Converting mtb power tap for road use

Anonymous

Hi guys a friends I selling an old wired mtb powertap sl+ it's currently on his cx wheel but he says it's mtb axle length .
Can it be converted to road axle length and be built up in a road wheel? Thanks for any advice!

schweiz

I'm at work so I can't get my hands on my PT hub to see how it is constructed. However, it could be possible. I had a 120 mm track hub machined to fit 117 mm and a 100 mm front hub machined to fit 95 mm (it was a circa 50 year old frame). With track nuts, the axle length didn't need to be shortened but with a QR you'll need to do that too.

Anonymous

Thanks for the reply mate, sounds a little more involved than I want to go with an expensive bit of kit!

schweiz

Depending on how the hub is constructed and how much 'spare' material there is on the nuts which provide the clamping surface of the hub, it's not a great deal of work for a someone with access to a metal working lathe. Basically you unscrew the nuts and take 2.5 mm of the rear side. That way the machined knurling that grips the dropout remains unchanged. When you screw the nuts back on, they will screw in further and the hub will be 5 mm narrower. With the axle, you just need to shorten it by 5 mm, centre it and make sure that the start of the thread is preserved should you ever need to remove the nuts again and then screw them back on.

moonshine

hutchy_belfast wrote:

Thanks for the reply mate, sounds a little more involved than I want to go with an expensive bit of kit!

an old wired PT shouldn't be expensive - i'd be surprised if you couldn't pick a road one up for more than £300 or so.. so it depends on how much of a good deal you are getting it for - you could tyy contacting paligap for the "official answer" if it can be done.. but you might find the hardware is no longer supported...
http://powertap.paligapltd.co.uk/service.php

schweiz

I wouldn't pay more than £150-200. I bought an ANT+ compatible PRO+ hub from the US for less than £500 a couple or 3 years ago. Even after you've had the hub calibrated then you've still got an old hub and also the problems of routing the wiring and stopping it from getting damaged.

Anonymous

Lol if I could find them for £150-200 I'd buy three. Everyone is looking double that. I'd prefer wired and it's allegedly faster refreshing and more importantly, my garmin doesn't support power so if I go ant+ I would need a new garmin too.

schweiz

There's no way I'd pay £400. It seems crazy to me to pay almost new prices for something that is 4-5 years old at best, most likely requires calibrating and has no warranty.

As to 'faster refreshing' the Garmin records the power value every second which given pedalling speeds of 80-100 rpm is good enough in terms of accuracy and detecting a change in effort.

Anonymous

Now would I pay £400 for one, I'm aiming for £250 inside a wheel, that's about a third of the price of a new one, not exactly nearly the same price.

schweiz

250 built up is fair enough, my pricing was just the hub.

schweiz

Here you go....

viewtopic.php?t=12901816&p=18106525#p18106525

£550 for wireless PT (non ANT+), Joule, disc wheel covers and a front wheel!