Road: put a bigger sprocket inside a 10sp 105 cassette?

Hi, I have a friend who’s doing the Etape. It goes up the Ventoux! He’s needing a bigger rear ring (30) but has no cash. My 105 10sp cassette has the smallest 6 rings loose, and the biggest 4 fixed together. So, we think you could miss out one of the smaller loose rings and put a loose 30t ring + spacer inboard of the fixed block. Would that work? Sounds worth a try!

al.

It probably will have a nasty shift between top and top -1, and bottom and bottom +1, and he may also need to lengthen the chian to allow the 30T bottom gear.

think it would work but he’ll have a big jump in the middle, shifting won’t be as good either as the sprockets in each cassette are aligned with one another in terms of the positioning of shifting ramps etc

Dam if only he had the budget for a triple.

Also, will the rear mech hanger be long enough for such a big sprocket?

Zaskar: that was my suggestion! But no. I think he’s going to die anyway, so he may as well blow all his cash 😉

al.

reckon I’d look at the chainrings – maybe you could bodge a mtb BB & crankset on there

OMG! Someone just sent me this:
The Profile : Montélimar > Mont Ventoux

al.

with an average of 7.2% and a a maximum of 12% it’s not that steep 🙂

Does he already have a 34t compact front ring? Or does he have some silly macho front chainring setup? 34t rings are quite cheap, although I don’t know if you need to mess with other things, cranks etc. to put them on.

I have a triple, which is great for situations like this. I don’t usually use the granny gear, but when you need it, it is nice that it is there.

Joe

Does the route go round in a semi-circle like that?

If 105 then the shifters will allow the use of a triple. At least old 105 did. Meaning that you would need a triple chainset, maybe a new bb and new chain, and ideally a long cage rear mech.

I can’t really see your idea working well at all.

I can’t think of any road cassettes that have a 30 tooth large sprocket. 28 yes. Does he already have a ‘compact’ chainset or a normal such as a 39/52 etc?

with an average of 7.2% and a a maximum of 12% it’s not that steep

Those are average gradients for each km aren’t they? Supposedly in a few places it gets >15% for very short bits (I’m guessing the corners). But your point is probably right – average of 7.2% isn’t *that* steep, although obviously the length will be a killer if you don’t pace yourself.

Joe

Cant decide if i like my compact or not,

38t seemed fine for 99% of my rides

34t just spins everywhere, and 50t is hard to get going!

If he’s fit enough to actually want to ride the Etape then he should be able to get up the Ventoux on a 34×28…

mudshark, hanger will make no difference

It’s a double compact front apparently. I have a triple front, and like has been said when you need it it’s there, but he’s hoping to put a cheap & cheerful solution on.

al.

I recently put a compact chainset on and find the jump between the rings a bit big however I do appreciate the smaller ratio on the 21% climb on my regular loop.

Mr Smiths profile pic would appear to be ‘the wrong side of Ventoux’. I thought L’etape was going up from Bedoiun to join the Sault road at Chalet Reynard, going up to the Summit and then descnding to Malaucene.

I started off with a triple, then I got rid of it for a normal 39/52 which was fine for the Peak District, incl Winnatts, then I stuck a Compact on for La Marmotte. In hindsight I used to say the granny ring was useful for emergencies, although with a middle ring of 42 it made more sense to actually use the granny to allow spinning below lactate threshold rather than having to use it in an emergency when you’re already screwed: Better to prevent getting tired, than having an escape route.

I recently fitted a compact chainset on my road bike as I just didn’t get on with the 39/53 set up. I always felt I was in the wrong gear. Been miles of smiles since fitting it.

I don’t have any issues with the 50t ring, inner ring is seldom used.

I’ve used compact gearing for years and as soon as the big hills start I sit in a small gear and wind myself up them. Its never been a problem and on long rides with a reasonable amount of climbing I’m never the slowest up the hills. 50/34 and 13/27 will get you up and down pretty much anything I can think of.

In case anyone reads this later, here’s the Bikeradar thread that started this line of thinking… (I just got this link).

12-30T – 10speed – Short Cage Ultegra

Cheers, al.

I think the route goes to sault – then back down hill again towards the Gorge Du Nesque then back up to the summit. Its a summit finish is it not? On the whole I found the gradient not too bad, it just always that gardient, theres no let up. By the time you get to Sault you’re already a fair way up the mountain, so going back down again to start from the bottom is really pretty fierce.

As FuzzyWuzzy says, 34-28 should get any half decent road cyclist up a wall! The trick to the Etape is to pace yourself, do NOT go off with the racey types unless you are one.

Splitting cassettes is doable but not really recommended, it tends to screw the shifting across at least some of the gears.

mtfu 😆