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Old 04-01-09, 08:56 PM   #1
peterhsd1
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Older Specialized Globe -- Seat Post Issue

The good news is that I just bought a hardly used '90s era Specialized Globe 3-speed. The bike was local to me and I doubt it has been ridden more than 10 times. It has the usual rotten tires and the hub needs adjustment, but boy does it move. I was cruising around the neighborhood last night at 17-18mph without much effort.

The bad news is that I did not notice the very high "minimum insertion" line on the seatube before I bought it. I have long legs and this is only a medium frame. I need the seat at least 2 inches above the minimum line. The tube is 26 x 400 and is unusual in that the minimum insertion line is only 10 cm below the top of the post. Most posts I've seen are the opposite (10 cm into the bike at min).

So, I'm wondering is this just a funky old seatpost that I can replace with a modern part with the usual lower minimum line or does this particular post have something to do with the Globe's unusual frame. I attached a pic. As shown the seat tube juts up about 15 cm above the top tube, kind of sticks up there all by itself. I put yellow tape at the minimum line on the seat post and on the frame where the bottom of the seat tube sits at my desired ride height. So, does the long seat tube insertion help to strengthen the seat tube? If that is the case, I assume I'm done and will have to re-sell the bike. The frame is steel and beautifully assembled. As you can see the post is just below the top tube but not by more than an inch at the ride height I need. If it is not a frame issue, I will definitely buy a new post that purports to be strong enough for that ride height I need. I'm really hoping I can make this bike work for me as a daily commuter.
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File Type: jpg Spec Globe.jpg (54.6 KB, 12 views)
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Old 04-01-09, 09:23 PM   #2
wrk101
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No way does this bike fit you. You need to get a large or even an XL frame.
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Old 04-01-09, 11:48 PM   #3
JiveTurkey
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It's generally good practice to have the seatpost stick down into the seat tube below the intersection with the top tube and/or seat stays. Perhaps that seatpost was specially matched to the frame given the large amount of seat tube sticking up past the top tube.
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Old 04-02-09, 06:51 AM   #4
DieselDan
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The short minimum insertion line is due to the seat protruding well above the top tube/seat stay junction. Your problem is less of a sizing problem but of a frame build problem. Good form, poor function.
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Old 04-04-09, 05:29 PM   #5
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That's pretty much what I figured, must have something to do with the long run of the seat tube over the top tube. Pretty and easier to step over but not the strongest setup. I see the new aluminium Globes have the same general shape but have strengthened the area with a short triangle tube.

However, I think I have workable solution. I took the stock road seat off and replaced it with a sprung cruiser saddle gaining an inch from that. I then lowered the seat post an inch and a half so I'm only 1.5 inches over the "min" insert line. At 175 pounds, I'm willing to live with that, about 2/3rds of the seat post is in the bike and there's about three inches below the top tube. I'll keep an eye on the post and frame for signs of cracking or bends.

I put some new brake pads and Specialed Fat Boys (26 x 1.25) on this morning and did 4 miles averaging 16mph without too much effort. Gears are a bit gummed-up, slipped in second on the way back so I'll have to work on that but I'm pretty satisfied with my sub-$200 investment (including brake pads and tires) so far.
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Old 04-05-09, 07:23 AM   #6
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Quote:
Originally Posted by peterhsd1 View Post
That's pretty much what I figured, must have something to do with the long run of the seat tube over the top tube. Pretty and easier to step over but not the strongest setup. I see the new aluminium Globes have the same general shape but have strengthened the area with a short triangle tube.

However, I think I have workable solution. I took the stock road seat off and replaced it with a sprung cruiser saddle gaining an inch from that. I then lowered the seat post an inch and a half so I'm only 1.5 inches over the "min" insert line. At 175 pounds, I'm willing to live with that, about 2/3rds of the seat post is in the bike and there's about three inches below the top tube. I'll keep an eye on the post and frame for signs of cracking or bends.

I put some new brake pads and Specialed Fat Boys (26 x 1.25) on this morning and did 4 miles averaging 16mph without too much effort. Gears are a bit gummed-up, slipped in second on the way back so I'll have to work on that but I'm pretty satisfied with my sub-$200 investment (including brake pads and tires) so far.
That should work.
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