 You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
A little help if someone can spare a moment. I've got a '05 vintage kona roast and over the last year i've been enjoying riding, maintaining and upgrading it slowly. i've learnt to build wheels, adjust gears, and i've fitted some shiny new (to me) pikes. My riding and fitness has been getting a tad better too!
Last ride, I noticed a course feeling upon pedalling. further investigation revealed that the crank bearings have become very rough in operation, no play as yet, but noisy. This seems like a perfectly good time to upgrade the original strong but very heavy crankset/BB, maybe to something like this:
[url= http://www.chainreactioncycles.com/Models.aspx?ModelID=20679 ]CRC shimano XT cranset, inc BB[/url]
Thing is, I have no idea if this will fit my bike at all, and if it will, which size to go for. I don't even know what the size relates to, diameter or width?
Could anyone tell me whether one of these would fit, and how I can find out which one? And what tools am I likely to need? I notice there is a vast array of choice when it comes to BB pullers and tools.
Cheers in advance people, let me know if any more details are needed to help.
Crank shells are 68 or 73mm width (MTB is usually 73mm) and external bearing BB's are designed to fit either using spacers. You will almost certainly need to get your BB shell "faced and chased" by your LBS. Cranks come in different lengths 175mm being the usual standard with 170mm for very small frames or to suit shorter riders. You will also need a BB tool for tightening the bearings into the shell and a preload tool ( usually bought together from any bike shop or on line).
In short I don't see any problems with this upgrade as I have just done something similar with my wife's 2001 Trek hardtail.
There is a good video on the Hope website which shows how to fit a Shimano crank and Hope BB into a frame.
You may also want to consider the Shimano SLX crankset
Cheers Old'un!
Just to clarify, Is the BB shell the actual frame tube itself? like the headtube? Do I need an 'extractor'? My current crankset is a truvativ isis drive thingy.
Could you point me towards the right tools? ta again
Not sure I agree that you need to chase and face the frame. This is normally something that is done once to a frame and should already be done, no?
Hmmm differing opinions... interesting. I suppose I should strip the bb and take a look at the condition of the, ummm, shell? then decide on a course of action
With a shimano bb facing isnt as critical as they use plastic 'top hats' on the bearings so any slight alignment issue will be taken up, if i were using a hope bb i'd probably get it done though.
In short, you dont need your bb shell faced, you'll need a crank extractor to take off your old cranks and a sq taper/splined bb tool to get the bb out, you just need a hollowtech 2 bb tool to put the cups in and a tool to tighten the bearing pre-load cap. X-tools do decent stuff, if you're feeling flush then go for Park Tool.
to fit the crankset and bb
http://www.chainreactioncycles.com/Models.aspx?ModelID=10179
to remove your old crank and bb
http://www.chainreactioncycles.com/Models.aspx?ModelID=14914
and
http://www.chainreactioncycles.com/Models.aspx?ModelID=10181
You will need one of these to install an external type BB
http://www.chainreactioncycles.com/Models.aspx?ModelID=4062
CRC has plenty of options cheaper though - make sure you get the spanner + small plastic preload device.
You will also need a tool to remove the old crank/BB - get the LBS to do it and avoid paying for a tool you will only use once.
On the matter of facing the BB shell - it all depends if the outer faces have been painted over or if they are clean. If not clean get it done otherwise it will result in premature wear on the BB bearings. Chasing refers to running a tap through the BB shell threads to clean them up prior to installation of the bearings. Yes you are correct in assuming that the shell is part of the frame. It is measured across the width of the frame ie its length (not diameter of the hole) 73mm is pretty much standard now.
Hope this all helps and Shimano cranks are easy to install
Brill, thanks guys 😀
http://www.hopegb.com/page_mep_force_58.html
Here's the link for the Hope video by the way. A quick google will probably find more!