I've ordered a new Deore M532 chainset for my christmas build and I've noticed the following on the web description.
We recommend that the bottom bracket is initially installed by a bike shop to ensure perfect facing and fit.
How hard is it to ensure this perfect facing and fit using the proper spanner. I regularly do maintenance on my bikes and have built up two bikes, both with square tapers. I feel confident mechanically but just wondering if there's a knack to the new external BB's?
External BB fitting
After reading the park tools website description on fitting these I've also decided to give it a go after all how hard can it be!!!
I think the two key things are making sure the faces of the shell are perfectly parralel to each other before you start (My frame is currently with Mercian being resprayed and this is something i've aked them to do, so this shouldn't be an issue) I think the only way to do this is get an engineer or your LBS to check, however if this is your new Thorn frame then I'll be suprised if they aren't perfectly faced already.
Once there faced the only other thing is making sure you get the correct sequence of spacers, this is where the park Tools website is really handy. After that just screw them in and tighten up.
You also need a special widget to hand tighten the little crank cap on the left hand crank arm, If you've got the park tool then this will have it included other wise you'll need to buy it.
Now all the following is my own musings, as of yet i havn't got my frame back, so havn't had chance to try, but I'm fairly confident it shouldn't be too hard. However I would love to find out how you get on!!
Park tools is here:http://www.parktool.com/repair/readhowto.asp?id=95#shimano
I think the two key things are making sure the faces of the shell are perfectly parralel to each other before you start (My frame is currently with Mercian being resprayed and this is something i've aked them to do, so this shouldn't be an issue) I think the only way to do this is get an engineer or your LBS to check, however if this is your new Thorn frame then I'll be suprised if they aren't perfectly faced already.
Once there faced the only other thing is making sure you get the correct sequence of spacers, this is where the park Tools website is really handy. After that just screw them in and tighten up.
You also need a special widget to hand tighten the little crank cap on the left hand crank arm, If you've got the park tool then this will have it included other wise you'll need to buy it.
Now all the following is my own musings, as of yet i havn't got my frame back, so havn't had chance to try, but I'm fairly confident it shouldn't be too hard. However I would love to find out how you get on!!
Park tools is here:http://www.parktool.com/repair/readhowto.asp?id=95#shimano
I fitted an external BB on the GF's bike. It's a piece of cake, as long as you have the right tool. I didn't bother getting the frame faced but if yours is in the shop at the moment then it's probably worth doing.
My top tips are to use thread lock, just in case, and tighten the bearing shell with a torque wrench as it's far too easy to over tighten it.
My top tips are to use thread lock, just in case, and tighten the bearing shell with a torque wrench as it's far too easy to over tighten it.
Bit Of hijack but closest thread I could find
External BB, Octalink, ISIS
OK the blurb at the time always tells us these are better less twisting etc. But has anybody found a noticable difference under normal riding conditions to give a discernalbe difference.
I suppose what I am asking is what are the real advantages of the dfiferent types of BB. Has anyone found any? or infact disadvantages.
OK the blurb at the time always tells us these are better less twisting etc. But has anybody found a noticable difference under normal riding conditions to give a discernalbe difference.
I suppose what I am asking is what are the real advantages of the dfiferent types of BB. Has anyone found any? or infact disadvantages.
NUKe
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The advantage given from an engineering point of view, is that the bearings allow the use of a lighter, hollow axle and are placed at the extreme ends of the axle which is desirable. However, given that they are now outboard, this also means that they are exposed to the weather and are certainly more vulnerable to muck and water.
Some doubts have been expressed as to their durability. It seems to be well-known that the outboard bearings used on the FSA Triple Gossamer C/S usually pack up at 2000 miles. Luckily these bearings tend to be cheap and the bearings mentioned above can be swapped with Shimano 105 ones which are reckoned to be more durable.
Given that these Chainsets are supposed to be installed using a Torque Wrench, the Park Tool linked above may not be as handy as the Icetoolz one which allows the use of a Torque Wrench.
http://www.ukbikestore.co.uk/Product/-1 ... aptor.html
As to facing the BB shell, while some new Framesets come with the Headtube and BB shells already faced, others do not. For example the Surly LHT frame has these faced before the frame is painted and only requires any paint to be scraped away. Others need to be faced although there is an on-going discussion going on as to whether this is strictly necessary in that although the faces may not be precisely parallel, the cheapness of the bearings means that this may be disregarded.
Some doubts have been expressed as to their durability. It seems to be well-known that the outboard bearings used on the FSA Triple Gossamer C/S usually pack up at 2000 miles. Luckily these bearings tend to be cheap and the bearings mentioned above can be swapped with Shimano 105 ones which are reckoned to be more durable.
Given that these Chainsets are supposed to be installed using a Torque Wrench, the Park Tool linked above may not be as handy as the Icetoolz one which allows the use of a Torque Wrench.
http://www.ukbikestore.co.uk/Product/-1 ... aptor.html
As to facing the BB shell, while some new Framesets come with the Headtube and BB shells already faced, others do not. For example the Surly LHT frame has these faced before the frame is painted and only requires any paint to be scraped away. Others need to be faced although there is an on-going discussion going on as to whether this is strictly necessary in that although the faces may not be precisely parallel, the cheapness of the bearings means that this may be disregarded.