You may recall i had some issues with my crankarm being fubar'd on the splines. Looking today after i installed the new crankset i wasn't entirely happy with the length of crank and the ammount of thread the small retaining plastic screw goes in.
The bike is a Giant XTC29er 2011 and has a 73mm shell. Now this makes me think i should have 1 2.5mm spacer on the drive side and none on the non-drive. However that means that the crank arm doesn't really come through very far.
So, pic 1 and 2 show the cranks with the BB installed with no spacers. Pic 3 shows the spacer installed, 4 and 5 show the cranks installed with the 2.5mm spacer.
Now, reading the Shimano stuff there is an instance were no spacers are required which is when on a 73mm with a brack type front derailleur. Now, do i have one of them? i dunno... It's just a stnadard front mech...
When i try and do up the retaining jobbie with 1 spacer installed, it's only catching 2 threads.... which doesn't seem right to me.
Let me know your thoughts please
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what BB is that?
reason I ask that it looks quite wide where the bearings are - did it have another make of crank fitted to it previously?
Those BB cups seem to have a lot more external to the frame than a standard Shimano component.
You might need an 83mm crank
interesting... that's a BB i bought... which may be in mistake LOL. I've got 2 standard Shimano ones, including the one that came with the crankset.
Install that with 1 drive-side spacer ?
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try the standard Shimano one with 1 spacer.
it could be you have one designed for Truvativ or FSA cranks there.
You... are a bunch of Superstars lads !!!
Miles and miles better with the Shimano BB installed..
Many many thanks.
Just out of curiosity - what is that other BB?
Is that helitape over the drain hole in the BB?
Why?
It will fill with water and ruin the BB bearings from the inside.
PaulD
PaulD - that'll be the frame protection tape supplied with the bike when built (you can see the QC sticker over it). The Shimano BB is supplied with a bearing cover which fits internally anyway - and lots of frames don't come with those holes.
It's still a good idea to remove the seatpost and turn the frame upside-down occasionally though.
I would just push a phillips screwdriver through the tape to let the water slosh out, though.
I'll check, basically it was one like these GUB ones, but from a UK selller at a sightly higher price. But i bought it outside of Ebay and can't find the link now i'm afraid.
I'll take that tape off that bit anyway.
thanks guys.
Can we expand on this thread with my first external bearing fitting whilst we're here?
Truvativ Stylo GXP 3.3 crankset, with kit supplied BB, fitting to a 2002(ish) model GT Aggressor. No instructions apart from bad youtube videos.
I have a nicely working BB fitting mech. It's not the subtle type either, it looks more like a chain device for a single ring, it's sturdy and meant to take abuse. When I fitted the BB/crankset my chainline was too far out. Only by removing the front mech and fitting two spacers on the non-drive side does the chainline look right. This was in part proved by the fact the mech couldn't reach the large ring.
Are there many bikes using external bearing BB's and a BB fitting front mech out there?
[i]the mech couldn't reach the large ring[/i]
Did you adjust the stops?
Measure the BB shell - it's probably 68mm but you never know.
Having not ridden anything more than my old trusty commuter for a while due to injury I'm more used to a 68mm fitting square taper Shimano UN53. Luckily I do know my way round a bike, or did with the old gear 🙂
<<-- my front mech
Is there something in the instructions I was supposed to know at this point? Are you saying the new external bracket systems aren't meant to fit 68mm frames?