Do I need a shorter stem?

MadDog1999

Hey guys,
So I have a second hand 52 cm road bike which by what I went from should be right as I am 5ft 5 inches. However on very intensive rides like going up new hills etc or even longish distances I get lower back pain to the point of crippling that I have to pull over and get off the bike. The stem on it currently is 115mm and while on the hoods I can see the hub behind the bars. I also feel slightly stretched out. Weirdly, I never experience this pain on the trainer, only while out on the road. Do I need to strengthen my core? I can't afford a bike fit and also tight on money so need to decide on proper stem length before I buy!

I have included pics of my position while holding hoods and drops. I am getting quite annoyed now. And to move the saddle very far forward it goes past the max lines.

https://m.imgur.com/a/Gs6mS

Also, I found out I have been using a too low saddle, but I have a problem trying to find the right height. I have used the LeMond method which I am 5ft 5in inseam 32inches(81cm) and got a saddle height of 71cm. However I set it there and I have a tiny bit of ankle up at the longest extension. I lower it and then I have too much knee bend. I cycled yesterday and felt like it was a bit too long, but then I lower it and it feels too low. Do I just need to adapt/get used to the correct saddle height after riding with a too low saddle for so long? Is there any way to fully dial it in because to me there's no height that feels right. To stand comfortably when stopped I also have to step off the saddle or else if I stay seated I am on tip toes. I can't afford a bike fit, and now I am finding my own bike fit frustrating. I think I also need a shorter stem

Thank you!

magicbastarder

what's the frame? have you googled it to see the geometry and what sort of stem length would have originally been sold with it (if it's not the one currently on it)?

MadDog1999

magicbastarder wrote: »

what's the frame? have you googled it to see the geometry and what sort of stem length would have originally been sold with it (if it's not the one currently on it)?

I got the bike with that stem but it is a Lapierre Audacio 200 2012, bought it last year for 400 euro(realised now I was ripped off but sure what can I do). It seems to have a sloping top tube. Specs I found don't give much info either

ninoon

My tuppence worth without going into the details of a bike fit, Yes if you can see the hub behind the bars as you describe you are probably over stretched but this is a fairly basic rule of thumb, secondly the *correct" saddle height often feels too low especially to someone starting out at cycling, also small saddle height adjustments are best,even less than 10 mm.

magicbastarder

anything i can find out about them online shows a ritchey logic stem, so it's likely it was changed. perhaps the previous owner thought the bike was a little small for them and put a longer stem on?

magicbastarder

obviously the geometry has probably changed since, but if it is roughly equivalent, that's a long stem for the frame size:
http://www.lapierre-bikes.co.uk/gamme/2017/road/sport-0/audacio-500

the size L is supplied with 110mm and XL with 120mm.

MadDog1999

Ya I can definitely say it's not the same stem as when the bike would have been new, it's not a ritchey stem on it. So what size should I get?

And about the saddle height, my hips don't rock with the LeMond height

Cee-Jay-Cee

Fit a 100mm stem and see how you get on.

As for saddle height, I always use the heel on the peddle method and it works perfectly for me.

Unknown Soldier

There are obviously a lot of different factors involved but for what it's worth I have the same inseam and my bike fit saddle height is 700mm(698 is you want to split hairs) and I use a 110mm stem but I am 5'7. 100mm would be slightly more relaxed as I do seem to be quite racey positioned compared to colleagues, but the bike geometry is quite racey anyways.

I measure 120mm from the back of the saddle, and that is the point that I use to set the saddle height.

A shorter stem won't do you any harm, I suggest a 100 too.

sin_26

Well...
Few factors comes into play. What is your saddle to handlebars drop, saddle fore aft, saddle level, how far is your saddle to handlebars etc.
As you said that it happened out not on trainwer I think it might be your core muscle issue. On the trainer they don't have to work to stabilise your body.
Heck even your cadence and gears chosen might cause this.

sy

Looking at your height and inseam measurements, it seems you have long legs and short torso..I'm 5'7" and 31.5 cm inseam. So my guess is that an 80mm stem will sort out your problem....maybe 90mm..worth borrowing one and trying it out. Where do you live ?

doozerie

There are lots of rules of thumb when it comes to bike fit, but at best they are very broad generalisations for someone of average height, flexibility, leg length, torso length, etc. Don't take them literally, they might get you into the right ball park or they might not.

One of those rules of thumb is that lower back issues can arise from a saddle that is too high. Again, take that with a pinch of salt, but it has an ounce of truth in it simply because having your saddle too high means that your hips will rock side to side as you pedal and that puts a lot of pressure on your back.

Rules of thumb such as whether you can see the hub behind your handlebars I'd ignore, personally - the results of that "test" will vary depending on length of wheelbase, length of rider's arms, length of torso, etc., etc.

There are lots of bike fit tips and advice online which are worth looking at, but again some of those will almost certainly be based on those rules of thumb too, and therefore very questionable as far as I am concerned. I've looked at some of the YouTube videos by "Bike Fit Adviser" and that guy seems well grounded in common sense (my personal assessment of course, for whatever that is/isn't worth). For him it seems that your hip (i.e. saddle) position relative to the bottom/bracket is one fundamental measure, and reach from saddle to base of your hoods is another. If you significantly alter one of those, whether to bring the other in line or for some other reason, you may be creating other problems for yourself.

That said, if you want to know what a shorter stem might feel like, rotate your handlebars in your current stem to bring the hoods closer. That's screw with the angle of the hoods but will at least give you a feel for whether the shorter reach might suit. It'll also raise the height of your hoods, and you might find that them being higher feels more comfortable too and may be easier on your back.

MojoMaker

One of my bikes is a Lapierre Xelius 52cm and I'm 5'10". It's exactly right for me, I'd say it's slightly on the large size for you. Stem is making you work even harder! Mine is 100mm.

MadDog1999

sy wrote: »

Looking at your height and inseam measurements, it seems you have long legs and short torso..I'm 5'7" and 31.5 cm inseam. So my guess is that an 80mm stem will sort out your problem....maybe 90mm..worth borrowing one and trying it out. Where do you live ?

I'm in Kerry, ya that is the predicament I've gotten myself in to, my legs are freakishly long and my body is as short

MadDog1999

MojoMaker wrote: »

One of my bikes is a Lapierre Xelius 52cm and I'm 5'10". It's exactly right for me, I'd say it's slightly on the large size for you. Stem is making you work even harder! Mine is 100mm.

That's the bad news I didn't want to hear, but there's nothing else I can do now to be honest, other than trying to make it work for me.