Stem Lengths - Actual Or Effective?

[cloozoe]

Hi,

New guy here. Have a hybrid with a top tube that's about 30mm too long for me (due to the vagaries of my specific proportions, fits well in other regards). Want to put a new stem on to shorten reach, and while I'm at it want to raise the bars by going from a + 6d rise to +17.

Question:

The actual length of my stem is 110mm, and since the rise is only 6d, the effective length is only a hair shorter (less than 1mm); with the 17, though, there would be a more significant difference (in the case of an actual 110mm length, almost 5mm) between the actual length and the reach (reach is less than length).

Do manufacturers measure their stems by actual length or effective length? If the former, I'd get a 90; if the latter I'd get an 80.

Thanks!

 

[classic1]

This might help. There are a few on the web. Google 'head stem rise graph' or 'head stem rise chart'.

http://www.habcycles.com/stemfit.jpg

They use actual length as far as I know, but there is one trick to keep in mind. Some manufactuers (Cinelli, 3T), measure length along the top. ITM measure along the side/mid line. It makes a difference of 2-3 millimetres, not that it is a huge amount of difference.

30mm too long is a lot IMO.

 

[kylerlittle]

I think it depends on the measurements, better to take it to a shop and a professional.

 

[cloozoe]

Classic: thanks for the chart; if I had seen that first, I could have saved my poor brain the effort of dredging up my trig skills. Yeah, I agree that 30mm too long is worth addressing - that's why I'm going to.

As an aside, said poor brain is having a hard time wrapping itself around why measuring along the top line whould be different than measuring along the mid line.

 

[alfeng]

Classic: thanks for the chart; if I had seen that first, I could have saved my poor brain the effort of dredging up my trig skills. Yeah, I agree that 30mm too long is worth addressing - that's why I'm going to.

As an aside, said poor brain is having a hard time wrapping itself around why measuring along the top line whould be different than measuring along the mid line.

FWIW. If you are not currently uncomfortable on your bike, then the stem length is not too long ...

If you are uncomfortable, then a stem which is 30mm shorter may be a benefit ...

But, it may not be ...

The guidelines are only that ... and, IMO, one can consider them to have been almost arbitrarily selected.

ONE alternate consideration would be a set of "beach cruiser" handlebars which will more-than-likely change your riding position by MORE than the shorter stem, alone, will ... which is also to say that if you find the shorter stem still leaves you leaning forward more than you want to, then they can be another consideration.

BTW. If you bought your Hybrid as a NEW bike from a "real" bike shop, then doN'T patronize them in the future because they did a terrible job fitting you to the bike ...

OR, take it back to them for a FREE replacement stem which is shorter BECAUSE you have paid a premium for the service they can-and-should provide.

 

[cloozoe]

Thanks alfeng.

Not terribly uncomfortable, but I'm getting on in years, don't race, ride casually --frequently with my very slow wife and kids-- and thought I'd experiment with a little shorter/little higher. If I don't like it, I'll slap the old stem back on.

Nope, didn't buy it from a bike shop, real or otherwise. I've been riding/messing with bikes my whole life and know what to look for in a used one. I would invariably opt for, say, a clean, sound $700 bike used for $300 than a new $500 bike for, um, $500. I'd do/have done the same if my budget were substantially higher or substantially lower.

As I mentioned in my OP, the bike fits me quite well in all respects other than the reach being a bit long, and the same bike with a shorter top tube is a bit small for me in other respects. In any event, have no one to blame for fit but myself.

Also, for what it's worth, I've had some terrible "fittings" over the years from "real" bike shops. I trust nothing and no one but myself when it comes to bike fit.

 

[alfeng]

Another alternative consideration to a shorter stem would be a BMX handlebar (check danscomp.com as a reference or source) ...

OR "Stingray"/("monkey") handlebar.

 

[cloozoe]

Again, thanks for the suggestion.

 

[classic1]

As an aside, said poor brain is having a hard time wrapping itself around why measuring along the top line whould be different than measuring along the mid line.

Because stems generally aren't 0 degree. What I said doesn't count on 0 degree stems, but not many are 0 degree.

For example if a -17 degree stem is 130mm along the midline it will be longer than 130mm when measured along the top of the stem because you are not measuring from the same point.