Bicycle Mechanics - High Rise Stem (30-40 Degree)? 2 or 4 bolt?
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10-19-10, 09:09 AM
I need at least two 100mm length stems with 26mm bar clamp and high rise angle (30-40 deg). For 1-1/8" steerer.
These are surprisingly difficult to find. When found they usually have 2-bolt bar clamps. I have never used a 2-bolt clamp and have heard that they "always" creak and you have to live with it since you can't grease. I don't want creaks. I suppose a shim made from old inner tube would prevent this, if worse came to worst??
These are for nice road bikes. I don't want to get too pricey, but I already have one Dimension stem (pretty cheap) which fits my parameters and it weighs a ton.
I'd really like to make a list of companies who make stems of this description and then I can shop, compare weight and price, etc. So please list them on here and also give your opinions about 2-bolt bar clamps. Thanks.
10-19-10, 09:23 AM
You could also go with the aluminum shim
These are a few that I found
Oval concepts adjustable
I think that you will have larger selection with the shim or get handlebars with a 31.8 clamp diameter.
10-19-10, 09:29 AM
I've seen Ritchey 4 bolt road stems. the pairs of bolts are closely spaced together...
blue threadlock, or next grade, red loc tite holds things that you want kept in 1 spot.
BBB is another parts company, Bike Mine is their US distributor,
no dealers with accounts there ?
R&E in Seattle might help you, I Got my special order BBB Stem [BHP-21] raiser
10-19-10, 10:09 AM
Over the years I've used a fair number of 2 bolt stems. As some would appear to have found the fit isn't as firm as a 4 bolt. The secret is the fit of the diameters. If the bars do not need to be lightly pushed to bottom in the saddle then it is too loose and it needs a pop can shim to achieve the correct seating. Once shimmed I never had any issues with creaks. But I've also found that while the stiffness isn't bad that 2 bolt caps often do not hold quite as rigidly as 4 bolt caps. But again shimming for the proper fit reduces the difference to very little.
If the bars are a "fall in" fit and the pop can shim is TOO tight then I would suggest a brass sheet shim. You can get brass shim stock in small sheets from hobby shops that cater to model airplane and model railroad hobbyists. And often the shops that are big into plastic models will have a rack of K&S metal and plastic products.
But under NO CIRCUMSTANCES would you want to use anything plastic, paper or rubber as a shim. The other options are far too soft and would allow significant bar flexing and in the case of the plastic shim would deform and creep out of position in no time flat.
10-19-10, 11:33 AM
Two-bolt removable face plate stems aren't particularly creak-prone if used with the now common bulge center bars. The real offenders were one-bolt stems wth non-removable bar clamps used with sleeved bars. These nearly always creaked.
BCRider is correct, you NEVER want to use any soft material as a bar (or steerer or seatpost) shim.
10-20-10, 08:39 AM
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