Eight to nine speed sorry

gbr236

Hi there
I cannot find where this has been covered before.
I want to convert 8 speed shimano bar end shifts to sti
If I get sti levers and new cassette, will that fit the hub etc.

Cheers

Bronzie

gbr236 wrote:

If I get sti levers and new cassette, will that fit the hub etc.

Yes, but you'll also need to replace rear mech and chain (9 spd uses narrower chain than 8 spd).

captaincavs

Slightly different version of the question from me.

I have eight speed rear mech (dura ace) and down tube shifters.

Happy to stick with 8 spd but I want to change to STI.

Can I use 9 spd STI levers? Advice on forums seems contradictory, and I can't understand the advice from the usually reliable Sheldon Brown

http://www.sheldonbrown.com/dura-ace.html

not sure how old my rear mech is (I inerited the bike)

all advice appreciated

redvee

In my experience, you can quite happily use 8speed chain on a 9 speed block! My road bike which I just sold was a mixture of 8 & 9 speed 105 drivetrain etc.

The set-up was as follows:

105 9 speed STI flightdeck levers
105 8 speed front & rear mechs (1056? silver grey colur)
105 8 speed hubs F & R, as above.
6500 Ultegra 12-27 9 speed cassette
Cheapo Sedis 8 speed chain.

Made the change to STI and bought chainset, STI, chain and BB and kept the old 8 speed F & R mechs. One sunday afternoon I thought, would the 9 sp road wheel mesh with my 8 sp MTB set-up so swap wheels over and obviously the gear levers didn't match the cassettes but the chain on my MTB meshed OK with my 9 sp road wheel and got some confirmation responses to the post a made on the BikeBiz (trade) forum.

maddog 2

captaincavs, 9spd shifters on a 8spd cassette won't work. So no.

to go from 8 to 9 you need STI, cassette and chain. Mechs will work okay but 9spd will be crisper, perhaps.

captaincavs

thanks Maddog. that's no problem then, I'll wait until the cassette and chain are ready to be replaced and then make the change.

and presumably the mech will cover the additional little bit of range needed from 8 to 9?

nicklouse

the mech has the same range as it is dumb and the cassette is the same width.. maybe changing the jockey wheels will help due to the thiner 9spd chain.

satanas

Bronzie is wrong: any 8 speed rear mech should be fine with 9 speed (except DA8, and the problem there is that there's no suitable lever as the cable travel is different from other mechs).

Captaincavs: ALL Shimano 9 speed STI levers have the same cable travel per shift as 8 speed DA levers; when Shimano switched to 9 speed in 1997, they changed the DA rear mech so that cable travel was the same as everything else they made. It's entirely sensible to use any 9 speed lever with a DA8 rear mech. (Also, DA9 mechs have another cable routing groove so they'll work okay with DA8 levers when used as a replacement.) Maddog 2 is wrong in the case of DA8; with a DA8 rear mech you can use ANY Shimano 9 speed shifter but MUST use an 8 speed cassette or shifting will be way out. Sheldon is right...

Jockey wheels don't usually make any difference, although the shifting might be infinitesimally quicker with thinner jockey wheels due to less slack to be taken up before the chain moves. In practice, most mechs will work with 7,8,9,10 as long as they have enough lateral movement available - sometimes a problem with pre-8 speed road mechs. (MTB mechs are usually okay.)

captaincavs

Thanks Satanas sounds like solid advice. SO...just to clarify...I can change the shifters to 9spd STI and they'll shift OK with 8sp DA mech and cassette. BUT if I then change to 9spd DA cassette (and chain) I would need to change the rear mech too.

I am just thinking ahead as 8sp seems to be becoming harder to get

aracer

Yes, you've got that spot on, captaincavs.

However I think it may even be possible to keep using your old mech when you go 9-speed if you use the hubbub mod as described at http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3946 (it doesn't say what you get with an old DA mech and hubbub mod, but I'm extrapolating from the fact that with a normal Shimano 8-speed system - which is in theory what you have with 9-speed shifters and an 8-speed DA mech - it lets you shift 9-speed spaced sprockets).

jpembroke

In case you want to stay 8 speed, you can get Shimano R500 STis, which are of 105ish quality and sell for around £100. Try CRC or Ribble. 8 speed runs just fine with a 9 speed rear mech, btw. I have 8 speed on my cross bike, which is set up with old Ultegra 8 speed STis and 105 9 speed front and rear mechs.

satanas

CC: Yes, you've got the gist of what I said. I'm not sure that the hubbub mod would work with a DA8 mech. I suspect that the cable clamp might not allow it in any case.

It's also possible that 10 speed shifters might work with a DA8 mech and 9 speed everything else...

Aracer: The hubbub mod is a way to use 10 speed Ergo levers with a 9 speed Shimano chain/cassette/mech; I couldn't see any evidence from the URL listed that it would do anything else useful. Once you start substituting bits randomly there's every chance it might not work at all. However, if you have all the relevant bits in the shed and the time to try out all the combinations, please report back to us!

aracer

satanas - check the tables at the liink I gave - the testing of all different combos has already been done. According to that, 8 speed Shimano shifters with a hubbub mod will let you shift over 8 cogs on a 9 speed cassette (if you have DT or bar end shifters this is useful as you can use the "extra click" to shift over all 9 with perfect indexing, and is indeed exactly what I did back in '97 with my new 9-speed stuff before I could get hold of proper 9-speed DT shifters for my TT bike). They also reveal that 10 speed shifters will work very well with an old DA8 mech (or indeed with any other modern Shimano indexed mech and the alternate cable routing) and 9 speed cassette.

I suspect you may be right about the cable clamp on a DA8 rear mech though.

satanas

aracer: I think I managed to figure out the table, but it doesn't appear to say anything about using the hubbub mod with a DA8 mech. Probably not an issue due to the placement of the DA8 cable clamp, plus there cannot be too many people who have DA8 mechs anyway - although I still have 2 in use...

It seems like with the DA8 rear mech that if you use any "normal" Shimano shifter you get n-1 for the rear cassette. That's why I'd guessed that a 10 speed shifter might work with a 9 speed cassette and DA8 mech.

I suspect that to get the "extra click" with Shimano bar-end shifters, you'd often need to modify the lever body; usually there's no room for the lever to rotate past the last stop IME.

Finally, while Chris Juden doesn't mention it specifically, IME it's usually possible to mix Shimano 7 and 8 speed stuff fairly freely - handy as 7 speed shifters are now basically extinct.

aracer

satanas wrote:

I suspect that to get the "extra click" with Shimano bar-end shifters, you'd often need to modify the lever body; usually there's no room for the lever to rotate past the last stop IME.

Have to admit I've not tested that and was just speculating - works fine with DT levers.

Finally, while Chris Juden doesn't mention it specifically, IME it's usually possible to mix Shimano 7 and 8 speed stuff fairly freely - handy as 7 speed shifters are now basically extinct.

He does at least in passing 'According to them it would seem that almost anything will "index perfectly" with anything vaguely similar! But some people have rather a low definition of "perfect" and all indexed gear systems have an allowance for wear and tear that may allow disparate components to rub along okay, when they are new. Just don't expect them to keep it up very long.' I'd suggest like him that it can be made to work, but you are relying on the tolerances which are designed to allow for wear and cable stretch, hence might have to adjust more often.

satanas

That's what I meant by "specifically"...

However, IME there is no need to adjust more frequently - any theoretical difference is small enough that it works just as well as using the "correct" bits. I've used both 8 speed cassette with 7 speed thumb shifters (which actually have 8 clicks anyway), and 7 speed cassettes with assorted 8 speed shifters and both worked perfectly. (And I'm fussy!)

aracer

My experience of using 8 speed cassette with 7 speed shifters is that it did work, but not as well as when I changed to the proper shifters.

fossyant

I have a a DA 8 speed mech, and cos they were so well made, nothing breaks, but that leaves me a good option to get DA 9 speed STI's to work with my 8 speed set up - I'm running a DA 9 speed chain as I have 9 speed chainrings (lurvly blue TA ones) Happy days.... the sheldon brown thing is a little confusing where the 8 speed DA mech is concerned....

Do prefer the 9 speed shifter design over the 'hard to get' 8 speed sti