Bicycle Mechanics - Upgrading 7-Speed MTB to 9-Speed

Pondering converting my 1990s Trek 6500 MTB into a tourer. It has the original 7-speed cog and derailleur on the back.

1) Can I assume this is a cassette (lock ring) and not a freewheel, and that a 9-speed cassette would slip on and work? Does a 9-speed cassette take the same width on the hub as the 7-speed currently does?

2) And if it would work, if I then converted the 7-speed Grip Shifters to Shimano 9-speed bar ends, would the 9-speed bar ends control the current derailleur up and down the 9 cogs correctly?

I’m thinking it would, as all the rear derailleur does is move the pulley arms the amount allotted by the shifter, meaning the shifter and cog must match, but the derailleur itself just has to have enough range (and capacity) to span the cassette range.

Bottom line: I’d like to be able to just add 9-speed bar ends and a 9-speed cassette, retaining my current derailleur and wheel hub. Workable?

Most Trek 7 speeds are freewheel. 8-9 speed are cassette. You don't say what derailer you have, but most don't care how many gears you have. That's controlled by the shifter. Basically you'll need chain, cassette and shifter. You might need a new rear wheel.

1) Probably a cassette hub but not a certainty. Lower end models may have used freewheels. Even if it is a cassette hub, you can not put a 9-speed cassette on it since a 9-speed is ~5mm wider than a 7-speed. Either way (freehub or freewheel) you could get a new rear wheel. 9-speed rear hub is 135mm OLD. Early 7-speed MTBs were 130mm and later ones were 135mm. I'm guessing most were 135mm by 1990. If yours is 130mm you could just spread the stays for the 135mm wheel.

2) Yes. You'd need a 9-speed chain, too.

Chances are you have a 7 speed freewheel. I could be wrong there, but even if it was a freehub, I believe the 7 speed freehubs wont fit 8,9,10 speed cassettes?

If you do need new wheels, your frame may not be spaced properly. Todays MTB standard is 135mm, Not sure what it was in the 90's.

It sounds like your trying to cheap out on getting 9 speed as well. You will need/want a new rear derailleur for 9 speed. Front derailleur would probably work ok.

Why not just look for some old 7speed bar end shifters on ebay? A WHOLE lot easier, IMO.

It sounds like your trying to cheap out on getting 9 speed as well. You will need/want a new rear derailleur for 9 speed. Front derailleur would probably work ok.

Why not just look for some old 7speed bar end shifters on ebay? A WHOLE lot easier, IMO.

Just the opposite - if it's more work/parts than I postulated, I'll probably just order an LHT or 520 and have a proper tourer. I'm not that in love with the aluminum 6500 frame to begin with.

I want the 9-speed so I'll have some closer ratios around the nominal speeds I cruise at.

I'll pull the wheel off tonight and look for a lock ring.

I'll pull the wheel off tonight and look for a lock ring.

It doesn't matter whether the current wheel is FW or freehub. You need a new rear wheel either way if you want to go from 7-speed to 9-speed.

It doesn't matter whether the current wheel is FW or freehub. You need a new rear wheel either way if you want to go from 7-speed to 9-speed.

No unavoidable need for a new wheel. If it is a cassette hub it's entirely possible to only replace the casette body. The seal arrangement tends to be a bit different, so best is if you can find a donor wheel to scrounge the whole axle assembly off. But if you don't insist on full seal performance it's entirely possible to only replace the casette body (and maybe add a spacer or two, it's been awhile since I did this)

Still, you might be able to find a replacement wheel for less money than a cassette body only, which'd make the idea of body replacement rather silly.

Just occurred to me: a middle ground, first step, might be to use any bar ends that operate in friction mode. I think any friction mode left shifter would handle the triple front FD. True? Question then becomes: how adroit are friction shifters (and me!) at shifting 7-speeds? Friction on a 5-speed hub was a joy. Are 7 cogs getting (physically) close enough together to make this less than enjoyable?

At any rate, that first setp (friction) might help me decide if I want to continue the conversion or just man up and buy a tourer.

Yes, all bar-end front shifters are friction. For the rear, all Shimano bar-ends have friction setting *except* the latest 10-speed, the SL-BS79.

I haven't friction shifted in years but I would think that 7-speed wouldn't be any harder to shift than 5-speed.

Friction shifters are actually more accurate than indexed in a trained hand, indexed shifters can suffer from cable stretch over time but friction shifters don't really have this problem. You can get bar-end adapters for any DT shift levers. I recommend getting some simplex retrofriction shifters and the adapters.

The adapters look like this(these come in several colors):
http://store.icyclesusa.com/shared/StoreFront/default.asp?CS=icycles&StoreType=BtoC&Count1=495540797&Count2=412681221&ProductID=23832&Target=products.asp&utm_medium=cse&utm_source=googlebase

Not sure if these ones will work with the simplex levers, there are other brands/makes of adapters.

1) If it is a cassette rather than a freewheel, the 7-speed hub body is too short to hold 9 gears. You can either change the hub body for an 8-9-10 speed or use the 8-of-9 on 7 trick. The 8-of-9 on 7 will only give you 8 gears, though, and may shift a little worse at the point you removed the cog.

2) Yep. Depending on the quality of your rear derailleur. An old, worn Acera won't be as crisp or accurate as a newer LX.

My touring bike is only 7-speed with friction bar-end shifters. And it works *great*.

Most Trek 7 speeds are freewheel. 8-9 speed are cassette. You don't say what derailer you have, but most don't care how many gears you have. That's controlled by the shifter. Basically you'll need chain, cassette and shifter. You might need a new rear wheel.

Not true. Both of my early '90's Trek 7spd's are cassette. I would go so far as to say the majority of 7spd are cassette.

As an example:
http://www.niagaracycle.com/product_info.php?products_id=1014

This wheel has a Shimano Acera freehub which will accept a 7, 8, or 9spd cassette. I believe a spacer may be necessary for the 7spd.
The older 7spd freehubs may be too short for 8 or 9 spd however.

Personally, I'd just stick with 7spd.

Many thanks to all for the insights. This is my neglected bike; almost all of my miles are on my Roubaix. But I thought with drop bars and bar ends it might be a useful tourer. And the 26x1.5 City Contacts I use on it are cushy smooth withhout being overly slow. I really haven't toured, but will try it out on this one. If I stick with the 7-speed, the conversion costs are minimal. I much prefer the closer ratios afforded by a 9-speed cassette, but not so much as to start with a new wheel and hub and all. I mean, I'm not sure if I even like this bike yet. ;)

I'm in the process of repairing an old 86-87 Raleigh Obsession MNT (7speed) to use as a winter bike. I just ordered the Nashbar 7 speed freewheel, some new STI shifters off ebay and a chain. Also went with the City Contacts to replace the old knobby tires. Didn't seem right (or cost justified) to try and morph it into something different.

ManyI much prefer the closer ratios afforded by a 9-speed cassette

Personally I don't feel I need close ratios for touring. I tour with an 11-34 7-speed. Lotsa big jumps on that cassette :)

It doesn't matter whether the current wheel is FW or freehub. You need a new rear wheel either way if you want to go from 7-speed to 9-speed.

Too bad that's wrong. It's possible to drop in another freehub if it's already a cassette rear wheel.

Friction shifters are actually more accurate than indexed in a trained hand, indexed shifters can suffer from cable stretch over time but friction shifters don't really have this problem. You can get bar-end adapters for any DT shift levers. I recommend getting some simplex retrofriction shifters and the adapters.

The adapters look like this(these come in several colors):
http://store.icyclesusa.com/shared/StoreFront/default.asp?CS=icycles&StoreType=BtoC&Count1=495540797&Count2=412681221&ProductID=23832&Target=products.asp&utm_medium=cse&utm_source=googlebase

Not sure if these ones will work with the simplex levers, there are other brands/makes of adapters.

Not true.

I can ram a 9 speed indexed shifter into many different gears precisely up and down the cassette faster with no thinking and no training. Indexed is superior to friction speed wise. If indexed shifters suffer from "cable stretch" (this should've been taken out during installation anyways) then the same will be true with the shifters on friction mode.

You can replace the freehub body with an 6,9,10 speed body, but you will need to replace the axle and redish the wheel. You will need to spread the rear triangle because it is most likely 126mm.
It is easier to stick with the 7 or go to a new wheel.
You could go with a half-step with a grandpa gear. Half step gearing would be spaced 20% in the back (11,13,16,19,23,28,34) with something in front spaced 10% like a 22, 40, 44. With an occasional double shift you have 10% spacing on all of your gears except for the very low bail-out grandpa gears.

You can replace the freehub body with an 6,9,10 speed body, but you will need to replace the axle... I think not. The OP stated that it's a MTB, and even from that era it's likely to have a 135 mm spacing already.


... You will need to spread the rear triangle because it is most likely 126mm.
Not most likely at all, due to the MTB statement.

Friction shifters are actually more accurate than indexed in a trained hand, indexed shifters can suffer from cable stretch over time but friction shifters don't really have this problem. You can get bar-end adapters for any DT shift levers. I recommend getting some simplex retrofriction shifters and the adapters.

The adapters look like this(these come in several colors):
http://store.icyclesusa.com/shared/StoreFront/default.asp?CS=icycles&StoreType=BtoC&Count1=495540797&Count2=412681221&ProductID=23832&Target=products.asp&utm_medium=cse&utm_source=googlebase

Not sure if these ones will work with the simplex levers, there are other brands/makes of adapters.

No, they won't work with Simplex Retrofrictions. No other brand will work with them, either. I adapted Retrofrictions to Shimano mounts, but it required modification and fabrication of parts.

http://inlinethumb46.webshots.com/5933/2263265140068014369S500x500Q85.jpg (http://good-times.webshots.com/photo/2263265140068014369ivrzAM)

Too bad that's wrong. It's possible to drop in another freehub if it's already a cassette rear wheel.

Don't forget to mention redishing the wheel after that freehub swap (not that it's very difficult).

Earliest bikepedia listing for a 6500 is 1995. Listing shows a 11-28 7-sp. Pretty sure with an 11T, it has to be a freehub.

Since you're after tighter gear spacing,
Here's a 12-21. Tightest 7-sp I could find, for $30. (http://www.loosescrews.com/index.cgi?d=single&c=Cassette&sc=Complete%20Shimano&tc=7%20Speed&item_id=LS-CC71221&id=648645924370)

Might wanna call first, however, as the description makes it seem like a bunch of loose cogs.

Not true.

I can ram a 9 speed indexed shifter into many different gears precisely up and down the cassette faster with no thinking and no training. Indexed is superior to friction speed wise. If indexed shifters suffer from "cable stretch" (this should've been taken out during installation anyways) then the same will be true with the shifters on friction mode.

Not true.

Friction shifting is not affected by "cable stretch". The shifter simply takes up the slack before making the shift.

Are you sure you're a bicycle mechanic?

Earliest bikepedia listing for a 6500 is 1995. Listing shows a 11-28 7-sp. Pretty sure with an 11T, it has to be a freehub.




It is a freehub. A 32 hole, 7 speed, 135mm spaced Hyperglide-C Alivio freehub to be exact.