# Is my bike too small?



## gmtfd (27 Feb 2018)

My MTB is a B'Twin Rockrider 8.1 which I've had for years and absolutely love. However, recently I've been riding more and have noticed that I'm often perched right on the back of the saddle, which is as far back as it will go on the rails (even beyond the 'max' marker). Does this mean the bike is actually too small for me? I'm 5' 11" and the bike is a large size, so theoretically it's the right size for me.

Are there any adjustments I could make to stop my bum constantly hanging off the back of the saddle? The stem is 100mm so I would guess fitting a longer stem is not an option? Wider bars maybe? Tilting the bars up?


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## Spiderweb (27 Feb 2018)

If my parents were taller and I’d reached the lofty heights of 5ft 11” then I would have thought the size Large Rockrider would be perfect for me.
On an MTB you do move around on the saddle, I often ride in the position you describe, it’s whatever suits. You could try a longer stem or some bar ends so you can extend your reach.
If you feel uncomfortable on the bike then make some changes but you don’t describe any discomfort so I would leave as is and enjoy.


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## Threevok (27 Feb 2018)

Another thing to check is your seat height - your knee should be slightly bent at the point where your pedal is furthest away.

I wouldn't worry about it too much though. the saddles are shifted back to the max on both my MTB's. The Virtue running a 90mm stem with bars uncut at 800mm, and the Inbred running a 110mm with the bars cut shorter 740mm (both 18" frames)

I am comfortable with both bikes


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## Racing roadkill (27 Feb 2018)

Try using a seatpost with more set back.


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## ianrauk (27 Feb 2018)

Put up a pic of you sat on the bike.


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## ChrisEyles (27 Feb 2018)

+1 for trying a longer stem if you need to be well back on the saddle, unless the seatpost you're currently using doesn't have much set back.


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## KneesUp (27 Feb 2018)

Fit rather depends on your proportions - I have relatively short legs for my height which means I tend to have the saddle back on the rails also. If it's right for your leg length then as others have suggested you can adjust for torso length by changing the seatpost and / or stem.


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## Levo-Lon (27 Feb 2018)

Racing roadkill said:


> Try using a seatpost with more set back.



This would be a good start, then the bars.


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## Nigeyy (28 Feb 2018)

I'm not sure a longer stem is necessarily a good idea (does the rider want to be more forward or is hanging off the back more indicative of needing to be in a more rearward position? There's a difference relative to how you can use your leg muscles on a downstroke). It depends on how much setback you currently have (bike geometries vary with seatpost angle) and whether you even have a setback on your seatpost. Obviously you can put your saddle as far back on the rails as you can as well. It's hard to tell since we haven't seen a pic (and even then individual preferences can play a part).

Since you seem to hanging off the back mostly, I'd recommend trying to move your body back rather than bring it forward with a longer stem -.e.g. saddle back on the rails, or a more setback seat post first. Having said all that, it's not unusual to be hanging off the back mtbing, so it could be just entirely normal


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## Levo-Lon (28 Feb 2018)

Most MTB bikes have a straight post.
And most droppers are straight .

I think they tend to be a straight post design?
Though a set back post works ok, I don't like the angle in relation to crank but that's just me.

Helps with stand over tho


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## Nigeyy (28 Feb 2018)

To be clear, when I mentioned setback on a seatpost, I was referring to where the saddle rails join the seatpost, not the seatpost tube itself. Thompson is a good example of a manufacturer that has no setback on some of its seatposts at all. But again, this also depends on the angle of your seatpost tube with frame geometry as well. Fit is such an individual thing!



meta lon said:


> Most MTB bikes have a straight post.
> And most droppers are straight .
> 
> I think they tend to be a straight post design?
> ...


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## ColinJ (28 Feb 2018)

gmtfd said:


> Are there any adjustments I could make to stop my bum constantly hanging off the back of the saddle? The stem is 100mm so I would guess fitting a longer stem is not an option? Wider bars maybe? Tilting the bars up?


Try a longer stem - 100 mm is fairly short! I have 4 bikes and the stems are 110, 120, 120 and 130 mm in length.

Tilting the bars up would effectively bring them closer to you, which is the opposite of what you are trying to achieve.


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## I like Skol (28 Feb 2018)

You need to be able to hang your ass off the back of an MTB so you can get your weight back when riding down steps and impossibly steep slopes!


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## ColinJ (28 Feb 2018)

I like Skol said:


> You need to be able to hang your ass off the back of an MTB so you can get your weight back when riding down steps and impossibly steep slopes!


But only a complete nutter would do something like that!


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## gmtfd (28 Feb 2018)

Many thanks for the advice everyone. I hadn't even considered the seatpost! Mine definitely has some setback but I'm not sure how much. I will measure it tomorrow and then see if I can find one which offers more. Failing that I will try a longer stem, but it definitely makes more intuitive sense to tinker with the seatpost first.


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## cyberknight (1 Mar 2018)

gmtfd said:


> Many thanks for the advice everyone. I hadn't even considered the seatpost! Mine definitely has some setback but I'm not sure how much. I will measure it tomorrow and then see if I can find one which offers more. Failing that I will try a longer stem, but it definitely makes more intuitive sense to tinker with the seatpost first.


get your set back right 1st , then reach 
http://www.jimlangley.net/crank/bikefit.html


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## gmtfd (1 Mar 2018)

cyberknight said:


> get your set back right 1st , then reach
> http://www.jimlangley.net/crank/bikefit.html



Really interesting article cyberknight, but I am somewhat confused!

Langley suggests that with the cranks level your forward lower leg should be at a right angle to the ground:













Image



__ gmtfd
__ 1 Mar 2018






On the other hand, this (http://www.mbr.co.uk/news/mountain-bike-geometry-326498) states "Modern bikes favour steeper [seat tube] angles that put the saddle directly over the bottom bracket, making pedalling easier and more efficient".

Surely there's a contradiction here?


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## smutchin (1 Mar 2018)

ColinJ said:


> Try a longer stem - 100 mm is fairly short!



You what? 100mm is very much within the normal/average range for a road bike, but for an MTB it's substantially longer than is typical.



gmtfd said:


> On the other hand, this (http://www.mbr.co.uk/news/mountain-bike-geometry-326498) states "Modern bikes favour steeper [seat tube] angles that put the saddle directly over the bottom bracket, making pedalling easier and more efficient".
> 
> Surely there's a contradiction here?



Not necessarily. The link @cyberknight posted relates to road bikes. You ride an MTB so requirements may be a little different.

This article relates specifically to fitting on an MTB: https://www.bikeradar.com/gear/article/technique-perfect-mountain-bike-fit-29498/

This article discusses stem length for MTBs: https://www.merlincycles.com/blog/buyers-guide-to-mountain-bike-stems/


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## ColinJ (1 Mar 2018)

ColinJ said:


> Try a longer stem - 100 mm is fairly short! I have 4 bikes and the stems are 110, 120, 120 and 130 mm in length.





smutchin said:


> You what? 100mm is very much within the normal/average range for a road bike, but for an MTB it's substantially longer than is typical.


Fairly short compared to what is available, rather than short compared to what is 'normal/average'!

The stem on my MTB is 120 mm and I had no problems with it.

I recently increased the length of the stem on my CAAD5 (road bike) from 110 mm to 130 mm and it suits me much better.


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## smutchin (1 Mar 2018)

As per the article I linked to earlier, stem length can significantly affect bike handling, so just fitting a longer stem might solve one problem but create another. 

Personally, I suspect the OP's problem is caused by the saddle being too low, but that's a bit of a guess. I don't claim any expertise on this matter, especially not with regard to MTBs.


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## cyberknight (1 Mar 2018)

smutchin said:


> You what? 100mm is very much within the normal/average range for a road bike, but for an MTB it's substantially longer than is typical.
> 
> 
> 
> ...


the article also covers flat bar and the above articles dont mention setback apart from somewhere in the centre afaik
I think my main issue was getting your saddle set back right first for the OP then sort reach out.It also depends on what sort of riding your doing, short intense efforts might benefit from a saddle over the BB but is it better for longer duration rides ?


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## smutchin (1 Mar 2018)

cyberknight said:


> It also depends on what sort of riding your doing...



Yes, hence my comment that the MBR link posted by @gmtfd doesn't necessarily contradict the link you posted - it's not a definite yes or no. He hasn't really given us much information about the type of riding he's doing though.


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## gmtfd (3 Mar 2018)

smutchin said:


> Yes, hence my comment that the MBR link posted by @gmtfd doesn't necessarily contradict the link you posted - it's not a definite yes or no. He hasn't really given us much information about the type of riding he's doing though.



Fair point! In the past it's mainly been off-road, but recently I've been using the MTB around town too, as I've been having knee problems and my single-speed bike obviously puts a lot more strain on my knees, especially uphill. It's since I've been using the MTB on the road that I've started to wonder whether it's too small.

Maybe, then, the answer to my dilemma is that road riding requires a different setup to off-road. Seems obvious now but somehow I'd never thought of that!


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## I like Skol (3 Mar 2018)

I'm not saying I am typical or even normal but the only changes I have to make to my MTB to switch from off-road demon to 100 mile cruiser is to swap the tyres. The right position is the right position.


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## Nigeyy (3 Mar 2018)

FWIW concerning "fit" articles (which interestingly can contradict each other anyway), I don't have too much faith in them. While they can be a rough guide, I think personal preferences can make a difference. Sometimes it's a case of experimenting until you reach your "right" position. And even then, that can change with age (my riding position has changed with the advent of age and err... extra stomach challenged dimensions...). 

Coming back to the OP, we still don't know whether you are tackling more extreme obstacles (sometimes requiring you to go back over your seat) or even a pic of you on your bike.....


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## gmtfd (20 Apr 2018)

Update: Having done a fair bit of reading around the subject, and taking into account all the helpful comments above, I realised that (as smutchin suggested) my saddle was set too low. I've now moved the saddles on both my MTB and single speed bike upwards and forwards. Everything is better: I feel more comfortable and more of my weight is over the front wheel, which helps with handling. I'm still naturally inclined to sit further back on the saddle when pedalling fast on road, but I think that's OK. Thanks everyone for helping me sort that one out.


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