K2 / Proflex Riders Group
General => Tech Forum => Topic started by: Oz-SUB on February 19, 2003, 09:37:32 am
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I know this is subjective, but I changed my old 'Proflex' stem on my Oz (came from my 957) and is 125mm, to an Easton 90mm (both 10o rise).
Next ride going up a very steep short track I had a problem keeping the front wheel on the ground (I normally stay in the saddle to maintain traction).
So I'm thinking of changing the easton for a longer 100mm unit.
Basically, I was suprised at how much difference shortening the stem would make!
Any experiences that you have had?
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I have a 45mm stem on my Monkey. Waaaaaayyyyy back when I first got it I had a 135, then a 120, 110, 90 and 45. I'm sticking with the shorter stem. For my riding it just makes sense. Granted on steep XC climbs my front tends to wander a bit, but if I keep my weight forward more I'm OK. [smiley=nod.gif]
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If your previous stem didn't affect your riding style, then stick with that lenght.
I've got a 70mm stem with a 2 inch riser bar. I've got to keep my ass on the front edge of my saddle to ride up steep hills. :o I won't give up that stem because it easier to ride down steeps and easier to pull the front up over things. ;D I also have to remember to keep the front end weighted sometimes or else I'll wash out. [smiley=coolfrown.gif] For an interesting read, see this from Go-ride.com:
http://www.go-ride.com/article_bike_dynamics.html
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I think a 10 deg. rise is a bit much. I use an 8deg 110. Depends also on the amount of rise in your bars. I agree with Jimbo, the tradeoff of an upright position, is worth the moving up on the saddle on the climbs.Nothing worse than feeling like you are going to endo. Rich
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105mm on my bike. Zero rise, but I have about 1.25" of spacers (carbon of course) and a low 1" riser bar.
My wife's bike has a 90mm stem, same rise and spacers, and a 2" riser bar. Also have a 120mm stem for it with a 10 degree rise. That's the spare in case somebody much bigger wants to ride with me... I've tried both and probably prefer the 90 even though the bike feels a little to short for me overall with it. The 120 isn't bad, but keep in mind that that's on a frame that's too small for me!
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Started off w/ a 140mm 8 deg. stem and original flat XC bars on my 856. I was feeling 'way' too stretched out...I'm a short guy on a large frame. So, I swithced to a 100mm no rise stem, 2" riser bar and about another 1" of carbon spacer...made all the difference in comfort and confidence.
I agree w/ the rest about keeping weight forward during the climbs, but according to the majority here...the trade-off is worth it.
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Well, I've got an 80mm stem with about a 1" rise in it and a 1" riser bar. I too notice that the front end lifts and wanders if I pull up too hard on a climb.
However, I've been working more at getting off the seat and pumping my climbs...it hurts a bit more, but it's good for ya and I'm able to keep my weight balanced on the rear wheel to stay hooked up. On longer climbs I still ride in the saddle but keeping my weight forward keeps the font end tracking.
I agree that the more upright riding position is better going down rugged terrain. I use to ride a Specialized that had a flat XC bar and bar ends. At first I felt a little uncomfortable with the upright position and I didn't like not having bar ends. But the more I rode the bike the more I began to appreciate the control going down hill.
I always use to feel like I could go over the bars at any moment on the Specialized (In fact I did have 3 or 4 really hard body slam endo's on that thing). Now that I'm riding the Animal with 5" of fork up front, I'm not afraid of bashing most anything. Much more comfortable with rugged stuff. :)
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Climbs? I run a 40 degree 50mm, short and steep, let's me slide off the back of the seat when the going gets steep.
Steve O
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Guys
Thanks for all your feedback. It's what I expect of like minded get out there and ride site members.
OK so before I consider swaping the stem out for a longer one at my LBS, I'm going to go for a couple of more rides on my standard route, and have a go at modifying my riding style. This route has some short sharp climbs and descents (amongst all the other bits - long slow climbs etc.).
Interestingly, for you weight weenies, the old Proflex ex 957 stem (cira. 1997) weighs less than the new shorter Easton unit! 176g against 184g. So Proflex were doing lots right at the time, apsrt from selling up to K2.
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I did the exact same stem swop on my Evo with the same results and I have no intention of switching to a longer stem. I now find that I don't have to pull up to do drops, I just ride off things ----wicked!
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Pro~Flex & k2's that came with xlink had super long stems, party 'uz they were supposed to be racy xc bikes and also 'cuz the xlink put the fork legs ahead of the hub, which caused a myriad of problems only to be suppressed with super long stem to slow the steering down, etc. etc.
i used the standard 135 on my stock 857 (xlink), with a teloscopic fork the stem is 100 on the 857SS. the Oz has a 90 with a 4 inch teloscopic. the rise i think is 10 or 15 and with a 1 1/2 inch rise bar.
to answer the second question..."How long is yours?" well, sorry, that's just too personal. :-*
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I was under the impression that the X-link forks didn't have any effect on wheelbase. Don't they put the axle in exactly the same location relative to the headtube and thus have the same steering characteristics? (Other than stiffness anyway).
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you have to ride one, i guess. mine was a 97 xlink maybe it had nothing to do with the stem, i dunno.
loved it for xc, but had a tendency to endo more easily than other forks, the fork legs are ahead of the wheel some and everything including me had a tendency to all go "forward"...ya know? :)
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CA,
[smiley=disbelief.gif]It probably was the stem. Check out the "paper" I wrote back in Nov. '01:
http://idriders.com/proflex/files/crosslink_travel.doc
Even for the '97 Crosslinks (which had the most "J" path offset) the horizontal difference between the travel path and a "theoretical" telescopic straight line is only 3-4mm. All other Crosslinks are on the order of 1-2mm horizontal difference. That's not going to be enough to make you go "superman".
Because of the action of the linkage, there is a perception that the front wheel is being "folded under". However, if you trace the axle path, it is virtually identical to a straight telescopic (especially at longer travels) with just a small horizontal offset at short travel (which can actually help reduce "bobbing")
The fact that the fork legs are in front of the axle has no effect on the handling since the location of the axle with respect to the headtube is not different. The head tube angle and fork trail (the horizontal distance between a line extended from the head tube to the ground and the contact point of the wheel on the ground) is unchanged.
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I'm running an FRM 90mm with 7 degrees negative on a Crosslink/Oz combo, uncut steerer with the stem spaced up to the top. Had an 80 at zero but it felt too quick. Stock 120 was so slow/sloppy when combined with whatever my abilities are or aren't. The Crosslink is an "exacting" fork to my mind, and riding. I really enjoy its performance Possibly I'd feel different if I was back in Reno, NV. where we had plenty of high speed descents of 40+.
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CA,
[smiley=disbelief.gif]It probably was the stem. Check out the "paper" I wrote back in Nov. '01:
[url]http://idriders.com/proflex/files/crosslink_travel.doc[/url]
Even for the '97 Crosslinks (which had the most "J" path offset) the horizontal difference between the travel path and a "theoretical" telescopic straight line is only 3-4mm. All other Crosslinks are on the order of 1-2mm horizontal difference. That's not going to be enough to make you go "superman".
Because of the action of the linkage, there is a perception that the front wheel is being "folded under". However, if you trace the axle path, it is virtually identical to a straight telescopic (especially at longer travels) with just a small horizontal offset at short travel (which can actually help reduce "bobbing")
The fact that the fork legs are in front of the axle has no effect on the handling since the location of the axle with respect to the headtube is not different. The head tube angle and fork trail (the horizontal distance between a line extended from the head tube to the ground and the contact point of the wheel on the ground) is unchanged.
thanks, Tom. come to think of it i did have a shorter stem with the xlink when it was rebuilt as a SS. it did handle better, faster, IMO. i am getting too old and i forget. i agree the j-path is perception more than reality...but i've never ridden a newer xlink though so can't compare the two if the difference can be felt. :-/ glad you crunched the numbers, though. i'd still have a headache even if i tried to do that!
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Well iam going against the tide here i can see that.My ol 20 inch 756 (way big in todays lingo had a 150mm yes thats right a 150 mm stem.The extra 15 mm in the stemm and 15 in the tt gives a 1inch extral length in the cockpit over a large.....I have just swapped back to a 135 with my "new"crosslink" both are prolly 5 deg rise with flat xc bars
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I'm currently running a 100mm, +5 deg rise Race Face SYStem on my OzM (med) with the stock Easton CT2 flatbars and 1999 Crosslink. I found the 120mm, no-rise stock stem to be a little much. Dropping back to 100mm and upping the rise definately improves my handling for some of the twistier/tighter singletrack around here while not sacrificing much of my race position (not that I race) and climbing.
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Well I started this one, so perhaps I should finish!
I've got used to the 90mm 10o stem now, and have found out some interesting things.
Stem length is more critical than we all think!
Yes, at first I found the tendancy of the front wheel to lift and go off wildly in all directions on short steep climbs very disconcerting. I've now got used to moving further forward for these climbs to counteract wheel lift off!
When negotiating steep trecherous downhill sections, I can get my rear further aft over the saddle, and with the disc brakes, the control is awesome.
I find the fork bobs less when climbing, I guess this is because there is a shorter lever with a shorter stem.
Finally, I'm in a more upright riding style, which is more comfortable than being stretched out too far. With age comes less suppleness!
I'd be interested to go back out 10mm to a 100mm just to see if I need that tuning.
Oz-SUB