Weaklink

I was just servicing my new '08 Cannondale Tandem and noticed that one of teh spokes sounded dead. The bike only has a few hundred miles on it. So I throw it into bike truing stand and whip-out the Park tensionometer. WOW!! The tension was all over the place. On the disc side, 50 Kgf on one spoke, 95 on the next one. On the drive side, 76 on one 105 on the other.

Anyone know what the recommended drive side should be? The hub is white industries and the spokes are straight 2.0.

I have built many sets of my oun mountain bike wheels, so it's no big deal to fix. I'm just amazed it's out so far only after a few rides.

I'm going to adjust the drive side to 95, and the disc side should fall out to be about 85 I would guess. If anything, that should be on the cautious side of the tension range.

Thanks in advance.

James

mrfish

I don't know the correct spoke tension for that particular rim/hub/spoke combination, but I'm sure you wouldn't be far out if you tension everything to the average of what you see at the moment, assuming the rest of the wheel isn't near collapse.

If the tension is about right (and assuming the manufacturer started with the right length of spokes) the spokes should be 1-2mm inside the top of the nipples when looked at from outside the rim.

Alternatively you could look on google for similar wheels and the tensions used. Just look for typical max tensions used for the same type of rim as the rim eyelets is generally the weakest point in the system.

This Park tool tutorial shows tensions for Campag, Shimano and Bonti rims, which will be a useful guide. https://www.parktool.com/repair/readhowto.asp?id=128

I just looked up that the Dale Tandem has A719 rims in google then used "a719 spoke tension" to get:

Mavic CXP33 rim, Open Pro rim, and A719 rim:
recommended rear drive side tension: 105-110 kgf
Spoke count not critical in regard to tension with these rims, just the keep the average tension around 105-110 kgf per spoke on the rear drive side.

Plus some useful discussion here:
https://www.bikeforums.net/archive/index.php/t-356482

TandemGeek

If you plug your rim specs into Spokcalc it will give you the required tension; just back it into your Park Tensiometer conversion table: https://www.sheldonbrown.com/rinard/spocalc.htm