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Old 07-08-03, 09:08 PM   #1
danr
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Headset Spacers - How much is too much?

To try and make a long story short, I would like more rise in my handlebars. I already have 32.5mm worth of HS spacers and a rising stem (1 1/8" threadless).

I am considering getting a new fork for my road rig, but I do not want to cut the fork. This means I will have about 50 mm of headset spacers.

Is there anything mechanically wrong with that?
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Old 07-09-03, 12:02 AM   #2
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First off, how much is your seatpost extended? Generally speaking, if your seatpost is way out on your road bike and you're looking for additional height in your bars, your frame might be too small for you. The traditional quilled stems on road bikes can rise as much as 50 - 80 mm or even more on road bikes so I see no reason why threadless stems can't sit up just as high.......but kinda looks funny and weird with all those spacers.....and usually, the higher you go, the longer the stem needs to be...
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Old 07-09-03, 05:04 AM   #3
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Quote:
Originally posted by George
First off, how much is your seatpost extended? Generally speaking, if your seatpost is way out on your road bike and you're looking for additional height in your bars, your frame might be too small for you. The traditional quilled stems on road bikes can rise as much as 50 - 80 mm or even more on road bikes so I see no reason why threadless stems can't sit up just as high.......but kinda looks funny and weird with all those spacers.....and usually, the higher you go, the longer the stem needs to be...
My seatpost is extended quite a bit. My dilemma is that I have long legs for my body. I almost have to fit a bike by top tube length over seattube length. If I were to fit strictly by inseam, I would have a bike that is 2 to 4 cm larger, but the top tube would be way too long. A custom frame is in my future, but distant future.

Right now, my bars are only about 3 cm below my seat. However, I would like for them to be higher since I get some back pains after longer rides. My current stem is a little too long, so if I do raise the steerer tube, it should work out fine.

As far as looks, I don't mind. I just don't want one of those funky triathlon stems.

Yeah, I know about quilled stems. I'm kinda wishing I did have a threaded headtube right now. It would make my decision much easier. I just don't know if with too much length in headset spacers, that would cause any types of problems. My imagination is running wild with this problems thing. I'll probably just try it and it will probably work out just fine.
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Old 07-09-03, 08:03 AM   #4
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Nothing wrong with a 50mm stack of spacers. I'm not 100% sure I'd do it on a carbon steerer, but that's just me -- supersitious and irrationally conservative. I have no evidence to support such a reservation.

My Airborne has 50mm of spacers on a cro-mo steerer; neither Airborne nor my LBS mechanic had any reservations. For me, that puts the bars about an inch below the saddle -- and that's with a "compact" frame. I have a lot of seatpost showing as well.

The bike fits like a glove.

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Old 07-09-03, 10:04 AM   #5
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danr.............some of the guys I ride with have 10cm of spacers and a riser stem, so go for it........but again, it looks a bit goofy, but nothing wrong with that...
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Old 07-09-03, 11:51 AM   #6
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Quote:
Originally posted by George
it looks a bit goofy
Eye of the beholder. To me, somebody riding in traffic with his butt in the air and his head so low he can't see 20 feet ahead looks goofy.

Goofiest of all is a fine road bike hanging in a garage gathering dust because it hurts its owner to ride it.

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Old 07-09-03, 12:31 PM   #7
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Quote:
Originally posted by danr

Right now, my bars are only about 3 cm below my seat. However, I would like for them to be higher since I get some back pains after longer rides. My current stem is a little too long, so if I do raise the steerer tube, it should work out fine.

Back pain after long rides - how long are these rides? I find that with my current setup, I'll get some pains after 90-100kms. Nothing to write home about, but I don't do many rides over 120kms on my 'racing' bike. Anything longer, I'll use my touring bike...

Your current stem is too long - remember when you put a shorter one on, you'll effectively shorten your top tube, and take pressure off your back.

Not too much wrong with 50mm of spacers. A stock Trek 820 comes with that!
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Old 07-09-03, 12:59 PM   #8
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Quote:
Originally posted by Rich Clark

Goofiest of all is a fine road bike hanging in a garage gathering dust because it hurts its owner to ride it.

RichC
Oooh....I like that!
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Old 07-09-03, 02:45 PM   #9
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Thanks for all the input and personal experience.

When I say longer rides, I'm talking about 30+ miles. It's not bad now, but I don't want to let it get to the point to where I need to start seeing a doctor. It is getting progressively worse.

As of now, I'm doing much more ab work. It is definitely helping, but I feel better with the higher bars.

Once again, thanks for the input and humor
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Old 07-09-03, 11:03 PM   #10
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Well, you clearly need a custom frame from what you've said, 30 miles is not very far before getting back ache! As to spacers, you will likely find that the fork maker has set a limit for this, usually about 11/2" for a 11/8" headset. I guess going above this will nullify any warrenty, and you are now delving into the unknown. From a design point of view the strain put on the steerer will have been designed for a heavyish rider using the bike hard, ie putting lots of strain on the steerer, to which will have been added some degree of safety buffer. However the stress on the steerer will, obviously, increase as the stack height increases. You may think you don't put a lot of stress on the steerer, but remember that you will do under heavy breaking. If you go above the makers' limit, then you've no come back if it fails and you break your head. So its down to you. I would suggest that going more than 50% higher than recommended is taking a huge risk, better to swap to a quill, or buy that custom frame, than end up in a wheel chair.
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Old 07-10-03, 01:02 AM   #11
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The maximum amount of spacers depends on the manufacturers recommendation. My Giant came with the maximum number of spacers which is 5cm/2inches. If Giant think this is a safe amount, I'll trust they know what they are talking about. I could flip the stem and reduce the stack height to 3cm but I don't think it would make it any safer.

CHEERS.

Mark
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Old 07-10-03, 11:13 AM   #12
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Dutchy,
you are no doubt correct, or rather Giant is. I use Reynolds forks, and they specify 11/2" for 11/8" steerer, or 1" for their 1" steerer.

Problem is if you have to go higher, and flipping the stem doesn't give enough. I had this problem and solved it, and the back ache, by having a custom frame made. However I do have 900gram small compact which I would like to use, but it will undoubtedly mean going higher than the recommended stack height. No, I cannot change to a quill as the headtube is already machined for the 11/8" hiddenset fitted. So if I do go higher then I have no warrenty, and I need to think carefully about the stresses to which I will subject the steerer. Not an easy problem to solve. I guess I'll go as high as I need, and be ultra careful. I don't use the bike hard, so will only have the high braking load problem to think about!!

Any suggestions would be welcome.
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Old 07-10-03, 02:51 PM   #13
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Quote:
Originally posted by jimtaylor
Well, you clearly need a custom frame from what you've said, 30 miles is not very far before getting back ache! As to spacers, you will likely find that the fork maker has set a limit for this, usually about 11/2" for a 11/8" headset. I guess going above this will nullify any warrenty, and you are now delving into the unknown. From a design point of view the strain put on the steerer will have been designed for a heavyish rider using the bike hard, ie putting lots of strain on the steerer, to which will have been added some degree of safety buffer. However the stress on the steerer will, obviously, increase as the stack height increases. You may think you don't put a lot of stress on the steerer, but remember that you will do under heavy breaking. If you go above the makers' limit, then you've no come back if it fails and you break your head. So its down to you. I would suggest that going more than 50% higher than recommended is taking a huge risk, better to swap to a quill, or buy that custom frame, than end up in a wheel chair.
I guess this was my concern. I was envisioning the excessive extension placing excessive pressure on the headset or headtube though.

The fork I am planning on getting is a heavyset steel fork with a steel steerer. Plus, at 5'10", 165 lbs, and being afraid to go over 35 mph, I don't see myself putting enough pressure on it to break. If I do, I'm probably leaning too much into the handlebars anyways and I'll probably flip before I snap.

Thanks for the input though. I really had not thought of the steerer tube breaking. I'll sit back and ponder.
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Old 07-10-03, 03:16 PM   #14
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I did find something. This relates more to carbon steerers. Not straight from the horse's mouth, but getting warmer.

http://www.competitivecyclist.com/za...E=FAQS#ques_28

Quote:
Originally posted by www.competitivecyclist.com Given that most of the forks we sell have carbon fiber steerer tubes, we are restricted by industry standards to a limited "stack height" of spacers. We can only stack a steerer tube as high as it is wide. In other words, for a 1" fork, we are permitted to stack the fork with 2.5cm of spacers. For a 1-1/8" fork, we can stack it 3.0cm.
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Old 07-10-03, 11:23 PM   #15
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Given what you say, danr, I THINK it unlikely that your use of your bike is in the 'heavy' category. I would guess that forks are designed for the use of the 'pro-cyclist' who will be of your general build, but will use the bike heavily. Just imagine the stress on the steerer when these guys are sprinting, and the when they brake heavily going downhill at up to 100Kms per hour!! Your use of your bike would suggest that you could safely go above the recommended stack height, question is how high can you go?

Can I ask why, having selected a fork, you cannot go to the manufacturer for advice? On second thoughts that's dumb, as they will want to cover their backs!!

Using that fork, ie not carbon, I would be inclined to go as high as 75mm. That's 50 + 50%, and use the bike with care. But the risk is certainly down to you.

Sorry I can't help you more at this time. Will look around the web and see if I can find anything.
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Old 07-11-03, 02:52 AM   #16
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Just a thought, and it might be a daft one - but is there any reason why you couldn't use an MTB stem? You might get more of a rise.

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Old 07-11-03, 07:40 AM   #17
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Just a thought, and it might be a daft one - but is there any reason why you couldn't use an MTB stem? You might get more of a rise.

Richard
Aside from the fact that he'd probably have issues with handlebar diameter, road stems also come in many different increments of rise angle. It sounds like he already has one.

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