Help Identifying Crank

[Davie4u]

Hello kind Ladies and Gents.

Below is a photo of my poor old decrepit crank. From my 3 year old Giant M2 Escape (hybrid) :/:/ (take note of the sharks teeth on the inner ring LoL).



Obviously I soooo need to replace this part (along with chain and Rear Sprocket). Might have to replace bottom bracket too but those three items top of my list (as budget is tight).

The internet is normal the wisest choice to a few pennies but I'm having a difficult time matching up the information from the crankset to parts I see listed on these websites.

I do believe the above part is a Shimano FC-M191 28/38/48.
(full cycle specs here: http://www.giant-bicycles.com/en-GB/bikes/lifestyle/347/31770/ )

Unfortunately as you can see on the photo above this is not written on it the crankset
All that is written on it is SR Suntour PFF

Which brings up lots of shapes and sizes if googled :/

Am I missing something here LoL is there a simply method in choosing new parts ?

Any help advise most welcome!

Thanks in advance

[JohnV]

The crankset is made by SR SunTour. You can find the part you need at their web site. The good thing is that they are not expensive cranksets. My Giant Cypress has a different model SunTour crank and it lists for around $38.00 at some Internet bike shops. The bottom brackets for these cranks run around $10.00. Somewhere on the crankarm, it should give you the length which is what you want to replace it with. I'm thinking it should be somewhere around 165 to 170 mm.

[GeorgeET]

You can also keep all your parts and just replace the cogs/gears and chain.

Most likely its a sealed BB so no serviceability. If not refresh it.

http://sheldonbrown.com/harris/chainrings.html

http://www.sheldonbrown.com/harris/cranks.html

[nfmisso]

You can easily fit almost any square drive triple on your bike. Ranging from this one:

http://www.amazon.com/Shimano-FC-M131-Tourney-Crankset-48-38-28/dp/B003ZMDJW6/

to something like this:

http://www.amazon.com/Shimano-M970-165mm-Crankset-44-32-22t/dp/B001IOU8Z4/

I put a M131 on my back up commuter, replacing a single 44T. My legs don't move so fast, and there was a big improvement in speed going from 44T to 48T. The M131 triple was cheaper than a single chainring crankset. Recently, I put on a front derailure, and the 28T front ring is great for really steep hills. The bike originally had a 14-34 freewheel, now is has a 13-28. All in all, the gearing is more suited to me now.

You also need to decide if a 48T large chainring suits you; would a 44T or 52T be better for how you ride?

[GeorgeET]

Wow thats a hell of a price range. The M970 must come with lots of bragging rights.:-))


The first one is perfectly (M131) adequate and at that cost cheaper than replacing individual cogs.

[Davie4u]

Thanks for your replies You have be most helpful

Sorry more newbie questions LoL:

So I understand that there is a lot of choice for square drive triples. However can I mix the Drive System parts or is it best to stick with certain systems?

If I change the size of crankset I guess I will have to adjust front derailleurs , shorten chain, etc ? :/:/

Not complaining though I have be cycling for long enough now LoL. Its about time I learnt how to maintain my bicycle Without the need to visit so called cycle repair stores and be sold the wrong parts and be given bad advise :o

Nfimsso your right about customizing the bike to suit ones needs. I think the original crankset is about spot on (if used correctly)

My cycle is primary used as transport to and from work, only a 6 mile there and back. Although my route does contain several sections i.e. Long up-hill/down-hill , tonnes of traffic, even light trail. Hence the reason I purchased a strong urban hybrid cycle.

[nfmisso]

Davie;

Generally, you want to keep the left and right sides the same. You can mix and match a great deal, and as you noted, somethings may require adjustment.

My back up commuter has a Sunrace freewheel now, the original was a Shimano. My main bike has a Shimano rear derailleur controlled with a SRAM MRX twist shifter.

[trevgbb]

If you replace your chainset with another make, you may have problems with chain line due to different design parameters!
If you increase the top ring tooth count, you will possibly have to replace your FD.
You will definitely need a new chain and probably rear freewheel/cassette and your jockey wheels.

[Davie4u]

Bought a cheap and cheerful Shimano FC-M191 28/38/48 and an expensive new chain, from a reputable chain store here in UK.

Parts went on easily enough. Followed the helpful Bicycle tutor video's and did have to adjust front derailleur and loosen cable considerably. Bit of tinkering was working very smoothly.

I was keen to get there and test it. Unfortunately for me old problem of chain slipping has returned.

I'm 99% sure this problem is cause by the old worn chain damaging a new rear cassette. Thanks to some very bad advise I was given from a different unreputable chain store LoL.

So I have no other choice to replace this part as well. If that fails I'll replace rest of the drive system I haven't already bought (i.e. bottom bracket, rear derailleur)

[JonB]

This wouldn't be Halfords would it? With a few exceptions most Halfords mechanics are completely useless and have no clue what they're talking about.

[car5car]

(03-15-2011, 02:05 AM)nfmisso Wrote:  to something like this:

http://www.amazon.com/Shimano-M970-165mm-Crankset-44-32-22t/dp/B001IOU8Z4/

$550???
Is motor included?

[JohnV]

Quote:$550???
Is motor included?

Good thing he's not doing this on a road bike and wanting Shimano Di2 components. It doesn't come with a motor, but it does come with a battery pack.

[07cbalmer]

Hi iv been trying to get my pedal off for hours and got so annoyed that I gave up on it and have decided that I'm going to replace the crank, the problem is it doesn't have a make on it anywhere so I don't know how to replace it, the picture is below