Converting a geared mountain bike to singlespeed! A couple of questions!

[bernieUK]

Hello all and Happy New Year!

A friend of mine has given me his Charge Mountain bike - namely a Duster Plus. I have never been into geared bikes so I am going to attempt to convert this into a single speed.

Can anyone please advise on the following. I will be removing the SRAM PG 1070 cassette and replacing it with a single speed cog, spacers and tensioner. Am I likely to have any compatibility issues with fitting the cog and spacers onto the hub? Is there a standard for hubs?

The crank is a SRAM X9 GXP 10S 42/28. Will it be a simple matter of removing the smaller ring and keeping the 42? I am assuming the single speed cog/spacer kit will take care of chain line. I am hoping not to have to buy a new crank. Hopefully I can recoup any expense by flogging the cassette and anything else that is removed.

I would appreciate any advice.

 

[RecordAceFromNew]

Mmmm it depends on which conversion kit you have.

Fyi mtb chainlines are generally 47.5mm or 50mm, so let us say 49mm for example. For average chainring pitch of 5mm, your outer ring is at ~51.5mm. This is in relation to typical road ss chainline of 42mm.

OTOH most mtb rear hubs are 135mm wide vs track/road of 120mm/130mm. Jumping forward fyi the centre of your "cassette", which is 36.5mm wide, will have a rear chainline of close to 45mm, from which you can work out where your sprocket needs to sit to match front and back chainlines. If your ss sprocket is just over 2mm thick I think you will need a spacer between it and the lockring close to 10.5mm (from my calculation on the back of a postage stamp!).

 

[bernieUK]

Many thanks for the reply. I am thinking of using the Surly Singulator tensioner with a 16T Surly cog along with a set of Halo spacers which should give me a pretty reasonable amount of accuracy with the chainline. I am looking at removing the 28T ring and staying with the 42T.

Thanks again!

 

[biggs682]

should be done easily as long as chain tensioner does the job

 

[bernieUK]

should be done easily as long as chain tensioner does the job

I must admit I have never used a tensioner before. Surly make good products as far as I know. I was looking at something called a "Paul Melvin" but at around 60 quid and hard to get - sod that!

 

[biggs682]

i have tried the surly ones with some joy but the best one i have used is a trial tech http://www.trialtech.co.uk/product.php?product_id=81

almost like a dummy rear changer

 

[GrumpyGregry]

will you be using it off-road? If so you may want a push up tensioner rather than a pull down to give you more chain wrap. Surly's can be configured push up or pull down. What surly don't tell you is you may need a specific size cone spanner to set the tension correctly (unless you have 'the knack')

When in doubt on such matters speak to VeloSolo or Charlie the Bikemonger. Charlie has some step by step videos on his site on how to do the conversion.