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Sunrace 8 speed to 7 speed

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Sunrace 8 speed to 7 speed

Old 05-27-21, 01:58 AM
  #1  
sd5782 
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Sunrace 8 speed to 7 speed

I am trying to find an economical indexed thumb lever for a 7 speed I am reconditioning for a friend. I did see the Sunrace SLM96 that looks decent although it is an 8 speed. Specs say 2:1 ratio. Can this work on the rear Shimano freehub with just one click not doing anything? Those vintage shimano 7 speed thumbies are very pricey.
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Old 05-27-21, 02:13 AM
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the spacing is close enough that many use 7spd shifters on 8spd cassettes, and 8spd shifters on 7spd cassettes. some will say it won't be perfect, but if it's good enough to work, then it's good enough

i ran 7spd deore xt thumbies on an 8spd cassette because i could get an extra click on the rear shifter. it worked fine across all 8 gears.

question.....what do you mean "reconditioning"? what exactly are you reconditioning? a bike or a cassette?
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Old 05-27-21, 11:25 AM
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There are lots of cheap options for 7 speed shifters, aside from the expensive Deore XT type. Like this Tourney one for example:
https://www.ebay.com/itm/393356946952

Just make sure the left shift lever is friction (like the one I linked to) and not indexed. The indexed ones are specific to either MTB drivetrain or road drivetrain, so not straightforward.
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Old 05-27-21, 01:01 PM
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Originally Posted by icemilkcoffee View Post
There are lots of cheap options for 7 speed shifters, aside from the expensive Deore XT type. Like this Tourney one for example:
https://www.ebay.com/itm/393356946952

Just make sure the left shift lever is friction (like the one I linked to) and not indexed. The indexed ones are specific to either MTB drivetrain or road drivetrain, so not straightforward.
i'm pretty sure this fellow started another thread about this already. in another subforum...maybe C&V? anyhow, he doesn't like the look of the tourney shifters. can't say as i blame him. i have a set and they aren't very elegant.
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Old 05-27-21, 01:29 PM
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these don't look half bad?

https://www.ebay.com/itm/32414734836...AAAOSwGvhULthK
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Old 05-27-21, 03:33 PM
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Correction

Originally Posted by thook View Post
i'm pretty sure this fellow started another thread about this already. in another subforum...maybe C&V? anyhow, he doesn't like the look of the tourney shifters. can't say as i blame him. i have a set and they aren't very elegant.
Yes, I started on the C&V, but when gear actuation spacing info was needed I thought more experts might lurk here. To answer another question, I am getting this bike rideable for a coworker. It has hung in a garage for years because of the shifting. He doesnít/didnít ever really ride off road, but bought this during the mtb craze of that era. That last shifter posted looked decent so I may investigate. Doesnít sound like the 8 speed to 7 would be something I would do for someone else. Okay for me, but fixing something for someone else I would want bulletproof. Thanks.
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Old 05-27-21, 03:53 PM
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Originally Posted by sd5782 View Post
Yes, I started on the C&V, but when gear actuation spacing info was needed I thought more experts might lurk here. To answer another question, I am getting this bike rideable for a coworker. It has hung in a garage for years because of the shifting. He doesnít/didnít ever really ride off road, but bought this during the mtb craze of that era. That last shifter posted looked decent so I may investigate. Doesnít sound like the 8 speed to 7 would be something I would do for someone else. Okay for me, but fixing something for someone else I would want bulletproof. Thanks.
rest assured you'll find the same expertise in the CV forum. many of the regulars in that section come here, too.

well, happy shifting whatever you decide on.
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Old 05-27-21, 07:09 PM
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Shimano's Tourney TZ500 series shifters are actually pretty good. They're dirt cheap and they work nicely. It's a stiff detent you have to pull through to shift to smaller sprockets, but it feels just right when pushing to downshift to larger sprockets. They don't have a barrel adjuster on the shifter body, but you likely have one on the derailleur already. It's simple, it's inexpensive, and it works!
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Old 05-27-21, 09:20 PM
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If you are buying new shifters, more than likely the chain and cassette could use a change as well so just go to 8 speed you will likely find more cassettes and chains are cross compatible and your derailleurs should work fine unless something odd like Dura Ace 7400!
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Old 05-28-21, 02:06 AM
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Actually chain is fine and cassette seems fine too. Low mileage bike. The TZ500 looks interesting too if he doesn’t want the co-op friction ones I put on it now for testing. I did tear apart the stock right shifter to find that the end of the upper coil spring was broken. Index would be the best for him since rd is compatible.
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Old 05-28-21, 08:52 AM
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I’ve been running 7 speed cassettes with 8 speed shifters on my mtb’s for years. I’m using 90’s trigger shifters and I felt 8 speed shifters were better than the original 7 speed.

You don’t get an extra click once you set the limit screws, although one exists.

Since most 7 speed cassettes can be broken apart, I open them up and sand the spacers from 3.15mm to 3.0mm. I do have the luxury of extra plastic and aluminum spacers in various thicknesses so I can fine tune the chainline if I want. You also get a slightly narrower cassette, which is a plus for positions 1 and 7.

I prefer 9 speed RD’s, but 6-9 SIS mtb and 6-10 SIS road, except (DA 74XX without a work around), will work

Obviously, good enough was never good enough for me.

John

Edit added: If it is a freewheel and not a cassette. Good enough might be your only answer.

If the cogs can be removed, (not typical on modern freewheels), you can fudge the first 4 cog spacing, but positions 5-7 are limited by the freewheel body shoulder. Then again, I haven’t been so inclined to screw up a good vintage freewheel for the sake of less expensive shifters.

Last edited by 70sSanO; 05-28-21 at 09:17 AM.
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Old 05-28-21, 11:45 AM
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Originally Posted by hokiefyd View Post
Shimano's Tourney TZ500 series shifters are actually pretty good. They're dirt cheap and they work nicely. It's a stiff detent you have to pull through to shift to smaller sprockets, but it feels just right when pushing to downshift to larger sprockets. They don't have a barrel adjuster on the shifter body, but you likely have one on the derailleur already. It's simple, it's inexpensive, and it works!
I think all the thumbies style shifters are fairly stiff -- especially stiff when you are playing around with it with no cables attached. I have the Deore XT ones and they are pretty stiff too.
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