Author Topic: Question about stems (Read 5876 times)

whisperdancer · « **on:** August 22, 2011, 06:04:08 pm »

Sorry to ask this (I feel kind of dumb...), but in my last two rides I felt I have too much pressure on my hands (my right hand is numb during half the ride) and my back hurt the next day.
I feel a more upright position would be nice (and I'm always trying to push my butt back in the seat as I seem to slip forward).

What are the changes I could make in the stem (combination between lenght and rise)? I guess one with a higher rise is the way to go, but is it better for it to be shorter or longer (this to get a more upright position and stay in the back part of the seat most of the time...).

w2zero · « **Reply #1 on:** August 22, 2011, 07:08:49 pm »

I know the feeling. My extra long/low original Girvin stem with the ULM incorporated dictated a road bike feel and stance. It was okay for years since I was a roadie from way back. Not now though, my back just screams and the rest of me whines in chorus. I replaced parts in the fork and switched to a tall short stem with wide riser bars and love it.

whisperdancer · « **Reply #2 on:** August 23, 2011, 01:14:24 am »

I switched from a flat bar to a riser one (a CNT MoneyLite XC - couldn't say no to a wife's gift), but it didn't do much... One thing I changed though were the handgrips: I had some Ritchey WCS foam with a thicker diameter on the outside, and changed to Ritchey WCS foam with an even diameter across the length. I may be feeling lack of support on the hand.
I once tried a higher stem, but I traded the looks of the bike for comfort. Was much pretty OK at the time, but now I think my age is showing for this kind of riding position…

Colin · « **Reply #3 on:** August 23, 2011, 03:34:14 am »

I've suffered in the past and still do occasionally from numb hands and have done a few things to try and address it.
I've put shorter stems on my off road bikes
Longer fork steerer tube - you can even buy an extension if it's been cut.
Riser bars with more sweep back. - cut to correct width as well.
Body Geometry Gloves - The best you can afford.
New WTB dual density grips.
Bar extensions with BBB foam grips - gives you a choice of positions and quite a bit softer than standard grips.
Get off and admire the view.........<GRIN>

Hope that helps, or gives you things to consider.

Col.

pczeilon · « **Reply #4 on:** August 23, 2011, 06:27:53 am »

Well, the front of your bike has been covered well. Shorter stem, riser bars, etc. Make sure you consider the saddle area as well. Are your saddle rails pushed all the way back? How wide is your saddle? Is the saddle mounted level? Try moving the saddle forward & back. A too-wide saddle will force your body forward as it searches for a narrower "perch" & room for your legs. Always mount your saddle level or even very slightly up, never lower in the front. Finally, you might try a different shape. If yours is "dished" try one with a flatter profile & vise versa.

whisperdancer · « **Reply #5 on:** August 23, 2011, 07:19:52 am »

I do have a short stem. I don't want to part of it because I really like the design (again, form over function, my bad)... The rise is low, but I will measure it.
The bar end is a thing I won't part of either. They are very confortable, and it was difficult as hell to get them.

As for the seat, I have it further back as possible, but the front end is a little low. It's a body geometry specialized seat, confortable enough. I do have one minor setback though: the seat post. Again a gift from the wife (thank you Dear, you're the best), it's a LOOK carbon seatpost, and the point where the seat attaches to it is right on the middle of the post. Some seatposts have an insert that pushes the seat further back.

I'll take photos of this items when I get home for you to see.

pczeilon · « **Reply #6 on:** August 23, 2011, 10:01:10 am »

Quote

I'm always trying to push my butt back in the seat as I seem to slip forward

This is what caught my eye. Your mention of a zero offset seatpost is a clue as well. If you have a short stem & a zero offset post you are most certainly far enough forward unless you have an extremely short torso. Perhaps too far forward.... Also, if you are this far forward yet still slide to the front try a different saddle. It's not "comfortable enough" if you don't stay on it. Bike fit can be a very fickle thing & it's quite easy to actually go the wrong direction in trying to fix a problem. I've been riding MANY years & thought I was pretty much dialed on my road bike. Just needed a slightly different saddle. I went to a small local shop with a semi-pro rider who talked me into just spinning on the trainer for 5 minutes while he watched. What a difference! Narrower bars (I'm 6'4", narrow bars were not on my radar) slightly lower seat height & a saddle I never would have considered in a 100 years. Ask around to find a good bike fitter, nothing wrong with fit-kit, etc. but it really comes down to the person working with you.

DREAMFLIER · « **Reply #7 on:** August 23, 2011, 12:51:32 pm »

hello, new to the proflex world. found a 855 local while searching craigslist for a new bike. live in east tn and the roads are too nasty to ride road bikes, ie glass, rocks, etc. many flats. wanted a new mt bike that could double as a road rider as well and could stand the road junk. found this bike for 75.00 with flats and no shocks (melted) took it home added some fresh rubber and homemade shocks and had on the road that night. was amazed that the bike felt as light as my road bike and am pleased with the speed and performance so far. did a little research b/4 i made the trip too look at and saw these on ebay for 3-400 dollars. my son now wants to take the bike from me, but i believe i will hang onto it awhile.

whisperdancer · « **Reply #8 on:** August 23, 2011, 02:59:28 pm »

Thank you for your inputs.
In fact, some little details make big changes, and one particular component may be de culprit of the problem.

Well, here are some photos of it.

The stem (95mm, 6º rise):

Handlebar (with strange colours due to flash hitting the resin), grips and bar ends (small but confortable):

I've moved the seat a little to get it straight (horizontaly leveled):

Before:

After:

Here is the global look of the bike.

The center of the grips are about 120mm lower than the top of the seat.
The frame is a large. The ideal for me was a frame between the large and the way big, as I had once a way big 757. I was good for road and for fast mountain descents, but on technical sections it was very tricky. I have around 189cm height, so I'm on the limit for the frame size.

One more question (that I never undestood): what is the correct position for the handlebar? If I rotate it to the front, will it be more confortable (will raise the tip of the handlebar an put it far away from me- gaining vertical angle and loosing horizontal angle) or is it the opposite?

Incredible that after so many years of riding, lack of knowledge arrises...

PS: the most confortable bike I had was a steel frame copy of a GT bike bought in Toys R' Us. Had a Shimano rapidfire at the time ('94) and never failed me. I was just starting to feel the terrain too much without any suspension...

fyrstormer · « **Reply #9 on:** August 23, 2011, 03:52:02 pm »

The seat looks way too high to me, but seats that are higher than the handlebars always look too high to me. I suppose it depends on the length of your legs more than anything else.

I use a flat bar, both because it's stronger and because there's no complex geometry associated with positioning it; I just tighten the clamp until it holds the bar steady, then twist it until it's comfortable, then tighten the clamp all the way.

Cane Creek's Ergo 2 bar ends are the most comfortable bar ends on earth, because they extend behind the handlebars as well as ahead of them, so your hands are resting the same distance in front of the seat no matter what you're holding on to -- no leaning further forward to hold onto the bar ends.

Foam handlebar grips will tire your hands because they change diameter as you squeeze on them. That causes you to instinctively clamp down on them harder and harder, trying to get a solid grip on the handlebar. You're better off with rubber handgrips. I prefer ODI's bolt-on grips with the Rogue tread pattern, because it offers good padding and a wide diameter as well as a solid surface to hold onto. Alternately, Cane Creek makes ODI-compatible handgrips that mesh with their Ergo 2 bar ends for a thoroughly uniform surface.

The fork you have probably isn't helping matters. Compared to a lot of forks nowadays, the Vector/Crosslink forks are pretty short and cause the bike to lean forward, and you along with it. That puts more of your weight on your hands. It may not look like it's leaning forward in your pictures, but the bike doesn't have your weight on it; when your weight is on it the springs will compress and the bike will lean forward noticeably. A newer fork will feel more plush, handle more consistently, and hold the front of the bike up higher too -- especially if you get a fork with an air spring, because then you can adjust it to have the perfect pressure so the bike doesn't lean forward or backward when you're sitting on it.

pczeilon · « **Reply #10 on:** August 23, 2011, 03:58:34 pm »

Very Nice! I wish my bikes looked like that.
Take a wrench on your next ride & try all the positions.... Generally up & forward is the way to go. Here is an in depth answer to this question I ran across several months ago. Something to get you thinking anyway.

"It seems to me that the sweep and width together determine how a bar will work for a rider. The goal I believe is to get a bar that doesn't force your wrists to be in an awkward angle.

Your wrists pivot and rotate in three directions. Extend your hands in front of you with the palms down and thumbs towards each other.

1. up/down - bend your wrists up/down by raising and lowering your hand. If you pretend that somebody is pulling on your finger straight out, this is the neutral angle in this direction.
2. in/out - bend your wrists towards and away from thumbs (still palm facing down). You want this to be as neutral as possible. Keeping one of your hands straight out and grab a pen. You will notice that the angle the pen makes relative to your forearm is not 90 degrees. This is the neutral angle for this direction.
3. rotate cw/ccw - rotate your hands (as if turning door knobs). This angle is often forgotten and is difficult to measure. Here's a way to visualize it though. With a pen in each hand, dangle your hands as loosely as you can by your side. Close your eyes, and raise your arms to level while still relaxing your hand as much as you can. Open your eyes and you should notice that the pens are not level. The angle between each pen and horizontal is the neutral angle for this direction.

Ideally you want all three angles to be as neutral in their respective directions as possible. For direction 1, brake lever angle, for direction 2, mostly sweep angle when bars are pointing to your shoulders. You can approximate direction 3 by rotating the bar towards your body (at the expense of reducing the sweep in direction 2 earlier). Of course all this is highly variable depending on terrain/style/skill/bike/body, so ultimately a compromise is needed.

As far as sweep goes for flat bars, up and back is indistinguishable--there's just one sweep angle. The reason up and back sweep is specified for risers is that if you rotate the bar, you also change your rise and reach as well. Although riders often cite better/worse feel when switching from/to risers, I think the wrist sensitivity is still mostly due to angles and not the actual rise. As far as wrist location and angles are concerned you could get the same results between flat and riser bars if you also play with the stem. Given identical wrist location and angle, the riser bar would use lower (maybe shorter stem) which would give you just slightly more crotch/torso clearance when front wheel is up.

BTW, I'm pulling all this outta my ass, but it seems to work for me wrist wise."

whisperdancer · « **Reply #11 on:** August 25, 2011, 01:55:25 am »

I will try some of the advice here and give feedback.
I also feel I have to rotate forward the handlebar to give me a more natural feel.
I'm experimenting with my old Titec Hellbent (wich I've cut at the time because it was too wide for me - bad move).

fyrstormer · « **Reply #12 on:** August 25, 2011, 01:19:42 pm »

What do you think of those Magura rim brakes, btw?

whisperdancer · « **Reply #13 on:** August 25, 2011, 04:58:02 pm »

Quote from: fyrstormer on August 25, 2011, 01:19:42 pm

What do you think of those Magura rim brakes, btw?

I really do like them.
It was something I wanted for a long time (I bought it about 3 years ago new from a local shop, they replaced a set of LX V-brakes.

I don't and usually don't ride on any disk brake bike, but they are similar in feel. Being a rim brake, they are not so good in the rain as a disk, but they are quite progressive, although a little bit difficult to set up for the first time (calipper distances from the rim).

One thing I couldn't stand though was the fluorescent and horrible brake boosters that came with them. I manage to get two original Magura carbon fiber brake boosters in the US. They completely turn the looks of these.

fyrstormer · « **Reply #14 on:** August 26, 2011, 10:05:11 pm »

Ah yes, brake boosters, I'd forgotten all about those. I haven't had front rim brakes since about 2003, so I haven't needed a brake booster in about 8 years now. (The rear brakes never benefited from a booster, on account of locking the rear wheel with much less brakeforce.)

It looks like a museum-quality late-90's mountain bike, lots of fun bright colors and technology of roughly matching vintage. It would be fun to have one like that, but my 756's frame isn't brightly colored so I wouldn't be able to kit it out with brightly-colored parts like yours. Anyway, the newer technology works so much better I'd probably never ride a bike like yours unless it were my only bike, which it wouldn't be. Better that it's your bike, all things considered.

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Author Topic: Question about stems (Read 5876 times)