90mm VS 70mm Stem...

milfredo

I have a 90mm and am suffering on my broken (not currently broken but damaged over the years) left hand and wrist and it hurts to do a day out riding on it. Broke the palm 15 years back, I have a damaged Ulnar nerve and can't grip with my small and second finger and have had a ganglion cyst removed a few years back which doesn't help either.

Would a 70mm be too twitchy on long rides or would I not really notice apart from loosing some pressure from leaning less on my hands and sitting more upright. Would climbing become harder and the downs easier?

Thoughts please.

Cheers,
Will

JK in the UK

First of all, have you tried Ergon grips? Do a internet search if you've never heard of them - they are designed to help riders with ulnar nerve problems as such of yourself. These could make by far the biggest difference to you...

Without knowing your particular bike set up, your height and shape of body (you could have long/short arms etc etc - you get the idea!) its very difficult to give you a simple answer regarding 70mm vs. 90mm.

I use 90mm stems on my XC bikes, but 90mm is often considered quite a long stem these days. A common set up now is a slightly longer top tube and run a shorter stem for 'snappier' steering.

So, basically, the best thing to do is try a 70mm stem and find out yourself! 70mm is no longer an unusual length on a MTB - quite the opposite; you'll probably be fine. Do you have any buddies using a 70mm stem? Maybe you can swap? Otherwise you're best buying one and finding out yourself...

Hope it helps,
John.

milfredo

I have some Ergon grips already and I do think they are great but not on the good hand. I'm actually going to only use one on my left hand and a normal one on my right.

I ride a medium Santa Cruz Blur LTC, I'm 5"8, probably short arms and longer legs... I think it's time to find one to borrow as I'm convinced it just will sit me up enough to almost make the left hand more redundant.

Cheers,
Will

bomberesque

a lot comes down to personal preference but I currently use 70mm stems mostly.

I first came to them as a compromise; my Evil frame is a bit on the short side and I was banging my knees on the shifters whilst climbing with a 50mm stem. A 90 just seemed to fek up the handling so decided to go halves and try a 70. It's not as direct as a 50mm for sure but it's still nice handling and I don't have bruised knees anymore

you're thinking of going the other way so I don't know what you'll find. For me I prefer a 50mm stem (call me twitchy) but for xc/trail I needed a bit more cockpit space. I find 70mm fine for long distance stuff. All you can do is try it out though, perhaps try and borrow one off a mate / out of your LBS's parts bin and see how you get on.

joshtp

i use a 60mm stem, and would like a 50mm, i believe that the shorter the stem, the better, it improves front end "feel" and makes the bike easyer to flick around and jump. they are also lighter, stronger, and stiffer....

RichMTB

I ride a medium Santa Cruz Blur LTC, I'm 5"8, probably short arms and longer legs... I think it's time to find one to borrow as I'm convinced it just will sit me up enough to almost make the left hand more redundant.

I run my Blur LT with a 70mm stem as well. I also ride a medium frame and I'm 5'8" Can't afford a carbon one though!

With the 70mm stem it is quite upright and a think the steering is spot on. I've not noticed any issues on climbs but I've only had the bike built up for a week or two and not done any serious riding on it yet.[/quote]

.blitz

milfredo: my Rize had a 90mm stem and together with a slack head angle it felt as though the front wheel was in the next county.

I tried a 70mm stem but it didn't really make too much difference and a 40mm stem was kinda short but not as short as you may think. Finally settled on a 55mm stem. The Rize doesn't encourage standing climbs so although the front end can be twitchy going uphill, it's not noticeable if I don't pull on the bars.

dave_hill

milfredo wrote:

Would a 70mm be too twitchy on long rides or would I not really notice apart from loosing some pressure from leaning less on my hands and sitting more upright.

I have a 70mm stem and 740mm wide, 50mm rise bars on the Giant, it's the best combination I've found for all-day comfort and control.

milfredo wrote:

Would climbing become harder and the downs easier?

The front end will be a little "lighter" going uphill but a slight change to your technique will overcome it. That said the Giant has always had a tendency to lift it's front end whatever length stem it had on (the OEM was 110mm!!). It may feel more secure at high speed, especially if you go for wider bars too.

ride_whenever

depends on the frame.

I run a 700mm wide bar on my xc bike, with a 40mm (IIRC) stem.

But i run a 680mm bar on my AM bike with a 50mm stem

milfredo

Thanks everyone, I'm going to make the swap and see how it goes.

milfredo

So I bought a 70mm and it has made a difference, no twitchyness I was fearing, in fact the bike feels much more alive and confident that I wish I had a 70mm from the start. With relation to the pain in my hand, it now just takes longer to build up so less pressure from sitting more upright is helping. I also now have an ergo grip for the left and a normal one for the right but I'm not too sure if this is helping or not, it might just take a little more setting it up to help relieve the pressure.

I think I might need to go and get it X-rayed again to see what might be going on in there.

CraigXXL

I may be missing the point but won't a shorter stem put increased stress on the wrists and palm of the hand by cocking the wrist. Would it not be better to try and get a straight line between the forearm, wrist and hand by angling riser bars as suggested by Dave Hill and maybe increase in stack height if possible or a stem slightly shorter with increased rise.

ride_whenever

Bend your elbows more, because the bars are closer you can keep the straight wrist by keeping bar-wrist-elbow straight and opening up at the chest. You work the front a bit more as well, but this is countered by the rearwards shift in your weight caused by the shorter stem.

delcol

i had a 90mm on the heckler and droped to a 50mm and a wider bar,. i then droped the pace from a 90mm to a 50mm ....

does effect the way the bike climbs the front end goes light,, but a change in technique sorted this out...

i personally prefare the shorter stem..