# Seat Mast Problem



## rboseley (Sep 28, 2007)

I have a 5.2 Pro and I love just about everything about it. One problem I am having is with the fore/aft saddle position. I like to get the saddle back pretty far, but the very suspect Trek clamp will not hold the saddle in position if it is shoved back. You get a sinking feeling, and it is not imaginary. I have tightened the clamp as much as I dare with no luck. I thought I read that Trek had three versions of the mast available, but I can’t find much info. Anyone know the cost of these masts?


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## PJ352 (Dec 5, 2007)

The link below will describe the three offsets offered - I don't know the cost.
http://www.trekbikes.com/madone/technology/comfort/

There has been a change to the assembly, but that's been thoroughly covered in another Trek forum thread. Just a FYI, I'm only mentioning the change because it exists, but it won't affect the offsets you're interested in.


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## 08Madone5.2 (Dec 25, 2007)

Call your Trek dealer, or better yet, Trek HQ and I'm sure you will be able to get pricing info. If you speak to a rep at Trek HQ, you may even be able them to send you a new one at no cost to yourself (especially if you have the original cap with silver clamp). I had no issues with my original cap/clamp combo but they swapped it for a new combo (with the new black clamp) for me at no cost.


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## Dale (Mar 13, 2004)

the cost is $119.00 I paid $75.00 for the new updated seat mast I got the 5mm offset.


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## zac (Aug 5, 2005)

I think you may be out of luck: your three offset options are -10mm (forward) and 5 and 20mm rearward. The standard mast cap is the +20mm one. I can't understand why so far back? You will be too far behind your cranks for best power. I am wondering if your frame is too small to begin with.


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## wrshultz (Feb 10, 2005)

*Seat cap clamp or seat rail clamp?*

Are you having a problem with the seat cap slipping down on the seat mast, or with the seat rail clamp not holding the saddle level? 

The Trek shop I deal with has had problems with the upper clamp for the seat rails not being able to hold the seat rails parallel. Trek has provided a different clamp module that has worked so far.

I have the older seat cap with the silver clamp on my Madone 5.2, and have not had a slipping problem there. However, I did need to have the seat rail clamp at the top of the seat cap changed out to keep my saddle in position. The original clamp allowed the seat rails to twist while riding, leaving one side of the saddle noticebly higher in the rear. No amount of tightening the original clamp would solve the problem, but the new clamp Trek provided works fine.

Anybody else had this issue?

Bill


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## WhiskeyNovember (May 31, 2003)

zac said:


> The standard mast cap is the +20mm one. I can't understand why so far back? You will be too far behind your cranks for best power.


Depends on the length of the rider's femurs.


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## 08Madone5.2 (Dec 25, 2007)

If someone doesn't have the new Madone, this will be hard to follow but... there are notches on the plastic housing that sits in the cap that the rail clamp on each side has to line up with. If you tighten the rail clamp without lining them up with the notches, the rail clamps wont line up correctly. Sometimes it takes a few tries to get it right.


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## zac (Aug 5, 2005)

WhiskeyNovember said:


> Depends on the length of the rider's femurs.


Yeah I was thinking that, but still the standard seat mast cap is the 20mm back one and the OP was trying to go back further.


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## PJ352 (Dec 5, 2007)

I think we're getting off the track. If you reread the OP's description, he suspects that once he sets the seat rails in position and tightens the clamp, it doesn't hold the position. I'm not sure that he want to increase his setback, as much as he wants where the seat is fastened (at the rails) to hold it's position. Wrshultz post better describes it.


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## PJ352 (Dec 5, 2007)

Hey '08, regarding the new mast assembly, did you notice if it included differently designed seat rail clamps? I'm wondering if that too hasn't been changed considering wrshultz post above.


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## 08Madone5.2 (Dec 25, 2007)

pj -

As far as I can tell, the seat rail clamps seem the same. The only real difference is the cap itself - it has no vertical slot at the bottom - and the newly designed black clamp.


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## I-Ride (Jan 18, 2008)

Any concerns about longer term design and replacements? The seat mast is proprietary and only by Trek, so if they change design, and no longer carry, replacement c/b an issue....


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## 08Madone5.2 (Dec 25, 2007)

No - this design will be around for at least the next 7 yrs according to the following review:

http://www.aboc.com.au/equipment-reviews/complete-bicycles/2008-trek-madone-5-2-performance


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## PJ352 (Dec 5, 2007)

This type of concern (which I share) is exactly why I posted the review (which '08 references). I've had my current bike for 17 years, and while that may not be the norm, I don't take solace in hearing that proprietary parts/ designs will be supported for 7 years. It's not just the seat assembly either. The BB bearings and fork are also proprietary. If anyone doubts this, let them try installing a crankset not yet supported or an Easton/ Reynolds fork. It's not just Trek doing this, LOOK forks also use a proprietary design.

These types of issues aren't a concern to some because they either change bikes fairly often or just don't care, but I'm not sure I'm comfortable being 'married' to a brand like that. There are many other choices (Trek included) that don't (yet) suscribe to this practice.


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## 08Madone5.2 (Dec 25, 2007)

PJ -
I don't necessarily disagree with what you are saying but Trek is a big company and I highly doubt 10 or 12 years from now you won't be able to get a seat cap or clamp replacement. One of the nice things about buying a Trek as opposed to a boutique brand is that you can be pretty sure they will still be around to service what they sold, even if it was 10 yrs ago. The same can be said of most major crank mfrs. As far as bearing replacements, that is a non issue now and always will be a non issue. The bearings are standard size bearings and there must be a slew of mfrs who make bearings for all kinds of industrial purposes that will also fit a Trek bearing cup. Nothing personal against you - I enjoy our back and forth - but it seems that so many people, and not just in relation to bikes, look for a million reasons not to do or buy something. Buy the bike, enjoy it, it won't be the last bike you ever buy and let the future take care of itself. While everyone is looking for excuses not to buy a new Madone, I'm out 3-4 x a week in this cold weather and enjoying myself, not to mention reaping the benefits of getting off my ass and out for some exercise. Whats the worst case scenario? Someone buys a bike and its obsolete in 7 yrs?? Uh Oh, I better not buy it now, maybe I should wait 7 years for the next latest greatest.


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## 08Madone5.2 (Dec 25, 2007)

After further consideration, this is all nit picky crap. Id be a lot more concerned about the construction of a CF frame or any frame material for that matter - whether or not it was constructed with quality materials, layups, engineering etc... Recently a gentleman where I live suffered a catastrophic frame failure of a name brand frame (made in Spain) that resulted in his death. That scares me a hell of a lot more than whether or not a replacement clamp or bearing might be available 7 yrs from now... Come on people, give it a rest!


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## prschatt (Aug 19, 2007)

PJ352 said:


> This type of concern (which I share) is exactly why I posted the review (which '08 references). I've had my current bike for 17 years, and while that may not be the norm, I don't take solace in hearing that proprietary parts/ designs will be supported for 7 years. It's not just the seat assembly either. The BB bearings and fork are also proprietary. If anyone doubts this, let them try installing a crankset not yet supported or an Easton/ Reynolds fork. It's not just Trek doing this, LOOK forks also use a proprietary design.
> 
> These types of issues aren't a concern to some because they either change bikes fairly often or just don't care, but I'm not sure I'm comfortable being 'married' to a brand like that. There are many other choices (Trek included) that don't (yet) suscribe to this practice.



BB bearings are not proprietary, I swapped them out for ceramics in about 5 minutes using a SRAM Force crank. TREK Provides an adapter for $40.00 if you want to use FSA & Campy cranks, . Regular bearings are the same used in the external GXP bearings with any crankset.
I have the new mast cap, the seat clamps are a pain. I had swapped the old cap because it was slipping, which was easier to adjust ASA the seat angle and clamping rails, something weird about the new one. Even lining up the plastic detents took a bit of back and forth adjustments.


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## PJ352 (Dec 5, 2007)

08Madone5.2 said:


> PJ -
> I don't necessarily disagree with what you are saying but Trek is a big company and I highly doubt 10 or 12 years from now you won't be able to get a seat cap or clamp replacement. One of the nice things about buying a Trek as opposed to a boutique brand is that you can be pretty sure they will still be around to service what they sold, even if it was 10 yrs ago. The same can be said of most major crank mfrs. As far as bearing replacements, that is a non issue now and always will be a non issue. The bearings are standard size bearings and there must be a slew of mfrs who make bearings for all kinds of industrial purposes that will also fit a Trek bearing cup. Nothing personal against you - I enjoy our back and forth - but it seems that so many people, and not just in relation to bikes, look for a million reasons not to do or buy something. Buy the bike, enjoy it, it won't be the last bike you ever buy and let the future take care of itself. While everyone is looking for excuses not to buy a new Madone, I'm out 3-4 x a week in this cold weather and enjoying myself, not to mention reaping the benefits of getting off my ass and out for some exercise. Whats the worst case scenario? Someone buys a bike and its obsolete in 7 yrs?? Uh Oh, I better not buy it now, maybe I should wait 7 years for the next latest greatest.


Hey, '08, for some reason I anticipated I'd get a response from you on this post. I must be psychic! :eek6:

Let me clarify some things.

The bearings themselves are not proprietary, but the installation of certain brands of cranksets requires an adaptor (may be the wrong term) designed and supplied by Trek. If you doubt this, sift through Treks website and you will find where they cover the issue. That given, you'd better hope that Trek will be around to supply parts for their proprietary designs because you'll have no other options. Which brings me to the crux of the matter, options, or lack thereof. 

As far as finding reason NOT to purchase a given item (bike, whatever) I can't speak for others but here's how I approach the purchase. As I've already said, my bike is 17 years old. In the 23 years I've been riding, I've had 2 bikes, so I'm obviously not a follow the fad kind of shopper. I get what I like, maintain it and stay with it for as long as it lasts, or I can make it last. If you saw my current ride, you'd understand.

So in my quest for a new ride I read as much as I can, ride as many as I can and do some analysis along the way hoping that ultimately, I make the right choice. It's that important to me. It has nothing to do with missing rides because I can still ride (if it weren't 17 degrees out) and shop for bikes and, thankfully, the Madone isn't the only choice. There are lots of others, Trek included.

So that in a nutshell (or three paragraphs) is how I'm approaching the issue. You don't have to subscribe to my philosophy nor I to yours. We just get to share our thoughts/ viewpoints knowing the other may or may not agree.


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## 08Madone5.2 (Dec 25, 2007)

My original cap/clamp slipped only after my first ride. When i properly torqued it to the recommend 8NM, it never slipped even a hair again. I too have the new cap with black clamp and it doesn't slip at all. Its torqued to the recommended 7NM. It did take a few tries to seat the clamp rails properly but that only requires patience to do properly. All in all, not a big deal. Im sure its a lot harder trying to assemble an older type of crank assembly with their many more pieces than it is to assemble the new Trek crank assembly with its 5 pieces. You know, any new bike that someone buys has to be tweaked and adjusted until it all gets seated properly. All things being equal, the new Madone is an awesome ride.


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## PJ352 (Dec 5, 2007)

Yes, you're right about the BB bearings. I clarified in another post here.


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## PJ352 (Dec 5, 2007)

No one is saying that on a grand scale there aren't far more important things to worry about in our lives, but everyone has the right to their opinion on the new Madone, both good, bad, or indifferent. That's what a forum is - exchange of thoughts and ideas and that's all that's going on here.


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## 08Madone5.2 (Dec 25, 2007)

Pj- 

You are correct with your opinion and on that note I hereby rest on this post! Its all good, one day maybe we can meet and go for a ride and look back and laugh. Maybe you will be laughing at me as my seat cap slips, my new black clamp cracks, my BB bearings disintegrate, my crank fails, my Ultegra SLs are too heavy, my head bearing seizes and we watch as my carbon frame crumbles to dust in a pile along the roadside!!! I hope your 23 yr old bike will be able to support our weight as I climb on for a lift back to Saratoga!!


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## PJ352 (Dec 5, 2007)

'08, I have no desire to laugh at you or wish anything but the best for you and your new ride. They're great bikes and no, I'm not just saying that. It's as you say, you ride and I ponder, but I'll get there eventually.


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## 08Madone5.2 (Dec 25, 2007)

Oh come on, I thought my post was funny! I'm sure whatever you decide to buy, you will love it. And you are correct in researching, analyzing, testing etc... I did the same but it was my test ride that was the clincher. I have no regrets and Trek has been wonderful in terms of their support and service for me. Now that I have my new cap/clamp, I hope I won't need their customer support for at least 7 years!!!!


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## PJ352 (Dec 5, 2007)

Yes, your post _was_ funny, I was smiling all the way through the read.

My test ride of the new Madone was the clincher as well. Literally, when I got off the bike I said 'this is the best bike I've ever ridden', and I still feel that way. But through a sequence of events, I'm back at square one today. But enough of that. I always say it'll all work out, and it will.

I now have a question in to Trek asking if they can describe the real world differences in ride qualities between OCLV and TCT carbon. I'm 1/2 expecting info peppered with marketing hype (sorry, it's the cynic in me), but will let you know the results if you're interested.


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## rboseley (Sep 28, 2007)

As the original poster, I guess I should weigh in again. I can live with the 20mm setback IF the rail clamps would hold. With the saddle back almost as far as it will go, and the clamp as tight as I dare tighten it – my 160 lbs sitting on the “sit bone” position of the saddle causes it to dip. My dealer is getting me the new clamp, but as I read the posts, this probably isn’t going to make any difference. As to WHY SO FAR BACK – that is a story too long to get into; except that a friend (former pro) got me into this position about a year ago. It took me about three months to get the hang of the power stroke he suggested, but now that I have it - I will never go back. Obviously this is an individual thing, except if he had not virtually insisted I use it for at least three months; I would still be in the KOPS position. There you are. Now I have to figure a way to get the saddle to remain level. Slipping down the tube was never a problem. :mad2:


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## zac (Aug 5, 2005)

I understand.

Do you know which version of the mast that you have? My shop also indicated a problem with the early released version (silver mast clamp). I wasn't paying particular attention (as it didn't apply to my ride) but now, in retrospect, I realize that he was talking about the saddle rails twisting out. I think he was telling me about some problems they had with some of their early 5.2s that they had.


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## PJ352 (Dec 5, 2007)

A couple of thoughts.. It may be worth your while to bypass your LBS and call Trek HQ/ support, whatever they call the division - about the seat rail issue. '08 Madone mentions HQ up a few posts, and I know they've been pretty receptive to his calls.

Secondly, I understand how one could get used to a set back saddle position after 3 months, but just like you got used to IT, why not go back to KOPS for 3 months and hopefully it will (again) be your new starting point.


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## prschatt (Aug 19, 2007)

The replacement mast cap that received (Bontrager) was a pain to get with regard to adjusting the saddle rails clamp and position, I finally overly greased the rotational part in the top piece, used a device that I use on my rifles for slope adjustment, and with force held it in position while tightening and watching the degree change. That done, it was then somewhat canted one side high, one side low. After close to 40 minutes of frustrating tweaking I finally dialed it in. It's not slipped and positionally is perfect, but I never spent soo much time tweaking a saddle.


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## rboseley (Sep 28, 2007)

I am totally confused. According to my LBS the only change was to the clamp. (mast clamp) From what I am reading the rail clamp is also changed? I know Trek is coming with a clamp to fit oversized rails, but that is down the road. If there is currently a new rail clamp assembly, then that is what I need. Of course it will be another single bolt clamp, which will still make me long for my FSA double bolt post. Guest I will try calling Trek OR as suggested just forget the setback and pedal via KOPS. That will make getting up these Florida mountains extremely difficult.

BTW – I DO love the new Trek, but it took some getting used to. I came off a ’04 5500, and for the first few hundred miles I was definitely slower. However, I have now overcome the deficit and have now gained over the 5500. Too bad LA isn’t still racing. I would love to know if he would actually embrace the new design. ( I know he says so, but that is the businessperson talking). A few “observers” around Austin are saying he is riding the ’07. I actually don’t believe that because he now owns some portion (minor) of Trek. But a slant tube bike? Don’t know.


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## PJ352 (Dec 5, 2007)

prschatt/ rboseley - seriously, IMO you guys should contact trek tech/ customer support and make them aware of these issues. They need customer feedback to learn what's going on and in turn, make the needed corrections - if indeed they are needed. 

rboseley - If you get a remedy for the seat rail issue, there's a good chance you'll be able to maintain most, if not all, of your current setback. It's worth a shot to try!!

Interesting comments re: Lance Armstrong. I personally think he'd ride either the '07 or '08 without much concern, because the title of his book demonstrates his attitude - _it's not about the bike! _


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## zac (Aug 5, 2005)

rboseley said:


> I am totally confused. According to my LBS the only change was to the clamp. (mast clamp) From what I am reading the rail clamp is also changed? I know Trek is coming with a clamp to fit oversized rails, but that is down the road. If there is currently a new rail clamp assembly, then that is what I need. Of course it will be another single bolt clamp, which will still make me long for my FSA double bolt post. Guest I will try calling Trek OR as suggested just forget the setback and pedal via KOPS. That will make getting up these Florida mountains extremely difficult.
> 
> BTW – I DO love the new Trek, but it took some getting used to. I came off a ’04 5500, and for the first few hundred miles I was definitely slower. However, I have now overcome the deficit and have now gained over the 5500. Too bad LA isn’t still racing. I would love to know if he would actually embrace the new design. ( I know he says so, but that is the businessperson talking). A few “observers” around Austin are saying he is riding the ’07. I actually don’t believe that because he now owns some portion (minor) of Trek. But a slant tube bike? Don’t know.



Maybe someone who has replaced the mast and has both on hand can chime in. Because I have no first hand knowledge, only what was relayed (albeit inattentively) to me. [I haven't had to adjust my saddle yet (we did all that at the shop and apart from having to tighten the mast clamp bolts and seat bolt more) it has been spot on. BTW I use blue thread lock on the bolts.]

I definitely would notify both your LBS and Trek directly about this issue. This seat mast is new for them and represents a complete redesign. It plays a key role in the frames vertical compliance. They need the feed back. Maybe the same stresses that the frame is relieving is being displaced into the mast stay. Weird twisting and deforming going on. Hey I hate to be a beta tester too, especially for $3000+ items, but we early adopters know that going in, don't we.


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## 08Madone5.2 (Dec 25, 2007)

I just received a new cap and clamp from Trek. The cap is slightly changed - no more keyhole slit. There is also a cutout where the rear part of the clamp is - this helps the clamp assembly clamp the seat mast itself. The clamp is changed as well - black, more streamlined and meets the mast in a parallel position as opposed to the silver clamp which met the mast at an angle. As far as I can tell, the rail clamps are unchanged. Go to the Trek site and you will see pictures of new vs. old cap/clamp combo. For what its worth, I have had no problems with either setup. The most important thing is to torque it correctly.


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