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-   -   Question? Can you spread the rear Drops, to take a 10 (https://www.bikeforums.net/bicycle-mechanics/29266-question-can-you-spread-rear-drops-take-10-a.html)

orguasch 06-10-03 05:40 AM

Question? Can you spread the rear Drops, to take a 10
 
I have this question that is hanging in my mind, I have read in one of the thread that guys have spread there rear triangle to take from 7 speed to a 10 speed cogs, my position on this is that there is no need to spread the rear triangle just for the bike to take the 10 speed cogs, the frame with a 7 speed cogset can take a 10 speed cogs, no doubt, because what is shrinking is the lenght of the hubs and not the other way around.
Now if you spread a steel cromoly frame will it damage the integrity of the steel frame, ditto to Titanium or aluminum frame, but why will you spread a Ti and an Aluminum considering the dollar you have spent fot the frame, if the life span of the frame will be compromise, and if the frame is under warranty I am certain that it will lose its warranty, Just asking please engligthen me on this one???, :beer: :beer: :beer: :beer:

Phatman 06-10-03 05:43 AM

the dropout spacing on a 7 speed hub is 126mm. The dropout on 10-speed is 130. It will not cause damage to spread a steel or ti frame, but it will damage an alloy frame.

Gordon P 06-10-03 08:27 AM

I was just reading about this yesterday on Sheldon Brown's web page. This page has the info on the what http://www.sheldonbrown.com/k7.html and this one has info on the how http://www.sheldonbrown.com/frame-spacing.html.

lotek 06-10-03 10:49 AM

any decent LBS should be able to spread the
rear of a bike to 130mm, even alloy frames (have
seen it done with C'dales etc.)
I say LBS since they can check the spread, ensure
the wheel will still be centered (i.e. spread isn't all
on one side of bike).

Marty

roadfix 06-10-03 11:08 AM

A few years back I 'muscled' my CroMo rear triangle from 126 to 130. The spread was actually so small, it was no big deal. The wheel centered properly. There was no need to 'tuck in' the dropouts.

captsven 06-10-03 11:26 AM

Once you spread the drops, after about a year or so, the frame will permanently stay at the 130mm.

I have a couple like this.

ComPH 06-10-03 11:26 AM

I've done it a couple of times on older steel bikes. One was actually adjusted from 126 to 135 mm to accomodate an ATB gear. It worked just fine and the bikes ride and shift very fine, but I did have to correct the geometry of the stays and the trueness of the dropout. Sheldon has some pointer on the process. I also found out that I could spread the stays fairly easily with an automobile jack.

orguasch 06-10-03 04:03 PM

so if you spread the rear triangle, the spread should be equal, like the left and the right drops should be move evenly , so that the tire will be centered to the frame, and if not you'll have a bike that is with the front tire centered and the rear tire of center, and if you used a Car jack the only one side will move.

sch 06-11-03 03:57 PM

[QUOTE]Originally posted by orguasch
so if you spread the rear triangle, the spread should be equal, like the left and the right drops should be move evenly , so that the tire will be centered to the frame, and if not you'll have a bike that is with the front tire centered and the rear tire off center, and if you used a Car jack the only one side will move.

Most likely both sides will move, perhaps not symmetrically but
unlikely to be all one side. Other problem is that the dropouts
are a bit off angle. With my steel and Ti frames that I spread
(and which never took a set), the dropouts were thin little things. Alloy drops tend to be pretty beefy, very hard to move.
Steve

Resident 06-11-03 06:29 PM


Originally posted by orguasch
so if you spread the rear triangle, the spread should be equal, like the left and the right drops should be move evenly , so that the tire will be centered to the frame, and if not you'll have a bike that is with the front tire centered and the rear tire of center, and if you used a Car jack the only one side will move.
Any shop worth its salt will have a frame alignment guide and t-tools to align the dropouts. Once the stays are persuaded to accept 130mm, they must be measured in reference to the head tube/seat tube. Once they are equal, the dropouts are aligned.

roadfix 06-11-03 06:55 PM

Spreading from 126 to 130 is so minimal, the rear triangle will conform to its new width in a matter of months, dropouts included, without doing absolutely anything on your part.

John E 06-11-03 08:43 PM

I have spread plenty of older steel frames, including my Capo, from 120 to 128mm.

1oldRoadie 06-11-03 10:15 PM

the spread from 125 to 130mm is 0.1574803"..or just over a 1/16" on each side....I think the paint is about that thick.

roadfix 06-11-03 10:59 PM


Originally posted by 1oldRoadie
the spread from 125 to 130mm is 0.1574803"..or just over a 1/16" on each side....I think the paint is about that thick.
I couldn't have said it any better.......
(best post so far)

DieselDan 06-13-03 05:54 PM

A US dime is 1mm wide.


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