MTB Crankset upgrade

[mtb_Josh]

Hi guys. I bought myself a Merida Matts 40 at the beginning of the year. I am happy with it, but some of the components are starting to take strain. The outer chainring is severely worn and the middle one looks as if its heading the same way. I honestly dont think its worth replacing the chainrings as the whole crankset is rubbish and has worn way to quickly.

 

 

 

I know someone going to england in about a months time, so i am considering buying a crankset from CRC. Any advice/ideas as to what I should buy? And please keep in mind that I'm a student with very limited funds...

 

 

 

And another thing i was wondering about: My bike is 8 speed, does it matter if the crankset is 9 speed?

 

 

 

Thanks for your help!mtb_Josh2009-08-13 10:35:53

[dirtrider]

don't worry bout the 8/9 speed issue . Your best crank will be the SLX .

[mtb_Josh]

thanks! Ja, I was considering the SLX. Dono if the budget will allow it tho...

[dirtrider]

Then you can look at the Deore . It will outlast your bike .

[Wernervdmerwe]

I would also vote SLX - incredible crank apparently, all the reviews are very positive.

 

If in any way possible, waiter, beg, wash cars for the bucks - will be worth it.

[Daxiet]

Before I can cast my vote and sell you down the river, a question.

 

What front derailleur do you have? Many entry level bikes come with SR Suntour Cranks or similar with SR Suntour front derailleurs, these do not work with standard cranks Deore and onwards (odd chainring sizes on the SR Suntour cranks). If you have a Deore FD or better then the simple answer is go for the SLX, excellent buy. If not, then go for the SLX, but add in a Deore FD to your order (not expensive). When buying a derailleur you will be give options of top swing and conventional. You make this decision based on your frame. Normally the water bottle mounting bolts on the seat tube can make this decision for you.

 

[Daxiet]

 

Further to my previous post.

 

I am pretty positive you will need to change the front derailleur. Ref: http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Alivio-Acera/FrontDriveSystem/SI-F920A-En_v1_m56577569830612827.pdf (PAGE3 Top)

 

Your current crank consists of 42-34-24 (standard crank 44-32-22).

 

I would recommend a new front derailleur if you go to Deore or SLX crank, etc.

 

Something the SLX manual does not specify, but it may be an issue is the use of an 8-speed chain. The 8-speed chain is wider than the 9-speed, this may or may not impact shifting and operation of the front gears. The last thing you want is problematic shifting, so consider this. If someone else has done this with success they could clear this up. I have an 8 speed MTB which I will endevour to test on.

 

Important

If your crank is worn, then your chain is mostlikely worn as is your cassette. Generally chain goes first then cassette then crank. So add these to your shopping list.

 

Daxiet2009-08-14 02:05:18

[chuck]

No need to change FD (except if it's broken or you want to) and do the SLX thing. Chain will also not be an issue except if it is already worn. I upgraded to SLX while keeping my budget 8 speed kit. No compatibility issues at all. Only upgraded to 9 speed after a few months. 

[bored girl]

My merida came with an Alivio one. I went from 8 speed to 9 speed with no hassles 6 months after I bought the bike. Never changed the crankset or FD. I changed it the beginning of this year for no other reason but I got a great deal on complete LX groupset. I also bought a LX crankset off CRC - was an awesome price and it was 170mm....what more could one want....

[Honkdonk]

Have a look here, I went from a Deore crankset to a Truvativ 5d crankset to this. After a while the internal BB powerspline thingy starts to feel like a pepper grinder. I also changed F/D from Deore to a SLX M770. This IS your answer.

 

[crasher]

What a good looking and performing  crankset and a third of the price of XTR

[mtb_Josh]

wow, thanks for all the advice! I think I've almost been won over by the SLX... I'm planning to get the SLX RD at the same time anyway. The current crankset and FD are both Shimano. Not quite sure what model the cranks are, but the FD is M190...but as long as I'm spending so much already, I may aswell add a few hundred bucks and get a FD at the same time.

 

The chain and cassette are both fine. The chainrings arent worn from doing too many kms, I think they are just seriously soft and I do ride rather hard

 

 

 

The FD that I have at the moment is a top swing, but Im quite sure a conventional one would fit. Is it worth the extra R150?

 

 

 

I just checked CRC and if I go for SLX crankset, RD and FD it will cost me R2000. Does that sound about right?

 

This might be a bit of a stupid question but I just want to make sure - the crankset does come with a BB right?

 

 

 

Thanks so much for all your advice!!!

[Honkdonk]

Sounds about right on the money - dont forget the post and packeging plus VAT when it lands here..

 

Yes it will come with a BB

 

[droo]

Nothing wrong with the Deore M532 either, just fitted one to a mate's bike. He got his from CWC for R850, might be worth checking if he's got any left.

[Serendipity]

You might want to consider a 9 speed casette and chain too. If you go SLX (9 speed) rd your 8 speed current casette and chain obviously would not work.

[droo]

You might want to consider a 9 speed casette and chain too. If you go SLX (9 speed) rd your 8 speed current casette and chain obviously would not work.

 

 

It will work. The cable pull ratios are the same for 8 and 9 speed.