Deep dish newbie stem questions, be gentle

Triathlon Forum
1

Despite racing since 2005, I have never, until now, dealt with deep dish wheels (HED3s and covered DT Swiss PT to now,). Not sure if I am overthinking this (likely) or whether there is some secret science to it.

Using a 60/90 combo. Came with silca valve extenders. I can get 80 mm RVC tubes from my LBS, plus a 20 m valve extender. Is that better/worse/same as getting 48 mm tubes and a 60 mm extender? Figure the 80s work fine on the 60 and just need a short extension for the 90s.

Do I just need to do simple arithmetic to get > 60 and 90m or is there some benefit to using a combo of shorter stem/extender?

Thanks

2

You are overthinking it. Just use whatever you need to get a valve stem long enough to stick out of the rim.

3

You are overthinking it. Just use whatever you need to get a valve stem long enough to stick out of the rim.

Figures

Thanks

4

A good rule of thumb is that you need your valve+extension length to be at least 10mm deeper than your rim depth for clinchers, so depending on your pump and portable inflation setup , 100mm total stem in a 90mm rim may be cutting it very close, or may be totally OK. Also be sure to check that your extenders work with your roadside inflation. Many CO2 inflators require the valve core threads to properly engage the valve, and many of the ‘over the top’ type extenders don’t have those threads present.

The most important thing to remember is that you will want to set your spare up for the longer length so it can work in either wheel… I can’t count how many times I’ve seen people stuck on the side of the road who had planned on swapping valve extenders only to find some incompatibility, wrong combination of things, fixed core in the spare tube, something breaks, etc… So just put the long combination on your spare and the worst case is you have to ride to the finish line with an overly long extender on your front wheel.

Josh

5

Thanks for the tips. Will test it out before I get 50 miles into a ride and have to call the wife for a mercy pickup. :slight_smile:

6

The most important thing to remember is that you will want to set your spare up for the longer length so it can work in either wheel… I can’t count how many times I’ve seen people stuck on the side of the road who had planned on swapping valve extenders only to find some incompatibility,

This is exactly why all my spare tubes for my TT bike are 40mm.

I chuck a long extender in there that will clear both my 60mm front or 80mm rear. I figure that way all my spare tubes will fit in my disc and worst scenario I have a long extender handing out of my 60mm front.