digger

Sorry, I honestly look in the previous threads to find my answer, but what I find are 'hints' at an answer.

This will be the last question on 8 to 9 speed conversion (from me anyway).

My Marinoni is 1998 Shimano 105 - 8 speed components. Hubs are Ultegra.

First of all, the STI shifters are on the way out, since i cannot buy 8 speed shifters I have been looking at a new pair of 9 speed STIs on ebay.

Second, since I need new transmission (chain, cassette & rings) anyway, I thought why not upgrade to a 9 speed. Problem is - I want to keep cost down (HAH!!) and use my 8 speed front and rear derailler.

Sooo, is there enough travel on an an 8 speed rear derailler to use with a 9 speed cassette?

Can I put a 9 speed cassette on an 8 speed Ultegra hub?

My first guess is YES to both questions above, but I always get caught with my pants down about something when I upgrade.

What am I missing?

Thks
Digger

Davet

The answers, I believe are: you can use the existing dérailleurs, they will do what the shifters tell them to do (shift 9 times on the rear,for instance) A 9-speed cassette fits just fine on the 8-speed hub (8sp/9sp freehubs are the same)

giantmdb

You could always go with a set of Shimano Sora shifter/levers. They are 8-speed and my wife's bike is 2 1/2 yrs. old with about 4000 miles on it and they are still accurate.

As for your current front derailleur, not a problem on a 9-speed upgrade and the rear should work just fine.

So, all you have to do is either purchase the Sora shifters and use the 8-speed system you have now or get a new set of 105 shifters, 9 speed cassette and you're on your way. You may want to be sure that the rear hub can adapt to a 9-speed cassette. That I'm not sure with it's age.

digger

Thanks guys, that's what I thought, but like I said, something ALWAYS nips be in the butt.

Errrr.....Sora? Ah gee I dunno. I'd be afraid that someone might see me.

Seriously tho, I thought about putting Sora shifters on. Still up there in price tho. If I can get a set of 105s on Ebay for the same or, most likely, less then I think that would be better.

The 105s I have now still shift, but since I need a new tranny AND I have the handlebar tape off (tried to clean and lube the shifter) I might as well upgrade now. IF the shifter goes part way through the summer and I have to take off that brand new beautiful handlebar tape......

It's a shame tho, the left shifter (triple) still works like a dream. Perhaps I'll sell THAT shifter on Ebay to offset the cost a smidgen.

Thks x 2

Digger

Retro Grouch 

I've not had success getting the front shifting to work to my satisfaction using an 8-speed derailleur on a 9-speed triple but I've been told it works just fine on a double.

demoncyclist

Was the 8 speed derailleur also a triple? The cage widths sometimes vary between a double der and a triple der.

Don Cook

The rear derailleur will work. The amount of rear and front derailluer travel is controlled in each case by an upper and lower limit screw. The rear isn't a problem since it is designed for substantial travel from the smallest of the cog set to the largest. You will be required to make the rear derailleur upper and lower limit adjustments. Unless you are changing the number of chain rings on your crankset, your front derailleur doesn't enter the picture.

ncernitz

I ran an Ultegra 8 spd triple front derailuer when I converted to a 9spd triple for about a year and it worked, but marginally. I recently installed a new 9 spd front and the difference is remarkable. It shifts smooth and effortless and trims much better. The small difference in cage width improves the shift.

Retro Grouch 

Yeah. I was told that the nine speed has a narrower cage than the eight speed to correspond to the narrower chain. Since the front derailleur moves the outside of the chain, cage width is a factor. I didn't measure how much difference there was, but the new front derailleur definitely did the trick.

The rear derailleur moves the chain by the jockey pulley in the center of the chain so it matters less. Limit screws shouldn't have to be changed because the 9-speed cassette just puts 9 cogs in the same amount of space previously taken up by eight so the side-to-side movement of the rear derailleur is the same.

digger

Hmmmm, so there MAY be a front derailler problem. They old derailler may be to wide to move the narrow 9 speed chain from one ring to another.

I'll ask my LBS. Perhaps I could...squish the old front derailler cage a tad with pliers to close the gap? IF there is a problem.

Digger

ncernitz

It will no doubt move the chain from ring to ring, but it will have to over throw on each shift to compensate for the wider cage. So your high and low sets will have to more than 1mm from the rings. Squeeze it, what the hey! Try and measure a 9 spd. so you will know the dimension you are after.

Brillig

How cheap are you trying to do it?

Performance has a pretty good deal where you can get brand new 9 speed rear der, shifters, cassette and chain (all 105) for a little over $200.

digger

I checked it out - shifters $140, Front derailler $22, Chain and cass $60 3 new chain rings $70. That'll be $300, not bad.

Thks

********

This taken from the Shimano website regarding 8 to 9 speed conversion:

13) What components are compatible between 8-speed and Mega-9?

First, Shimano® only guarantees index performance with an entire 9-speed drivetrain that includes shift levers, front derailleur, crankset, 9-speed chain, cassette, and rear derailleur. The hubs are the same dimensions. Although several 8- and 9-speed combinations are rideable the performance and durability will not be up to Shimano standards. The following rideable combinations have potential drivetrain problems.

When using an 8-speed rear derailleur it may not clear the 34-tooth cog on some frames.


The 9-speed chain is ~0.5 mm narrower and so is the front derailleur cage.
Using a 9-speed chain with 8-speed front derailleur and crankset will result in sluggish shifting and the adjustment is more critical. You may have to continue to hold the shift lever in an "overshift" until the shift is complete. In the worst case, some 8-speed chain rings have shown a tendency for "chain jamming" during downshifts with a 9 speed chain.
The 8-speed chain is too wide for 9 speed front derailleur; the chain will rub during cross shifting (large/mid ring/large cog).
9-speed chain should be no problem for an 8-speed rear drivetrain.


The 9-speed chainring release teeth and pick-up teeth are reprofiled for narrower chains, therefore you can not use an 8-speed chain, and the pick-up teeth will make noise against the chain during minor cross chaining.

Furthermore, success with one bike may not guarantee the same result with another bike due to the different dimensions between frames and production tolerances of components. It might be OK, but Shimano® can't guarantee it. Finally, although you may be partially upgrading to 9-speed you may downgrade the shifting performance.

sch

I would avoid used 8spd STI, the shifters have a
definite life span and the R hand shifter especially
tends to break a pawl detent somewhere between
7k and 15kmil, I have two of the beasts, both
broke at between 8 and 10kmiles. Of course if
the price is right... say less than 1/3d retail or
$50 might be worth a try. Steve