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Help identifying front derailleur-80's Trek

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Help identifying front derailleur-80's Trek

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Old 07-08-18, 07:56 AM
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NewATBikeComute
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Help identifying front derailleur-80's Trek

Bought a Trek 800 Mountain track last fall, now upgrading components (for commute bike).

I wanted to install a larger front gear set, but can't figure out what to do with the front derailleur; label says it's a Shimano Altus, but it's not a style I'm familiar with.

Can I replace this with a clamp on, and how do I remove the old one? Anyone familiar with this type FD?


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Old 07-08-18, 08:17 AM
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Mech Removal - Front - E-Type | Cycle Systems
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Old 07-08-18, 10:17 AM
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Thanks. Looks like I will have to stick to the existing size crankset gears. Lesson learned.
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Old 07-08-18, 11:59 AM
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It can be replaced with a clamp on that is compatible with the shifters
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Old 07-08-18, 03:17 PM
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Originally Posted by NewATBikeComute View Post
Thanks. Looks like I will have to stick to the existing size crankset gears. Lesson learned.
Why? Most of the replacement cranks you might consider are going to require you remove the BB anyway, why wouldn't you remove the derailleur.

That said, it's an 800. What sort of gearing do you need to make this entry level bike go?
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Old 07-08-18, 04:38 PM
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If you try to stay with those square tapers you are going to limit your choices of cranks and chainwheels. Figure out what size chainwheels you want to run, then find what crankset has them and then get the bb that matches the bb shell and the type cranks you are getting.

Yes a clamp on can be had for that bike. Both my bikes have clamp on front DR's. You need to know the external size of your seat tube is to the nearest tenth of a mm so you can get the correct size which might also require an adapter sleeve, bushing, shim or what ever you want to call it.

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Old 07-09-18, 08:45 PM
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Originally Posted by Iride01 View Post
If you try to stay with those square tapers you are going to limit your choices of cranks and chainwheels. Figure out what size chainwheels you want to run, then find what crankset has them and then get the bb that matches the bb shell and the type cranks you are getting.

Yes a clamp on can be had for that bike. Both my bikes have clamp on front DR's. You need to know the external size of your seat tube is to the nearest tenth of a mm so you can get the correct size which might also require an adapter sleeve, bushing, shim or what ever you want to call it.
this is a practical learning tool in that I am trying to commute , trying to learn both what works for commuting and to learn about maintaining my own bike, and learn what works for me for fitness at my age ( nearly 60). Oh and not break the bank while doing all this.

Bike was under 100, but either it was worse off than I realize, or I chewed up the gears by not replacing the worn chain. Got a tourney freewheel and basic chain but gearing was a little lower than what I started with. Previous large cog in front was 42, inexpensive replacements were either the same or 48 (if sticking with Shimano). It anything larger than 42 wonít fit the current derailleur.

Dont mind the the cost of a new derailleur, but didnít want to throw too many variables into the mix if I can avoid it.
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Old 07-10-18, 08:41 AM
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Cost can quickly get out of hand if you simply replace one thing and fail to notice that something else needs changing. DR's aren't expensive, but when you are talking about a 100 dollar bike, anything you add is lost money. So all you can do is chalk it up to your tuition for an education in bicycle mechanics and balance the cost of fixing up that bike as opposed to getting another bike.

We haven't got all the info to give us a full picture of your situation. Was the previous gearing correct for what you needed? Is the new freewheel the a different gearing and you are trying to make it work by now changing the chainwheels? Are the existing chainwheels okay? Might be cheaper just to get another freewheel that might give the appropriate gear ratios as opposed to the cascade of things you might have to change.
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Old 07-11-18, 08:20 AM
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Originally Posted by Iride01 View Post
Cost can quickly get out of hand if you simply replace one thing and fail to notice that something else needs changing. DR's aren't expensive, but when you are talking about a 100 dollar bike, anything you add is lost money. So all you can do is chalk it up to your tuition for an education in bicycle mechanics and balance the cost of fixing up that bike as opposed to getting another bike.

We haven't got all the info to give us a full picture of your situation. Was the previous gearing correct for what you needed? Is the new freewheel the a different gearing and you are trying to make it work by now changing the chainwheels? Are the existing chainwheels okay? Might be cheaper just to get another freewheel that might give the appropriate gear ratios as opposed to the cascade of things you might have to change.
Fully agree with above, put it back sell start again, another issue you may have is if you go for a bigger chain set / crank it "might" hit the chain stay, I did that once many years ago then had to install a wider BB then the chain line becomes an issue.

SIMPLE look at everything 1st - not one item at a time
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Old 07-11-18, 10:14 AM
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Originally Posted by Bike tinker man View Post
Fully agree with above, put it back sell start again, another issue you may have is if you go for a bigger chain set / crank it "might" hit the chain stay, I did that once many years ago then had to install a wider BB then the chain line becomes an issue.

SIMPLE look at everything 1st - not one item at a time
My stubborn streak is not rational, but something I have to overcome sometimes.

Yes, replaced the rear gears, found few options, nearest fit was a bit more compact, starting higher where I have been getting faster over the same commute and really could take advantage of higher, not lower gearing.

So my 'bright idea' was to get a larger front crankset, accepting that I might have to use the smallest front gear from time to time (which I wasn't using at all during my commute). Didn't check for clearance, just pushed the 'buy' button.

One learns from mistakes, and from helpful advice. The mistakes I make on my own, but the forums are great for the latter, even if I find it a bit embarrassing to fess up.

I would like to get this bike into decent shape, ride it the rest of this summer, and pick out something at the next bike swap early next season, and sell this one, knowing that I wasn't passing on a bunch of problems, and that I will be able to feel a sense of pride at being able to evaluate, diagnose, fix, and tune my own ride.
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