Secondhand Raleigh Junior Rigid MTB: lemon or worth a punt?

[Reynard]

@Reynard - Kids Racing do short cranksets but they're not cheap: https://kidsracing.co.uk/collections/short-cranksets-kids-cranks-lengths-narrow-q-factors

Personally I'd be searching on eBay for a second-hand one, or an old kids bike to dismantle.

Alternatively do you have a bike workshop near you that recycles bikes? They're likely to have one spare for a small sum.

I did check Kids Racing out earlier, but they didn't have what I was after. And you're not joking about them not being cheap!

Secondhand is definitely an option while I save up the pennies for something nice, perhaps. Might put a request in the "wanted" section on here as well - that's always worth a punt. Someone might have something suitable knocking around...

Yes, there is a bike co-operative in the next village along, but they're not that great, which is frustrating.

 

[Reynard]

https://www.spacycles.co.uk/smsimg/17/3534-12079-full-rd2-triple-black-black-1-17.jpg

This any good, 165mm crank length available

EDIT thought it would link to the product not just a picture. They do one with a 48 tooth big ring as well as the 50

They also do this: https://www.spacycles.co.uk/m8b0s109p3052/SPA-CYCLES-TD-2-Touring-Triple-Chainset-with-Zicral-Rings

They do a 46-34-24 which would be nice, but I'd have to save up for that... It *is* very nice, though, and would look lovely on the bike. But I've got to be realistic.

I think that it looks like I'll be going down the secondhand route for now.

 

[DCLane]

Secondhand there's a £30 delivered 165mm 46/36/26 option on eBay, although it's square taper: https://www.ebay.co.uk/itm/Vintage-A-Ero-165-Length-Triple-Crank-46-36-26-Eroica/184397460309

 

[Reynard]

Square taper is what I need.

I don't need one yesterday, so am prepared to look at all the options.

 

[DCBassman]

OK, cheers.

Are those the bottom ones that work with all brake types?

Yes, sorry for late reply!

 

[Reynard]

OK, I did a fair bit of thinking and measuring and looking things up online yesterday.

The "build my own triple" idea is off the table as it's just not financially viable if using even half decent parts. Still, it was an option worth exploring. And I really do want to stick to my £200 budget for now.

The longest cranks I can realistically fit on the bike are 165mm. With the FSA Veros fitted, there is only about 5mm clearance between crank and chainstay. Plus I get a similar overlap with the front mudguard when I turn the steering, so I'm at risk of constantly clipping that while riding. OK, it's not a biggie, I can trim the guard down a bit, but still...

Which definitely means anything with cranks bigger than 165mm are off the table. This is irritating, as the cranksets that are within budget either have the right ratios and the wrong crank length, or the right crank length but less than optimal gearing.

Spa have some lovely options which would work, but right now, I have to say no, I can't afford that. Especially since I'm still not sure exactly where I'd like the gearing to be. I can only do this by riding the bike. The maths can only tell me so much.

Which means that at this point, I shall have to compromise.

This is something that you guys riding bigger frames don't generally have to think about - you fit stuff to suit your tastes and away you go. But there is a dearth of affordable parts designed to fit on small frames - it's not for the want of looking. My guess is that junior bikes, other than at the premium / super premium ends of the scale, are considered essentially disposable, which is why replacement parts seem to be made out of the fabled unobtanium. Kids grow out of bikes, I don't. The downside of being a short adult rider.

The original cranks fitted to the Raleigh are 152mm, and my Wiggins Rouen road bike runs 160mm, so I'm going to have to stay in that sort of ballpark in order to avoid clearance and toe overlap issues.

I did find THIS last night on the Bay of E - a Suntour junior crankset. 152mm cranks, 42-34-24

The big ring is probably slightly too small (same number of teeth as the original) but the middle and inner rings are in the ballpark of where I want to be. I'm still going to look around a bit, but I'm thinking that for £15 it's certainly worth considering.

 

[raleighnut]

OK, I did a fair bit of thinking and measuring and looking things up online yesterday.

The "build my own triple" idea is off the table as it's just not financially viable if using even half decent parts. Still, it was an option worth exploring. And I really do want to stick to my £200 budget for now.

The longest cranks I can realistically fit on the bike are 165mm. With the FSA Veros fitted, there is only about 5mm clearance between crank and chainstay. Plus I get a similar overlap with the front mudguard when I turn the steering, so I'm at risk of constantly clipping that while riding. OK, it's not a biggie, I can trim the guard down a bit, but still...

Which definitely means anything with cranks bigger than 165mm are off the table. This is irritating, as the cranksets that are within budget either have the right ratios and the wrong crank length, or the right crank length but less than optimal gearing.

Spa have some lovely options which would work, but right now, I have to say no, I can't afford that. Especially since I'm still not sure exactly where I'd like the gearing to be. I can only do this by riding the bike. The maths can only tell me so much.

Which means that at this point, I shall have to compromise.

This is something that you guys riding bigger frames don't generally have to think about - you fit stuff to suit your tastes and away you go. But there is a dearth of affordable parts designed to fit on small frames - it's not for the want of looking. My guess is that junior bikes, other than at the premium / super premium ends of the scale, are considered essentially disposable, which is why replacement parts seem to be made out of the fabled unobtanium. Kids grow out of bikes, I don't. The downside of being a short adult rider.

The original cranks fitted to the Raleigh are 152mm, and my Wiggins Rouen road bike runs 160mm, so I'm going to have to stay in that sort of ballpark in order to avoid clearance and toe overlap issues.

I did find THIS last night on the Bay of E - a Suntour junior crankset. 152mm cranks, 42-34-24

The big ring is probably slightly too small (same number of teeth as the original) but the middle and inner rings are in the ballpark of where I want to be. I'm still going to look around a bit, but I'm thinking that for £15 it's certainly worth considering.

Don't forget you are changing from a freewheel at the back with a 14 top gear to a freehub/cassette with 11 teeth as a 'top'.

 

[12boy]

With a 34 tooth sprocket, a 22 tooth chainring and tires with inch long spikes you will be able to climb trees. The toelap problem is also found on short wheel base bikes such as my Fuji Track. It does take a little getting used to and preparation before a sharp turn.

 

[Reynard]

Don't forget you are changing from a freewheel at the back with a 14 top gear to a freehub/cassette with 11 teeth as a 'top'.

Indeed. That's one of the many variables that I'm taking into account while thinking this through.

If I match that Suntour triple with the 11-34 version of that cassette, it gives me a range that's almost as wide as my Chartres hybrid. On paper, I can see that I'm losing out more at the top end than at the bottom, but I won't really know what it feels like until I ride the bike.

And to be honest, I'd rather not find out that I don't like the gearing after having spent serious money and totally blown the budget. Talking to the people at Spa Cycles is always an option for the future if I decide that things do need tweaking.

 

[Reynard]

With a 34 tooth sprocket, a 22 tooth chainring and tires with inch long spikes you will be able to climb trees. The toelap problem is also found on short wheel base bikes such as my Fuji Track. It does take a little getting used to and preparation before a sharp turn.

I've no shortage of trees - I live on the edge of a wood. Hopefully the bike should be a capable winter mudplugger.

Toe overlap was something I originally ran across when shopping for a road bike a few years ago. It was the reason I plumped for a bike with 650c wheels as opposed to 700c ones. One thing less to make me fall flat on my face, you see...

 

[Reynard]

Eh, possibly scrub the 11-34... It's one of those megarange jobbies - seven sensibly-spaced sprockets with a dinner plate stuck on as an afterthought.

11-32T: 11 / 13 / 15 / 18 / 21 / 24 / 28 / 32

11-34T: 11 / 13 / 15 / 17 / 20 / 23 / 26 / 34

As far as I can see, all the Shimano 8-speed 11-34 cassettes are the same.

I think I'd much rather lose two teeth on the biggest sprocket and get a more sensible progression right across the whole range. When it's really windy here, I tend to spend a fair bit of time on the middle ring (on the hybrid), so that's another factor I have to consider. It's not all about the biggest and smallest gears.

 

[DCBassman]

11-34T: 11 / 13 / 15 / 17 / 20 / 23 / 26 / 34

Exactly why I went to the 12-36 9-speed cassettes. Nice smooth progression.

 

[All uphill]

I had a Megarange 7sp cassette on a Trek hybrid. Soon got used to using it as a six speed with an emergency low gear for those "holy sh*t" moments. Quite useful imo.

 

[Reynard]

Guess it depends where you're riding, though.

 

[Reynard]

You know, it's rather dangerous to work on assumptions. As an engineer, I really should have known better i.e. check everything. And just as well I did...

I assumed that the lady from whom I bought the Chartres hybrid only replaced the big ring on the bike, and that the middle and inner were the original rings. So I was doing all the maths and gear selection for the Raleigh on the basis of the Chartres running the stock gearing of 44-32-22. But it wasn't. Ooops. The Chartres is actually running 48-38-28, which is a whole different kettle of fish.

So scrub the idea of buying that 42-34-24 for the Raleigh off the Bay of E. That's going to be waaaaaaaaaaaaaaaaay too low on the gearing. And it's actually identical to the original chainset on the bike, so essentially would have been wasted money. And my original impression of the gearing on the Raleigh can be said to be flawed, simply because the damage to the drive train would have made it feel like the gears were bigger than they actually were. if I replace like for like, there will be a lot of whizzing round of legs and not a lot of going anywhere.

Anyway, I redid all the maths and stuck the results into a spreadsheet. What I've done is compared the gearing on the Chartres, the Rouen road bike and on the Raleigh. I've done the calculations for latter assuming the same chainset that is fitted to the Chartres. Anyways, the plots are given below, where H is the Chartres, R is the Rouen roadie and M is the Raleigh mountain bike:

Chartres: 113.42 - 21.41 gear inches (48-38-28 & 11-34)
Rouen: 108.72 - 29.47 gear inches (46-34 & 11-30)
Raleigh: 104.72 - 21 gear inches (assuming 48-38-28 & 11-32)

So it looks like a 48-38-28 is more or less the right way to go if I want comparable gearing to the other two bikes. Actually, it gives me (on the big and middle rings) something very similar to the road bike. Based on my previous chainset hunting, unless I can find something on the Bay of E, I may as well go straight to Spa Cycles, as I need the shorter cranks. Their XD-2 touring triple looks like it will fit the bill if I don't want to blow the budget completely out of the water.

As an aside, the chainset on the Chartres is showing signs of wear, so when I replace it, the graph shows that I could probably come down a couple of teeth on the big ring, and quite possibly on the other two as well, as I'm not as strong a cyclist as the original owner. At least on the Chartres crank length isn't quite so critical due to the different frame geometry, so there are more options available.