Compatibility Shimano 7 & 8 speed

[sukuinage]

It's 10-speed Ergos (Centaur) that I'm planning to use. I've just bought them second hand so hope that they're OK. Both my wife & I have 10-speed Campag on our road bikes and I've got 10-speed/ 8-speed Shimergo mix on my touring/ gravel bike so trying to keep everything the same. I've ordered the other parts (mostly new drivetrain), stripped most of the parts & greased the headset & hubs so will build it up in the next week or so and see what happens!
Thanks for all the replies!

[Brucey]

I would check that the 10s ergos are in good order and that they are 'the right type'; there are several variations of Centaur and whilst all have the same RH cable pull (so all will do 8s shimergo OK, in theory) they can work best with different mechs (spring force) and some don't play well with different front mechs from those that are meant to work with them.

cheers

[sukuinage]

I would check that the 10s ergos are in good order and that they are 'the right type'; there are several variations of Centaur and whilst all have the same RH cable pull (so all will do 8s shimergo OK, in theory) they can work best with different mechs (spring force) and some don't play well with different front mechs from those that are meant to work with them.

cheers

The Ergos are in good order - they're around ten years old according to the guy I bought them from and probably from a flat bar conversion as they came with bars and cables - saves me a lot of hassle!. They're apparently not much used and look like it. I'm not sure how to tell what type they are so I'll just try fixing them up and see what happens. I've got a couple of possible rear mechs if the one from this bike doesn't want to play. If the front mech has a problem I'll be back on asking for advice

[sukuinage]

Almost finished, just the back mudguard to add and minor adjustments as per the wife's orders . Shifting and braking both working fine with the 8-speed cassette reduced to 7-speed as suggested. She's very happy with the fit & the handling and particularly that the Ergos are the same as her roadbike. Looking forward to exploring some of the trails around here during the winter months. I've geared it around 21 - 104 for a mix of road and trails

Total cost for those interested: €260
S/H Bike - Frame, forks, headset, wheels, saddle & post, brakes & mechs: €45
S/H Bars, Ergos & Cables: €60
New Tyres, A-Head Adapter, Canti Brake Hanger & Guards: €65
New Transmission (Crankset, Chain & Cassette) €90
Stem, pedals & bottle cage from my parts bin (would add about €50 to the price if new)

[sukuinage]

Many thanks to all the suggestions on the build and the answers to my questions. Really helpful and much appreciated!

[Brucey]

looks like a tidy build that. This route can offer cracking value if you are prepared to put in the spanner time, and puts an otherwise unwanted old MTB to a good use too.

Nice one!

BTW it is a very great shame that so many later MTBs have longer top tubes and don't lend themselves so well to conversion to dropped handlebars.

cheers

[sukuinage]

looks like a tidy build that. This route can offer cracking value if you are prepared to put in the spanner time, and puts an otherwise unwanted old MTB to a good use too.

Nice one!

BTW it is a very great shame that so many later MTBs have longer top tubes and don't lend themselves so well to conversion to dropped handlebars.

cheers

Thanks! I've read enough of your posts to know that you know what you're talking about!
We'd used the bike as a general runaround but then the shifter broke and I had the idea of a winter bike conversion. This is the second one I've done - the other was from an old trekking bike - so didn't take me long. All the bearings were good and nothing stuck enough that the old Glasgow screwdriver couldn't shift. Really an enjoyable build especially when the shifters just worked!
I wanted to include the costs to show what can be done for very little money as it's often recommended on this forum. It's not too difficult here in Germany to find 7 or 8 speed bikes with LX or XT kit in quite good condition. S/H 10-speed Ergos can also be got at reasonable prices for Campy users
Top tube on this was also fairly long hence the short stem.

[gbnz]

Hmm..........a bargain price, "90's", 7spd gear system, clearance bike to be delivered next week

Primary interest is in immediately having a bicycle which works, in every respect. Value of the frame/parts useable elsewhere, made the purchase worthwhile (Nb. 2 months of issues with the primary bicycle, January with the secondary bicycle good, but not excellent !)

But can 7spd STI (Nb. Flat bar shifters), work with a 8 spd system? (Nb. Both Shimano, both triples)

Hadn't valued such on purchasing the bike, but would actually be useful to swap a slightly knackered 8spd shifter system, onto the new bike, using the brand new 7spd shifters on the existing "primary" bicycle, when it's resprayed/sorted out (Nb. steel tourer). Would be quite happy to have a range of 21 gears, have actually made do, with "8 gears" on the primary bicycle since August '24

[Brucey]

....But can 7spd STI (Nb. Flat bar shifters), work with a 8 spd system? (Nb. Both Shimano, both triples)

it'll work nicely if you use a 7s cassette, or use 7 from 8 sprockets, respaced slightly wider. In both cases a spacer is required if fitting to an 8s freehub. It is not difficult to respace sprockets by adding shims cut from beverage cans.

[gbnz]

....But can 7spd STI (Nb. Flat bar shifters), work with a 8 spd system? (Nb. Both Shimano, both triples)

it'll work nicely if you use a 7s cassette, or use 7 from 8 sprockets, respaced slightly wider. In both cases a spacer is required if fitting to an 8s freehub. It is not difficult to respace sprockets by adding shims cut from beverage cans.

Thanks, that's quite a benefit ...........have 2 No. 8 spd and shortly the 7spd, parts from the new (7spd) probably to be used on the others, over time

[Brucey]

the other thing you could do is to slightly lower the shift ratio of the RD, eg. by making a replacement tab washer. Then you could retain 8s sprocket spacing, albeit using only 7 of the 8 sprockets.