IanS

The free wheel on our rear Bontrager Racelite tandem wheel went last week so we thought we'd just replace it. However, when my pilot took the rear hub apart the mechaism is totally different to anything he's seen before.

Rather than a standard free wheel with pawls, there are 2 small (around 4-5 cm) splined wheels. The outer engages with the cassette carrier body which has slots that the splines fit into, and the other engages with the hub body. These two seemingly identical splined wheels are then pressed together by springs on either side of them and the splines are shaped such that they engages when driving forward and allow the wheel to spin freely otherwise.

These are very warn and so I was just wondering whether anyone knows what they are called and whether I can simply by replacements? Or whether there is a fixed wheel version of this interface that we could use to convert the wheel to fixed gear. ie, rather than 2 sparate pieces, just one thicker piece that engaged with both the hub body and the cassette carrier?

I'm affraid i don't even know what these would be called to even look for them so any help would be appreciated.

The hubs I believe are DT Swiss Tandem.

Cheers
Ian

DubT

I would suggest contacting DT Swiss. I was able to obtain spare axles for the Bontrager wheels from them.

diabloridr

The parts in question are called "Star Rachets".

I believe you are correct that this is a DT Swiss hub built for Bontrager.

I've retired all my Bontrager wheels but I still have the instructions for overhauling this type hub. If you can figure a way to get me an email address I'd be happy to shoot a PDF of these instructions.

PMK

While not impossible to be worn, I doubt the drive rings are truly worn. That would involve a huge amount of coasting.

We run DT hubs on our road and off-road tandems. The typical concern is to clean and relube to prevent them drives from sticking, thus not engaging. If the drives have stuck and you slipped them, it may have rounded the teeth tips. This could be the wear you see. Make certain all items slide freely. Reassemble, test it and run it more if it engages properly. There is a special DT Molykote grease for the drives. Normal grease it too viscous. Even with DT Molykote, a thin layer is all it requires. FWIW, some of our hubs are run with oil and work fine. Just require more frequent cleaning and relube.

PK

justcrankn

You need the DT Swiss service kit. It contains ratchets, springs, and grease. You might even consider a "36 T upgrade kit for star ratchet® hubs", but I'm not sure if it's available for this hub.

Edit-Never mind the upgrade kit. It's not for the tandem hub.

PMK

FWIW, the kit listed fits many hubs. Should fit all small axle hubs, including the TD which is a tandem hub, and more than likely the 540 also. $45 seems steep though.

PK

IanS

Thanks for the suggestions. I've sent an email to DT Swiss anyway as suggested to see what they say. I also wanted to know whether it was possible to set this hub up as a fixed wheel. It would seem straightforward in theory as all you'd need would be a single star rachet that engaged with both the cassette carrier and hub body but suspect the demand for such a thing would be somewhat limited so may well not exist.

Just to be clear though, the drive has failed on the wheel so tjust spins when we turn the pedals. You can feel it trying to engage but it just doesn't. We hardly ever free wheel when out on rides either so am guessing it's not possible to do anything with the warn out star rachets?

This is the second Bontrager racelite tandem wheel that has failed in this way but they they have both done around 8,000 miles each of hard riding and have just been fantastic during this time. It's probably ready for replacing anyway but this latest wheel to have gone has still got a little life in it yet, hasn't even broke a spoke which on the road round here is very unusual, and so like to see if it can be fixed. Or as mentioned above, converted into a fixed wheel.

Cheers
Ian

PMK

With the ease of disassembly and reassembly, have you cleaned the parts, assembled dry to verify the rings slide freely. Then reassembled to test, even with a light oil? These drives are so simple to work on and with, the most common cause of drive failure is lack of just cleaning and relubrication.

Is this a double or single spring setup? Early Hugi hubs were single spring, later styles use two springs.

FWIW, our road tandem drives are cleaned and relubed normally each rear tire change. Adds about 10 minutes to the tire change task.

Hope you get it resolved to your comfort level.

PK

DubT

Would you please email me the PDF instructions. I have the Bontrager wheels on our tandem. wthais@mchsi.com Thanks

IanS

There are 2 springs, in the hub, either side of the 2 star rachets. So from your comment, this is a newer Bontrager wheel? It's about 3 years old if that helps?

Do the TD Swiss maintenancekit referred to above come with the parts I need or do I need tandem specific star rachets?

And does anyone know whether there is a star ratchet that would convert the wheel to a fixed gear setup?

PMK

As for the fitment of that kit, it probably will fit since there are not many variations on DT drives.

Knowing you want it locked for a fixie, save your money on the repair kit, the trashed drive rings will make a great locked hub. Take the two drive rings to a good welding shop. Have them clean them, then clamp in the locked position, tooth to tooth. Carefully weld the high spots of the splines with decent penetration, smooth them for a good fit in the hub. Reinstall with the pair of springs and do whatever it is fixie riders do.

The drive torque will be handled by the ratchet, the weld merely holds the ratchets from separating. With a good weld on each spline segment, even the most apt to stop the peddles rider will not fracture the welds.

PK

wheelspeed

Hi diabloridr... I'm also using a set of the RaceLite Tandem wheels. I sent you a P.M.