Cheapest and Easiest Way Upgrade to 1×10 Cyclocross

My daughter has an Islabike Luath and doesn’t like the thumb shifter on the Sora leavers.

Thought I would change them to 105 shifters and at the same time change the current double setup to 1×10. As it’s a £500 bike wanted to do it as cheap as possible.

Was originally thinking of getting a 10s chain and cassette (£30) plus a narrow/wide chainring (£25). Total £55

However, the cranks are 5 bolt 110bcd and can’t find a narrow/wide chainring in 32/34 teeth for 110bcd.

So looks like the options are either:

1. 10s chain, cassette (£30) and chainring (£12) with some kind of chain guide (£50). Total £92
2. 10s chain, cassette (£30), new 160mm crank arms (£50) and narrow/wide chainring (£25). Total £105

Once I factor in the cost of the shifters both options are more than I really want to pay so anyone one else done something similar in a cheaper way?

Thanks for any help.

Chain guide could be under £50 maybe:

nGEAR jumpstop (£10) + outer bash about $25 delivered:

http://bbgbashguard.com/products/110-bcd-34t-black
http://bbgbashguard.com/products/110bcd-32t-black

Edt this should negate the need for a NW ring, or a NW ring should avoid the need for a chainguide. Guess it depends on how hard it is being ridden.

Will the rear mech work ok with the 10 speed shifters btw?
Also, will the cassette have sufficient range with a stock offering?

No-one likes the little thumb shifters on the old Sora. That’s why they changed it to a proper dual control shifter like 105 & upwards.

So you could go 1×9 pretty easily with a change of crankset and a n/w chainring?

However, the cranks are 5 bolt 110bcd and can’t find a narrow/wide chainring in 32/34 teeth for 110bcd.

You won’t get a 110bcd 32t chainring – won’t go small enough. TA used to make a 33t version but thats not wide/narrow.

Spa Cycles do a Stronglight chainguard for a tenner, plus a couple of quid for a Dogfang to keep the inside sorted too if a Jumpstop is too rich for you.

Do some checking on the rear mech compatibility – not sure if you might need to factor a rear mech as well…

I had been looking at the Paul chain guide but the above seems a cheaper way so will have a look into it.

Mech is Ultegra so hopefully will work ok.

Thanks for comments.

Rather than a chain guide, how about leaving the current front mech on, and using the H/L screws to fix it in place as a guide?

Yeah thought about that but wanted something that looked a bit nicer.

In the end I ditched the idea of 105 shifters due to cost.

Went for Claris 8 speed shifters, sold the current shifters for more. Got the bashguard and Dogfang mentioned above.

All works ok and has been ridden a few times in the woods with no chain drop.

How about a Lindarets road link, no need to worry about front ring so much as it opens up the possibility of bigger cassette on a short road mech. I’ve just fitted one and it works. I found that Blackspire do a 36t n/w in 110bcd.