Road race gear set

[Bosveldbaas]

Hi. I have a Scott mtb with Chain set: Shimano FC-M627 2-piece Design 700 Series: 38x24 T, and rear casette: Shimano CS-HG50-10 11-36 T. I have a set of slic tyres for road riding, but want to change my cassette to different gear ratio. I run out of ratio on descents. What cassette will be more suitable for road race?

[Veebee]

Change of cassette isn't going to help, you need bigger rings upfront to help with your problem, or rather just buy a road bike and leave the mtb where is belongs

[DJR]

I agree with VB, the shortcoming is too small a big chainring upfront. Not sure how big you can go and still have it work with your derailleur, but if you want to have a chance to keep up with the roadies on the fast flats and downhills, you are going to need something with at least around 50 teeth. 

 

From my experience, you will be frustrated and buy a road bike sooner or later, purely because it is the right tool for the job. You can buy real 2nd hand roadie bargains that are a few years old but still competitive, will not lose value and won't cost much to maintain. (Unlike mtbs)

[NotSoBigBen]

Must agree with Vb and DJR, either accept the limitations of using an MTB in a road race or beg, steel or borrow the right tool for the job ...

[Bosveldbaas]

Thank you all!

[A.K.A]

Hi

 

You can change the front rings to a 40/28 set up

[Bosveldbaas]

How hard can I pump these slick tyres with a tube for mtb? 700x35C 28x 1 5/8x 1 3/8

[DJR]

A quick thumb-suck?

 

See if there is a pressure indicated on the outside of your tyres. I think 60 to 80 psi (5 bar) should be pretty efficient and comfortable for an average weight rider (70-80 kg) on large volume tyres like yours.  But you can go up to 100 -120 psi (7-8 bar ) which will reduce rolling resistance but also increase harshness and reduce grip. Lighter riders will get the same effect at lower pressures, heavier riders will have to up pressures a bit.

 

Best is to get a floor pump with a good gauge and experiment around the block. I find that I intuitively "feel" where the ride quality feels best - where the sweet spot is - and that is the pressure I use.

[bertusras]

A quick thumb-suck?

 

See if there is a pressure indicated on the outside of your tyres. I think 60 to 80 psi (5 bar) should be pretty efficient and comfortable for an average weight rider (70-80 kg) on large volume tyres like yours.  But you can go up to 100 -120 psi (7-8 bar ) which will reduce rolling resistance but also increase harshness and reduce grip. Lighter riders will get the same effect at lower pressures, heavier riders will have to up pressures a bit.

 

Best is to get a floor pump with a good gauge and experiment around the block. I find that I intuitively "feel" where the ride quality feels best - where the sweet spot is - and that is the pressure I use.

 

Remember that MTB rims are not designed for the same pressure as road rims.

[DJR]

Remember that MTB rims are not designed for the same pressure as road rims.

Where is the sensible upper limit? (Asking because I don't know and I don't want anybody to blow a rim at 40 km/h. in the middle of a bunch.)

[DieselnDust]

Hi. I have a Scott mtb with Chain set: Shimano FC-M627 2-piece Design 700 Series: 38x24 T, and rear casette: Shimano CS-HG50-10 11-36 T. I have a set of slic tyres for road riding, but want to change my cassette to different gear ratio. I run out of ratio on descents. What cassette will be more suitable for road race?

 

 

You're pretty much maxed out on the available chainring sizes for the 104/64 BCD cranks.

 

Your options are too;

 

1) fit a CX crank with 110BCD

 

2) fit a 10T cassette  (very limited gearing upgrade)

 

3) get a road/CX/gravel bike

[DieselnDust]

Where is the sensible upper limit? (Asking because I don't know and I don't want anybody to blow a rim at 40 km/h. in the middle of a bunch.)

 

 

most are rated 65psi max as the tyres are max 55psi.

[jdwet1980]

I have never owned mtb rims that was rated for more than 4 bar.

[DJR]

So, please ignore my high pressure advice above. 

Just buy a road bike!

[arendoog]

Hi

 

You can change the front rings to a 40/28 set up

I did exactly that with a hardtail mtb and pumped my tyres to 2.5 bar .It was my first road bike .On a 100km race you will lose about 6-8 min because of the bike 

[A.K.A]

I did exactly that with a hardtail mtb and pumped my tyres to 2.5 bar .It was my first road bike .On a 100km race you will lose about 6-8 min because of the bike

 

Pump youre tyres 3bar + all depending what the rim &tyre allows ,my buddy did a 3h28 on his mtb in his first argus on this ratio