bartel.michiels

I've a Trek T50 tandem (+- 1994) and I want to change the threaded headset (ball bearings) to a threaded headset with industrial (cartridge) bearings.
This makes it easier to take my fork off for traveling (no grease, loose parts, ...).

I don't know what size headset I need. I can not measure the inside diameter of the head tube (crown race inside diameter) because I don't want to remove the old cups before I have a new headset.

The outside diameter of the head tube is 40,69 mm. The fork is the original Tange fork. The headset is ACCOR.

What size of headset (crown race inside diameter) do I need and are there suggestions for a specific brand and model with industrial bearings that will fit?


Thx

Bart

WPH

Bart


These frames came with 1 and a quarter inch threaded headsets (1&1/4in). Sheldon Brown shows the dimensions here: Sheldon Brown's Bicycle Headset Dimension Crib Sheet I gather this is a slightly different size from the 1.25in headsets used by Santana tandems, but I am not certain.

This size headset is hard to find these days. The only new ones I have found on the internet have been expensive. https://chrisking.com/specs/headsets_all - the 2Nut is threaded and will be compatible with the T50's cantilever brake hanger.

Several of us on this forum who have the old Trek steel frame tandems have opted for a different solution to the travel problem you have. Nitto make a threadless stem adaptor to fit inside the 1 & 1/4 Trek tandem fork steerer tube. The top of the adaptor takes a standard oversized road or MTB stem, which normally come these days with a 'front loading' removable clamp. Simply undo 2 (or 4) 4mm allen key bolts and your handlebars come away. No need to remove the whole fork or any brake hangers etc. Plus you get to use stems which are available in a wide range of lengths and angles and which can take modern oversized handlebars.

Here are the details: Nitto MT Column Adaptor for 1 1/4 Threaded Systems - Harris Cyclery bicycle shop - West Newton, Massachusetts. I bought mine from Tandems East because they seem to be unavailable in Australia - you may have more luck locally in Belgium. The adaptor is very good quality, much better than the $15 adaptors for 1 inch frames. I have been very happy with this Nitto adaptor and plan to leave the current Shimano XT threaded headset in place until it dies.

Cheers



Will

bartel.michiels

Will, thanks for the information,

I already have a classic quill pen with 31,8 clamp for my On-one midge drop bar. Although the pen is an adjustable pen, I prefer a pen in one piece, but I didn't found one.

So, to remove the drop bar is not an issue. But I prefer to remove the whole fork: I use a Groundeffect body bag for traveling and the tandem with the wheels taken off fits in the bag (with no margin). However the bag with the tandem inside measures 185 cm and is to large for transportation in trains in Spain and the U.K. With the fork removed and strapped at the side of the frame, it measures 165 cm, which is the size of a single bike and accepted in most trains and busses. I need the bag as we like to travel with airplanes, trains and busses with the least hassle.

Velo Orange makes a nice "Rinko" headset (to be taken apart with no tools) but doesn't fit my frame. Apart of the CK 1 1/4 headset I find no other threaded headsets with cartridge bearings.

Bart