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Discussion Starter · #1 ·
I'm retiring an old Trek 830 I've had for 20 years. Here is my ridiculous stem and riser bar combo:

Bicycle part Bicycle accessory Bicycle frame Bicycle Bicycle tire


stem + bar rise = 6.5"
bar sweep = 7"

tot = 13.5"

Bike has 19" frame. The rise was actually just adequate; I wouldn't have minded 1-2" more for comfort :eek: .

Though I rode this mostly on the road, I also took it on some fairly technical trails. (I grew up riding enduro motorbikes since age 7, so I'm very comfortable off road). Never had a problem with steering (never even had to adjust it). Bike is pretty difficult to jump, so wasn't doing much of that.

After looking at the newer Trek 29ers, I recently found a bike that feels great: a Giant Talon 2.

If I get the bike I'm going to want to raise the steering up, though nowhere near what I did with the 830.

My riding position actually feels pretty good on the bike stock; much better than the 830 felt with it's stock flat bars and no riser stem.

I'm looking to maximize both comfort and safety in my bike mods.

The bike shop guy tells me that ANY mods to the steering will void the warranty.

So, I'm wondering if there have been any studies that can quantify how much modifying the steering increases risk of breakage. And, what combinations of stem risers/bar risers will help minimize risk. Like, are there certain brands of aftermarket gear that can take the extra force without transferring it all to the bike? Or are there ways of buttressing the risers that help reduce stresses?

From what I've gathered on the site, riser bars are less risky than riser stems. And shorter stems are less risky than longer stems.

I assume other factors would include:

- rider weight
I'm 5'10" 170, so I'd imagine that's a minor risk factor on a large frame.​

- riding style
I'll be doing 80% road/gravel riding, with some trail riding, but probably not much on technically difficult terrain. My body is a bit beat up, so I'm looking to minimize riding risk off-road, and wearing BMX gear when I do any serious off-road rides. I'll be doing some simple jumping, but no big-hill jumps, or fast, steep descents.​

- front suspension
The fact that MTBs have front forks I assume makes it safer to modify steering on these than hybrids without forks. (like my ancient 830).​

Any advice/guidance on these issues is appreciated.
 

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...The bike shop guy tells me that ANY mods to the steering will void the warranty...
It's totally common to make reasonable mods to stems and bars to fit the bike to the customer's needs. It's done all the time and does not void the warranty. In some cases there are specified limits, in others it's a judgement call as to what's reasonable. Without question, your old 830 was unreasonable. Anything that increases leverage on the fork's steerer is what can cause problems. Too many spacers under the stem, a really long stem, bars with extreme rises or any combination all increase leverage on the steerer. There is no hard and fast rule, or any quantitative rule as to what's acceptable, except perhaps for 30mm of spacers under the stem in most cases.

For most experienced riders, bars so high would not be comfortable or provide proper control for any kind of technical riding.
 

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Congrats on the new bike! It’s been 3 yrs since I parked my 830 and started RIDING...LOL. I’ve built up a ‘14 Stache for my wife with plush Manitou fork, Thud-buster seatpost, and 80mm Diety riser bar for comfort. It was a hard sell to get her back on a bike but she loves the upright position riding the flat creekside trails. I also enjoy the control the riser bar provides me on the fast flow and moderate downhill trails. Many riders say the mid-rise 40-50mm bars greatly improve their riding experience.
 

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Discussion Starter · #7 ·
Congrats on the new bike!
Ain't got it yet, but am jonesin' for it. :)

It's been 3 yrs since I parked my 830 and started RIDING...LOL. .
Yeah, couldn't kill mine. Still like the bike; feels solid and stable. Frame is fine, but the gears/chain are messed up and I don't want to bother fixing it.:madman:

Plus...hardnose MTB is so 30 years ago.
 

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I agree with the comments about getting a bike that fits and keeping it reasonable and normal. That should be the best all around!

In the event you want more rise than is available with standard MTB stuff you could also run BMX bars if you really need the rise. I have S&M 29'ers on my BMX race bike and while very heavy by mtb standards, they are fairly light and strong in the BMX world. You'll need a BMX stem to match as they are different diameter than MTB bars.

I wouldn't personally worry about torque on the steerer tube from taller bars too much provided you are using a good quality trail-style fork (Fox 34 or 36, MRP Ribbon, Ohlins RFX, RS Lyrik or Pike, etc.). They are really strong and withstand some extreme riding. If using really tall bars I would err on the burly & high quality side for the stem (Hope or Thompson perhaps).

FWIW I have 20mm riser bars on my size large Intense Spider 275C with a 40mm, 0 degree stem and maybe 7mm of headset spacers and find it really comfy. I'm 5'10" and 176lbs.
 

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I would not give a second thought to running however much rise you want, whether it be achieved through spacers, stem rise, or bar rise.

Any stresses you will put on the head tube and steerer will pale in comparison the the stresses already being introduced from the front wheel and fork.

I would go for the frame that has the proper reach, and if you need a bunch of spacers and risers, so be it.
 

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Discussion Starter · #13 ·
Any stresses you will put on the head tube and steerer will pale in comparison the the stresses already being introduced from the front wheel and fork..
I was thinking that with two much leverage the bars might snap off at the stem given too much force.

Happened to a local motocross rider in my area; bars snapped off on a jump, impaled and killed him (obviously defective though).
 

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- riding style
I'll be doing 80% road/gravel riding, with some trail riding, but probably not much on technically difficult terrain.
Buy a gravel/cross bike.

No point buying a bike that is only good 20% of the time. it will make the other 80% miserable.

You know what gravel/road/cross bikes don't have? Riser bars.
 

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Try some more bikes to see if you like fit. You have ridden an odd setup for a while so anything new and "normal" is unlikely to feel right.

Forks can have a Max height for spacers under the stem. I presume that they take into account the oddball 3" riser bar and stem with rise when they dtermiNe the max spacers. There is a good thread on this topic on MTBR.

I have longer arms and torso and shorter legs. My most recent bike with new style geometry was uncomfortable on longer rides, my neck and shoulders hurt. Pedaling position is fine. I put a high riser bar on it and problem solved.



Sent from my moto x4 using Tapatalk
 

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Am I missing something here???

A 5'10" person on a 19.5" frame, raising the bars 13"???

That's not a bike fit issue. Sounds like you want a cruiser bike.
 

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Yes, OP trying to replicate oddball fit isn't going to work.

Given he doesn't yet know how mountain bike should fit, he should try different bikes and perhaps a professional fit.

Sent from my moto x4 using Tapatalk
 

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Am I missing something here???

A 5'10" person on a 19.5" frame, raising the bars 13"???

That's not a bike fit issue. Sounds like you want a cruiser bike.
Exactly my thoughts--someone that either doesn't want to or can't bend at the hips for a proper bike fitment. That stem height in the picture was ridiculous. They should get a beach cruiser if that's the type of geometry they like.
 
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