|
|
Thread Tools | Display Modes |
#21
|
|||
|
|||
Opinions on new bike for 12-yr-old boy
On 20 Feb 2007 13:00:45 -0800, "David Martin"
wrote: I don't find that particularly long. It gives about 5cm more adjustment than we had on the Giant so probably a 250mm or maybe 300mm seatpost. I replaced it with a 350mm seatpost that is almost long enough for me to ride it properly. 5cm more adjustment would be 62.5% more. I would disagree as you have failed to take into account the crank length ;-) I think I'm still missing something. A 26cm frame (approx 10.5") will only take about 23cm of seatpost, so with 13cm of adjustment 10cm of the seatpost will still be in the seatpost tube, probably the minimum recommended for a secure fit inside the seatpost tube. Indeed, the seatpost itself is almost the same length as the seatpost tube, and I know this to be the case because only today I removed the seatpost to replace the seatpost clamp with a quick release clamp. Yup. But with Alan's bike, he outgrew the original seatpost rather quickly and it was the most cost-effective way to keep him comfortable. Yes, it seems a sensible and practical solution. I am going to look into this option. The minimum and maximum inside leg measurements for the Beinn 20 are 47cm and 60cm respectively. The minimum and maximum inside leg measurements for the Beinn 26 are 64cm and 74cm respecively. If I can get a 5cm longer seatpost for the Beinn 20, children can progress from the 20" model to the 26" model. Isla Rowntree herself will be the person to ask. I'll be looking for a 20" kids bike soon. Peter is almost ready to leave his 16" Raleigh behind. Possibly have it taken down south for the other cousin. At £150, £200 if you want mudguards and a rack, the Beinn 20 isn't cheap. But its a very robust machine and children find it very easy to ride. I have no hesitation in recommending it if you are prepared to spend that sort of money. I'll wait and see. If he protests too much at Rachel's as a hand me down, then I might have to get something. Mudguard and rack sounds good but £200 is a lot of notes. Have to find out how many returns she has in her reconditioned bikes.. The other bikes get passed on into the family. We have the oldest children. So you spend the money!? |
Ads |
#22
|
|||
|
|||
Opinions on new bike for 12-yr-old boy
"Colette A. O'Brien" wrote: In message of Mon, 19 Feb 2007, John B writes I would strongly advise you learn how to roughly size a bike to your son. You could ask your LBS how to adjust the saddle height and bars - it really is quite simple. They should be able to show you. I am more familiar now with making sure the bike saddle and bars are the right height, and I often tell other kids when I think their bikes are badly adjusted. I am just no good at things like brakes and anything involving cables! I would love to do a course in basic bike mechanics as we are building up quite a collection of nice bikes and I want to look after them properly. But I haven't found any courses locally. If you are in the Hampshire area you could try: http://www.hampshirecycletraining.org.uk/ They run courses for exactly what yu require, personalised to your needs. If you live elsewhere I am sure if you contact them they will point you in the right direction. John B (I must express an interest) |
#23
|
|||
|
|||
Opinions on new bike for 12-yr-old boy
On Feb 20, 9:52 pm, Tom Crispin
wrote: On 20 Feb 2007 13:00:45 -0800, "David Martin" wrote: I don't find that particularly long. It gives about 5cm more adjustment than we had on the Giant so probably a 250mm or maybe 300mm seatpost. I replaced it with a 350mm seatpost that is almost long enough for me to ride it properly. 5cm more adjustment would be 62.5% more. I would disagree as you have failed to take into account the crank length ;-) I think I'm still missing something. The length you are adjusting is from the saddle to the foot. With a 10" frame you have about 250mm + the saddle height (say 50mm) + the crank length (110mm), so about 400mm to start with. You can adjust by about 130mm which gives about 30% adjustment (depends whether you measure as a proportion of the maximum. I've measured as a proportion of the minimum) Upping that by 50mm would give about 45% extension. A 26cm frame (approx 10.5") will only take about 23cm of seatpost, so with 13cm of adjustment 10cm of the seatpost will still be in the seatpost tube, probably the minimum recommended for a secure fit inside the seatpost tube. Indeed, the seatpost itself is almost the same length as the seatpost tube, and I know this to be the case because only today I removed the seatpost to replace the seatpost clamp with a quick release clamp. Yup. But with Alan's bike, he outgrew the original seatpost rather quickly and it was the most cost-effective way to keep him comfortable. Yes, it seems a sensible and practical solution. I am going to look into this option. The minimum and maximum inside leg measurements for the Beinn 20 are 47cm and 60cm respectively. The minimum and maximum inside leg measurements for the Beinn 26 are 64cm and 74cm respecively. If I can get a 5cm longer seatpost for the Beinn 20, children can progress from the 20" model to the 26" model. This is effectively what Rachel has done, going from a 20" to a 26". We could have done with the extra 5cm, and having an aheadset style stem allows rapid resizing of the front end as well. We got a Thorn seatpost from the bandits of Bridgewater. A 350mm seatpost would do what you want and, if ready fitted with a saddle, would be about 10 secs to change. The other bikes get passed on into the family. We have the oldest children. So you spend the money!? It seems like it. But we are in Dundee and they are in the horribly expensive South East. And I know what a decent bike looks like wheras mostly they don't. So my second oldest neice (age 5/6) has Rachel's old bike (Kobo 16). I'm going to try to pass off the Raleigh Max (16") for my nephew who is 4, the likeabike copy for the three year old nephew. And possibly Rachel's old 20" bike for my oldest neice (who used to cycle to school in Germany and is now a few hundred quiet yards away from school in the south west of Reading) if Peter really decides he doesn't like it. ...d |
#24
|
|||
|
|||
Opinions on new bike for 12-yr-old boy
On 20 Feb 2007 15:54:19 -0800, "David Martin"
wrote: I don't find that particularly long. It gives about 5cm more adjustment than we had on the Giant so probably a 250mm or maybe 300mm seatpost. I replaced it with a 350mm seatpost that is almost long enough for me to ride it properly. 5cm more adjustment would be 62.5% more. I would disagree as you have failed to take into account the crank length ;-) I think I'm still missing something. The length you are adjusting is from the saddle to the foot. With a 10" frame you have about 250mm + the saddle height (say 50mm) + the crank length (110mm), so about 400mm to start with. You can adjust by about 130mm which gives about 30% adjustment (depends whether you measure as a proportion of the maximum. I've measured as a proportion of the minimum) Upping that by 50mm would give about 45% extension. I think we've been talking about different things. This was my calculation. The Beinn has an inside leg min and max length of: 47cm - 60cm respectively. Assuming the Giant has 52cm - 60cm. [(60-47) - (60-52) / (60-52)] = 62.5% more adjustment on the Beinn that the original Giant. |
#25
|
|||
|
|||
Opinions on new bike for 12-yr-old boy
In article , Tom Crispin wrote:
Long seatposts are cheap, but may not fit smaller frames if they need to be set right down (so I would be surprised if the Islabike has longer than 250mm, having a 10.5" frame) Buying a handful of seatposts and saddles could be a good investment to stretch the smaller bikes to the larger children. I can see your point and the advantages in having a range of seatposts and saddles, but I think that it would be preferable to have a range of different frame sizes. Islabikes scale up the various components for larger fames, so the pedals on the Beinn 20 and 24 are Junior aluminium flats and on the Beinn 26 Intermediate aluminium flats, the brake levers on the Beinn 20 are very short reach and on the Beinn 24 and 26 are short reach. Also how much can you raise a saddle before you really want the handlebars higher than the stem adjustment will allow for? They do at least have the sort of stem where you don't have to take everything off one side of the bars to change it for a different one. |
#26
|
|||
|
|||
Opinions on new bike for 12-yr-old boy
On Tue, 20 Feb 2007 18:58:42 +0000, Colette A. O'Brien wrote:
I would love to do a course in basic bike mechanics as we are building up quite a collection of nice bikes and I want to look after them properly. But I haven't found any courses locally. Hmmm, north Somerset? Bristol isn't all that far away.... http://www.lifecycleuk.org.uk/events.php?id=161 Mike |
#27
|
|||
|
|||
Opinions on new bike for 12-yr-old boy
In message of Thu, 22 Feb 2007, Mike Causer writes
Hmmm, north Somerset? Bristol isn't all that far away.... http://www.lifecycleuk.org.uk/events.php?id=161 Bristol is within easy reach. That course sounds perfect actually. But I can't do Wednesday nights, I'm usually in Macclesfield on a Wednesday! But I'll keep an eye on that website, looks good. -- Rgds Colette |
#28
|
|||
|
|||
Opinions on new bike for 12-yr-old boy
On Tue, 20 Feb 2007 18:58:42 +0000, Colette A. O'Brien wrote:
I would love to do a course in basic bike mechanics as we are building up quite a collection of nice bikes and I want to look after them properly. But I haven't found any courses locally. Hmmm, north Somerset? Bristol isn't all that far away.... http://www.lifecycleuk.org.uk/events.php?id=161 Mike |
#29
|
|||
|
|||
Opinions on new bike for 12-yr-old boy
Mike Causer said the following on 22/02/2007 22:00:
Hmmm, north Somerset? Bristol isn't all that far away.... It might not be in miles, but it's a whole culture away :-) -- Paul Boyd http://www.paul-boyd.co.uk/ |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Bike Fit - Some Opinions? | K-Paws | UK | 3 | November 13th 06 06:14 PM |
mountain bike opinions | [email protected] | Techniques | 0 | September 26th 06 09:43 PM |
Opinions on versatile bike | Fred Barney | General | 27 | July 27th 05 10:56 PM |
Opinions on the New Breed of bike | DT | UK | 9 | June 29th 04 04:05 PM |
Opinions on bike-in-a-bag? | Pyromancer | UK | 6 | May 14th 04 08:15 PM |