|Question about stem rise||DINOSAUR|
Feb 7, 2002 9:19 AM
|I'm in the market for a new stem, I want to go from a 12cm to a 11cm. When checking on various catalogs they all list different rises for the same stem. Example: Ritchey Pro Ahead Stem 73o rise, another catatog 15 o rise. The 15o rise is listed as a road stem. Another catalog lists the Ritchey Pro as a 83o rise. I'm getting confused....Currently I'm using a Syncros 12cm 73 rise. I want to keep the same rise but go to a short length. It would probably be easier to go with another Syncros but I'm short of funds and they around $119.00, on sale.
I saw threads below referring to how stem rises are measured and it got me thinking...
Also, is it necessary that I have a star nut installation tool, or should I just let my LBS handle the install?
|I've been throught this, and have spoken with a couple of||Paul|
Feb 7, 2002 11:54 AM
|mechanics. It's very confusing, but I'll pass on my experience, I'm not professing to be an expert. I have a Ritchey WCS 84 dg. rise which is advertised as +- 6 deg. |
Subtract 6 from 90, get 84. Some advertise 90 and 0 deg. as one in the same. Now, this 6 deg puts my bar up about 1.5 inches as measured from the difference in a 90 deg. stem. If I reverse the 84 deg stem, it brings it down about 3/4 inch. I thought i would get a neg (performance advertises this way e.g. -17) rise, like going below the bar. But that's not the case.
These measurements are really taken from the head tube angle of the bike in a diagram I saw.
But -17 is really a zero deg., (parallel with the top tube) which again is really 73 deg, subtract this from 90 (I also have the Ritchey pro 73 , runs parallel with the top tube, but can be reversed like any of them for a greater rise). I actually went in to the shop, took a bunch of stems, and along with the mechanic(he has always been confused about advertised rises) who has won 11 National Champonships, and been in 4 Olympics (has metals), put these stems on a bike, and made our observations.
Just buy a 11 cm 73, or 90, or 0 rise, or -17, i'm pretty sure should be all the same. Maybe we can get some more expert opinions. There is a diagram that shows how these angles are taken in a stem catalog. Check it out.
Don't need a star nut tool for installation of a threadless stem (replacement). Just loosen up the stem bolts first, then take off the bolt that puts the pressure on the bearing cups. Put back in reverse order. Make sure you fork is secure to the bike before doing this, or on the floor, as you could have the fork drop out and lose bearings if they are not the sealed kind. Really an easy job.
Again, just my experience with this confusig issue.
Are you the retired CHP officer?
|I've been throught this, and have spoken with a couple of||DINOSAUR|
Feb 7, 2002 2:32 PM
|Thanks for that information, it does get confusing. I actually ordered a Ritchey Pro Ahead stem from Bike Nashbar, then I had second thoughts about the rise I wanted and I canceled my order (another story in itself). So I just dragged my bike down to my LBS and we looked at all the stems they had in stock. I knew exactly what I wanted if I could just see it. I went with a Profile Design 110mm 73 degree rise, which is pretty much parallel to my top tube, which is what I wanted. Now I'm down lower and closer to the bars which is what my body has been telling me on my rides. I forgot about the headtube angle, that would make a difference. I know Profile isn't exactly chi-chi, but I like the polished silver look, it's reasonably light, strong, and best of all it fits! Now if I could just get rid of this lousy cold I've had for the past week and if it stops raining I can start riding again!
Yes I am a retired CHP...believe me if I wasn't retired I wouldn't want anyone to know what I did for a living. Now I'm just an old dinosaur, out of step with the times (and glad of it)...
Thanks for your help
|Not to bust your bubble...||bigdave|
Feb 7, 2002 3:20 PM
|But I had a teammate that had a Profile crack at one of the welds. He swapped it out before any harm was done, but it made me want to stay away from Profile.
Just .02 and my own observation... I'd hate to have anyone eat pavement due to poor stem quality.
|...even a cop?||johan burnt eels|
Feb 7, 2002 3:58 PM
|..er...just kidding officer
|Not to bust your bubble...||DINOSAUR|
Feb 7, 2002 4:08 PM
|Thanks for that info, I'll keep an eye on it..Profile has a new lineup for 2002...anyway if I really like this set up I can upgrade later to a different stem...I would have like another Syncros, but $128.00 was out of my price range at this time....|
|I should have mentioned..||DINOSAUR|
Feb 7, 2002 4:18 PM
|All one piece, no welds.......|
Feb 7, 2002 4:42 PM
|You're confusing rise with stem angle--no need to do that. Ex: a stem angle of 90 degrees = 17 deg. rise; a stem angle of 73 degrees = 0 deg. rise. This comes about because the head tube of most road bikes is angled at 73 degrees above horizontal, give or take a degree. Since the stem shaft is an extension of that tube, it too will automatically (when installed) be at an angle of 73 degrees above horizontal (i.e. vertical is 90 degrees).
A 73 degree stem will produce a "flat" rise, i.e. it's top is parallel to the top tube. There's no way that's the same as a 90 degree stem.