MacGyverBurrito

I'm working on a Bridgestone t500
the catalog shows it originally came with a 5 speed freewheel.
the original owner swapped the suntour arx stuff to shimano 600 6208 including the freewheel which is now a 6 speed.
the clearance on the dropout is really tight, it doesnt look he moved spacers around.
my plans were to make this a more upright commuter and use 6 speed deore shifters but now I'm thinking I should go back to 5 speed and use suntour shifters.

now assuming the axel wasn't properly spaced and the wheel wasn't dished will I run into any issues if I keep it a 6 speed? I didn't test the shifting out when I bought it because the cables rusted and I didn't want to bother with it if I was going to take it apart?

icepick_trotsky 

Dish and chain rub on the dropout will be your only issues. How does the wheel sit between the stays? Does the dish look wrong?

dddd

I've replaced the 5-speed freewheel with 6-speed standard-spaced freewheel quite a few times where no axle respacing was needed.

Having the smallest cog closer to the dropout is ideal unless it causes a chain contact issue, better chainline and the strongest axle and wheel geometry when you can use fewer driveside axle spacers.
A narrower chain can often make the difference if some contact with the stays were to occur, and usually improves shifting as well. I would usually use 8-speed chain with any Asian 6-speed freewheel, but 9-speed chain often seems even better.

MacGyverBurrito

the dish doesn't look wrong, but the axel is shorter than one I have that is spaced for a 6 speed. I only noticed this because I swapped out the screws on the rack to use Allen keys and the screw was too long. I can deal with chain rub. I just didn't want to buy the parts only to find out I couldn't use them

MacGyverBurrito

thanks, that just what I wanted to hear. I was worried about chainline too

eschlwc

i would use the freewheel that fits the dropouts best. if the spacing is 120ish, use a 5-speed. if the spacing is closer to 126mm, use a 6- or 7-speed.

i have a project now that came with a 5-speed, but the drops measure about 125mm. the hub o.l.d. is well short of that, so the skewer is asked to pull the drops together significantly. the axle is only 130mm. so i went to the co-op, bought a used 133mm axle and am converting it to a 6-speed the frame will better fit.

for me, it's all about the frame. i don't like anything to fit tight or short of perfect. if i get a rear flat out on the road, i don't want to struggle with removing the rear wheel. it should simply "dropout."

dddd

Yes, exactly. I have found older bikes with 120mm or so spacing, and with same-spaced rear hub/wheel that was spaced and dished for a 6-speed freewheel.

Seems that the rear wheel can be built strong enough to accommodate this, though could of course be stronger still if spaced at 124 or 126mm.

Some of the bikes have protruding bolts/nuts at the inside face of the dropouts, used for derailer claw hangers or axle stop hardware. To the extent that these protrusions can be milled down using a Dremel, will often allow a wider freewheel to fit, using the same hub/wheel as the 5-speed bike came with.

I modified this "5-speed" Peugeot rear hub to just barely accept a 7s freewheel and still fit with little effort into the 121mm-spaced PX10LE's dropouts.
The MA2 rim is dished and tensioned strong as heck, and the axle protrusion past the face of the smallest cog is but a scant 3.3mm, so the special (Maillard/Roval/Edco) fine-threaded axle remains very strong as well.
I shift it with 8s Ergolevers and derailer since the LE is such a hard-core racing bike where the extremely steep geometry often has me wanting to keep both hands on the bars!

eschlwc

^ yikes. that looks a little too close for comfort for me. i like at least 3mm of axle in the dropout (even though sheldon may say otherwise) and ample clearance between seat stay and chain.

but, if it works, it works.

dddd

Actually, since I used the original axle and only widened the over-locknut width from 121 to 124mm, the axle stub protrusion on each end went from 4.5 to 3mm.
Not a problem at all, especially since the fine-threaded axle puts nearly a whole four threads on that 3mm length.

I like to put the smallest cog as close to the frame as permissible in all cases, for the benefit of chainline, axle and wheel strength, and to prevent a chain ever getting jammed between the frame and the small cog. With narrower chain, the clearance can go down to only 3mm(!), just like on modern bikes.

Oh, and here's the bike that I found and ended up using this wheel on, shown here still wearing a five-speed freewheel and Shimano derailer with cable-attaching trick to achieve indexing:

John E

Since I cannot live with only 5 cogs in back, I have converted all of my 120mm OLD bicycles to 6 speeds. (The alternative would be a triple chainring.) The Peugeot and the 1960 Capo got ultra-6 freewheels, which work well at 122mm OLD. I stretched the 1959 Capo to 126mm for a standard 6-speed freewheel.

dddd, that white PX-10 is gorgeous.

Cougrrcj

I have modified my old '10-speed' '75 Fuji S-10S by upgrading the original five-speed SunTour Perfect freewheel to a SunTour New Winner Ultra 6-speed freewheel. No modifications to the original rear spacing.

Jimsl78

If your chain does not touch I don't know why you would want to do this, but if you want to go back to a 5 speed and don't really use the smallest cog, you may be able to just remove one cog on the existing free wheel. Presto! I've done this with an old Mailard set and got the benefits of more gears within the "sweet spot" and gained the clearance I needed between the dropouts.

MacGyverBurrito

I really didn't want to go back to 5 but would have if it meant I didn't have to go through the trouble of dishing and re-spacing the wheel. its a touring bike and already has a triple so 5 on the back is pleanty.

my concerns arose when I switched the screws for the rack and the chain got stuck on the screw. I noticed how small the clearance was between the cog and the dropout.

the frame is spaced to 126 so a 6 speed is right at home on this bike.

CliffordK

You don't need much clearance. I think I have about 1mm clearance on my old Colnago, perhaps even less (now 9 speed, 126mm OLD).

The advantage of less clearance is that it is impossible to drop the chain on the outside, and less dishing is required, making a stronger wheel. Perhaps one also needs less lateral range for the derailleur.

Perhaps the only disadvantage I can imagine is that some derailleurs may lack adequate pull to shift back down to high gear. Is there a slight risk of scratching the frame? Minimal? I would think dropping the chain on the outside would be worse.

Grand Bois

I don't follow your logic there.

The Golden Boy 

Maillard 700.

Must spin like it's made of butter.

dddd

Addressing the "axle strength" issue here, by having minimal axle (I should have said "locknut") protrusion past the smallest cog, the unsupported length of the axle (between the bearing and the dropout) is kept to an absolute minimum.

The part about the rear axle's fine threading (.8mm iir) is just that it gives a further boost to axle strength, since the finer threads are cut shallower. Good thinking, though from the same company that later brought us the dreaded Helicomatic hub designs.
A larger number of threads contacting the dropout for any given amount of threaded axle protrusion also has to be good.

I evaluate many rear wheels that I work on for the possibility (and justification) of axle-spacing rework, especially if the needed re-dishing can be simply part of the normal spoke tuning that most wheels that I haven't worked on before will get. This way, there is a minimal total investment in effort/hours by making axle-respacing part of a routine hub rebuild and making re-dishing part of a routine re-tensioning.