Trek is pretty picky about stem design to prevent steering tube damage - they want no open holes on the backside of the stem clamp, clamping bolts spread out and no large holes on the inside of the clamp where it joins to the horizontal tube. Just had my fit redone and I need a 130mm stem, but there isn't a Bontrager 130mm RXL that I can see, they stop at 120 and I don't really want a carbon stem. Any suggestions on a stem that meets the Trek recommendations for stems? The only thing I could find is maybe the new Zipp Service Course SL stem, but I can't see how big the hole is on the inside of the steering tube clamp in any online pictures.
Srode
I wasn't sure if I understood so goolged pictures of Bontrager RXL to get an idea of what you were looking for then took a look at Domanes on Treks web site and it doesn't appear they are following their own advice on all the Domane models.
I think you're safe ignoring those requirements. A carbon steering tube is a carbon steering tube (they're all carbon and all round) so if a stem is good enough for any bike brand, which 99% if them are, it's good enough for a trek.
I think you're safe ignoring those requirements. A carbon steering tube is a carbon steering tube (they're all carbon and all round) so if a stem is good enough for any bike brand, which 99% if them are, it's good enough for a trek.
I can believe that Trek believes it.
For a while they and many other bike companies would void your carbon frame warranty if you used the frameset in a stationary trainer.
For a while they and many other bike companies would void your carbon frame warranty if you used the frameset in a stationary trainer.
About five years ago, Trek did send out two tech bulletins on incompatible stems for carbon steerers after some steerer failures during races. Can't find either bulletin on the web, but they are cited or summarized on many sites.
From a description of the second bulletin, quote:
"The issues with other stems has to do with placement of cutouts, size of lightness holes, and even angle of the clamp bolts. Proper stems should have no clamp cutaways like pictures on the FSA stem to the left, as according to Trek’s engineers, the cutaways can allow the separate parts of the stem to dig into the steerer.
Also, the lightening hole inside the steerer tube clamp must adhere to a sizing guideline. The hole must have at least 10 mm of stem material between the edge of the hole and either lip of the stem. A lightening hole that is too large can allow the edges to gouge the steerer tube as the bars are muscled around.
The issues with other stems has to do with placement of cutouts, size of lightness holes, and even angle of the clamp bolts. Proper stems should have no clamp cutaways like pictures on the FSA stem to the left, as according to Trek’s engineers, the cutaways can allow the separate parts of the stem to dig into the steerer."
Another issue according to Trek is edge treatment. Sharp edges around cutouts, holes and at the ends of the clamp could dig into the steerer carbon. The recommendation, of course, is "use only stems the Trek bike came with," which (for me, anyway) threw some doubt on all these dire warnings from Trek.
Source of italic quote above: Broken Trek Carbon Steerer Tubes: Result of the Wrong Stems?
From a description of the second bulletin, quote:
"The issues with other stems has to do with placement of cutouts, size of lightness holes, and even angle of the clamp bolts. Proper stems should have no clamp cutaways like pictures on the FSA stem to the left, as according to Trek’s engineers, the cutaways can allow the separate parts of the stem to dig into the steerer.
Also, the lightening hole inside the steerer tube clamp must adhere to a sizing guideline. The hole must have at least 10 mm of stem material between the edge of the hole and either lip of the stem. A lightening hole that is too large can allow the edges to gouge the steerer tube as the bars are muscled around.
The issues with other stems has to do with placement of cutouts, size of lightness holes, and even angle of the clamp bolts. Proper stems should have no clamp cutaways like pictures on the FSA stem to the left, as according to Trek’s engineers, the cutaways can allow the separate parts of the stem to dig into the steerer."
Another issue according to Trek is edge treatment. Sharp edges around cutouts, holes and at the ends of the clamp could dig into the steerer carbon. The recommendation, of course, is "use only stems the Trek bike came with," which (for me, anyway) threw some doubt on all these dire warnings from Trek.
Source of italic quote above: Broken Trek Carbon Steerer Tubes: Result of the Wrong Stems?
Thanks, for a minute after reading some responses I thought I perhaps was imagining it - but that's information I was referring to. Maybe it's dated and/or the issue was a not related to the stems to start with. Looking at my current Bontrager stems, they all seem to follow the guidance mentioned above though. Hard to imagine why there would be a difference in carbon steering tube design enough so that there would be a special requirement for one manufacturer. Maybe I'm over thinking it.
Just gets new bars with a reach difference to use with the existing stem to the desired reach result.? Excuse to get those chi chi carbon bars... ???
I have an OVAL stem with the canted slot on my Six 13, and that angle stress makes a lot of sense to me the @ 90^ frankly..
I have an OVAL stem with the canted slot on my Six 13, and that angle stress makes a lot of sense to me the @ 90^ frankly..
Ordered a Ritchey WCS 4 axis OS stem today, from what I can tell it checks all the boxes including the lightening hole inside the steerer tube hole. Found out Bontrager does make an RXL 130 but it isn't available in until January.
The handle bar drop is 5cm. The fit was done on a Guru Fit bike using a FIST protocol, then moved on to a 3D Retul fit process on my bikes (both the Niner and the Domane). The Guru fit process let's you plug in your info from the fit bike to find the right size frame in any line and it picked the 58 on my Domane which is what I have. The adjustments moved my saddle forward on the Domane by 2.5 cm which placed my knees right over the pedal axis and also added reach of about 1cm including the drop and longer stem vs where I was before. I'm a little over 6' tall, so anything bigger than a 58 wouldn't work well for me. I could move the saddle back a cm and use a 120 stem but that would defeat the purpose of having used the FIST protocol as the basis for the fit.
Did you check the Trek Store:
Stems - TrekBicycleStores.com - Bikes, Cycling Clothing, Gear and More
They have two 130mm stems made by Profile Designs. One is 7D, the other is 17D. They don't appear to have any cutouts.
But before you do anything, I'll ask a question nobody here has asked yet. Did you go back to the LBS who sold you the bike and ask their opinion as to what you should do and what is safe?
IMO, this is no laughing matter. I do a lot of my own work on my bikes, but when it comes to a carbon steerer, I let the experts at my LBS handle that one.
If you make a mistake here, you only make it once!
Stems - TrekBicycleStores.com - Bikes, Cycling Clothing, Gear and More
They have two 130mm stems made by Profile Designs. One is 7D, the other is 17D. They don't appear to have any cutouts.
But before you do anything, I'll ask a question nobody here has asked yet. Did you go back to the LBS who sold you the bike and ask their opinion as to what you should do and what is safe?
IMO, this is no laughing matter. I do a lot of my own work on my bikes, but when it comes to a carbon steerer, I let the experts at my LBS handle that one.
If you make a mistake here, you only make it once!
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