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Wheels on a 1984 Trek 720

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Wheels on a 1984 Trek 720

Old 07-01-20, 07:35 PM
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Sjtaylor
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Wheels on a 1984 Trek 720

I just acquired this bicycle and Iím going through it for the first time. I have the rear wheel on the trueing stand. From the 84 catalog I see the wheels have been changed from 27Ē to 700c. The rims say Mavic made in France, the hub has 7 cogs and 36 spokes, the hub center is very skinny with Shimano and a spring clip sleeve covering a small hole in the center of the hub.

The front wheel and hub look the same so itís a matching set. I hear what might be a bearing sound in the rear wheel and the rim is not perfect. I can true the rim and live with the slight dip in the roundness.

I notice that the hub measures 126mm and the dropouts measure ~123mm. Iím obviously not a wheel expert so...

Are these wheels ones I should service and use for touring? Should I splay open the dropouts for a newer wheel?

This bike is in very nice shape and components seem correct except the derailleurs and wheels. Iím not a flipper and plan to ride this bike.

Any thoughts or advice?

Thanks.
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Old 07-01-20, 08:20 PM
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The wheels are not OEM in my experience. Also likely done because of the French hub/cog system used as the spec one on that bike, the heilocomatic system was unique and not supported by any other company.

Whether they are touring grade and in good condition will wait till I see them in person Andy
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Old 07-01-20, 10:50 PM
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I just removed the QR from the axle and gave the axle a spin. The axle is bent, bent enough to grab hold of the QR. Now I’m reading posts about bent axles with seven speed free wheels. I need to get the right free wheel removal tool so I can disassemble or do I opt for another wheelset. I’m 230lbs and plan to tour with this bike.

I guess I’ll check for bearing damage and install a new axle.
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Old 07-02-20, 05:14 AM
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Touring vs riding around might guide you. If I was planning to tour, and especially at your weight, I'd get a current freehub wheelset.
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Old 07-02-20, 06:07 AM
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There should be a model number on the hub. I suspect it's a freehub not a freewheel
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Old 07-02-20, 07:04 AM
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Originally Posted by dedhed View Post
There should be a model number on the hub. I suspect it's a freehub not a freewheel
I doubt this. The hub description sure seems to be a Shimano 105 or 600. But we'll all find out soon. At the OP's weight and then adding a touring load I would not run a freewheel hub on a tour if I could help it. Andy
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Old 07-02-20, 07:58 AM
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Originally Posted by Sjtaylor View Post
I just removed the QR from the axle and gave the axle a spin. The axle is bent, bent enough to grab hold of the QR. Now I’m reading posts about bent axles with seven speed free wheels. I need to get the right free wheel removal tool so I can disassemble or do I opt for another wheelset. I’m 230lbs and plan to tour with this bike.
I guess I’ll check for bearing damage and install a new axle.
As mentioned old freewheel hubs are not great for heavyweight loads such as touring and your weight combined. The problem is that the driveside hub bearing is close to the center of the axle creating a lot of leverage to bend and break the axle there. A cassette hub design puts the DS bearing further towards the end of the axle and is much stronger. You could certainly do better with a 130mm cassette hub which should be OK but a 135mm mountain bike hub would be stronger. You would only need the a new rear and the old rim could be re-used and laced to the new hub but a whole new wheel would about the same price if you're paying a shop to do the work. Only issue is if your frame can handle the extra 5mm of spread of a 135mm hub (130mm would almost certainly be safe) which you can consult a good mechanic about as it needs to be done right with having the dropouts aligned after having them spread. I'm assuming you have downtube friction shifters? which would allow you to switch to an 8-10 speed cassette if you wanted.

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Old 07-02-20, 08:19 AM
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Originally Posted by Andrew R Stewart View Post
I doubt this. The hub description sure seems to be a Shimano 105 or 600. But we'll all find out soon. At the OP's weight and then adding a touring load I would not run a freewheel hub on a tour if I could help it. Andy
I suspect his hub is one of these. https://velobase.com/ViewComponent.as...a784f&Enum=110
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Old 07-02-20, 09:12 AM
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Originally Posted by Sjtaylor View Post
I just acquired this bicycle
Post some photos of this bike when you get a chance - always fun to see a 720 'just acquired' from the wild.
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Old 07-02-20, 09:21 AM
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720 Photo


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Old 07-03-20, 11:17 AM
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Originally Posted by Sjtaylor View Post

Very nice - where/how did you find it?
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Old 07-04-20, 04:02 PM
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They are definitely not the original wheels which came with Maillard Helicomatic hubs. Hard to tell from the pics, but the hubs look like black Shimano freewheel compatible hubs and the freewheel looks very tight for touring. If you could take closer pics of the hubs and rear freewheel we could all give you some more info. By the way, gorgeous bike ! I just built up a complete bike from a 720 frameset.
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Old 07-05-20, 06:06 AM
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The dropouts measure 123, so maybe it was a transition model from 120 to 126 where either could fit? My Cannondale measures 128 and was specifically done for that. Putting a 130 wheel on is literally a stretch, putting a 135 on it would be too much without cold setting it. And also, if the wheel does not completely true up without a hop, give up on it completely. Don't try to reuse a rim that is bent. You are already replacing a bent axle. The Shimano FH1055 hubs I believe are 7sp freehub with 126 spacing and would fit easily. Any 130 freehub could be used too if you spread it, and could go up to 10sp, except I think the 10sp is specific to some models. 7/8/9 was older, then they came out with 10, then 11 is even wider at 131.

Modern cassettes with ramps will shift a lot better even without indexing, and the more speeds the easier it gets as the cable pull gets shorter. And because the spacing is tighter you don't find yourself between gears as much. It becomes very natural to shift with friction (I'm assuming those bar ends are friction). And if you are touring you might appreciate all the gears with 10sp.
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