already and I think your correct its just the sleeve. Glad I am not the only one who has had a bit of trouble checking this as I was starting to feel stupid. I thought I read somewhere that the original set up on this frame was exactly as I have done it
, but cannot find that now. I have copied it on to a bit of paper but did i make a mistake ? No way of knowing as cannot find it on my browsing history.
i might just try it in the morning as i have time with just one spacer each side and check it over carefully. Thanks for all your time and thoughts.

Very helpful. Ta.

No worries; glad it helped. Did just pop down the shed to do some measuring but that proved non-viable due to the crank fitment / access issues. Might have the dims elsewhere though.

How did you arrive at your current setup - did you replace the BB and crankset at the same time?

As @fossyant says, the most straightforward way to know for sure is to check the engagement of the NDS crank arm on the axle - the end of the axle should come to near the outside face of the arm. If the BB is incorrect as suspected, the end of the axle will be sat 5-6mm inside the arm.

 

[Yellow Saddle]

Yes, that's rushing as my tea was ready. Sorry. 68mm it is.

In that case, your spacer arrangement is perfect, assuming that each spacer is 2.5mm wide. On a 68mm BB shell with your type of derailer, you need two spacers on the right (i.e. 2.5 plus 2.5mm =5mm) and one on the left.

It seems there's another reason for your FD to not reach all the way across. May I ask if you understand the function of limit screws?

 

[Deleted member 121159]

In that case, your spacer arrangement is perfect, assuming that each spacer is 2.5mm wide. On a 68mm BB shell with your type of derailer, you need two spacers on the right (i.e. 2.5 plus 2.5mm =5mm) and one on the left.

It seems there's another reason for your FD to not reach all the way across. May I ask if you understand the function of limit screws?

The spacer arrangement is as they should be if installing an MTB crankset due to the longer axle length. As the OP installed a road crankset with a shorter axle, spacers shouldn't be used (see pic below). The chainline on road FDs will is something like 43mm compared to 48-49mm on MTB FDs. Since the chainrings are 5mm further out than they should be, the FD will have issues covering the space even when the H limit screw is maxed out.

 

[Gillstay]

In that case, your spacer arrangement is perfect, assuming that each spacer is 2.5mm wide. On a 68mm BB shell with your type of derailer, you need two spacers on the right (i.e. 2.5 plus 2.5mm =5mm) and one on the left.

It seems there's another reason for your FD to not reach all the way across. May I ask if you understand the function of limit screws?

Yep its not the screws, but your right to ask it is an obvious route to the problem..

 

[Gillstay]

Yes the FD is a triple Tiagra one and it is at its maximum. It was an alfine set up before.
Which just made me think i could try that Bottom bracket as well. A busy morning awaits me.

 

[Gillstay]

Yep, the spindle is not far enough through.

 

[Gillstay]

Spotted a correct tiagra bottom bracket, which has no spacers, for £14. Bought it.

So if anyone needs a MT800 ? Thanks for all thoughts and the discussion, Its been a school day.