Is swapping to a drop bar giving you an increased effective stem?

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NetworkMan
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby NetworkMan » 31 Aug 2018, 10:59am

Manc33,
Have you read Colin's fitting guide?
http://wheel-easy.org.uk/uploads/docume ... 02017a.pdf
I found it a big help.
Also when you get the drop bars on remember that changing the bars is an option too. I was happy on the tops but found that the hoods were too far away. A change to compact bars with only about 75-80 mm reach remedied this.

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531colin
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby 531colin » 31 Aug 2018, 1:52pm

531colin wrote:……….Just do it. 2 cm isn't enough to alter the weight distribution noticeably. As already said, nobody notices differences in steering when moving their hands to the different bits of drop bars.

Sorry, brain fart when I posted this.
I thought you meant 2cm stem change with the same bars, which is insignificant.
I now think you mean changing from flats to drops, and shortening the stem 2cm.....this will give you a much more stretched-out position.
Changing bar width won't have any significant effect on reach

NetworkMan
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby NetworkMan » 31 Aug 2018, 2:49pm

Hi Manc33,
I just looked at that Thorn brochure I mentioned upthread:- http://www.sjscycles.com/thornpdf/thorn ... ochure.pdf and it does directly mention switching between drops and flats on page 22. It's a bit gloomy, saying that you are likely to have to reduce the stem length by about 55mm. I don't know if 55mm is relevant in your case but if you haven't yet got far with the change it might be worth checking you have the saddle distance correct and then deciding if the reach to the flat bars is correct, too long or too short before going any further. You don't want to finish up needing a stem that is too short, or even zero or negative in length which would mean that the frame is just too long.

Manc33
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby Manc33 » 2 Sep 2018, 11:35pm

531colin wrote:Changing bar width won't have any significant effect on reach


It has to when your hands are coming in 15cm each side. :P

I put dots 760mm apart, then in the center of those I put dots 420mm apart, then I put a single dot 800mm above those dots in the center. It was about 55mm further comparing the distance from the center dot to the left (or right) 760mm dots, compared to the dots that were 420mm apart.

If that does alleviate 5.5cm of the +11cm reach caused by going from flats to drops, there's only another 5.5cm to deal with. This 55mm also matches what was said on page 22 of the PDF file posted earlier by NetworkMan where it said doing this bar swap means shortening your stem by about 55mm, which is not what I plan to do, it's just the reach difference.

I already have my saddle fully back on flat bars and I could probably sit another 4cm back without it bothering me on the reach. I plan to put the saddle forwards 4cm which leaves 1.5cm then put a stem on thats 2cm shorter, putting it +0.5cm in the clear.

The problem is, the drop bars I am putting on have 1.5cm more reach than the ones I tested with, again putting it -1cm out. :roll:

I can possibly live with it (because deliberately sitting 4cm back on the saddle wasn't exactly reaching for the bars) but I will just have to see. If not I will get an inline seatpost (which will give it +1.7cm back) putting it +0.7cm in the clear.

I used to have my bars high up and have been gradually getting them lower and it not bothering me. It only seems to bother me when I first swap. After weeks riding with the bars lower I am fine with it.

If all of that fails I might buy a complete, small MTB and sell off the parts, but keeping the frame and fork.

Looking at the top tube lengths it would need to be something like a 15" MTB frame to equal out the reach on drops, compared to a 19" frame on flat bars, because it needs a 55mm shorter top tube.

Going from M to S only shortens it by 35mm:

Image

I haven't even mentioned trying to get 22.2 rapidfire shifters to fit a 23.8 road bar yet :P

That's why I can't just fit any old bar, I want my 22.2 shifters on it and the options are really limited. There's a bar at CRC with 90mm reach but it's out of stock, £25 and I cba waiting, so I got one from China (Delt bars) but those have 100mm reach. The Triban 3 road bar I tested has 85mm reach.

I can't bring myself to bore out a M970 shifter clamp :oops: I am sure those are built just thin enough as it is and 0.8mm would need boring off the internal diameter per side. I'd rather just get the 22.2 drop bars and figure out a way to get the reach lessened. I need to have a ride on it first but if it's good I might get a Rockrider 520S in a small size specifically so drop bars makes it a good fit. The only problem then is I'd always be scrunched up on it if I went back to flat bars.

Someone managed to get 22.2 shifters to fit a 23.8 bar by doing this:

Image

Then you can't ever use it on a 22.2 bar again, or maybe you could by using something like a piece of inner tube to shim it.

Shimano are gits for not making the M970 clamp a spare part. :x Then I could at least try boring a pair out to 23.8 without risking the only ones I have, and those Yumeya ones are out of the question.
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531colin
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby 531colin » 3 Sep 2018, 11:28am

The only way to really find out if this bar swop will work for you is to try it.
There are reports on this site of people fitting drop bars to bikes (eg "hybrids") which are nominally "designed for" flat bars and being happy with the results. I have never yet found a frame which was short enough for me to ride with drops and also long enough for me to ride with straight bars, whatever length stems I used; but I wanted the same position with both bar types, and the cycle industry (generally) assumes that flat bar riders want less reach than drop bar riders. Fitting bikes to bodies is a bit more complex than drawing a few dots; for example, if you were going the other way and fitting your wide flat bars at the equivalent reach to drop bars, you would find that you couldn't turn the bars much before one end of them was out of reach.
I would be the last person to encourage you to buy road STI shifters, but if you want to get your MTB shifters "round the bends" of drop bars, you are going to have to be able to spring the clamps to more than the diameter of the bars. Long ago, I reamed out the clamps of some (8 speed, probably) MTB pods to 26mm to fit Profile aero basebars; they may still be knocking around, I never used them, I did this instead...https://forum.cyclinguk.org/viewtopic.php?f=5&t=113772&hilit=bullbars. There is also a monster thread here https://forum.cyclinguk.org/viewtopic.php?f=5&t=57027&hilit=skinflints&start=120 about alternative ways to mount shifters on drop bars.

Manc33
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby Manc33 » 3 Sep 2018, 12:53pm



Cheers 531colin.

I remember having shifters on the down tube years back, then recently I saw some mounted on a quill stem and wondered why they didn't all have them like that back then. Having rapidfire or STI is handy, but I'd argue having shifters anywhere on the bars or near there like on the stem is a big leap from them being on the down tube.

Ideally I want normal road bars on because there's endless options with some having a really short reach. The Tektro RL520 brake levers (road brake levers designed for v-brakes) say they fit 22.2mm and 23.8mm bars, so the only problem is the rapidfire shifters.

Maybe the 22.2 shifter clamp can be bent but I wouldn't risk it on M970's :P Also I did stress them fitting them to some egg shaped (meant to be round) cheap Chinese bars in the past. :oops: That's the price for paying £6 for a new handlebar.

Saying that I just bought drop bars from China, hopefully they will be round and 22.2mm.
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RickH
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby RickH » 3 Sep 2018, 3:33pm

When I drop-ised the tandem I got some straight bars with a narrow centre bulge (which I trimmed down to the width I wanted) & some drop bar shaped bar ends so I could use the straight bar shifters. (I also got drop bar brake levers & replaced the straight bar brakes with interrupter levers, both V brake compatible).

In my case it was a cheaper option as the bike has an Alfine IGH & 3rd party drop bar shifters seem to be expensive.

Manc33
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby Manc33 » 5 Sep 2018, 1:36am

RickH wrote:When I drop-ised the tandem I got some straight bars with a narrow centre bulge (which I trimmed down to the width I wanted) & some drop bar shaped bar ends so I could use the straight bar shifters. (I also got drop bar brake levers & replaced the straight bar brakes with interrupter levers, both V brake compatible).

In my case it was a cheaper option as the bike has an Alfine IGH & 3rd party drop bar shifters seem to be expensive.


I have seen those bar end things but never thought to put the brake levers on. It would all need bar tape but I bet it could end up with the same effect.
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Manc33
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby Manc33 » 10 Sep 2018, 12:25am

My top tube is 57cm. I worked out if I added 2cm to the stem (it should be longer ideally) and put the saddle in the middle of the rails (back 2cm) where it should be, I would effectively need a frame thats got a 450mm top tube!

That to me sounds like a 15" mountain bike, like an XS size.

They just don't make that cheap Rockrider that small, the S has a 55.5cm top tube, that's not going to cut it.

12cm off the top tube sounds a lot, but going from flat bars (that angle back about 1cm) to the hoods of drops, is indeed getting on for about 11cm or 12cm more in reach.

I remember having a 48 road bike and with drops it was bliss, even though all the sizing charts will say I should be on a 57 frame. That was a road bike though. On a 57 road bike on flat bars, again its bliss, whereas drops are too reachy.

I think I just need to go to Decathlon and sit on a few bikes. :lol:

I always think if a road bike with drops is too small you can be getting within 5cm of hitting your knees on the drops. I measured before and there's a good 25cm gap at the moment so reducing the top tube 12cm is not going to start causing that.

I wonder how small is too small when smaller bikes weigh less and you can just put a longer stem on and pull the seat post up more. Then it causes a shorter wheelbase and different (worse?) handling, I guess.

I think I am just a really weird guy with long legs and a short upper body. :x

This made me laugh, from elsewhere:

"...the Islabikes Luath 24 has a 45cm top tube, and that’s a 24″-wheeled bike for 8 year olds at 4’3"


Although he is talking about a road frame which, if it was a MTB, would presumably be about 48cm top tube.

:lol: :lol: :lol: :roll:
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Manc33
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby Manc33 » 14 Oct 2018, 2:40am

Even though going to drops and bringing my hands together from 760mm (flat bars) to 440mm (drop bars) which in theory should cause a 5.5cm difference (where, you are creating the need to reach another 5.5cm by going from 760mm bars to 440mm bars) this just isn't the way it pans out in reality, as I think Colin eluded to earlier, the difference seems to be more like 1.5cm, that is, going to drops if your reach was 800mm from sit bones to hands on flat bars, on drops your reach at about 815mm feels the same. None of this makes any sense and I am still wondering where the 4cm difference went. Why is it 1.5cm when it should be 5.5cm!

I have no idea why this is but it seems to be the case.

My (medium) frame MTB has an effective top tube of about 570mm, the frame works out to about a 18" or 19" frame and I had the saddle back, while on flat bars. Even on a 14" frame the effective top tube is only reduced by 10mm to 560mm and with drop bars on, that feels too reachy.

So I am going to give up with all of this faffing and just get a CX or road frame where I have not got over 1ft of seat tube sticking out, but I wanted suspension!

That's all this was ever about, making a small MTB with suspension work on drops.

It's insane that you'd need to go even smaller than a 14" frame, beyond that the frames are kids frames with 24" wheels and you're never going to have a seat post safe enough to use, even if it's a 500mm one (which mine is). The flex is outrageous and that's with the saddle about 80% forwards.

It doesn't fit and never will, my knee isn't where it should be (in line with, or just in front of the pedal axle when the crank is parallel to the ground) and the whole thing is all the wrong fit.

Even if I went smaller to a 12" frame (vastly undersized for my height) I would not really get any decrease in the top tube over a 14" frame (maybe 1cm) but I'd have another 5cm of seatpost sticking out, when it's already flexing a lot now and not far off its minimum insertion.

Conclusion: You cannot have a suspension frame for use with drop bars. :lol:
Only weird bikes are interesting anymore.

Brucey
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby Brucey » 14 Oct 2018, 9:19am

old (some very old now) MTB frames come with shorter top tubes and these fit dropped bars better. Obviously you can put a suspension fork in anything too, so the net effect is that yes you can front suspension and dropped bars if you really want. That is how many MTBs were raced BITD.

Image

more to see here

https://www.bikeforums.net/classic-vintage/828426-show-your-vintage-mtb-drop-bar-conversions-42.html

Is this enough 'suspension'....?

Image

cheers
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reohn2
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby reohn2 » 14 Oct 2018, 10:04am

Or the subject of this thread:- viewtopic.php?f=5&t=125018
CX bikes have a high SO so the bike can be easily shouldered and run with,and agressive race geometry for short 1hour racing.
Last edited by reohn2 on 15 Oct 2018, 10:47am, edited 1 time in total.
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andrew_s
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby andrew_s » 14 Oct 2018, 11:11am

CD = ?
SO = ?

Brucey
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby Brucey » 14 Oct 2018, 11:18am

andrew_s wrote:CD = ?
SO = ?


CD = CX ?

SO = Stand Over...?
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reohn2
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Re: Is swapping to a drop bar giving you an increased effective stem?

Postby reohn2 » 14 Oct 2018, 1:13pm

Brucey wrote:
andrew_s wrote:CD = ?
SO = ?


CD = CX ?

SO = Stand Over...?

Correct Brucey,
The CD is predictive text's fault and me not checking the post :oops:
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