Upgrading crankset on a 2012 Boardman HT Comp

clydefrog

Hi,

After having nothing but problems with the bottom bracket on this bike:

http://www.boardmanbikes.com/mtb/ht_comp.html

and after somehow stripping the thread in the crankarm when trying to remove it which has resulted in Halfords having to saw the thing off, I need to buy a new crankset and bottom bracket.

I am looking at this Shimano Deore M590 crankset/BB:

http://www.halfords.com/webapp/wcs/stor ... yId_165545

and it has the same amount of teeth as the current crankset (44/32/22T) meaning I won't have to change the chain or cassette right? I just wanted to see if there is anything I haven't thought of that will mean this crankset is unsuitable for the bike as it is e.g. the front derailleur or anything else.

Also does anybody have any opinions of whether it is worth spending about twice as much for the Deore XT M770 instead. Really I'd rather not as I didn't want to spend over £100 but I'm wondering how much better it will be in reality, also considering I mainly use the bike on towpaths and roads and not for anything special.

Cheers.

felix.london

I'd say the Deore is the one to go for but it can be had for cheaper elsewhere;

http://www.chainreactioncycles.com/shimano-deore-m590-9-speed-triple-chainset/rp-prod40496

poah

if you want to upgrade consider getting the SLX crank - only weights 38gs more than the XT and that's the different chainrings but cheaper

The Rookie

38g MORE.......

Is the BB pressfit or threaded?

poah

threaded uses the same BB as XT

The Rookie

No the FSA doesn't use the same BB as XT....

poah

The Rookie wrote:

No the FSA doesn't use the same BB as XT....

thought he ment the shimano one

clydefrog

The Deore XT uses the same BB as the SLX, the BB70. The one that was on my bike was an FSA PowerDrive and it was on its 4th one in just over a year with not even loads of use, they are bad.

I chose the normal Deore M590 in the end, I decided it wasn't worth paying twice as much for something that is likely not nearly twice as good for how I use the bike anyways. It seems to have a good reputation and good reviews in most places so hopefully it was a good decision. The guy in Halfords recommended me an FSA Gamma Drive with a MegaExo type BB but I didn't really read good things about it and it also cost £36 more than the Deore chainset.

cooldad

The Deore is fine, but the BB is a bit marginal. When it goes replace it with an XT or XTR BB - much better sealing and still only around £20.

clydefrog

cooldad wrote:

The Deore is fine, but the BB is a bit marginal. When it goes replace it with an XT or XTR BB - much better sealing and still only around £20.

Ah so it will be compatible with the XT type then? Good to know I guess but I hope that I won't have to do it any time soon, although I'm not expecting it to last ages. I wonder in that case should I just order the BB70 as well and get them to fit that one instead of the BB51 that comes with it, and give me the BB51 as a spare?

clydefrog

I'm thinking of maybe doing what I said above (buying the XT/SLX BB to be installed instead of the Deore one). Does anybody else who knows about them (and you cooldad) think it's worth doing?

Chunkers1980

No point. When it goes change it.

clydefrog

Well I got the deore and Halfords installed it for me. They've put what I think must be 2.5mm spacers 1 on each side. My mate reckons that's not right, any thoughts?

Ps the bike has a 68mm bb shell width and normal type front derailleur.

cooldad

Should have two on the drive side and one on the non drive side, assuming you don't have anything else BB mounted.
If so, sort it out quickly or your new BB is toast.

clydefrog

cooldad wrote:

Should have two on the drive side and one on the non drive side, assuming you don't have anything else BB mounted.
If so, sort it out quickly or your new BB is toast.

Ok thanks, So what size spacers should be on each side then? Also how come it needs another when the 2 on it have taken it up to 73mm? I'd just like to know so I don't phone them telling them it's wrong but not knowing why.

cooldad

73mm BB shell gets one on the drive side. So 75.5mm total width. 68 needs three 2.5mm spacers.
Tell them to read the fitting instructions.

clydefrog

Goddamn Halfords, knew I couldn't trust them to do it properly but didn't have much choice and they said they'd fit it for free.

cooldad

£5 BB tool from Superstar plus the little plastic preload tool, which costs a couple of £s and DIY. It's a 5 minute job.

Kowalski675

What's the plastic preload tool?

cooldad

The tool to preload the bearings when you fit the cranks. Fits into the little plastic preload nut thingy.
That's the technical term anyway.

Kowalski675

Is that just for the Shimano setup? I'll be needing to remove and refit my FSA Comet cranks and Mega Exo BB when my warranty frame arrives, but I think the preload bolt on that is a standard allen bit fitment.

cooldad

Yep

Kowalski675

Cheers.

clydefrog

Ok I just rang them, they said it can be different for different bikes, and if they put 2 on the drive side it would've knocked the chainline out with the cassette so they only used 1 on each side instead. Is this nonsense or is it true? I have a feeling they don't know what they're talking about for some odd reason...

If they're talking rubbish I think I'll just get my mate to add the extra spacer on there for me, don't think I trust halfords to do much with my bike anymore.

cooldad

It's nonsense.
If they'd but two on the non drive side it might make sense, but the spacers are there to space. The space between the cranks and BB is the same.

clydefrog

I just had another look and noticed they have filled in the drain hole in the bottom bracket shell with grease again as well, clowns.