djb

Hi,
Have a donor bike, a flatbar GT somethingorother, 7 speed. In great shape, has good potential for a family member interesting in trying touring--it has 36 spoke wheels, eyelets for rear rack, fenders, stock crank is a 42/34/24, and 7 speed (has a 11-28 cassette)
135mm rear spacing

I was thinking of using parts I have kicking around to convert it to 9 speed, put on trekking bars I have, and buy a used 9 speed right trigger shifter, use existing crank and front friction trigger shifter.

question is about the rear hub:

I just took off the 11-28 cassette and tried putting on a 9 speed 11-32 I have, and see that the 9 spd is too big and will not fit fully over the freewheel body.
I do see that not putting on the 11t cog, it will fit on, so I guess I could make it into a 8 spd bike, 12-32 , but what are my options/possibility to go 9 speed?

Is this hub Acera FH-M290 limited by the freewheel body?

caveat-I have done lots of work on hubs over the decades, but have never removed a freewheel body, so is this something that can be changed to a wider 9 speed one?

what is realistic and worth it to do?

As it is 135mm rear spacing, would it be easier just to find a used 9 speed wheel?

I also do realize that the rd may not be able to handle 9 speeds, its an Alivio RD-M014, but I dont have the experience to know if a 7 spd RD if this era can handle a 9 spd cassette. I was planning to try this out with an XT 9 spd trigger shifter I have (but wasnt planning to keep on the bike) when I ran into the problem of the 9 spd cassette not fitting on the freewheel body)

I see the possible costs as
-just find a used rear wheel
-new or used mid level 9 speed trigger shifter
-new or used 8/9 speed mid level rd

and then the various whatnots
-new tires, I have a rear rack, front rack, we have panniers kicking around in the family, I have some trekking bars, maybe some fenders, and it would be a good working touring bike.

I realize I could just leave the drivetrain as is at 7 spd, with the present 11-28 it has 23.4-104 gear inches, so not shabby, but it would be nice to try to get it to 9 speed to lower the gearing a bit and having smaller jumps between shifts.

thanks for ideas, specifically about what is realistic to get a 9 spd cassette onto this hub.

squirtdad

Why not just put a wider range 7 speed cassete on. 12-32 is easy $15 or so SRAM PG-730 7 Speed Cassette > Components > Drivetrain > Cassettes | Jenson USA

gets you to the goal of lower gearing and good bang for the buck

shelbyfv

+1

djb

that is certainly the easiest route, in fact I forgot to mention that I have a 13-30 7 spd cassette on my 1990 touring bike that could get moved over to lower it a bit.
I toured on 6 and 7 speed for quite a while, so I know its perfectly doable, I'd just like to be able to get it to 9 speed just so that the bike would have the nicer jumps between shifts.

Also, as the crank is a 42/34/24, I know that 11 cassettes will have least have a reasonably higher top gear, better than the 13t, and somewhat more than a 12t.

I'm looking at this as a learning experience, as I thought I could just plop the 9 cassette onto the wheel, I had only measured the 135mm spacing so thought it was a given, or maybe to only remove some spacers or something, but its all new to me.

thanks for the link, Im sure I could find an inexpensive one here in a store (being in Canada, not dealing with shipping and cross border fees etc)

bradtx

djb, I too think that a wider range 7S cassette is enough, at this stage anyways, to allow your relative to experience bicycle touring. Once they have tried it, and if they like it, then let the upgrading begin.

Brad

djb

looking at the b screw on the rd, there is still about 5mm to go, so I figure it could handle a 30 easily, maybe a 32.

I'm still interested in seeing what can be done with the hub. I like bike tinkering and it will end up being a good bike no matter what, has cantis also.

Bill Kapaun

You can't just skip the end cog, since it has the built in spacer.
You can remove 1 other cog and do 8 of 9 with 9 speed shifters & chain.
Shimano Cassettes & Freehubs
Scroll down about 3/4

Most older >7 speed Shimano FH bodies will swap. Just stay away from some of the old Dura Ace.

dsbrantjr

I also agree with the suggestion of a wider-range 7-speed cassette for starters. Just make certain that the chain is long enough, or better yet, replace it and keep the old chain with the old cassette. I would not worry about finding a cassette with an 11 small cog, 12 or 13 will be fine. This is a touring bike after all, no need to go over 100 GI. And 24 x 30 or 32 will yield a pretty low gear for those uphill slogs.

djb

ah, roger on having to use the end cog. got it.
Will read up on the other stuff to hopefully have a better idea of hubs, cassette compatability etc.

djb

I toured for years on my old 7 speed 24x30. With 28 slicks it gave a bit under 22g.i. Worked well.

AlexCyclistRoch

I've seen people doing "8 cogs out of a 9 speed" thing before (heck, I'm doing "7 cogs out of an 8-speed" on one bike), but it only works if you are using a 9-speed shifter.

djb

given that I don't want my xt trigger shifter to be on this bike (if it gets stolen) I would only get a 9 speed shifter if I were to be able to get a 9 sp setup on it.

nfmisso

Put me firmly in the 7 speed camp.

But if you insist on going to a weaker chain 9 speed....

You need a 10mm hex to remove the existing freehub, like the one in this set:
https://www.amazon.com/Capri-Tools-C.../dp/B007UQLQQ4
and of coarse a socket wrench or rachet to put it on.

This freehub will probably fit:
https://www.amazon.com/dp/B0012K7M44

You'll need to shift the axle to the right a few mm, you may need new spacers.

And finally, you need to re-dish (re-center) the rim - move the rim towards the drive side.

While you are at, replace the bearing balls, and regrease with marine grease.

djb

Weaker 9 speed, you've gone all retro grouch on us!

Ya, saw some vids showing the removal, and read about the redish. We'll see if I ever get to that point.

First step is simply to get the trekking bars on, it's a threaded stem, so will look for either one of those insert thingees to use changeable stems, I have some shorter standard size stems in a box, or just get a used shorter older style stem for threaded and feed the butterfly bars through it.
And yes, plan to clean and regrease all the bearing areas, although I'm sure the bearings are good, really hasn't been used much.

Bike Gremlin

8+ speed cassettes require wider freehub body, which means wheel that is more dished, which makes it a bit weaker. I'd stick with a wide range 7 speed cassette too.

canklecat

That original combo triple and rear 7 sounds fine for touring as-is. My errand bike weighs nearly 40 lbs, has a 28/38/48 triple and 14-34 Shimano MegaRange freewheel, and even hauling 50 lbs of stuff on top of the existing heavy bike I've never felt I needed more. If anything I've considered swapping to a 13 or 14-28 MegaRange.

The main problem with the 14-34 is the huge jump from 34 to 24. The 24 to 34 shift isn't bad, but there reverse is always awkward. It's almost impossible to shift smoothly when hauling a heavy load uphill and cresting.

To me, that GT's triple with a closely spaced 11-28 sounds perfect for hauling and moderate hills.

More hand positions on the trekking bars you mentioned might resolve any minor issues with the existing 3x7 combo. Sometimes a different hand position and resulting body position can improve the feel of a gearing combo even with the limits of a 3x7. Swapping from riser bars to flat bars on my errand bike improved efficiency significantly, especially climbing hills with a loaded bike.

70sSanO

Here is my take on it. Seven speed shifters are generally harder to find, good vintage, and newer ones are not that good. I don't think the old 7 speed triggers are that good to begin with. I would just remove a cog and run 8 speeds out of 9 speed cassette, with a 9 speed shifter. I would then swap out that 42t for a 44t or 46t so you will still have a decent top end on GI.

I had an old GT mountain bike with similar components and you'll be pushing 30lbs without the rack, fenders, etc., so it will not be a speed demon by any stretch of the imagination. However, if you have to run 9 speeds with an 11t, just get another wheel with the correct freehub. It's not like that Acera is all that good of a hub to mess with freehub swap,

John

dabac

I find 9-spd stuff wear faster than 7-spd. So, "less durable" - yes, "weaker" - as in likely to snap while JRA - no.


With a triple crank, I'm generally quite happy to stay with 7-speed for everything but proper mountain touring -1 mile elevation gain in one consistent climb, that kind of thing.
For that, I prefer 9-spd to get both range and nicely tight ratios. Staying away from mountains, I can get both tight ratios and range enough in 3x7.
I think people often exaggerate the importance of high gears.
Staying on power during descents might feel good, but it takes some very special circumstances before it'll have have any noticeable impact on average speed, and through that travel time and/or daily mileage. I'm quite content to coast once past 25-27 mph. It rarely keeps up long enough to be important.

Bike Gremlin

For touring I'd get any friction shifters and not worry.

djb

Thanks all for the responses, in really more interested in the hub details to go to 9, and I think I understand properly what's involved now.

Re gearing, I'm a total gearing nerd and have been touring on and off for about 25 years--from 6 through to 9 speed bikes, and am pretty comfortable with knowing what gearing is reasonable for a given load and given terrain.

This situation is really looking at what dollar investment and a certain amount of time is involved to get this bike setup, and yes, as is at 7 speed it's reasonable. The low is about 23gi and I could get it down a bit with my 13-30.

The bike would work fine as is. If it works out getting it up to 9 speed, great.

I'm just back from a 2 month long bike trip and it would be a fun project to do with the family member, we'll just see how involved it gets past regreasing the hubs, headset, changing out the bars, tires and putting on racks....

bradtx

djb, I just realized that my beater/back-up touring bike has the same drive train that your GT presently has. When I first bought it all of the upgrade gremlins within were nagging at me. While it will eventually have the wheel set from my main touring bike (to compromise with the gremlins), with it's 8-10S free hub, it's really pretty nice for now and would work well medium loaded on most ascents.

I do like many of the 9S gearing options. I don't think I'll replace a perfectly good 8S drive train on my main touring bike, but I've used them on my latest two roadie builds and I just have not seen the wear rate to be any worse than the 8S roadies.

Brad

PS I did change the main touring bike from 7S to 8S and I had to back out the L screw all the way on the RD for it to reach the bottom gear sprocket. This maybe because the Cannondale has wide drop outs, but is something to be aware of.

mtnbke

For touring 9 speed and anything more is a problem trying to rationalize itself as a solution. 7/8 chains are stronger, 7/8 cogs are thicker and less "finicky" to keep in tune as a simple function of cog spacing, 7/8 chain wheels are thicker. Everything lasts longer under load and away from convenient access to a bike shop/spares.

A 7 speed wheel is less dished than an 8 speed, that is stronger.

You can get the same upper gain ratios upper/lower so why chase your tail "downgrading" the bike to 9 speed?

70sSanO

I run 7 speed on my road and mountain bikes (spaced for 8 speed triggers). I don't think cassette cogs are any thicker than 9 speed. Old freewheel cogs are thicker, but I have not found that with cassettes. Spacing is obviously different. If you have a good source for dedicated 7 speed chainrings, I'd sure like to know about it. I don't know of any, except an occasional eBay find, so I usually run 9s chainrings. Not sure how much more chain strength with good shifting technique, but I do agree with poor shifting under load.

John

djb

guys, just so you know again, the whole 7 vs 9 or whatever isnt what I want to discuss.
Mtnbike--its a case of been there, done that, and my 9 speed bikes drivetrains last pretty much the same as my 7, neither have been finicky for any gearing issues, and wheels and spokes have all lasted for eons, so its really not an issue.

its about having smaller jumps between gears for the same wide spread cassette. Lets leave it at that por favor.

Brad-thks, will watch for that.

Given the bike will be for one of my kids, and given that the 7n speed shifters are pretty mediocre, this all just came from thinking of what would be involved in getting some nicer 9 speed shifters and the costs of getting to 9 in general. I really didnt want to get into a discussion of older vs newer, and heck, 9 is certainly not new and me and tons of people have toured perfectly well on 9 dished wheels.

I also figure if I do change the bike (and who knows, may end up not) then going to 8 or to 9 is the same cost essentially, so pourquoi pas?

cs1

You beat me to it. The old Sheldon Brown 8 of 9 on 7 trick. It's really more than you need. The race to 11 speed is just a marketing ploy because every other idea was already done.