Upgrading 8 speed to 10 problem

HI I have an 8 speed tourer with shimano hubs i tried to put an old 10 speed sram cassette on to the freehub and it is to tall for the freewheel body, is there a fix for this or is it possible to leave of the small cog and run it as a 9 speed would i need a 9 speed or a 10 speed shifter for that ? the reason is to lower the gearing on the tourer. ❓

8 speed is the same as 10 so there’s something up.
Now if it was an old 7 speed freehub then 10 wouldn’t fit. Pull it off and make sure that its clean, flat and nothing is in the wrong place.

Ok thoroughly cleaned and degreased, all the cogs go on but the engagement with the splines for the last cog is minuscule less than a mm is that normal before tightening the lock ring?

It’ll squish down a bit. Engagement is usually a mm or 2.

You’ll need a 10 speed shifter (road) 8 or 9 speed mech should be fine as long as it’s in good nick.

mountain shifter wont work ? its an mtb cassette with Deore derailer so i was expecting to use an mtb shifter on the rear and a road shifter on the front tigra crankset and tiagra derailer

You’ll need 10 mtb shifter and 10 mtb mech then.
Anything else will require significant bodging.

And as far as I can remember 7 and 8 use the same spacing. The cassette is just one cog wider. 9 and 10 both reduce the spacing to get 9 and 10 speeds into the space of an 8.

Rear mech geo is pretty much the same 7 8 9, completely different 10.

Sounds like a bit of a lash up to me actually.

But you’ll need a 10 speed road shifter and a 9 speed deore mech. Then you’ll index over all 10 speeds.
Or are you using flat bars?

yes its a flat bar lash up 😳

Oh dear.
So what bits are you dead set on using?
I’ll try and spot mismatches.

Tiagra triple cranks + BB
Tiagra Front der
Deore rear der
Sram 12/36 Cassette

these parts I have shifters i expect to buy.

and thanks for the help.

If that’s a deore 9 speed rear mech
You’ll need Shimano Tiagra 4603 3x10sp Flat Bar Shifters. That’ll just be plug and play. Front and rear.

lovely thank you very much 😀

1 last (I hope problem) both SJSC and CRC list these shifters with the right hand shifter being for doubles , I dont see why there could be a difference between a double and a triple for the right hand shifter or am I missing something again ?

10sp cassettes sometimes use a spacer at the back – if there’s one there (maybe glued on with grease) try taking it off (but check that cassette doesn’t foul hub/spokes and that your mech doesn’t get too close to the spokes)

(rear shifters are independent of double/triple AFAIK)

Yeah, thats a point, some cassettes have a 1. something mm spacer behind them. The hub body sometimes needs it, sometimes not. And it’ll usually work with one even if it doesn’t need it. But if you haven’t got one fitted and you do need it, the cassette will rattle……. if that makes sense.

As for the shifters, you’re probably looking at 4600 shifters (2×10) you need 4603. Combined with lazy proof reading, right hand shifters don’t care whats going on at the other end.

https://www.sjscycles.co.uk/gear-shifters/shimano-tiagra-sl4603-10-speed-rapidfire-shift-levers-for-flat-bar-triple/

And i’d not dick around buying from SJSC, not sure exactly what the €/# rate is at the moment, but these are cheaper……

https://www.bike24.com/1.php?content=8;product=23794;menu=1000,4,38

Actualy sjsc are cheaper than bike 24 by the time they apply tax and postage.

I think you’ll find the SJS price is in Pounds and the bike24 is in Euros.
At current exchange rates it is £66.53 inc postage and VAT.

bike 24 66.8549688 British pounds
sjsc £64.98 gbp

And sjsc are nice guys who know there stuff over the years I have had great service from them.

Sjsc comes up as 80 quid for me.

antity Description Price Total
1 Shimano Tiagra SL-4600 10 Speed Rapidfire Shift Lever for Flat Bar – Double – Right Hand
Product code: 37947 £29.99 £29.99
1 Shimano Tiagra SL-4603 10 Speed Rapidfire Shift Lever for Flat Bar – Triple – Left Hand
Product code: 37948 £23.99 £23.99
Sub Total £53.98
Delivery (International EU Tracked) £11.00
Total £64.98