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-   -   MTB Fit: Is this step next? (https://www.bikeforums.net/fifty-plus-50/879061-mtb-fit-step-next.html)

North Coast Joe 03-21-13 05:31 AM

MTB Fit: Is this step next?
 
Thanks for looking, folks. I'm new to biking since Nov.'12, and STILL trying to make the bike fit as comfortably as possible. I do ride daily, FWIW

My current gripe is that not only do I seem to be carrying too much weight on my hands, but when "taking a breather" and sitting up straight (sucking air), I can reach the bars with only the fingertips of one hand. Doesn't seem right. The other fly in the ointment is I keep sliding forward, necessitating pushing myself back occasionally.

I've made progress adjusting the seat position, but it's as far forward as I can make it....even reversing the original seatpost that has a small amount of offset. The saddle is nose up to the point that "the boys" have started to complain slightly. I'm happy and comfy with the leg/pedal end of things.

Is this the longest way you've heard to ask: "Do I need a shorter stem?" Currently a 105mm, 10 deg....I'm thinking 50mm, or is that too big a change?

stapfam 03-21-13 05:57 AM

MTB's are peculiar in fit as the top tube is normally longer Frame size to a road bike and handlebar reach is where you want it. Pics would help of you on the bike.

But many things to get the bars comfortable and Riser bars were my last change 12 years ago to bring the bars back and up after surgery and never bothered to change back.

Pamestique 03-22-13 12:27 PM

In buying a MTB the fit is not near as precise as a road bike but essential is being able to reach the bars and brakes without effort especially considering at times you have to be way off the back of the saddle. Ways to fix the problem... are your handlebars too wide? Is the stem too long? Is the seat back too far? Is your bike too big? I get the last one is hardest to fix... Try a riser stem but don't shorten it too much as the length affects steering. Already moving the saddle forward, it sounds like the bike is too big. Small bike easier to adjust, big bike just have to make due.

droy45 03-22-13 01:44 PM

If you have room to raise the bars try that. If they are riser bars, turn them more toward you. You can also try a riser stem and as short as you can find. It sounds like the reach is too much on that bike for you. I use a large frame MTB 21in, (just because it rides better) and at first I felt that way too but have become comfortable with it after many tweaks and adjustments.

jimc101 03-22-13 01:54 PM


Originally Posted by North Coast Joe (Post 15413550)
"Do I need a shorter stem?" Currently a 105mm, 10 deg....I'm thinking 50mm, or is that too big a change?

With out knowing the type of bike, your height etc, this is impossible to answer, Stems have been getting shorter over the years, 20 years ago 130-150mm would be standard, 10 years ago 110-100mm, 2-3 years ago 70-90mm, now 35-70mm. At the same time, the geometry of the rest of the bike has evolved to accommodate this, so putting a 35mm stem on a 20 year old MTB won't bring the handling up to 2013 standards, you need a 2013 frame designed for a super short stem for this.

From what the issues you are describing with you bike fit, you really need to go to a good bike shop, ideally the one where you got the bike from, as they should have been able to advise if the bike was the correct size, and any adjustments which need to be made. Add to that you are reversing the seatpost indicates that you have some major setup issues with the bike, and it probably is the wrong size for you.

GeorgeBMac 03-22-13 02:06 PM


Originally Posted by jimc101 (Post 15419387)
With out knowing the type of bike, your height etc, this is impossible to answer, Stems have been getting shorter over the years, 20 years ago 130-150mm would be standard, 10 years ago 110-100mm, 2-3 years ago 70-90mm, now 35-70mm. At the same time, the geometry of the rest of the bike has evolved to accommodate this, so putting a 35mm stem on a 20 year old MTB won't bring the handling up to 2013 standards, you need a 2013 frame designed for a super short stem for this.

From what the issues you are describing with you bike fit, you really need to go to a good bike shop, ideally the one where you got the bike from, as they should have been able to advise if the bike was the correct size, and any adjustments which need to be made. Add to that you are reversing the seatpost indicates that you have some major setup issues with the bike, and it probably is the wrong size for you.

+1

I was amazed at the difference...

After I got my cyclocross the LBS offered to do a free mini-fit on the trainer. I was skeptical -- but the guy has ALWAYS been right and has always treated me well. So I went. He put the bike on his trainer and we experimented with different stems and spacer configurations as well as several different handlebars...

The difference in ride quality, comfort and power has been amazing. The bike feels incredibly natural to me now.

I commented to him about my hesitation and concern that the fit would force me into some performance configuration -- but he said: "We can do it either way: If you want performance we can fit you for that. If you want comfort, we can do that as well". And, I have to say, it was a joint effort: it wasn't him telling me how it should be -- it was him suggesting things and changes and then asking "How's that?"...

If you are able to do something like that, I would think it would be a good idea for you...

And, BTW, congratulations on riding everyday up there in Erie. That's tough conditions in the winter...

North Coast Joe 03-22-13 02:54 PM

Thanks for the thoughts, folks. Just to help with the whole picture, I'm roughly 5' 10"/ 190lbs. and the bike is an 18" 2011 Trek 3900 Disc. I purchased it used, so there's no LBS to consult for a fitting. I may wander the 30 miles to a local co-op for help getting it right, but more than likely not. The bike seems to feel right in the pedal to seat length, and is comfy there, it's just this sliding forward thing makes me nuts. The seat is as nose-up as I dare make it without endangering.....never mind. Even with the reversed seatpost, the deepest part of the saddle is directly above and slightly behind the seatpost tube. It just feels like bringing my hands back would put me into a more balanced position.

I'm going to see about aquiring a shorter stem, say a 70mm or even a 50mm with the same angle. I can probably pick up a used one for the cost of the gas getting to the co-op. I'll sell it or the original if it does or doesn't work.

If the weather holds up, I'll try to get a ride-by picture or two that may/may not help your much appreciated input....thanks again!

stapfam 03-23-13 01:05 AM

18" Trek and I rode that size and I am 5'6" short. If sliding forward on the saddle then reach may be your problem and a shorter stem could work and so could an inline seatpost if you are not forward enough on the saddle.

GeorgeBMac 03-23-13 06:13 AM


Originally Posted by North Coast Joe (Post 15419622)
Thanks for the thoughts, folks. Just to help with the whole picture, I'm roughly 5' 10"/ 190lbs. and the bike is an 18" 2011 Trek 3900 Disc. I purchased it used, so there's no LBS to consult for a fitting. I may wander the 30 miles to a local co-op for help getting it right, but more than likely not. The bike seems to feel right in the pedal to seat length, and is comfy there, it's just this sliding forward thing makes me nuts. The seat is as nose-up as I dare make it without endangering.....never mind. Even with the reversed seatpost, the deepest part of the saddle is directly above and slightly behind the seatpost tube. It just feels like bringing my hands back would put me into a more balanced position.

I'm going to see about aquiring a shorter stem, say a 70mm or even a 50mm with the same angle. I can probably pick up a used one for the cost of the gas getting to the co-op. I'll sell it or the original if it does or doesn't work.

If the weather holds up, I'll try to get a ride-by picture or two that may/may not help your much appreciated input....thanks again!

Thanks for the update:

My LBS is mostly a Trek dealer -- but they work on ALL bikes regardless of make or where they were purchased. I suspect that most LBS's are the same...

And, I have found that I save time and money going to them with questions and ideas and problems before going it alone. They have the knowledge and experience --- and the parts -- to get me where I want to go the first time without going down the expensive trial and error route.

It sounds like you need a fitting: This could be anywhere from an eyeball from an experienced LBS to a $75 comfort fit to a $350 full blown computerized performance fit...

A good LBS can not only save you time & money -- but make your cycling much more enjoyable.

jdon 03-23-13 08:13 AM

Unless you have very unusual body geometry, (I am talking Tyrannosaurus Rex) that bike should fit you. The two most common problems I find when people complain about pressure on their hands are, core strength and saddle height. The first, well, get on the floor and start those crunches and planks. The second is a little more technical.

Start by reversing everything you you did with your seat and post. Yes, hit the refresh button, return it to how it was. ;) Sit on the bike and maybe rest a shoulder against a wall or door frame. Place your foot on the pedal in its normal riding position. This should be around the ball of the foot, not the arch. with the crank arms parallel to the ground drop a plumb bob from your forward knee (the one you will be pushing down with to start cycling) down to the pedal spindle. The string should be resting on the bone inside of your knee cap, not on the knee cap. The front of that bone should be pretty much centered on the pedal spindle. That determines your forward aft position.

Once you have done that, rotate the pedal to the bottom of your power stroke. If you could see yourself from the side, the crank arm would be at about the five o'clock position (sux if you think in digital time). In that position, your knee should have a bend of 15 to 20 degrees. That will determine an approximate saddle height. Your hips should not rock when pedaling. A lot of old school (old) guys are looking for a straight leg at the bottom of the pedal stroke, you know, like most of us were taught back in the day. That simply is incorrect.

Once you have done that, take the bike for a good spin and see how it all feels. If you are still too far forward, well, maybe a slightly shorter or more inclined stem will work for you. Good luck!

ps. That is the $75 dollar bike fit. The $300 fit is far more complex. ;)

GeorgeBMac 03-23-13 08:40 AM


Originally Posted by jdon (Post 15421790)
Unless you have very unusual body geometry, (I am talking Tyrannosaurus Rex) that bike should fit you. The two most common problems I find when people complain about pressure on their hands are, core strength and saddle height. The first, well, get on the floor and start those crunches and planks. The second is a little more technical.

Start by reversing everything you you did with your seat and post. Yes, hit the refresh button, return it to how it was. ;) Sit on the bike and maybe rest a shoulder against a wall or door frame. Place your foot on the pedal in its normal riding position. This should be around the ball of the foot, not the arch. with the crank arms parallel to the ground drop a plumb bob from your forward knee (the one you will be pushing down with to start cycling) down to the pedal spindle. The string should be resting on the bone inside of your knee cap, not on the knee cap. The front of that bone should be pretty much centered on the pedal spindle. That determines your forward aft position.

Once you have done that, rotate the pedal to the bottom of your power stroke. If you could see yourself from the side, the crank arm would be at about the five o'clock position (sux if you think in digital time). In that position, your knee should have a bend of 15 to 20 degrees. That will determine an approximate saddle height. Your hips should not rock when pedaling. A lot of old school (old) guys are looking for a straight leg at the bottom of the pedal stroke, you know, like most of us were taught back in the day. That simply is incorrect.

Once you have done that, take the bike for a good spin and see how it all feels. If you are still too far forward, well, maybe a slightly shorter or more inclined stem will work for you. Good luck!

ps. That is the $75 dollar bike fit. The $300 fit is far more complex. ;)

Yes, probably at some shops -- probably the lazy, greedy ones. It certainly wasn't at mine. The stuff you mentioned was taken care of in the first 2 minutes of a 30-40 minute ($75.00) fit. The rest of the fit was working with bar and stem configurations after the seat position was adjusted correctly. The result was that it took a bike that I thought fit pretty well and transformed it into a bike that now feels like an extension of my body...

For the OP: it is entirely possible that the bike you have is too small for you -- but you have the seat raised to compensate -- which then throws the rest of the configuration off -- thus causing discomfort as you ride... I'm not saying that that IS the problem -- just that that MIGHT be the problem -- or one of the problems...

Bike fitting is bringing a lot of different things together into a whole that works for you...

jdon 03-23-13 08:59 AM

Don't take offence to the last line George. It was a joke. But then again, the best jokes stem from the truth..

GeorgeBMac 03-23-13 09:14 AM


Originally Posted by jdon (Post 15421884)
Don't take offence to the last line George. It was a joke. But then again, the best jokes stem from the truth..

No offence taken -- but thanks for asking...

I responded strongly because I suspect that many people have the same misconception about fittings as I did. I avoided having one because: 1) I thought they were expensive, sophisticated things used mostly by performance riders. 2) I was afraid I would be told "this is the correct configuration. You have to adapt to it."

I only had it done because: The manager at my LBS offered it to me gratis after I bought the owner's LeMond -- and he wanted to be sure it was a good buy for me. And, I have learned to trust this guy -- even when I don't agree with his opinion (he's always been right!).

And, after having it done I found that he was right once again... I ended up with a bike that fit me far better than I ever dreamed a bike could fit.

I became a believe! (so now I have to proselytize)

jdon 03-23-13 09:22 AM


Originally Posted by GeorgeBMac (Post 15421929)
No offence taken -- but thanks for asking...

I responded strongly because I suspect that many people have the same misconception about fittings as I did. I avoided having one because: 1) I thought they were expensive, sophisticated things used mostly by performance riders. 2) I was afraid I would be told "this is the correct configuration. You have to adapt to it."

I only had it done because: The manager at my LBS offered it to me gratis after I bought the owner's LeMond -- and he wanted to be sure it was a good buy for me. And, I have learned to trust this guy -- even when I don't agree with his opinion (he's always been right!).

And, after having it done I found that he was right once again... I ended up with a bike that fit me far better than I ever dreamed a bike could fit.

I became a believe! (so now I have to proselytize)

Fit is paramount. I have been involved as a part owner of an LBS for 15 years and we do basic fits the old school method. We also do BG Fits but they cost a little more. I simply gave the OP the basics for getting himself set up on the bike. What I mentioned, is the foundation of a fit. The rest is tweaking. BTW, we don't charge for a basic fit unless you bring in an off brand bike. :)


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