Chain sets

[HovR]

So I'm looking for a new chainset, which would be easy, you might think - But I've managed to make it awkward!

I currently run a 52/42 square taper, which is great and all, but it's getting worn out, and I'm looking into starting some light weekend touring, so easier gears would be favourable.

I want to keep the same derailleurs, the rear of which is fairly short cage, so I believe a compact is not an option? Don't want to change the front derailleur, so a triple won't work?

When using the 42 ring of my current setup, I can reach 27+mph on a flat smooth road, still with gears to spare on the rear - Which makes the 52 ring kind of redundant, especially since I prefer to spin as opposed to grind.

So I was thinking, since I get far less usage out of the 52 ring, I might as well have something around the 42 to 46 mark as my biggest ring, and a 32 to 36ish as my lowest ring, which should greatly help me on the steep hills.

Now here's the hard part.. I can't for the life of me find a chainset, which is square taper, with near those ratios! I was looking at spending no more than £50, as it won't be going on the most expensive bike. Looking for 170mm cranks.


Suggestions? If anyone knows a chainset that would fit the bill, then that'd be great.

 

[subaqua]

http://www.chainreactioncycles.com/Models.aspx?ModelID=43207
any good ?


or is this better http://www.chainreactioncycles.com/Models.aspx?ModelID=78792

 

[HovR]

The first link appears to be a 50/34 compact which unfortunately won't work with my bike, however the gear ratio on the second link appears to be ideal.

A few questions though. Firstly, are all square tapers the same? The description says "Compatible with JIS Square Taper BB’s and power driver BB". The bike this would go on is the steel Dawes in my display picture, which has a standard cup-and-cone style BB - Not the newer sealed type - Would this chainset be compatible?

And is there anything else I need to consider? Chainline maybe?

I'd also be willing to consider something at a slightly lower price-point, if anyone has any more suggestions, as this one really stretches to the top of my budget.

Thanks very much!

 

[Baggy]

How about a Stronglight double in 46/36 or 48/34 from SPA? It's square taper but recommends running with a 107mm bottom bracket.

 

[subaqua]

this is where mickle and his years of bike mechanicing will help. MICKLE , MICKLE

 

[HovR]

How about a Stronglight double in 46/36 or 48/34 from SPA? It's square taper but recommends running with a 107mm bottom bracket.

This is also ideal, aside from the fact that if my BB isn't this size, I'll have to spend an extra £10 to £20 on a sealed bottom bracket (+ extra for new tools)? That's my understanding anyway. Or can I just buy a different axle size for my current loose ball bearing BB?

What is this BB size that keeps being mentioned actually a measure of? Axle tip-to-tip without cranks attached?

 

[youngoldbloke]

Why won't a compact work with your bike? You can use a compact with a short cage rear mech. What is worn with your current chainset? If it is just the rings you could replace them (Spa Cycles) though I expect the smallest you could fit would be a 38.

 

[HovR]

Why won't a compact work with your bike? You can use a compact with a short cage rear mech. What is worn with your current chainset? If it is just the rings you could replace them (Spa Cycles) though I expect the smallest you could fit would be a 38.

Currently the chain is set at it's perfect length to get in to the big/big ratio, yet when in the small/small ratio the derailleur is doubled back on itself almost completely - It physically can't take up any more slack in the chain - And if it were to, the chain would start rubbing on itself as the derailleur is completely doubled back. I figure that the derailleur is only designed to take a 10 tooth drop on the front.

As I said, it's an old chain ring - The original one on the bike - And the large chain ring is physically attached to the crank and is not removable, hence why I can't change the rings.

Thanks for the thought though!

 

[Baggy]

What is this BB size that keeps being mentioned actually a measure of? Axle tip-to-tip without cranks attached?

Yep!

 

[youngoldbloke]

I see. I have bought a replacement axle (only) in the past - when I changed from a single to double chainset on an old Carlton I had. But that was a long time ago. Whether LBSs stock them nowadays I don't know.

 

[Judderz]

I had a 52/42 Suntour square taper chainset on my bike, swapped it for a 50/34 Compact Shimano 2300 square taper chainset. Took out 2 chain links...works fine, so not sure why you can't change to a compact?

 

[HovR]

I had a 52/42 Suntour square taper chainset on my bike, swapped it for a 50/34 Compact Shimano 2300 square taper chainset. Took out 2 chain links...works fine, so not sure why you can't change to a compact?

I'm not completely certain that I couldn't go with a compact, but keep in mind that this is a 30+ year old 531 framed bike, the derailleur is only designed for 5 gears on the back, and those are only 22t to 14t - So not much drop there compared to modern gear systems.

Besides, considering I barely get any use out of my current 52t ring, a compact would be fairly useless for me, as the lower ring would be geared too low for any sort of speed, and the higher ring would be geared higher than my preference.



I measured my current BB, and it is 122mm ish. Seems like quite a change from 122 to 107 - Will this still work without issues? The last thing I want to do is spend closing in on £70 only to find out that it won't go together!

Oh, and strangely triples seem to be far cheaper - How well would buying a triple and taking off the granny ring work?

Thanks a lot for the help everyone!

 

[HovR]

I measured my current BB, and it is 122mm ish. Seems like quite a change from 122 to 107 - Will this still work without issues?

Oh, and strangely triples seem to be far cheaper - How well would buying a triple and taking off the granny ring work?

Bump.

 

[Psyclist]

Why not get a retro chainset?

 

[HovR]

Why not get a retro chainset?

I'm actually watching one on eBay at the moment. Some how I managed to find a retro chainset suiting my specifications!

Not sure how much it'll go for, but considering it's second hand I wouldn't want to spend too much on it.