Chainring/cassette woes...

[Andrew G]

By the way just what are you planning on riding up with a 34/28 .

Turning pedals on a stand puts no strain through the drivetrain so won't show things up too well. If you have the right components and set it up correctly then it should work perfectly on the stand and the road though.

Problems could be:
Other components have worn.
Missed a spacer or got them in the wrong order on the cassette.
Wrong length cage on the rear mech for the gearing you've now fitted.
Wrong length chain.
Indexing not set up correctly.

Apart from that it should be fine .

I think Elliot is right and you need a longer cage to run that gear combo. With such big differences in gears you need a longer cage to take up the chain slack correctly. As a set up I would have thought you could have issues anyway as asking it to cope with a range from 34/28 to 50/11 smoothly is asking a lot. There'll be big jumps in ratios (so won't ride too smooth) and the rear mech is going to have a lot of work to do sorting out the chain slack/strain. Normally if you want a big gear spread like that you'd run a triple with a closer ratio cassette, it would run much smoother throughout the whole range of gear ratios.

[Phil H]

"They" say you can use a normal short cage with the SRAM 11-28. The size of the big sprocket wouldn't - I would think - affect the performance on the 11/12s. More likely to be spacers/alignment.

I used 34/27 a couple of times on the ToBM (although I realised at the top of the Devil's Elbow that I'd gone up on the 23). When you're tired, it's nice to have. Riding around here 25 is enough even for me. Took my chainrings off to clean on Monday and the 50 looks quite battered but the 34 is pristine.

[Dan_K]

I've just bought a new big ring £39 minus 10% from GBs so will try that first.
Also got a Dura Ace BB (£25) whilst I was in there as I've had a horrible clicking noise for ages and i'm hoping that'll solve that problem.

That will narrow down Andrew's idea's to just a few other things so if i'm still not happy, i'll have to admit defeat and take it into a bike shop....

I'm planning on climbing everest by the way.....

I was running a compact 12-27 anyway but was spinning out so wanted an 11-27 as I still want the 27 for when i'm up north or knackered. Shimano 11-27 is over £100 though whereas SRAM do an 11-28 that I got for £35. Doubt the 28 will be used much.

I'd read online that the short cage is fine with an 11-28 compact set up so thought i'd give it a go. Apparently, Specialized ran it as standard on their Roubaix model a while back:

[url]http://www.specialized.com/us/en/bc/SBCBkModel.jsp?spid=33108&menuItemId=0[/url]

[Iliya]

All these messages got me thinking as I just received my cassette. I decided to go from 12/25 to 11/25 just so I get an extra gear on flats and down hills but still enjoy the same gears on up hills. Is this change in the smallest sprocket likely to cause the same issues that Dan is experiencing?

If would be good to know before I unpack the cassette as I can still exchange it as Wiggle.

Thanks

[Dombo]

[quote="Andrew G"]By the way just what are you planning on riding up with a 34/28 .

[Jon C C on a Bianchi]

[quote="Iliya"]All these messages got me thinking as I just received my cassette. I decided to go from 12/25 to 11/25 just so I get an extra gear on flats and down hills but still enjoy the same gears on up hills. Is this change in the smallest sprocket likely to cause the same issues that Dan is experiencing?

If would be good to know before I unpack the cassette as I can still exchange it as Wiggle.

Thanks

[Phil H]

My problem was caused by the wheels (Mavic Aksiums). There was a spacer with the cassette and also one (thick one) on the wheel. I just put the thick one on but I should've put both.

Apart from that, it's pretty hard to mess up.

[quote="Jon C C on a Bianchi"][quote="Iliya"]All these messages got me thinking as I just received my cassette. I decided to go from 12/25 to 11/25 just so I get an extra gear on flats and down hills but still enjoy the same gears on up hills. Is this change in the smallest sprocket likely to cause the same issues that Dan is experiencing?

If would be good to know before I unpack the cassette as I can still exchange it as Wiggle.

Thanks

[Andrew G]

Well...? You've had plenty of time to get it done .

[Iliya]

[quote="Andrew G"]Well...? You've had plenty of time to get it done .

[Andrew G]

. Thought from...
[quote] all set to start the operation now

[quote="Andrew G"]:( . Thought from...
[quote] all set to start the operation now

[Dan_K]

Thanks for all the advice on this guys.
Changed the front ring and the problem's gone away I think to be replaced by a broken left shifter. Derailleur had trouble getting up to the big ring and then "twang" jammed.
Went into GB and they've sent it off to Shimano for a warranty claim. Apparently, there's a known issue with the springs in left 105 shifters.
So, got no road bike for a week or so and have resorted to riding my mountain bike which is a different kind of fun...
Drums home the fact that I really need to get a winter bike, even as backup.

I'll pick up a cheap Allez or something I think at some point next year, although i've seen Decathlon do a really cheap entry level bike that could suit. Is this too cheap to be any good?
[url]http://www.decathlon.co.uk/EN/sport-1-54-57-69567468/[/url]

[Andrew G]

I wouldn't touch a new bike at that price, it will be built down to the cost which means everything about it will have to be so cheap. You're better off getting a secondhand bike for your winter hack and getting one designed for purpose with full mudguard clearances. Plenty come up on ebay that would be far better and you can either go the bike route, or the frame and bits route and build it up yourself. Plenty of mid range kit like veloce can be had secondhand at good prices because it's a few years old. Still perfectly good and quite a few shops sell old stock on ebay, I've picked up mechs, chainsets, shifters for very good prices because they were 2 years "old", still new in the box though.

Also try GBs at the end of the year as they sell old stock off cheap, line up bikes and the odd frame out front that they're just trying to clear space and get rid of. I know a couple of people who've got decent winter bikes cheaply that way. Also in the 20% sale you can pick up brakes, chainsets etc that are old stock, I got 4 pairs of calipers with blocks for less than the blobks would have cost on their own a couple of years ago.

EDIT: Forgot to say keep tabs on CTC Forum and YACF as you can get good winter/touring bike deals there, you may need to register to see the for sale sections

[Dan_K]

Thanks for the advice Andrew, i'll keep my eyes peeled.......