9 posts • Page 1 of 1
So I've got an opportunity to buy a wired SRM power meter cheap
Including the PCV thingo and all cables etc
Does anyone have any experience with the wired srm units, in particular
Is it doable on your own or if not how much at a bike shop?
How often do you service / where/ how much for ?
I know it's very cheap for what it is but I'm studying/not working much/ short on cash so if the cost to install or service it is too much id probably be better off saving up for a stages power meter I think.. Haven't even been able to find any service places in Aus from googling
Otherwise if I can just buy it and be ready to go I'd be extremely happy with it
The guy I'm buying it off also says he will send it off for service / battery replacement for an extra 100, but he he tested it against another power meter and it was accurate when he last used it
I don't really know much about srm power meters so any help is appreciated
Last edited by gromek on Tue May 06, 2014 7:30 am, edited 1 time in total.
I have 5 (mix of wired and wireless) so probably can answer a few of your questions...
Installation - simple fit crank. Wiring pickup under the bb guide (assuming you have the newer power pick up) then attach wires up the down tube and bars with cable guides and electrical tape. Power pick up can be a little temperamental getting the distance of the power pick up and back of the SRM right but not that bad.
Service - this is where your $400 item could quickly go north. When were the batteries replaced? Expect to replace both the PM and PCV every couple of years. Closest service centre is now NZ - costs excluding your shipping there or return are...
Battery changes can be done at home if you are handy with a soldering iron. Enough instructions online if you do a search. If they are offering to get both batteries replaced for only $100s I'd take it!
Accuracy against another PM has nothing to do with the battery. Making sure the slope is correct does and also can be done at home if you have an accurately measured weight (something like a 20kg barbell plate measured at your local post office). Once again instructions online.
Other servicing beyond batteries is quite rare. Some things that can happen - spider can crack at the chainring bolt holes and cannot be fixed. Had this recently with an old FSA unit so know the process... Looking at ~$1200 for a replacement spider from NZ which will be wireless. The solders for the plug at the back of the PCV can get damaged by vigourous unplugging which can be repaired though locally you would need to find someone handy with the soldering iron or send to NZ.
Over the years I've only had 3 issues across all the units. PCV plug solder on one of my PCVs, once had the coil damaged by baggage handlers and fixed in NZ for free while they replaced the battery and finally the cracked spider.
Wow thanks so much! Answered everything I wanted to know and stuff I didn't even know I want to know yet.
Ah so the only "servicing" it really needs 'every 1 or 2 years' is the batteries?
I was under the impression that they have to be calibrated for accuracy or something every year..
I'm pretty good with a soldering iron from electrical eng at uni and usually do that sort of stuff on my own anyway as I buy cheap out of warranty stuff, and I've looked at the battery replacement guides - they don't look too bad.
That was covered with this bit... "Making sure the slope is correct does and also can be done at home if you have an accurately measured weight (something like a 20kg barbell plate measured at your local post office). Once again instructions online."
Search for 'SRM slope calibration'. Realistically on an older unit keeping the chain rings and bolts torqued the same the slope is pretty stable, but still best to recalculate semi-regularly.
So i got the meter today and it looks okay, apart from the fact i can't get a power/cadence reading from the cranks :/
I tried waving the cadence sensor against the 'reed switch' like the manual shows on the srm website and nothing happens - although i could get the speed to show up by moving a magnet across the cadence sensor
the guy said he hadn't used it for two years so maybe since then it died..
Does this mean i have to open it up, get a new battery and get soldering ?
Have a rough idea depending on which batteries are in your crank. PCV batteries now locally not so sure...
I can't solder so have always sent mine off. Till relative recently there used to be someone in Melbourne who used to do battery replacements but he isn't doing these anymore.
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