Help needed with vintage Bottecchia road bike replacement parts.

[Will.Evans.11]

Hi all,

I'm new here, so unsure if this is the correct place to post! But I am in need of some help with replacing some parts on my vintage Bottecchia road bike.

Here it is:

I bought it on eBay a few years ago from a very nice older gentleman, and I love it. But now its rear wheel/block needs replacing, as well as the crank set, as both are very heavily worn. But I am unsure of where to start looking for vintage parts, or how to be sure they will be compatible with my bike. Though with a cursory look on eBay, it does appear that similar Stronglight crank sets are somewhat available.

I'm quite young and something of a novice in this field, so I am looking for any advice or help where I can get it.

Here is another photo if it is any help


Thank you,
Will.

 

[sjcprojects]

Welcome to the forum! Looks like a lovely bike.

eBay does tend to be the best place to look for parts. If you want to keep the same gear ratios that you already have, you're probably best sticking with Stronglight ones which tend to come in those sort of ratios where the smaller chainring is a 34 or 36 tooth one (yours looks like a 36T), rather than the more standard road bike 39 or 42 smaller ring. I would guess your bike originally came with a Shimano 105 or 600 crankset, which would have had a 39/42 smaller ring. So I guess this is a chance to make the bike more original, but that does depend how many hills you go up, as a more original setup will be higher geared making hills more of an effort, potentially. But you're young so that should be fine for you anyway!

You could potentially just replace the chainrings rather than the whole crankset, but it might be harder to find the exact ones you need for that - the velobase website is a good place to use to try and ID what model of chainset you have, which will help with finding replacement chainrings if you do decide to try that.

In terms of the rear wheel, I'm guessing it's a cassette rather than a freewheel, which would be good news as those are generally easier to remove and replace. If you want to know for sure, then take the wheel out and see if the end of the hub where the smallest sprocket looks like this:




Then you just need a replacement Shimano one with the same number of sprockets (7 or 8 I would guess looking at yours). Luckily you can still get new ones of these, and if it's a Shimano fit (which most are), it'll be perfectly compatable. Your rear derailleur will take up to 28T biggest sprocket. If it's a freewheel instead, the same applies except you need a freewheel rather than cassette and there are a few different standards for these, so it's less simple.

You'll also need a new chain if you're replacing the cassette and chranket - any 8 speed one will do, really.

 

[sjcprojects]

Also, are you planning on replacing the parts yourself or getting a bike shop to do it? Replacing these parts is generally a relatively easy job, but of course you do need a few specific tools first...

 

[Will.Evans.11]

Wow, thank you! Your help is much appreciated.

I'll answer to the best of my ability, though things are complicated somewhat by my bike currently being at my local shop (took it in for a service a few days ago, they confirmed over the phone to me today that I needed these things replacing), so I'm also having to use photos for reference.

Firstly, I think you're likely right about the crankset originally being a Shimano 105, much of the rest of the components are from that range. However, the ones I have found online are all recommended for a 7/8 speed bike, while mine is a 5.

Secondly, I am going to replace the whole crankset, as the cranks are slightly bent from years of use, and it just seems an opportune time to do so anyway.

As for the rear wheel, unfortunately it is a freewheel rather than cassette, which as you say does complicate things.

And I will be getting the guys at the local bike shop to replace the parts for me, as I don't have the requisite tools! I'm trying to find matching parts myself to maintain the classic look of the bike, but if I can't do that, they're going to source some contemporary ones that should work.

Thanks again for your advice!

 

[hamster]

Chainrings are still available new from Spa Cycles; you need 86 BCD. Obviously you can also get them used from eBay, but Spa are often no more expensive with new!
https://spacycles.co.uk/m8b0s149p0/Drivetrain/Chainrings-Stronglight

 

[sjcprojects]

If your rear wheel has a 5 speed freewheel it's a fair bit older than the bike itself, and the rest of the parts - but anyway, there are plenty of 5 speed freewheels out there, so that's not a problem. The difference in standards is mainly around what removal tool you need to use, but seeing as the bike shop are doing that, they should have the right tool whatever one you get, so just look for any 5-speed one you can find, more or less, although it would be best to check what hub is on the wheel before buying the freewheel.

It terms of speeds for the chainset, there's not really such a thing as a 7,8, etc 'speed' chainset, especially when it comes to older parts like these - it doesn't matter how many sprockets you have, the chainset will still be fine, so 105 is still an option. Whether you stick with Stronglight or go the Shimano route, there should be plenty out there, anyway.

 

[Will.Evans.11]

Chainrings are still available new from Spa Cycles; you need 86 BCD. Obviously you can also get them used from eBay, but Spa are often no more expensive with new!
https://spacycles.co.uk/m8b0s149p0/Drivetrain/Chainrings-Stronglight

Thank you that's an excellent recommendation!

 

[hamster]

If it's any comfort, I am running an identical chainset with a 10 speed cassette, chain and 105 rear mech. So no worries on compatibility

 

[sjcprojects]

A bike that nice also deserves some nicer shifters 105 ones of the right era aren’t too tricky to pick up, or as I presume you’re not using them with indexing with a 5 speed block and 8 speed derailleur, any decent pair of shifters would be an improvement looks-wise.

Of course I realise I’m adding an additional job there, but it is one that doesn’t require any special tools. Maybe one for the future.

I’d be curious to know what the wheels are; they definitely won’t be original as those would have been 8-speed. The hubs look like they could be Sachs or similar…

 

[Will.Evans.11]

If it's any comfort, I am running an identical chainset with a 10 speed cassette, chain and 105 rear mech. So no worries on compatibility

That is good to know, thank you!