Shimano BB51 upgrade

Phil63

Noticed recently that my BB51 is sounding a bit on the 'rough' side. Covered various rides off' road in dry (not many given recent weather) and gloop (plenty) in the last 6 months (since I bought the bike new) - approx. 800-900 miles. Read a few topics on the forum and it appears this BB is a bit light weight and does not last long before water/dirt ingress and start to foul the bearings. So, was thinking of an upgrade (BB only not cranks) and would appreciate some technical/price guidance from those in the know. Thanks.

nicklouse

any HT2 BB will work fine.

loads out there.

coursemyhorse

I have the same Bottom bracket and I am not sure how to tell if it is going. With just the bare cranks fitted and all lubed up fresh, it makes some noise when I spin them with a slight resistance. It is not notchey or a grinding sound, just a constant low amount of noise. I took a video of it and can post it but it will sound loud as the camera is near to it and the garage silent otherwise.

Phil63

Thanks for that nicklouse.

coursemyhorse - one 'wise man' once told me if you clean anything on your mtb after every ride make sure its the chain - thoroughly - and lube sparingly. Wise words indeed , chain, cassette and derailleurs are much better for it. With this in mind the 'rough' noise i seem to get can only be left to the BB. Would like to see/hear your video - level of noise would I guess be dependant on amount of wear. Mine no longer appears to be as smooth as it was a couple of weeks ago and when rotating cranks in isolation (no chain) seems to confirm this.

gazeddy

bearings generally get noisy before they get crunchy

coursemyhorse

Here's the video of what mine sounds like.

https://www.youtube.com/watch?v=dHuXRHUCxsA

Phil63

Easy fix on your BB, hit mute on my keyboard and it sounds perfect :-) Seriously, that does sound rough. Stripped mine down over the weekend and sounds similar to yours although the noise appears inconsistent, few cranks seems fine then random 'crunching' - perhaps it's on it's way to a catastrophic failure...eeek. Another check I have now made was for any lateral movement in the crank - this is minimal but it is only going to get worse so digging deep and looking to order a Shim XT SLX BB.

Asif Tufal

The Hope bottom bracket has been well reviewed and can be purchased with either steel or ceramic bearings. Wiggle had the best price on the steel one, the last time I looked, especially if you subscribe to their newsletter and get a further £5 off.

coursemyhorse

Like I say the mic on the above vid is up high and obviously any sound will sound loud. But, are bottom brackets meant to make any noise when they spin? Surely there will always be some noise?

gazeddy

yes but it sounds gravelly to me where as it should be a quiet almost hum

hairy_boy

coursemyhorse wrote:

Like I say the mic on the above vid is up high and obviously any sound will sound loud. But, are bottom brackets meant to make any noise when they spin? Surely there will always be some noise?

Yours sounds fine to me - When I change mine for a new one it sounds the same I think (with the chain off and up close) - wouldn't worry me, get out and ride man !

Original poster:
Was your BB51 fitted from new ? Was your frame 'faced' before the BB51 was fitted as non-faced frames cause the bearing to install slightly 'wonky' which I keep hearing can lead to premature wear.
If the frame was faced there should be no paint on the face of the frame where the BB tightens against it.
Maybe the pre-tension on the crank arm when installed was a cranked a bit high which can cause wear.
If your changing the BB I would just stick another BB51 in - if you are riding a lot in all weathers and have to change every 6-12 months then so be it - the BB51 is cheap as chips anyway.

Neal_

My BB51 didn't last long and Shimano BBs aren't easy to service so I got an Uberbike components steel bottom bracket for £35 http://www.uberbikecomponents.com/categ ... ckets-here

Better sealed than Shimano BBs and easily replaceable bearings so similar to Hope but much cheaper.

Phil63

Hairy Boy - thanks for the advise...not sure if frame was faced as bought the bike new from LBS (is it standard practice for this to be done by an LBS on assembly of a shipped in product from Europe??). Took BB off difficult to tell on inspection. You also mention pre-tension on the crank arm, how tight should this be? I have a small 'screw cap' that fits into the crank and pulls/squeezes the crank (drive/non drive) onto the BB with spacers fitted. When I took it off it was v.tight i.e. mole grips and some leverage to remove - appeared overly tight to me. Any thoughts?

Phil63

Neal_ wrote:

My BB51 didn't last long and Shimano BBs aren't easy to service so I got an Uberbike components steel bottom bracket for £35 http://www.uberbikecomponents.com/categ ... ckets-here

Better sealed than Shimano BBs and easily replaceable bearings so similar to Hope but much cheaper.

Cheers Neal...nice bit of bling for anybike.

Neal_

Phil63 wrote:

Hairy Boy - thanks for the advise...not sure if frame was faced as bought the bike new from LBS (is it standard practice for this to be done by an LBS on assembly of a shipped in product from Europe??). Took BB off difficult to tell on inspection. You also mention pre-tension on the crank arm, how tight should this be? I have a small 'screw cap' that fits into the crank and pulls/squeezes the crank (drive/non drive) onto the BB with spacers fitted. When I took it off it was v.tight i.e. mole grips and some leverage to remove - appeared overly tight to me. Any thoughts?

The pre tension cap sounds like it was hugely over tightened which quickly knackers the BB bearings, the tool is made of plastic to try and prevent people torqueing it up too much. Tightening it up finger tight will usually be too tight, all you need to do is tighten it until the cranks just touch the BB faces and it just takes the play out of the crank arms once the pinch bolts are tighten...see below.

http://www.parktool.com/blog/repair-hel ... tra-torque

IMO the uberbike BB is a good investment, you can see in the photo below that the top hat seal has a lip on the outer edge (unlike Shimano BBs) which should help keep the crud away from the bearings longer.

hairy_boy

Phil63 wrote:

Hairy Boy - thanks for the advise...not sure if frame was faced as bought the bike new from LBS (is it standard practice for this to be done by an LBS on assembly of a shipped in product from Europe??). Took BB off difficult to tell on inspection. You also mention pre-tension on the crank arm, how tight should this be? I have a small 'screw cap' that fits into the crank and pulls/squeezes the crank (drive/non drive) onto the BB with spacers fitted. When I took it off it was v.tight i.e. mole grips and some leverage to remove - appeared overly tight to me. Any thoughts?

If a LBS fitted the external BB to a new frame they should have faced the frame first although that doesn't mean they did !
If after removing the cups the frame BB shell has no paint on the edge which the cups tighten against then I would suggest it has been faced - if there is paint on the frame facing then I would suggest it hasn't been faced. The facing process tends to remove most/all the paint from this face of the frame. Can you check and if not done I would be inclined to go back to your LBS and get them to face the frame before you fit a new BB.

Pre-tension sounds too tight to me. Although if you haven't got the correct tool and using mole grips its difficult to say. This tool is a good one for removing/re-fitting both the BB cups/bearings and also the pre-tension bit:
http://www.jejamescycles.co.uk/icetoolz ... tAod_SMAAg

This 'Hope' video is brilliant for getting a good idea on the whole process, particularly the pre-tension - from 8:30 shows how to tensions the cranks - using the tool to tension, back off and then re-tension. This has always worked well for me:
https://www.youtube.com/watch?v=UAqAanDsAKA

From where you are now I suspect the overly tightened pre-tension is your biggest problem. I would check the frame facing and then get a new BB51, fit with the correct pre-tension and see how it goes.

Phil63

Hairy Boy, sound advise thanks again. Having watched the Hope video it's confirmed my worst thought, the BB was overly tight - the technician in the video clearly demonstrates a good method for tightening the BB and I will use this when fitting my new one which I've now received. Given how the original one was so tight before this probably caused the BB to fail prematurely - no big deal as they take a lot of stick when riding trails anyway but it does raise my concern over the LBS assembly procedure!!

Phil63

coursemyhorse wrote:

Like I say the mic on the above vid is up high and obviously any sound will sound loud. But, are bottom brackets meant to make any noise when they spin? Surely there will always be some noise?

Just thought I would update you with the progress on my BB. Have now fitted a new one and it runs smooth and 'quiet'. On this basis I would suggest yours needs changing. Given it's a simple enough task, fairly cheap and not to difficult to do well worth a go. Hairy Boy posted a really good link to the Hope tech shop here it is - https://www.youtube.com/watch?v=UAqAanDsAKA

Phil63

Hairy Boy wrote:

Phil63 wrote:

Hairy Boy - thanks for the advise...not sure if frame was faced as bought the bike new from LBS (is it standard practice for this to be done by an LBS on assembly of a shipped in product from Europe??). Took BB off difficult to tell on inspection. You also mention pre-tension on the crank arm, how tight should this be? I have a small 'screw cap' that fits into the crank and pulls/squeezes the crank (drive/non drive) onto the BB with spacers fitted. When I took it off it was v.tight i.e. mole grips and some leverage to remove - appeared overly tight to me. Any thoughts?

If a LBS fitted the external BB to a new frame they should have faced the frame first although that doesn't mean they did !
If after removing the cups the frame BB shell has no paint on the edge which the cups tighten against then I would suggest it has been faced - if there is paint on the frame facing then I would suggest it hasn't been faced. The facing process tends to remove most/all the paint from this face of the frame. Can you check and if not done I would be inclined to go back to your LBS and get them to face the frame before you fit a new BB.

Pre-tension sounds too tight to me. Although if you haven't got the correct tool and using mole grips its difficult to say. This tool is a good one for removing/re-fitting both the BB cups/bearings and also the pre-tension bit:
http://www.jejamescycles.co.uk/icetoolz ... tAod_SMAAg

This 'Hope' video is brilliant for getting a good idea on the whole process, particularly the pre-tension - from 8:30 shows how to tensions the cranks - using the tool to tension, back off and then re-tension. This has always worked well for me:
https://www.youtube.com/watch?v=UAqAanDsAKA

From where you are now I suspect the overly tightened pre-tension is your biggest problem. I would check the frame facing and then get a new BB51, fit with the correct pre-tension and see how it goes.

As my earlier post to coursemyhorse says, I've fitted a new BB based on the video clip and it now runs a dream. Pretty sure the frame hasn't been faced as there is clearly paint on the frame. Now I know what signs to look for with a BB I will run this one and wait for it to need replacing and then have the frame faced and BB bracket done together. On a separate point the front derailleur needed slight adjustment, probably because the alignment shifted with new BB, spacers etc. Cheers for your guidance.

hairy_boy

Pleased to hear you have got it sorted.

Enjoy your weekend riding your new, quiet BB ! Make sure you check that the crank arm bolts haven't worked loose over the next week or two.