Viscount Grand Prix compact chainset

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buzzkirk007

New Member
I have a Viscount Grand Prix with a 50/40 chainset. I have replaced the rear freewheel with an 11/32 but I still struggle on large hills. I would like to replace the front with a 50/34 or whatever is available. Could anyone plase tell me what I should be looking for or if it is even possible to do this.

I have looked for a 34 tooth front but I think it is a 116 BCD and they are rare.

Many thanks.

Sorry to post this in two places but I was not sure which one was the best.
 

tyred

Legendary Member
Location
Ireland
As a Viscount owner, I can advise that this can be a tricky issue. It is worth of persevering though as these bikes are quite unusual now and very nice to ride and I consider them very under-rated.

If you can't find a suitable chain ring in the correct BCD (try SJS, they have a lot of oddities), then you will have to replace the chainset and this is where it can get interesting. Your bike probably has a pressed fit bottom bracket bearings. These bearings are cheap and easy to replace if they are worn despite what some might say.

The bottom bracket axle is different from the norm as it is straight with no bearing surfaces. Is your current chainset the square taper type or is the almost unique to Viscount square fitting without the taper? If it is the tapered variety, you should be able to use any other standard square taper chainset if the width is correct. If you do have the non-taper chainset or your BB axle is the wrong width for your new chainset, straight bottom bracket axles are out there if you search hard enough. I got one from Spanish Ebay for mine which allowed me to fit a Stronglight Impact 50/36.

Alternatively, patience with a file will remove the bits of chainstays and seat tube which extend into the bottom bracket shell and allow you to fit a threadless cartridge bottom bracket.

Also, check if you have a steel or alloy front fork.
 
OP
OP
B

buzzkirk007

New Member
As a Viscount owner, I can advise that this can be a tricky issue. It is worth of persevering though as these bikes are quite unusual now and very nice to ride and I consider them very under-rated.

If you can't find a suitable chain ring in the correct BCD (try SJS, they have a lot of oddities), then you will have to replace the chainset and this is where it can get interesting. Your bike probably has a pressed fit bottom bracket bearings. These bearings are cheap and easy to replace if they are worn despite what some might say.

The bottom bracket axle is different from the norm as it is straight with no bearing surfaces. Is your current chainset the square taper type or is the almost unique to Viscount square fitting without the taper? If it is the tapered variety, you should be able to use any other standard square taper chainset if the width is correct. If you do have the non-taper chainset or your BB axle is the wrong width for your new chainset, straight bottom bracket axles are out there if you search hard enough. I got one from Spanish Ebay for mine which allowed me to fit a Stronglight Impact 50/36.

Alternatively, patience with a file will remove the bits of chainstays and seat tube which extend into the bottom bracket shell and allow you to fit a threadless cartridge bottom bracket.

Also, check if you have a steel or alloy front fork.

Many thanks for that.

I have the tapered type as the original stripped the threads.

If I replace the complete chainset will the chain and gear shift be OK?

You mention SJS, do you have any contact details for them?

They are the non death forks.
 

tyred

Legendary Member
Location
Ireland
Assuming the chain isn't worn in the first place, it will be fine. If you're fitting a smaller big ring, it would be best to shorten it to suit.

The derailleur should be okay. It's clamp on type on these bikes so can be moved to suit.

SJS
 
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