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Advice sought on bike rebuild...

UnderscoreUnderscore Posts: 730
edited February 2008 in MTB workshop & tech
Mornin'

I'm considering a little project and would appreciate some advice before I commit any money to the venture! Please excuse the rambling...

It all stems from a child seat. I have a Giant XTC 4.5, which is great, but the mounting bracket for our child seat does not fit. Currently this is not a problem as I get the wife to have the bairn on the back instead. :shock:

However, we are expecting our second child in May, so I need to have a bike that can have a child seat fixed to it, which can then be removed for a quick blast when it's the wife's turn to play with the kids for a bit.

Having looked at other child seats, it seems that my XTC was not designed to take a child seat (well, d'oh!) but I do have one of these in the garage (though the picture is not of mine):

Talerabefore.0.jpg

It was the first MTB that I ever bought and, yes, it still has biopace chainrings!

It needs a new cassette and I would change the cantis for v-brakes but, apart from that, it should be a serviceable starting point. However, I do know that I could do with some spares (cones, metal seals) for rebuilding the hubs (IIRC, they are Shimano but, obviously, from '89 or '90). So, does anyone know whether there is any chance of being able to get spares for hubs that old? If not, is there any reason that modern hubs wouldn't fit? I know that I would need a spacer to fit a 7 speed cassette onto a 8/9 speed hub, but are the axles lengths the same, etc.? It could be fun to have a go at building a new wheel myself...
Also, is it still possible to get spares for a 21 speed drivetrain? Is there any reason why it couldn't, at some point, be upgraded to 27 speed?

And, yes, I'm aware that I'm not going to break even on this; I just think that this could be a fun thing to do and I would end up learning a lot about bicycle maintenance...

TIA,

_

Posts

  • nicklousenicklouse Posts: 81,520 Lives Here
    spares should not be a problem, But you will become best friends with your LBS as they will have the stock hidden away in the back.

    going to 27spd will require the rear being sprung out as the hub is wider. (new rear wheel and crankset and shifters and chain. to go to V's you will also need V brake compatable levers. different cable pull.

    TBH with what it would cost with the ideas you have i would get the LBS to quote for doing it and also for a new bike for the kid duties.

    I think a new bike could be the cheaper option.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • nicklouse wrote:
    think a new bike could be the cheaper option.

    Thanks for the reply. Yes, I'm aware that going for a new bike might be more cost effective but part of the reason for doing this is to learn more about maintaining my bikes. If there is no problem getting spares, I'm happy to stick with 21 speed. So, initially, a strip down and rebuild of the hubs and headset plus a new cassette and a Deore v-brake kit (£25 from Merlin) should keep me busy for a while and give me something to haul wee-uns around the place.

    Thanks again,

    _

    Edit: BTW, you mention different hub widths between 7spd and 8/9spd. I think that 8/9spd are 135mm; what are 7spd hubs?
  • nicklousenicklouse Posts: 81,520 Lives Here
    it depends on the bike and year. i could be 135 but... measure the hub.

    the gear shifters are sperate?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Yep, separate shifters. A bit beaten up - one of the levers on the rear shifter had to be brazed back on after an off - but still serviceable for the time being...
  • Just a quick update. The front hub is a HB-RM50 with date code NJ, putting it as October '89. The rear hub is FH-HG50 which, from what little I could find on the web, was available in 126, 130 and 135mm widths. Measuring the drop-outs, they are 131-132mm but, when I put the wheel back in, they were slightly narrow. This leads me to hope that the hub is 135mm but, more importantly, that the frame would be able to take a 135mm hub if I needed to replace the current hub (possibly with a bit of "cold-setting" courtesy of Sheldon Brown).

    So it looks like the project is a goer - I'll strip down the hubs and headset this weekend and make sure that it all the surfaces look OK; is there anything else I should check for condition before I start to buy parts?

    Thanks,

    _
  • legolego Posts: 769
    I can't help with the bike but as you've got one bike that'll take a child seat have you thought about a kiddy trailer for your bike? I used to use a seat but felt abit top heavy so I brought a spokey joe trailer from argos. Bags more room for all day trips out and quite robust (goes along the SDW with no problems). Just a thought.
  • lego wrote:
    I can't help with the bike but as you've got one bike that'll take a child seat have you thought about a kiddy trailer for your bike? I used to use a seat but felt abit top heavy so I brought a spokey joe trailer from argos. Bags more room for all day trips out and quite robust (goes along the SDW with no problems). Just a thought.

    Thanks for the idea but I'm not convinced that it would work for (e.g.) the blue/green routes at Thetford that we ride - let alone the occasional gentle singletrack on Cannock Chase when visiting friends. Maybe that's just my preconception...
  • meagainmeagain Posts: 2,774
    "This leads me to hope that the hub is 135mm but, more importantly, that the frame would be able to take a 135mm hub if I needed to replace the current hub (possibly with a bit of "cold-setting" courtesy of Sheldon Brown)."

    IF c.132 spacing then really shouldn't need to do more than manually spread the stays as you insert the wheel. Cold setting usually only necessary if going from say 120 to 130 or 126 to 135.
    d.j.
    "Cancel my subscription to the resurrection."
  • meagain wrote:
    "This leads me to hope that the hub is 135mm but, more importantly, that the frame would be able to take a 135mm hub if I needed to replace the current hub (possibly with a bit of "cold-setting" courtesy of Sheldon Brown)."

    IF c.132 spacing then really shouldn't need to do more than manually spread the stays as you insert the wheel. Cold setting usually only necessary if going from say 120 to 130 or 126 to 135.

    Even better! Thanks.
  • SplasherSplasher Posts: 1,528
    Why won't a childs seat fit?

    The XTC doesn't look any different to any other MTB hardtail frame.
    "Internet Forums - an amazing world where outright falsehoods become cyber-facts with a few witty key taps and a carefully placed emoticon."
  • Splasher wrote:
    Why won't a childs seat fit?

    The XTC doesn't look any different to any other MTB hardtail frame.

    It's the braze on that holds the outer of the front gear cable. It's too close (by about 5mm) to where the seat stay joins the seat tube to allow the bracket to fit. Fitting the bracket below the braze on (assuming that it is OK to fit it over the nut in the frame for the bottle cage mount) means that the seat is too low to clear the tyre.

    I have just found out that Hamax do a replacement set of bars that raises the seat by 60mm, so I'll have a look how much clearance that would give but I'm concerned that the seat would still rub on the tyre once loaded.

    _
  • SplasherSplasher Posts: 1,528
    Hamax used to do a set of stays that ran from the child-seat to the seat-stays as well. This meant that as long as you had some clearance, the seat didn't bounce and cause contact with the tyre.
    "Internet Forums - an amazing world where outright falsehoods become cyber-facts with a few witty key taps and a carefully placed emoticon."
  • Drfabulous0Drfabulous0 Posts: 1,539
    Many child seats are designed with this in mind and come with clamps which go around your cable without interfering with it. Admit it this is all just a ruse to avoid putting a kiddy seat on your decent bike without your missus kicking off.
    I can relate to that so if I were you I'd get the V brakes, replace those stupid chainrings and get hold of a second hand 7 speed wheel, either from the back room at the LBS or Ebay, alternatively just buy an axle kit from any bike shop and mess around with the spacers till it fits.
  • carlos-gcarlos-g Posts: 522
    http://www.weeride.com/

    this is what we use for our little one , it has the added bonus that your child is nestled between your arms meaning you can talk to them properly and they can also see where they're going.
  • had look at that weeride and it looks great, what bike do you have it fitted to? does the front go around the stem or steerer tube at the front of the bike?
  • carlos-gcarlos-g Posts: 522
    had look at that weeride and it looks great, what bike do you have it fitted to? does the front go around the stem or steerer tube at the front of the bike?

    It's been fitted to both my mtb's although it's more sensible on the Orange than the GT(Luke prefers the GT cos he's a freerider in training,imagine a nearly 3 year old laughing and giggling going down rooty singletrack and you get the idea :lol: ) , we tried fitting it to my wifes F700 Cannondale but it's an xs frame and the top tube is too short.
    The front of the seat holder bar clamps to the headtube.
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