Older Santana drivetrain question

[bgross]

Hi gang --

We are adding another tandem to our stable: 1984 Santana Arriva.

It has a 5-speed rear cog and the triple looks like a 53/42/granny.

Being Clydesdales (370# team) we'll need to bring the drivetrain into the 21st century, or at least into our sunset years!

Does anyone have an idea how far we can go on the rear end before we're into a new wheel/hub? I don't yet know what the rear spacing is (we pick up the bike at noon today) so I'm just fishing -- wondering if anyone here is familiar with the vintage Arriva specs.

Thanks for any input -- I'll post more info as it becomes available.
Can you tell that we're excited?

Bret

[ct-vt-trekker]

It's a 5 speed freewheel. You could go up to a 7sp freewheel with the same overall width just the spaces between the cogs will be less. You'll have to go to a narrower 7sp chain.

[bgross]

Thanks for the info.
That should give us a little more flexibility in riding.

[nfmisso]

one of the many nice things about Santana is that they all have wide rear spacing. http://santanatandem.com/Leadership/Innovation.html Your is 140mm, and a 145mm will fit in okay. Thus if you decide to change your rear hub, you have the same choices as most new tandems.

[briwasson]

Indeed, it's pretty easy to pop a 145mm-spaced rear wheel in there and use a 7-speed cassette. That way you shouldn't have to upgrade too many of the drivetrain components. I did that on my first Santana, a 1989 Rio.

[bgross]

The shop called and the bike is ready.

He said that the way the rear wheel is built & dished, there wasn't enough room for the 7-speed on the threads. So he switched out the old 5-speed which had a 32-tooth with one which has a 34-tooth -- just the thing that a couple of geriatric clydesdales need.

I plan on doing several solo rides on it to get used to using the bar-con shifters (a new experience for me) and the front/rear ratios.

Thanks for all of your suggestions.

[briwasson]

Be aware that there are downsides to a freewheel hub on a tandem in that they are more prone to breaking axles than a cassette hub. Freewheel hubs don't support the drive-side part of the axle as well as cassette hubs, resulting in greater stress being put on the axle. Basically the freewheel hub has the axle hanging out a ways past the bearings (the length of the freewheel) in an unsupported manner, giving it more leverage to break. A cassette hub supports the axle on bearings basically to the outside of the cassette body. It may be just fine, but with a heavier team you have a chance of having problems at some point. See Sheldon Brown's page on the difference, and especially look at the picture at the top that shows the way axles are supported in the two types of hubs: http://www.sheldonbrown.com/freewheels.html

Just something to be aware of. If it does end up breaking, it's probably a good time to upgrade to a cassette freehub and run a 7-speed cassette (or better). Also, the torque from two riders often makes freewheels nearly impossible to remove on a tandem.

Here's what respected wheelbuilder Peter White says about freewheels:

"I no longer stock freewheel type rear hubs for tandems. There are several reasons for this. Freewheels are difficult to remove from tandem hubs because of the added torque of two riders. With only a few exceptions, freewheels don't offer Hyperglide shifting ramps which are particularly effective on tandems. Those exceptions are either not ruggedly built for use on tandems or don't offer a suitable range of gears. No eight speed freewheels exist in the correct spacing for Shimano's eight speed shifters.

The only freewheel type rear tandem hub that I recommend is the Phil Wood. [...] But I would strongly recommend getting a cassette hub if at all possible."

[idcruiserman]

The hubs on my 15 speed Santana are Phil Wood.