# Chainset Replacement - will it fit and which gearing?



## l4dva (3 Oct 2012)

Hi Guys,

I've been riding my langster for a while now, and finds its current gearing to low for me (42 tooth chainring and 16 tooth freewheel). One of the cranks is damanged so I think id rather change the entire chainset eventhough this is prob more expensive.

Anyway was woundering if the below chainset would work for my bike:
http://www.planet-x-bikes.co.uk/i/q/CSSTTR2K/stronglight_track_2000_crankset

I have a 2010 specialized langster I havent got a clue what types of fitting the frame will take. I will probably get a new bottom bracket while im at it too soo any ideas what type i will need for the frame as well?

The next question is the gearing - they have 44 tooth and 48 tooth I'm guessin the 48 tooth will be too high a jump so im going to go with the 44 i reckon and if need be in future i can always go for a smaller freewheel at the back? Dose this sound sensible?

Also im guessing i will need a new chain if I get a bigger chainset what type of chain would I need to buy I notice they come in different variations too.

Thanks


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## biggs682 (3 Oct 2012)

go 48 and give yourself a work out !

new chain yes and would also recomend rear sprocket .

i have just finished my 2nd fixie with a 46 front and 15 rear and i am finding it well undergeared for my flat commute , 1st fixie ran 52 x 15 and was a nice relaxed ride where as this 1 is very busy


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## colly (3 Oct 2012)

Depends on how hilly it is and how far you ride. (and how good your knees are)

I'm still riding my first fixed, in fact it's my only ride at the moment and I started on 44 x 18. Quite spinney when it's down hill, even on the flat at times. Even so can still average 16 mph at times. When the road rears up though I'm glad it's no higher, and it's hilly where I do most of my riding. 
I'm going to swap the rear sprocket for a 17 or 16 just to test the waters. That is when I can grab me a lock-ring remover.


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## smokeysmoo (3 Oct 2012)

I've just bought that same chainset for my fixed/track bike in a 48. I also swapped my cog for a 15 to give me 86 gear inches for Velodrome use.







When I use it on the road it's fixed at 46:16, and round here that's not too bad.


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## dave r (3 Oct 2012)

I'm using a 44x18 with 165 cranks, gives me a 65 inch gear, good for a slightly lumpy commute and longer Sunday rides/club rides, gets me into the low twenties with an average around fifteen-sixteen mph. The thing is gearing is personal, what suits one rider is unlikely to suit another. You also need to know what the bottom bracket is, and what condition its in, if its worn you need to change it, if the new chainset is for another type of bottom bracket you need to change it, what size chain are you using?

http://www.velosolo.co.uk/shopcrank.html

Look down the page for the Lasco chainsets.

http://www.cyclechat.net/useralbums/daves-bikes.11/view


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## l4dva (3 Oct 2012)

When you say gear inches dose that mean the number of links on your chain? Is that a good unit of measure for what gear your in? I don't quite get the logic of that - fewer links on the rear sprockets would lower your chain count but put you in a higher gear. Your gear inches would drop in this scenario right?

I reckon a 44 or 46 Chainset would be best for me at the moment, I could always get bigger chain rings later if I feel the need to go higher. Plus if I ever take the plunge and flip it over to fixed I don't want to be in a real high gear. Looking around it would seem the lowest freewheel possible is a 16? Can you go lower than this?


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## Old Plodder (4 Oct 2012)

l4dva said:


> When you say gear inches dose that mean the number of links on your chain? Is that a good unit of measure for what gear your in? I don't quite get the logic of that - fewer links on the rear sprockets would lower your chain count but put you in a higher gear. Your gear inches would drop in this scenario right?
> 
> I reckon a 44 or 46 Chainset would be best for me at the moment, I could always get bigger chain rings later if I feel the need to go higher. Plus if I ever take the plunge and flip it over to fixed I don't want to be in a real high gear. Looking around it would seem the lowest freewheel possible is a 16? Can you go lower than this?


Gear size in inches, is what size wheel you would have, if you rode an 'Ordinary', (Penny Farthing).

To find your 'gear'; multiply your wheelsize (diameter) by your chainring (number of teeth) & then divide by your cog (teeth on rear cog).

e.g. 26.5 (wheelsize) x 46 (teeth on chainwheel) / 16 (teeth on cog) = 76.19

As an aside, the 'continentals' use 'gear development', which is the distance travelled by one revolution of the pedals; but I don't remember how it's calculated.

Now, depending on the type of terrain you plan to ride regularly; I would suggest between 70 & 80 on the flat, but from 65 to 70 if it's hilly.

HTH


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## l4dva (4 Oct 2012)

Ahhh that makes more sense - thanks for clarifying that! 

If my calculations are right I'm on about 72 gear inch. My commute is half hilly, half flat. The hills aren't massive there's just quite a few of them. I actually find I push harder on my 10 speed bike because I prefer to spin in higher gear. On my langster I'm kinda forced to relax a bit because of the low gearing so don't get as knackard. I still work up a big sweat on my 11 mile journey tho. Ill try a small jump to 46 tooth chain ring first and see how that goes. Like you mention trial and error. Ill get one ordered and get the lbs to fit  

Thanks for the help


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## l4dva (4 Oct 2012)

Is anyone able to clarify which bottom bracket I will need for my frame? 

The matching one for the strong light Chainset that in going to get comes in two lengths...

http://www.planet-x-bikes.co.uk/i/q/BBSTJP400/stronglight_jp_400_jis_bottom_bracket


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## fossyant (4 Oct 2012)

My fixed takes a 110mm BB axel, you don't need a stronglight BB for that chainset.


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## MrGrumpy (4 Oct 2012)

your current BB length is 103mm, however whether you need a different length for the new crankset I dunno?? As for gearing I went from a 42 to 48 and yes it was a jump but you get used to it. However alot has to do with your cycle route. For my commute its about right for the weekend rides I have been doing lately its been killing me as its all hills . 

BTW I ride a langster as well


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## l4dva (4 Oct 2012)

Nice one! Looks like I might have to go for the 48.. Purely because I'm cheap - planet x dont have the 46 inch tooth and other suppliers cost a fair bit more.

Let's hope a winter on that and ill have legs of steel by next year! 

Another question - Chains.. this one is a fiver..

http://www.planet-x-bikes.co.uk/i/q/CHKMS1/kmc_s1_singlespeed_chain

I know kmc make good chains but a fiver seems very cheap? Will it be rubbish?


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## simon.r (4 Oct 2012)

It says on your original link that the chainset is compatible with a 107mm BB (just above the picture).

For a tenner I'd be tempted to buy a new BB. If money's an issue try fitting it to your 103mm BB and see what the chainline's like. You'll probably* be able to sort the chainline by shimming the ring in on your crank.

*I do not accept any responsibility if for some obscure reason this can't be done


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## simon.r (4 Oct 2012)

Never used the KMC chain, but the SRAM PC1 is a good and about the same price. It comes with an easy 'Powerlock' joining link.

Also available in gold, which is very understated bling (if that's not an oxymoron)! Though I think it costs £2 or £3 more.

Edit - a quick google and the cheapest is actually £8 and I can't see any gold ones. Odd.


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## l4dva (4 Oct 2012)

I will get a new bb as well, but I think I'll just buy that from the lbs that fits the Chainset, at least then they will know exactly which one i need and I'm sure they won't charge more than £20 for a bb? I can live with that seen as I'd of saved loads more buying the Chainset/chain and possibly new freewheel too from the internet.


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