Power crank - chainring issues

[Rick]

Hi

 

I recently received a Quarq FSA SL-K. In short: pedals-good, BB-good, looks-good, chainring-***

Now here's the problem, i swapped out a DA 7950 for this so chances are i've been spoilt but this thing is just flat-out unreliable getting onto the big ring. At high cadence low torque it's fine, but when the conditions aren't so good it sucks. This might not be such a big issue with a non-compact, but the thing with the compact is it allows me to have a tight ratio casette, so on hills i like to just swap chainring when i get out of the saddle rather than shift 4 down.

 

Anyway, so here's the puzzle:

 

1. Swap the chainrings for something better. DA will not work, but i'm sure others are just as good. Quarq mentions a re-callibration, but only if you are changing the size of the chainring, so i assume this would not be necessary, anyone confirm?

 

2. Send it back and swap for the SRAM S975 crank. I have only ever read possitive reviews of this crank. I know the 53-39 is a red chainring, but i think the compact is a force. Can anyone comment on the shifting perfomance of these (specifically the compact)?

 

3. Send it back, get a credit and just go ape and get the SRM DA7900 once i've got some cash together.

 

I must be honest I'm liking option 3 just coz it seems regret-proof, but is it over-kill, will the S975 be perfectly good enough?

One concern about the SRM is this annoyance of sending it away to have the battery changed. Anyone with an SRM, please tell me what this process involves, where it goes and just generally how much of a mission it is.

 

Thanks guys

[Tankman]

you lost me at non-compact!

Edited March 27, 2011 by Tankman

[Trubie]

I'm currently running a campag chorus 11 spd set up

ordered a quark SRAM S975 and had to order 2 new chainrings, Stronglight BCD 130 in order to stay on 11 spd .

Havent arrived yet, so can't comment on the performance yet...will do asap

[Tankman]

Lets look at your first issue, shifting on the chainrings, right?

 

You dont say what compact you have on 50/34 or 52/36.

Do you have a 10 or 11 speed crank? What groupset and what speed chain?

 

but the thing with the compact is it allows me to have a tight ratio casette, so on hills i like to just swap chainring when i get out of the saddle rather than shift 4 down.

 

 

You have to plan your shifting, especially on a compact crank. Do you shift to your big chainring before you get out of the saddle or while standing? I dont think it is the best practice to shift to you big blade while already going uphill, rather stay in you big blade for as long as possible or plan your shift properly.

 

(a "non-compact" is called standard)

[Christie]

The accuracy of the quark power measurement is affected by the chainrings. If you change brand or size, it needs to be re-calibrated.

 

7900 rings are supposed to be the stiffest in the business, and I have read some other complaints of FSA rings flexing (apparently an issue when used with Di2)

 

Stronglight rings sound like a good option, but then you need a re-calibration.

 

As far as power meters go, SRM is bomb proof, but it has the hassle of needing to send it to Germany or America for battery replacement. The 7900 SRM is not a real 7900 SRM, but a 7800 crank that can take 7900 rings - not quite the same Best SRM crank is the Cannondale one!

 

Garmin and Polar/Look will have pedal based meters on the market in the next year or 2, hope they will be successful.

[Rick]

Tank, sorry if my terminology is sub-par there. "standard" is the word I should have used you're absolutely right.

I'm trying to gather info here from people who have experienced these products. There is only one compact configuration on the SL-K quarq and it's a 34-50 so I didn't figure i needed to spell that out. Likewise on the 10 speed, there is no 11 speed...

Also, thanks for the advice on shifting behaviour, it's not really the problem I'm trying to solve right now, but i'll bear it in mind for when I'm next riding.

If you have any experience with the shifting performance of the chainrings in question, fire away. Ta

[Rick]

Sorry I realise that my question was really long-winded.

 

Short version: The SL-K chainrings shift like a pig, is the SRAM S975 much better of should I cork for a SRM DA 7800/7900 or the canondale as suggested.

[Tankman]

Tank, sorry if my terminology is sub-par there. "standard" is the word I should have used you're absolutely right.

I'm trying to gather info here from people who have experienced these products. There is only one compact configuration on the SL-K quarq and it's a 34-50 so I didn't figure i needed to spell that out. Likewise on the 10 speed, there is no 11 speed...

Also, thanks for the advice on shifting behaviour, it's not really the problem I'm trying to solve right now, but i'll bear it in mind for when I'm next riding.

If you have any experience with the shifting performance of the chainrings in question, fire away. Ta

 

No worries and no need to spell anything out. I havent used those cranks but I have used many different blades and my compact crank didnt stay the normal 50/34 for long. Thats why I asked, I chopped and changed blades so many times it is difficult to remember all ratios and speeds, had 50/52/34/36 blades and was in the process of getting 53/39 There are 11 speed FSA blades available by the way.

 

Changed back to standard a year ago and much happier.

 

Good luck in finding what are looking for.