Tandem Cycling - Bearings or cartridge for older tandem?

We have two older tandems and one of them was probably made in the 90's (Northwoods brand). After checking the bottom bracket, i noted the bearing cup on the stoker was shot. My LBS says to bring it in and maybe a cartridge can be ordered for the thing.

Anyone with info on where cartridges for older off brand tandems can be gotten?


thanks

Duo

If the LBO determines that the BB threading is ISO standard (highly likely) then you'll have a ton of cartridge bearing choices going from cheaper off brands all the way to Phil Wood, SKF, etc. The two magic numbers are BB width (68 or 73mm typically) and spindle length. Match them up and you should be good to go. The third magic number is $. Plan on $25 min plus installation all the way up through the roof.

If the LBO determines that the BB threading is ISO standard (highly likely) then you'll have a ton of cartridge bearing choices going from cheaper off brands all the way to Phil Wood, SKF, etc. The two magic numbers are BB width (68 or 73mm typically) and spindle length. Match them up and you should be good to go. The third magic number is $. Plan on $25 min plus installation all the way up through the roof.

thanks

What a relief, i thought that being a tandem and off brand it would not work. Would i be correct in assuming that the spindles on tandems are not the same as single bikes? This bike does not have an eccentric, so that may work in my favor.

i am hoping to install the cartridge myself. This is not a problem i hope?

Duo

Phil Wood requires a special installation tool. Also, if you spend the $$ for PW, it will be the last one you will ever need. They last forever.

thanks

What a relief, i thought that being a tandem and off brand it would not work. Would i be correct in assuming that the spindles on tandems are not the same as single bikes? This bike does not have an eccentric, so that may work in my favor.

i am hoping to install the cartridge myself. This is not a problem i hope?

Duo

The BB parts are the same as that of single bikes. There are just two of everything. When you get your BB parts just be sure to get the installation tool and you should be good to go. Just remember that the cups on the left side of the bike are RH threading and on the right side they are LH thread - same as on a single bike.

The BB parts are the same as that of single bikes. There are just two of everything. When you get your BB parts just be sure to get the installation tool and you should be good to go. Just remember that the cups on the left side of the bike are RH threading and on the right side they are LH thread - same as on a single bike.

thanks again. i have been bracing myself for bicycle terror and uncertainties. It has been fun sometimes trying to repair these things, especially when the LBS doesn't feel qualified to touch them. Actually i think he is too busy to learn, but that has played in my favor to learn myself.

Opening up the BB and hubs has been kind of a treasure hunt; never know whats down there. Sometimes i do find some grease and feel better about the bike. i also am try to repair a Schwinn Duo Sport from the 80's, the last challenge is to completely overhaul the captains BB. Very odd looking parts to deal with from first observance.

Duo

Phil Wood requires a special installation tool. Also, if you spend the $$ for PW, it will be the last one you will ever need. They last forever.

Not true. PW is highly overrated. They might last forever if you ride in the US southwest where it seldom rains and people are even more seldom likely to ride in the rain. But in the Pacific Northwest, where cyclists ride in heavy rain and snow and the streets are salted and sanded in the winter, I have destroyed PW hubs and bearings in as little as one month of riding.

L.

The BB parts are the same as that of single bikes. There are just two of everything. When you get your BB parts just be sure to get the installation tool and you should be good to go. Just remember that the cups on the left side of the bike are RH threading and on the right side they are LH thread - same as on a single bike.

Well, sort of. The front bb axle is like a track axle that accommodates a single chainring on the left and a bare crank on the right. The rear axle needs to take a single chainring crank on the left and a triple chainring crank on the right.

Threadings listed above are for English-threaded eccentrics and rear bottom brackets. "Northwoods" sounds like it would have been built with English-threaded bb's. If the threadings are Italian, the cups are all right-hand thread. (Just in case you ever acquire a Pogliaghi tandem...)

I'm surprised there's no front eccentric. How do you adjust the timing chain? And how would it work in your favor to not have an eccentric? The bb merely threads into the eccentric.

Cartridges are not as durable as cup-and-cone bearings; in fact, Shimano still uses the older technology because bearing cartridges are not really appropriate for use on bikes. Cartridges are fine on motors, where the load is from a fixed source applied radially. On a bike, loads are transferred at right angles, so you get thrust loads, which are more appropriate for cup-and-cone design. I think they're starting to use asymmetrical cartridges in headsets. Anyway, a cup-and-cone bearing, properly maintained, will outlast many cartridge bearings on a bicycle.

L.

Well, sort of. The front bb axle is like a track axle that accommodates a single chainring on the left and a bare crank on the right. The rear axle needs to take a single chainring crank on the left and a triple chainring crank on the right.

Threadings listed above are for English-threaded eccentrics and rear bottom brackets. "Northwoods" sounds like it would have been built with English-threaded bb's. If the threadings are Italian, the cups are all right-hand thread. (Just in case you ever acquire a Pogliaghi tandem...)

I'm surprised there's no front eccentric. How do you adjust the timing chain? And how would it work in your favor to not have an eccentric? The bb merely threads into the eccentric.

Cartridges are not as durable as cup-and-cone bearings; in fact, Shimano still uses the older technology because bearing cartridges are not really appropriate for use on bikes. Cartridges are fine on motors, where the load is from a fixed source applied radially. On a bike, loads are transferred at right angles, so you get thrust loads, which are more appropriate for cup-and-cone design. I think they're starting to use asymmetrical cartridges in headsets. Anyway, a cup-and-cone bearing, properly maintained, will outlast many cartridge bearings on a bicycle.

L.

This Northwoods bike was made in Indonesia, very little info seems to be available on the thing.

My LBS said a cartridge is the way to go as cups/cones are not available. He did say to bring it in and see if he has some old cups that might fit.

The chain doesn't use an eccentric as there is an external chain tensioning wheel. We have a problem getting the chain tight, so the LBS has a half link on order.

thanks

Duo

Not true. PW is highly overrated. They might last forever if you ride in the US southwest where it seldom rains and people are even more seldom likely to ride in the rain. But in the Pacific Northwest, where cyclists ride in heavy rain and snow and the streets are salted and sanded in the winter, I have destroyed PW hubs and bearings in as little as one month of riding.

L.

Oops...sorry. We don't get much rain here, so i don't have much experience with PW & rain.