Stem length/Bike setup

ChrisSA

Hello All,

I'm in the process of trying to tune the fit/setup of my ebay-bought road bike. I've had this since Feb and probably done 100 or so miles on it (cross training for running).

I've got my saddle in roughly the right place now (more work to be done later). Ignore the nose-up saddle - it was level before today's ride and moved - a new seatpost with a more accessible clamp will resolve this. I'll probably replace the saddle soon too.

Once the saddle position is all set I need to move onto the stem.

I currently have a quill stem. The effective length of the stem from centre of headset to centre of bars is ~125mm (if it was a 0deg), and the actual length of the stem from the top of the vertical-ish section to the centre of the bars is ~145 mm. The quill stem is as high as it can go. My plan is to use a stem converter so I can try different stem lengths.

How long should the stem be? In this set up the tops and hoods seem a reach, and my elbows are almost straight, but I can get into the drops without any issues. I'd like to be in a position to reach everything comfortably.



Thanks,
Chris

neeb

There is no correct length for a stem - it's highly personal, but important to get right for the bike to fit. As a rough guide, you should be able to have your hands on the hoods with an approx. 30 degree bend in your elbows when you are in a comfortable and efficient riding position. The best thing to do would be to get a proper bike fit, otherwise it's just down to trial and error. There are online programs to calculate ideal reach based on body measurements, but IME they usually come up with weird results.

Bear in mind that the shape and position of the bars and the position of the levers also affects reach. From the picture it looks like your bars are shaped to give a relatively long reach to the hoods.

You don't really want the stem (as measured from the side, from the center of the steerer to the center of the bar clamp) to be any shorter than 90mm or longer than 130mm. If I have understood you correctly and the current length is 12.5cm, you could certainly go a bit shorter.

Paulroth

One rule of thumb on correct stem length, is a visual one.

When riding with hands on the hoods, look down at the front wheel hub.
If you cannot see the fornt hub (ie hidden by the bars), then stem length is correct.

If you can see the hub and it is in front of the bars, the stem is too short.
If you can see the hub and it is behind the bars (ie closer to you), then then the stem is too long.

Not very scientific, but a gauge on what is right / wrong.

Paul

1_reaper

Just had a look at my bike stem length. and if that rule of thumb that Paulroth posted I'm bob on

father_jack

Paulroth wrote:

One rule of thumb on correct stem length, is a visual one.

When riding with hands on the hoods, look down at the front wheel hub.
If you cannot see the fornt hub (ie hidden by the bars), then stem length is correct.

If you can see the hub and it is in front of the bars, the stem is too short.
If you can see the hub and it is behind the bars (ie closer to you), then then the stem is too long.

Not very scientific, but a gauge on what is right / wrong.

Paul

On both bikes I can see the hub, the hub is in front of the bars. If I have a longer stem (12cm on my OCR) the stem blocks the axle. But if feels far too stetched.

macondo01

Another rule of thumb is to put your elbow on the nose of the saddle, forearm and fingers going towards the stem. Your fingers should be close to touching the handle bars. More here
http://davesbikeblog.squarespace.com/blog/category/bike-fit?currentPage=2

father_jack

I just tried that Macondo01, bang on.

ChrisSA

Hmmm......

I'm bars-over hub on the hoods, but it feels very stretched. Of course this is dependant on arm bend and neck angle.

By placing my elbow against the nose of the saddle, I'm about 3.5" short of the bars. I think my saddle needs to go back to get a good KOP position.

I'm 5'10". Top tube C-C is roughly 56 cm (22"), and the seat tube C-C is roughly 53.5 cm (21").

As predicted, all on-line bike fits seem wrong. My LBS couldn't help with the quill-converter as they insisted the stem was 21.1mm, whereas I've measured it at a 'standard' 22.2mm. Looks like I'll head to one of the local bike-fit places instead, and see what they can do with the quill adaptor.

TMR

Macondo01 wrote:

Another rule of thumb is to put your elbow on the nose of the saddle, forearm and fingers going towards the stem. Your fingers should be close to touching the handle bars. More here
http://davesbikeblog.squarespace.com/blog/category/bike-fit?currentPage=2

I tried that on my MTB this afternoon, and my my fingers were over the stem by 2-3 cm. Does that mean I need to slide the saddle back?

father_jack

probably different for MTB..about road bikes?

macondo01

I just tried that Macondo01, bang on.

Good!

I tried that on my MTB this afternoon, and my my fingers were over the stem by 2-3 cm. Does that mean I need to slide the saddle back?

No. This guide isnt meant to apply to MTB - just road bikes.

nferrar

Don't mess with your saddle position to adjust the reach, set the saddle up first so you're following the plumbline behind the kneecap through the pedal axle thing and then leave it alone.

As for stem length/reach then as others have said it's a personal thing and depends on your current flexibility and back/neck strength. Pros generally run long stems to stretch out for a more aero position but they also work on their flexibility/strength and do a load of miles on the bike so it's comfy for them. For most of us it would be too much of a stretch so just adjust to suit you.

Going by your pictures it does seem a fairly long stem so if it does feel too stretched then try something a couple of cm's shorter. I'm not sure I'd bother with an adaptor, you should be able to get quill stems for bobbins these days (second hand) to experiment with. Just get one with a removable faceplate so you don't have to take the bar tape off to change it.

Monty Dog

Agree regarding getting your saddle height and setback right first - then leave it alone. The seatpost you have doesn't allow for much setback either - depends on your leg length, but if you have long legs, generally = more setback.
Stem length is a factor of reach and flexibility - but looking at the proportions of your set-up, I'd say your position is too far forward - it'll just give you back and neck ache, particularly if your elbows are extended. As earlier poster said, your bars are rotated too far round too - drops should be nearer horizontal. Too much weight far forward means you're more likely to wash out the front wheel when cornering too.

ChrisSA

Any saddle adjustments made will be to get it to the right position for my legs - not the reach (been there - sore neck). New seat post with more setback already ordered.

I'll rotate the bars down and move the shifters up.

The advantage of the stem adaptor is I can swap just the stem out, and there seem to be a lot more sizes/angles of ahead stem available than removable-fronted quills.
That said there seem to be some 100mm adjustable quills on ebay.

ChrisSA

So I've changed the seatpost and saddle, and then changed to a quill convert with a 90mm +10deg stem. I've also rotated the handlebars and moved the shifters up.

I'm unsure if it feels better. There is more pressure on the thumb webs where they rest against the hoods, and the font hub sometimes appears behind the bars. However I'll probably leave it how it is for a while and see how I get on.

2alexcoo

Those shifters look far too high on the bars to me. I imagine it will make braking from the drops very difficult!

fenski

I agree. The top of the shifters should be more or less parallel with the ground so that they act like an extension to the bar.

Try searching Google images for 'road bike' and you'll find a million and one reference images.

carlton nick

Paul Roth wrote When riding on the hoods look down on the front wheel hub. If you cannot see the hub (ie hidden by the bars) then the stem length is correct.

I'd seen a similar comment before (in the Haynes bike maintenance manual) but that says when riding on the DROPS if you cannot see the hub then the stem length is correct.

I checked this out and found my own stem length complied with the latter on both my drop bar bikes.

dmch2

Comments earlier on in the topic talked about setting seat height and setback first. But they didn't say how to do this...

Can anyone explain it to me please?

sparkins1972

I found this guide to be useful when setting up my new bike

http://www.youtube.com/watch?v=FAl_5e7bIHk

dmch2

Ta

Will watch that tomorrow

ChrisSA

To close this one out, I had a bike fit (BikeFitting.com) at the road LBS.

They didn't adjust much - just set the bike up as per the drawing that the PC spat out (Comfort Road aka Sportive). Unfortunately the bars still need to come up another 35mm, but there is no more adjustment.

Today's ride was fantastic. The bike felt so much smaller, and a part of me. The entire ride was done on the hoods (before was a mix of tops and drops as reach was out). No wrist pain, no neck pain. I was able to see where I was going without feeling like I needed to lift my head up, and there was hardly any weight on my arms.

I'm still considering a compact bar, but will wait to see how I get on. All in all, money well spent (£35 for standard fit, £15 for the tweaking and turbo check).

davenice

Any chance you could post a comparison photo?

It wouldn't really help anyone else but having seen the before and middle photos, it'd be interesting to see what you ended up with!

Cheers :-)

Dave

ChrisSA

If I can get it done tomorrow I will.